Solar Grid Tie Systems

Renewable energy generated by solar panels and wind turbines is an excellent alternative to non-renewable energy produced by oil, coal, and natural gas. But, using renewable energy can seem a little complicated compared to using energy right off the power grid which our homes and businesses are already set up for. Fortunately, using a grid tie power inverter grid is an easy way to feed solar and wind energy directly back into the power grid. Thus, taking advantage of the generous feed in tariffs offered in many countries.

Inverters are necessary to convert energy produced by wind and sunlight into AC energy that can be accepted by both your home and the power grid. Why should renewable energy be connected to the power grid? The energy supplied from renewable sources such as wind and sunlight will help ease the demand on nonrenewable energy, especially during peak power times. Because sunlight and wind are more or less free resources, this can drive down the cost of energy substantially. In addition, you can receive energy credits by putting watt-hours back into the power grid, making your own energy bills extremely cheap, and even profitable.

The SWEA (Solar & Wind Energy Applications) makes an inverter for small wind turbines and solar panel systems. The SWEA inverter is an excellent solution for home owners and small businesses who want to put power back on the grid. It is not a complex system, but simply a power inverter connected to a grid tie that plugs into existing power outlets. This allows renters to join home owners in helping to reduce carbon foot prints. With today's grid tie inverters, you don't have to be an electrical engineer to use green energy anymore. (Please check your local regulations) You simply have to have a passion for helping the environment.

If the complexity of utility connection is preventing you from considering green energy for your home, a power inverter and grid tie system can eliminate the issue. Simply plug your AC power generated by the inverter directly into an outlet in your home, just as you would a microwave or toaster. Not only will your energy costs go down, but you will be helping the overall cost of nonrenewable energy go down for everyone. Easing the demand on nonrenewable energy is great for the environment and your wallet.

Frequently Asked Questions

  1. QUESTION:
    How much would the installation cost for a solar grid tie system?
    How much would an electriction charge to install a system (say 1400 watts) in a house and tie it to the grid?

    • ANSWER:
      Installation costs vary from state to state. I would call some electricians and get a free estimate to do this work.

      Here in Montana the average cost for installing a solar system on a residential home is approximately .50 per watt. There are also lots of grants to help offset this cost. A good resource for these grants is www.dsire.org

      If you need further assistance, please visit:
      http://electricalblog.gilchrist-electric.com

  2. QUESTION:
    Is a solar grid-tie system allowed in Houston, Texas?

    • ANSWER:
      they're allowed anywhere, but they may not offer net metering. most states offer a buy back (net metering) some do not.

  3. QUESTION:
    which is more beneficial/ cost effective: solar grid-tied systems or off grid systems?
    We just bought a house and are debating which is better, on grid with feed back, or totally independant. We live in a downtown type area, but are trying to be sustainable... has anyone gone through this, and what did you decide?

    • ANSWER:
      A grid tied solar system is the lower cost approach. There is no need for a battery storage system and/or a back up generator.

      A stand alone (off grid) system has the advantage of operating even if the grid goes down but is more expensive.
      A hybrid of these two systems is a stand alone system, with a two day battery storage, and a commercial battery charger. The PV panels charge the batteries. When the batteries get low the battery charger kicks in to recharge. Power from batteries goes to a couple of inverters and then to home circuit box. Better savings than a grid tied system and you have power even if the grid goes down.

  4. QUESTION:
    with a 3KW solar grid tie system what would be my net KWH per month?
    I am investigating a 3KW system and am interested in the net gain I live in the midwest zone 5 and wondering if there would ever be a payback, if I broke even it would be fine as I wouldnt be using foreign oil and helping the enviroment. the inital expense wouldnt be a concern but is it worth it??

    • ANSWER:
      i live in texas... which has a LOT of sunshine... last time i checked.. the savings would have required about ffiteen years of use before it paid for itself... HOWEVER... the avg lifespan of a solar panel is only ten years... so no it would never have paid for the outlay of cash...

      the one thing i did NOT look at and honestly have no idea on.. is how much evergy and materials are required to BUILD the solar panel... i was looking strictly for cost savings.... but if you are doing this for green purposes don't forget to include that in the equation..

  5. QUESTION:
    How many people out their use solar and are off the grid or just have grid tie off systems?
    If you are off the grid, what kind of batteries do you have?

    • ANSWER:
      Our system is grid-tied, and frankly, I don't know of anyone who had grid power who decided to disconnect after getting solar. The only people who seem to be off-grid are those who never had access to the grid in the first place (remote cabins).

      As for batteries, there is a good forum on which to ask that question: http://www.wind-sun.com/ForumVB/index.php . Lead-acid AGM batteries are common.

  6. QUESTION:
    What are things that you look at to purchase a Grid-tied Solar System?
    I work at a Grid Tied PV System Sales and Installation business and I am trying to enhance the way we do business and I would like a little more information on the things YOU would look at when purchasing solar for your home, church, business, barn, garage, whatever. Thanks for your time.

    • ANSWER:
      I had a system installed last year, I got quotes from 3 companies. The company I chose had a licensed structural and electrical engineer on staff. This helped me feel confident that we wouldn't run into any problems. Another positive was a list of referrals who were willing to let me call them or view their systems. All of the companies gave me info on refunds and tax incentives, the company I went with was willing to front the utility rebate, so I didn't have to come up with the K that I would get back later. Another big plus was the "sales man" wasn't a sales man, he was a contractor, one company I got a quote from had a typical slick sales man who made me feel like I was being sold a rundown used car. All of the companies seemed to listen to what I wanted to accomplish and they all recommended comparable systems. My goal was to offset part of my bill and maximize my rebates. Another thing I liked about the company I chose was they gave me an accurate ROI estimate, based on my usage, which they were able to get 2 years history from my utility.

  7. QUESTION:
    If i have a grid-tied solar system that generates more than i use, is the electric company required to pay me?
    I know green mountain energy started a program where they pay customers who have a system that generates more electricity than they use.
    is this true for all electric companies in all states?
    i am in Texas. i have reliant energy.

    • ANSWER:
      Not all states, but most of them. They pay you peak rates 24/7.

  8. QUESTION:
    I have a grid tie solar power system how do i keep power when the grid goes down?
    Now my panels connect to a grid tie invertor that makes 240 ac and feeds that back into the utility grid, but if the grid ever fails my system goes off line to protect islanding, I want to figure a way to still have power during the day (no batteries) so I was thinking if there was a way to shut off the main breaker to the outside world and install somehting to make the inverters think the grid was active so they would produce power.... I dont know like backfeed a very small generator and let the panels sync to that? I would prefer some form of puseodo sine wave generator thinggy to trick the inverter into producing power

    • ANSWER:
      A grid-tied inverter is generally designed to anticipate this kind of trick. It will monitor the frequency of the line, and even its impedance.

      If you have power that goes out often, what you need is probably just a small generator and a transfer switch.

  9. QUESTION:
    Solar System Size (Grid Tie)?
    I have upgrade all and I mean all electronic (include'n A/C) to energy efficient. I have collected my electric bills for the past 10 months. I know my kwh per month and day soooo how in the world do I calculate the size of a solar system required?

    Thanks

    • ANSWER:
      I too am starting to look at a grid tie system. I'm not an expert, but the factors that I would look at would be your location, weather, shading where you would locate the panels, and the local laws or policies of your utility for grid tie systems. Also, there is no reason that you need to generate 100% of your energy from the sun for a grid tie system. In fact many recommendations are for your system to be slightly undersized as many grid-tie laws will not allow your electric bill to become a source of income should you generate more than you use. I've listed a couple of books below that are sources of information that can get you started and don't forget to search on the internet as well.

      There is another long-shot alternative that might eventually become available and that is grid tie system rental. There are a couple of companies that are generating interest and have websites. None of them to my knowledge are actually delivering systems to customers (other than possible trial systems) just yet. I believe that the rental company will survey your home and recommend sizing.

      Home Depot provides solar systems and will estimate the system size for you. (Don't know what markets they are doing this in though). Any reputable solar contractor will survey your home and recommend a system size for you as well.

      Timothy D.
      West Melbourne, FL

  10. QUESTION:
    What is the best solar panel available, and what company does the best job for a grid tie system.?
    Thinking the sharp 235 is near the top.

    • ANSWER:
      Hey Hockey, here's my short answer, there is no "Best." Not trying to let the wind out of your sails, but it's like asking, "What's the best car to buy?" If you have kids, the minivan is hard to beat, but it sucks as a 4 wheel drive SUV. Solar panels all use the basic same type technology, but to compare features goes a whole lot deeper into the rabbit hole. If you live in Chicago and have limited roof space, it's probably worth spending the extra buck and getting Sunpower units, they produce the most per square foot. If you want more hours of energy without tracking, single crystal is the way to go. If space is not an issue and you're using rolls batteries, and a fixed rack, a multicrystal might be better for you. The point is, first determine what you want to do, then decide what product will fill the perscription the closest.

      If you are really in the market for panels, my suggestion is to get a sub to Home Power Magazine. Then use your account info at their website to scour past issues. They had one about a year ago comparing all commercially available solar panels by all manufacturers, about a 9 page spread, with all their specs, including warranty info, power curves, and so on. Then you'd be in a position to make a real decision.

      We've been powering our home for almost 10 years now with solar and wind. In our case, we selected Kyocera KC-120s, a multicrystal panel, installed on fixed racks. The cost, availability and warranty was the deciding factor. Turns out we had one panel go bad last year, something even my installer never had happen. Kyocera paid round trip shipping and installation cost in addition to sending me a new panel for no charge, they really stood behind their product. In my experience talking to other solar knuckleheads like me, most of the manufacturers are doing the same, because they have very little trouble with their products. Most panels are warrantied for 25 years, and typically they run much longer than that.

      The Sharp is a good panel by the way, I know two people that have been using them for a few years, and they love them, mainly because they don't ever have to look at them to keep them working. It's been much the same with all our panels too. Check out Home Power, and some of the non profit groups I have listed below. In the end, whatever you decide to do, you will at least be well informed. Take care, Rudydoo

  11. QUESTION:
    Question about home solar panel systems?
    Online stores selling solar photo-voltaic generation kits gives specs indicating the power generation capability of the system. For example, Solar World Grid-Tie Solar Electric System with 245W Panels & PV Powered PVP2000 Inverter, 1.2 to 2.4 kW. This seems to indicate that the system can generate 1.2 to 2.4 kW. Is that per day? Per month? I'm trying to calculate the return on investment, but can't because I don't know how much power a system such as this will generate in a month.

    • ANSWER:
      There are several items here.

      1) the panel produces 245 Watts of energy that can either be used directly to power items or charging batteries up to the output of the 245 Watt panel. Loads in excess of that amount would be fed via a battery up to the amount of charge on the battery or the capacity of the inverter.
      2)The size of the battery determines how much and how long you have power and the size of that battery determines how effectively you can charge it in a day.
      3)the inverter is the device that is converting that Direct Current from the panel and stored energy in the battery to Alternating current for unmodified AC appliances, entertainment, etc. The size of the inverter determines how much current you can draw from it at a maximum of 1.2 Kw continuous to 2.4Kw peak intermittent, such as starting an electric motor. The rating is in effect instantaneous ratings.

      To determine what size panels you need, you first need to know what your current usage is per day in Kilowatt Hours.

      To figure out how long it will take to pay for itself, take your current Kilowatt Hour charge on your electric bill, divide that number into the total cost of the system, multiply it by 4.1 and that gives you the hours you need that system producing energy in terms of Kilowatt hours, so however long the weather and daylight permit you to reach that amount of time should be considered your break even point of cost recovery.

      In short- that system might be enough to eliminate the need to plug in an RV to an AC source, or for a small cabin or home. with maybe 1 kilowatt hour to 2 kilowatt hours of usage each day assuming a lot of sunny days. Assuming heat is not electric and hot water is not electric. and that you are not powering a well for irrigation.

      If you are looking to go off grid, in one fell swoop, 245 Watts is not enough for an average family without some serious changes to usage patterns. 2000 Watts of panel "might" be adequate for some, but people still need to change usage patterns.

      If you are looking to have a system installed, you can get some idea of some components and vendors through http://www.builditsolar.com and http://www.homepower.com The latter's magazines tend to read more like a sales brochure than a magazine.

      If you plan on doing the work yourself- be sure to get it inspected for a multitude of reasons. You can get some additional pieces through http://www.northerntool.com From panels, to inverters, to controllers, etc. Just look in their alternative energy section.

      If you happen to have aboutt 30,000 dollars to drop on the installation and you plan to live their more than 10 years, talk to your power company and they can set you up completely.

  12. QUESTION:
    solar panel in a grid tied system?
    how many solar panels in a grid tied system would it take to take see a difference in your power bill?

    • ANSWER:
      Typical solar panels used on household systems generate between 100 and 150 watts each. You might get the equivalent of five hours of sunshine per day on the average. 500 to 750 watt hours per day would be the average output. Where I live that would save only about six to nine cents per day.

      Learn more about photovoltaic solar systems by searching for "solar panels" on the Internet, and in the green search box above on this page.

  13. QUESTION:
    Solar Power vs Grid Power?
    We have been looking at investing in solar power for a while now. It seems that for now the systems are way out of our price bracket. Last month our electric bill ran about 0 for 2362 Kwh for the month. I was wandering if this is a bit excessive energy consumption or average. I live in the east Tennessee area which tends to use more power anyway. Is there anything I can do to get this usage down a lot. We already have all the lights CFL. Could this be attributed to freezers or refrigerators. I know someone for example who has two upright freezers and has a pretty large bill. I have read about guides to help you MAKE your own solar panels from buying solar cells and constructing them yourself. From the sites I've been to this is mainly for 200-400 watt power generation to use emergencies, RV's and other off-grid applications. Has anyone had experience with these guides, and can they be used to make say a 3kw grid-tie system?
    We do have electric heat opposed to gas, however we haven't used it. Lately we have used the AC only about 30 minutes a day. The only thing I can think it would be is possible the water heater which is a 50 gal tank and most likely uses tons of energy to keep that water ready-to-use. I have thought about actually kicking the breaker off for it till we need to shower or do dishes or clothes. Hopefully this will help.

    • ANSWER:
      You should consider solar water heating before looking into solar electric. It is 85% efficient, as opposed to < 20% efficient for electric. That translates to a lot bigger bang for your buck.

      http://www.altestore.com/store/Solar-Water-Heaters/Climate-freezes-Closed-Loop-Systems/Closed-Loop-Systems-for-1-4-People/Closed-Loop-PV-Powered-w-Tank/AET-PV-w-80-Gal-Tank-64-SqFt-Collectors/p172/ (A thermosyphon system is not appropriate for your location, you need more freeze protection than it can offer. A solar powered system like the this also uses no electricity, or more accurately, it makes its own)

      You should also get an energy audit to see why your bill is so high, that is a lot of energy you are consuming. Many utility companies will offer them for free or at a discount.

      Also get a Kill-a-Watt meter that you can plug devices like refrigerators into to see how much power it is consuming. http://www.altestore.com/store/Meters-Communications-Site-Analysis/Meters-Battery-Monitors/Power-Meters/P3-International-Kill-A-Watt-P4400-Kill-A-Watt-Power-Meter/p932/

      If you have older fridges and freezers, they could be using a ton of electricity, it may make sense to replace them with a new energy star appliance.

      Tenn doesn't have a rebate for solar, but the federal tax credit will save you 30%. There are also tax credits for improving your energy efficiency, http://dsireusa.org/.

  14. QUESTION:
    What is the best homedepot gift card selling website?
    I used to buy homedepot giftcards off of a local pawn shop for 20% off of face value. Does anyone know of any websites or stores that sell them? I dont care if it is a giftcard or merchandise card. I am going to buy a 20k grid tie solar system from homedepot and would like to pay for it all with cards. I can pay cash or moneyorder.

    • ANSWER:
      You are probably going to have to stick with the local pawn shop, no one else offers that kind of discount.

  15. QUESTION:
    When will solar and wind power be affordable to the average home owner?
    I have been doing some research on solar panel and wind turbine systems. The pricing is crazy. For a 10Kw solar grid tie kit system is between ,000 and ,000. If you install batteries add ,000-,000. 10Kw will only power a small to medium home without electric heat. Using my electric usage and info from my local electric company payback is 60 years for solar and 361 years for wind. This is unexceptionable. The manufactures of the solar and wind are gouging the consumers. They are using the excuse of supply and demand for the high cost. When demand goes up so will mass production and the price will go down. This is true, but they are making a huge profit on what they are making now. Some items are in the 3000% markup range. Are the power companies keeping the price up so their profits don't suffer? My local electric supplier has an "ENERGY PARK" that you can go see solar and wind power in action and check out real time data online. They have a 4Kw solar array installed and claim it cost ,378 installed and a 2.5Kw wind turbine that cost about ,000 installed. I think they are giving false numbers to consumers so you won't go green. I was able to find a 3.5Kw kit online for ,000. This doesn't include any type of mounting materials. You can add 0-,200 for these materials. An installer will will charge you ,000-,000 to install it. For the sake of argument lets say this will cost you ,000 to install but still way out of line for you and me to install. That is a far cry from the ,000 the power company claims. The power companies don't want you to make your own electric. They are keeping the cost high so they will still make money off you. A 210w panel sells for around 0. They probably manufacture it for under . The cost needs to be 0-0 to the consumer to make it affordable to the average home owner. 50 210w panels make a 10Kw system. That would be ,000 not ,000. The manufactures are raping us and the power companies are helping them to keep prices high. When will we get the technology at a proper cost? Let me know what you think.
    In response to the first 5 answers, Yes, if demand increases so will mass production and thus supply will increase and this will drive the price down. I looked into panels from China. From what I was able to find panels sell for [FAQ-QUESTION].17-[FAQ-QUESTION].45 per watt. In the U.S. they sell for .00-.00 per watt. Manufactures in the U.S. have lobbied for a higher tariff on solar products that makes them impractical to import on mass. These companies want to keep the price high so their profits stay high, and the power companies do not want you to produce all your own power. That would put them out of business.
    In response to Steve R, You need to do more research before you post another retarded comment like that. Air "DOES" have mass (just not very dense). When air is in motion it is called "WIND". This motion creates energy. Have you ever heard of a "tornado"? Get your facts together next time.

    • ANSWER:
      Cut the incentives, import tarriffs, and special grind tie rates. That will make prices truly competitive for those that want to participate in home green energy, and not put any cost on those that do not want to.

      The important thing is the incentives, which artificially raise the prices of equipment.

  16. QUESTION:
    use of solar panels with electric baseboard?
    Has anyone got a solar system (grid tie in / net metering) that the home is heated with electric baseboard?

    I want to reduce the amount of oil heat that is used in my home. 00 per season in oil is getting outrageous.
    (I am hoping that someone steps up with a lower cost bio-diesel for heating oil in the future . . . . . .)

    ( I.E The greedy ones in Washington. Families are freezing to death)

    I am thinking of putting a system in that "runs the meter backwards" during the summer to hopefully "break even" during the winter.

    Any thoughts.

    I have also thought about geo-thermal also.. or a small cylinder style windmill

    • ANSWER:
      GABY your math is a little off.
      260,000 / 350 is 743 panels.
      So using your math here's the logic.

      In a Iowa cold winter I'm using 6700 or 233 kWh per day
      233,000 per month or 1.00
      They have 200 watt panels now.
      200 * 7hr of sun light = 1400 watts per day per panel

      233,000 / 1400 = 166 panels @ 0.00 ( per watt) = 2,800
      2,800 / 261 = 42 years to pay for themselves.

      If they did a fair deal at per watt
      66,400 / 261 = 21 years pay back

      In Spring Summer and Fall I average 1400 kWh at 0 electricity per month so lets say I just worried about 9 months non winter average of 47 kWh per day.

      47,000 / 1400 = 34 panels = 27,200 (@ per Watt) / 0.00 = 17.5 years payback. 20 years for 9 month seasons. because you still got to get help in the winter from the electric company. They charge
      All electric discount plan.
      .07 for 1st 1000 kWh and
      .03 for every kWh after that.

      At a fair deal of a watt panels it's
      47,000 / 1400 = 34 panels = 13,600 (@ per Watt) / 0.00 = 9 years payback. 10.5 years for 9 month cheap
      seasons. because you still got to get help in the winter from the electric company.

      Panels are suppose to last 25 years

      Still not a great investment but if that's your dream it may be dueable someday when they offer a fair deal at a watt.
      I think that 30 panels would fit on my house and my back roof faces south.

      If the hours of sun light change per day the math will change.
      But there will also be cloudy days.

  17. QUESTION:
    When connecting solar photovoltaic panels to the grid?
    some material that says the inverter ties into the meter and power flows from there to the distribution panel: http://www.altestore.com/store/Kits-and-Package-Deals/Grid-Tied-Systems/Alt-E-Designed-Grid-Tie-Packages/AltE-Grid-Tied-Package-System-A-1kw/p6629/

    While other material indicates that the inverter is before the panel and after the meter: http://homepower.com/basics/solar/#SolarElectricSystemComponents

    Is one or the other "correct"? If both are used when is one preferred over the other or what are the advantages of one installation over the other? I am presently asking about the different approaches rather than a practical application.
    Thanks for your answer Brian. Then how do you explain the first cite with its nice pictures showing a different configuration?

    • ANSWER:
      The inverter output is tied to your breaker panel. The breaker panel is fed from the meter. You always tie in at the breaker panel so you have a safe method to shut it off and so you have the breaker over-current protection.

  18. QUESTION:
    Where do I connect a grid tied solar inverter?
    OK, let's say we have the solar modules up (2kW), connected to the inverter.. But where do we need to put the inverter?

    Can the inverter be on the top floor, just plugged into the wall socket and the house's system takes it up?
    Or the inverter has to connect next to the meter?

    • ANSWER:
      Do Not plug the inverter into the wall socket.

      Your inverter must be connected to an AC disconnect and then into the meter. The AC disconnect must be mounted beside the electrical meter. When you register you solar system with the utility you must declare the location of this disconnect. The disconnect allows the utility to switch off power from your inverter when they are doing maintenance.

      If you would like to see a detailed layout visit:
      http://www.aurorapower.net/alternative-energy/solar-electric.aspx

      Also if you inverter is 240v make sure you connect it to the correct legs.

  19. QUESTION:
    Solar Power Eco-Development Engineering Questions...?
    I'm considering integrating solar power systems and components into an eco-development here in Costa Rica. I have some questions in order to budget for these systems:

    I cant determine if we need a "grid-tie" system or an "off-grid" system. I believe we need parts from both, or a "hybrid" system. I want to offer solar power as a standalone system with a large battery backup that utilizes the solar power until the batteries are exhausted. When there is no power left from the batteries, it would automatically switch to local power company, only as a backup. It is doubtful that the local government-controlled power company would issue credits for "selling power back to the grid", so a "grid-tie" system as shown on your packages would not work. The energy from the solar panels would have to route into a large battery bank, not back to the grid. It is also different from an "off-grid system" in that, if depleted, the system would need to automatically switch to local power source.

    This solar power system would need "pure sine wave" inverters - capable of supplying energy to any standard appliance as well as a sensitive automation control system with touchscreens in the home. I believe the Magnum MS4448 (http://www.wholesalesolar.com/products.folder/inverter-folder/Magnum_MS4448.html) fits the bill, but I'm not sure.

    Finally, I would like to link 7 of these eco-home solar power systems together in order to capitalize on power sharing for a more reliable and robust system - especially since it is likely that at least 1-2 homes would not be occupied (they're vacation properties) at any given time. I believe that by burying Romex electrical lines between the homes and linking each homes' bank of batteries would do this... correct? Then, just one of these systems would be linked to the power company to switch over once all batteries are drained - since the charge would be evenly dispersed across all homes.... correct?

    I would use locally-bought marine-grade batteries for storing charges in each eco-dome. I'm not sure how many batteries or what type. I would want each 2,000 sq.ft. eco-home to be as self-sustaining as possible on solar power. Assuming a maximum power draw of 500KWhs per home per month, what parts do I need? (I'm looking at the website: www.wholsesalesolar.com for parts to import)

    Also, is there a better way of doing this, or do any of these ideas seem unfeasable?

    Thanks

    • ANSWER:
      Your system is basically doable.

      As to pure sine wave inverters, these do not truly exist. All inverters work by taking the DC voltage from the batteries or other source, and chopping it onto the output lines. This is done with solid state devices such as IGBTs. The smoothness of the output power is determined by how fast the DC level is switched. All inverters put out high frequency harmonics. The general method is to run the output of the inverter through an inductive device such as a transformer, the reactance of which tends to smooth out the switching impulses.

      Many home appliances could care less about the noise on the power lines. Some home electronics are sensitive and should be run of inductively isolated circuits. Your phone system is most likely not all that susceptible, it probably has it's own power supply that creates the local voltages. These supplies are usually switchers these days, which are just a variation on an inverter. I would talk with the phone system supplier to determine if there is a problem.

      Batteries: I would place all the batteries in a central location, for safety and connivance. As to the number of batteries needed, you will need at least 15 in each bank to give you 160 VDC. This will then come down to the 120 VAC that you will want out of the inverters. The total number of batteries you will need is dependent on the peak instantaneous current demands of your systems. The current draw can be determined by I = E/P where I is the current, E is the voltage, and P is the power. You list 1/2 MegaWatt per home per month, but what usage do you expect at any given moment. The 1/2 Mega Watt per month would only come into play if you intended to run the entire system off batteries for one month, and I'm sure that you don't want to do that. You need to determine how much power you will be supplying at a given time and size your battery array to that usage.

  20. QUESTION:
    how do I convert the out put of solar panels in watts to kilowatts per month.?
    I am looking at a set of solar panels that produces about 400 watts of electricity and plan to use them on a grid tie system. My house uses about 700kwh per month.

    • ANSWER:
      Multiply 400 watts times hours per month time efficiency. Divide by 1000 to make kW.

      Say 400W * 200hr/mo * 90% /1000
      = 72kW-hr per month.

      The efficiency above is for misalignment to the sun. As the sun moves during the day, it's rarely perfectly oriented. Also, some panels often don't put out rated current. If they get dirty, less power.

      BTW, two big issues are that solar cells make direct current (DC), often at 12V or 24V nominal, and you may need electricity when the sun doesn't shine (like overcast winter days or at night). Thus, you need storage batteries. These loose another 10 to 20% of the power. Since houses use 120V AC, you need an inverter, which loses another 10 to 20%. Driving 240V loads, like dryers, ranges, air conditioners pretty much out of the question.

      Solar generally not economical for most of us; if you're Ed Beggley, cost is no problem, go for the solar!

  21. QUESTION:
    Solar power for 1300 kWh each month. Suggestions?
    We use approx. 1300 kWh each month as a family of 6 and we live in southeast Texas. What kind of load requirements are we looking at for a grid-tied solar-power system? I have found several sites but am more than a little confused in figuring this out.

    Also, what's the life expectancy of the average solar power system?

    Is there a decline in performance as the years go by?
    Very good Carol! I don't know if this system would work for us, the water table is quite shallow where we are. What most folks do is just dig a big hole and use the soil to build up the foundation to help guard against floods. The hole fills in with just ground water and is your personal pond you stock with fish! Perhaps we could still build above ground and cover with soil to insulate and top with solar panels. I am for anything possible, my hubby... not so much. ;)
    So, I figure it would take us between 36.82 and 39.85 years for the solar-power systems to pay for themselves. Ouch! This is from info gathered from Standard Renewable Energy and based on our normal yearly average usage.
    Wind power interests me, though we're not in a super windy area, we only have about an average mph. of 7-8. An ,500 wind mill would give us about 300-400 kWh per mo. Not enough to sustain us, but about ,000 less than an equivalent ,000 solar panel system of 400 kWh per month. Any thoughts?

    • ANSWER:
      Google for public interest/non-profit groups that support green energy, and you will probably find a very informed and willing assistant to help you realize your project. You might also contact sales for the 3 largest solar power home systems and ask them to COMPARE products or tell you where to look for feature comparisons. Also, always try Consumer Reports and magazines on remodeling.

      My mom's cousin back in Kansas builit on a hillside lot - ground level in back, but that became the basement when you reached the front of the house. It was a great source of family humor, that he built his basement and no tornado ever took the top of the house off the foundation, that he prepared by not putting any house up there in the first place. (That IS how it looked from the street.)

      They had a fireplace, which was cheery but didn't really offer so much heat but fresh air. For a family with 5 kids at home (1st of 6 was grown and living next door), it was really a wonderful home. The earthen walls on over half the sides provided excellent insulation. And he built solidly.

      I thought a lot about it, how they might have gardened atop the house (pre-solar panels), but this might also be an idea you could use, then place solar panels atop.

      I would suggest a setup sufficient to provide your own energy needs and a bit more. How they do it here, is they hook you into the city or county energy system and there's a meter that tracks how much you use or contribute. (You might need more than what your panels would give at one part of the year and less at another.) Whatever the surplus is, you get paid for that. Or you could gauge your own system and just release power to the local utility when you had a surplus. (More control on your part, if they agree. Or you might do a coop with neighbors.)

  22. QUESTION:
    Anyone know about eco-housing, cob building and building permits in Prince Edward Island?
    Hi all. My fiance and I are going to buy about 15 acres in Prince Edward island and move up there next Spring (from Massachusetts.) We want to be able to build a cob house or wooden yurt to live in year round. We intend to install a grid-tied solar panel system and to build our house several acres away from the road for lots of privacy. We are trying to find out about the nature of building codes and building permits in Prince Edward Island. Can anyone tell me if they know whether we would be allowed to erect some eco-buildings of this sort on P.E.I? Do you know of any cob, straw bale or yurt dwellings on the island? If you do, can you put us in touch with the owners or tell us where these houses are located? Thanks in advance!

    • ANSWER:
      Each community has their own set of rules , I left a link below maybe this can help or maybe just a phone call . Many places will let you do cobb or straw bale housing if you have the engineering approved .

  23. QUESTION:
    What are my options for solar power in Wisconsin/Midwest?
    I'd like to set up a Grid Tied system on a pretty large scale. I'm a total novice at the whole concept, and I live in Wisconsin, so I would think I would have some limits. Any help on the situation is accepted...Thank You.

    • ANSWER:
      It will work fine. It will be VERY expensive power, but it will work fine. Just call your local supplier and have it installed. This is very old technology and is proven.

      If you don't want to have to pay out the initial cost, look at the link below. They will install a good system basically free, and you just pay for the power it produces. You are guaranteed to only pay the same rate as you would have to your electric company, and the rate never changes.

  24. QUESTION:
    Grid inter-tie inverters with batteries and real time pricing? to save money?
    Are there any companies that sell the control systems or grid inter-tie inverters that can be coupled with a battery system and real time pricing from the power company to automatically buy power when its low and sell when its high? Usually buying at night and storing in batteries and using during the day when the electricity is costly! Thanks.

    I live in a area where I have real time pricing from my power company and my house is all electric. I have some solar but I want to save more money. Its also more environmentally friendly to use grid power at night.
    The real time pricing i have tells me how many KWH's i use every hour. Just to clarify I don't want to sell my power company any power.I just want a automatic system to decide to use the grid or my batteries, biased on the price. My power company e-mails and texts me the price.

    • ANSWER:
      post a link to your utility companies tariffs. I'd bet they would buy back electricity at a rate lower than the cheapest sell rate. Couple in the loses from the system and you will lose money.

      If your plan worked, everyone would be millionaires.

  25. QUESTION:
    When doing a Photovoltaic grid connection...?
    I have noticed some material that says the inverter ties into the meter and power flows from the meter to the distribution panel: http://www.altestore.com/store/Kits-and-Package-Deals/Grid-Tied-Systems/Alt-E-Designed-Grid-Tie-Packages/AltE-Grid-Tied-Package-System-A-1kw/p6629/

    While other material indicates that the inverter is before the panel and after the meter: http://homepower.com/basics/solar/#SolarElectricSystemComponents

    Is one or the other "correct"? If both are used when is one preferred over the other or what are the advantages of one installation over the other?
    Thanks Percy, my email is available, but I am presently more curious about the different approaches than a practical application.

    • ANSWER:
      i am not sure, both should work same way but i doubt that any utility company would be ok with users connecting anything to the grid before meter. if one has access to power before meter, what prevents them from stealing power?

  26. QUESTION:
    when building a solar panel should the diode be on the positive or negative side?
    when building a solar panel should the diode be on the positive or negative side

    little more detail i just built a solar panel and im running it to a grid tie converter should i put diodes in if i add another panel or are they only for battery systems?
    do i need blocking or bypassing and how do i tell the diff?

    • ANSWER:
      Bypass diodes would be in parallel with groups of solar cells in a panel. For example, if a module has 72 cells, maybe every 8 cells, there will be a bypass diode. A bypass diode does nothing except salvage some of the energy from the panel if some of the cells are shaded, and others are not. Or, if you have multiple panels in a series string, the bypass diodes allow the other panels in a string to continue to contribute energy when one panel is shaded. Unless you're forced to put the panel(s) where there will be shade during the day, the bypass diode does not matter. Commercial panels all include bypass diodes.

      Blocking diodes are generally NOT included on commercial panels. If you're going to a grid-tied inverter, you probably don't need one. There are stringent regulations on how panels must be grounded, and whichever side of the panel is grounded should not have a blocking diode. NEC regulations call for a continuous ground to earth. For example, if you have negative ground on your system, the blocking diodes, if any, should go on the positive terminal of the panel.

      By the way, if you're in the US or Canada, do understand that a home-built panel will not be legal to connect to a grid-tied system. And a grid-tied inverter that plugs into the wall will also be illegal. I'm only saying this because I don't want you to get hurt, or your house to burn down. Line power is nothing to be trifled with.

  27. QUESTION:
    What is the cost to install solar panels?
    I want to install five photovoltaic 200 watt solar panels on the roof of a home in Texas. It is a grid tie system and all the equipment has been purchased already. I received two quotes from solar installation companies and they both want about ,000 just to connect the wires. Is that normal? Can I just hire a licensed electrician to do the job? Thank you for your reply.
    Everything has been paid for already roof mounts, wire, inverters, panels..... everything. I just need someone to do the final connections to the grid. For that the solar installation companies want ,000. Is there anyway I can get this done cheaper? Thanks.
    I don't think its a waste of money getting photovoltaic panels. My electricity use is 2000 kwh per month at [FAQ-QUESTION].15 per Kwh. So I pay 00 per year for electricity.

    • ANSWER:
      I don't know about Texas, but in California, doing a self-install does not invalidate the rebate. And it certainly does not invalidate the Federal Tax Credit on form 5695 http://www.irs.gov/pub/irs-dft/f5695--dft.pdf . Take a look at the form and instructions. I got both rebates installing myself. Florida requires professional installation for their rebate, I think.

      You must still be compliant with your local building codes. What you could do is hire a roofer to put up the standoffs and panels, then later, an electrician to hook it up to your service panel. The electrician can run conduit as needed. Or you could do the physical job of putting up the panels, yourself, then call the electrician to hook it up. Just be sure to get all the necessary permits and inspections.

      k is way too much for just installation. That should buy a 3 kW system, parts included, installed.

      If you want to see roughly what's involved so that you can direct a roofer, you can see a video here: http://www.archive.org/details/DIY_self_installed_solar_photovoltaic_panels

  28. QUESTION:
    Will the power company pay me?
    Suppose I install a grid-tied solar panel system, and also make my house more efficient, so that in the end, my solar system actually makes more power than I use. Every month my power bill is less than zero and I start stacking up a big credit balance with the power company.

    Is that credit balance like a gift card, where I can only spend it on power company products? Or will they actually cut me a check that I can turn into Real Cash Money that I can spend on groceries or car payment?
    This is a question about how power company billing works. I'm interested in hearing from people who know answers to the question, not those who would judge my personal finances or spray their political or economic biases my way. Thanks!
    Fodaddy, you did what I said not to - spout economic biases instead of giving a knowledgeable answer.

    To rebut... First k is not staggering, it's 0/month on a 6% fixed mortgage. At which point it becomes plausible for the panels to make enough power to pay for themselves. Especially with demand pricing, incentives, and figuring future power prices.

    To make more than you use, the cheapest way is just use less!

    As far as "economics 101"... take another semester. "electricity economics 205": Electricity doesn't store. But supply and demand still applies. That means it's worth a LOT during peak load, which happens to be when the sun is shining :) THEIR incentive is to take my precious peak power and pay me residential flat-rate. MY incentive is to get demand-pricing.

    • ANSWER:
      In most places in the US they will. Some even pay more than the standard rate, WE Energies in Wisconsin will pay 22.5 cents per kw/hr nearly twice the normal rate for solar. This is because the solar is producing when demand is at its highest, on sunny hot days when everyone uses their AC. They also like it because when the government asks them what percentage of their power is from renewable sources your production is included.
      Fred has good advice, call your power company and ask or go to their website. They will probably want you to sign a contract and they probably want to come out and test the system to make sure it does not cause any problems and that it shuts down when the power goes out so you don't electrocute any line workers. They may also require you to carry liability insurance.
      If you go to this page and scroll down to your state, you should find what your state requires the utility to do. http://www.dsireusa.org/library/includes/seeallincentivetype.cfm?type=Net&currentpageid=7&back=regtab&EE=0&RE=1
      I have a wind turbine and get a check any month that I have extra power sent back to the grid.

  29. QUESTION:
    People who know about Solar Power and Wind Turbines?
    I am looking at my bill and I use on average about 50 KWH per day.....I dont know if thats high but I want to know what size of an solar power panel should I get or wind turbine to at least cut this in half or more....I would rather want the system to be grid tied.

    By the way I live in middle Tennessee we are in zone 4 so we get 4.5 hours of direct sun and I dont now about average wind speeds.

    • ANSWER:
      So basically to get 50 KWH in 4.5 hours, you would need 12 KW of panels. At about a watt installed, that would cost you 0,000. I think a wind turbine would be less expensive but you'll have to check to see if your neighbours will let you have one.

      You should work on insulating your home first to try and get your power usage down. If you have airconditioning, you may want to consider running an absorption chiller off hot water from some evacuated tube solar collectors. Running absorption based air conditioners directly off solar heat is a bit of a toss up since small scale chillers are expensive but the solar thermal collectors are cheap compared to photo-voltaics.

  30. QUESTION:
    Requirement for tying into West Florida Electric with solar power?
    Looking to build in the area of N. Florida that has power supplied by West Florida Electric and would like to install solar panels with an invertor to tie into the grid system. Anyone with info that has done this with West Florida or any other power co.in Florida would be helpful.

    • ANSWER:
      Obviously, you have to talk to West Florida Electric, ideally before you start spending money on equipment or installation. They may specify a small set of equipment that they allow (if they allow it at all) to serve as the interface. You want backup power when you don't have enough sun and they want to protect their people from being electrocuted by your supply on their lines.

  31. QUESTION:
    Is it wise to connect Solar Power into a wall outlet, rather than directly at a breaker?
    Is it wise to connect Solar Power into a wall outlet, rather than directly at the MDP breaker, for a grid-tied system? The reason I ask is, I am out of panel space here at the apartment I am renting. I would put a DC disconnect before the inverter, and a resettable fuse after the inverter (before the wall outlet). But I still want to know (code issues and anything you wish to rant about ... please let me know) if there would need to be any power conditioning equipment required ... etc?

    • ANSWER:
      as long as the circuit breaker is off and no one has access to it but you, so it won't be accidentally turned on.

      as long as you don't over load your circuit i.e matching wire size to over current protection device

      the weak link sounds like the receptacle, (worn contacts, degraded, loose connections) change it with a new one and make sure it is rated the same amperage as the breaker in the MDP, if the circuit is a 20A and the receptacle is only rated 15A then you can only use a breaker rated at 15A on the back feed.

      wrap the wire around the screw type or saddle clamp type receptacle not the push in crap. make it tight, that includes wire nuts...loose connections cause fires.

      and i would use a DC rated circuit breaker to protect the inverter instead of just a manual disconnect and an AC rated circuit breaker for equal to or less than the lowest ampacity item in the circuit.

  32. QUESTION:
    How long would it take to charge a 212 amp hour 12 volt deep cycle battery using a 60 watt solar panel?
    I'm trying to develop a DIY grid tie system & know only the basics about electrical work.
    No worries guys I'm a master plumber & have a friend who is a master electrician who would be doing all the wiring. He wasn't around for me to ask initially. Thanks for the answers!

    • ANSWER:
      A typical 60W panel has a 4A short circuit current from spec in first link below. This is most likely about 3.5A of peak sun charging current.
      Depending where you live, you may get 2 to 5 hours of peak sun charging current a day. You should be able to find this figure on the internet for your area. It is the number of equivalent full sun hours (that the panel will provide 3.5A). It will take all the daylight hours to achieve this equivalent. Lets say you have 3 hours equivalent, so you will get 3.5A x 3h = 10.5Ah per day average.

      The battery is 212Ah, so it takes (1.4 x 212 = 300Ah) to charge it. How many days is this? Divide 300Ah by 10.5Ah per day to get 29 days. This assumes no power lost from the battery over that time. Basically the battery (depending on type) could lose almost that much charge over a month from self discharge, so this panel would just keep a battery of this size more or less fully charged if there is no load.

      With an MPPT (Maximum Power Point Tracking) controller this figure could be improved, as the charge is derived from the maximum power, not the maximum current, and could provide more current than the maximum from the panel (using internal electronics).

      If you want a grid tie system you need a higher voltage to operate the grid tie inverter. You don't need batteries, that is one of the reasons for using such a system. These inverters typically require 150-500V from the panels. This is for good reasons of efficiency and cost. Look up "Sunny Boy" (a German model popular in the US and Australia and Europe at least) to get an idea. This inverter adjusts the load automatically to use the input voltage that gets the maximum power from the panels (MPPT tracking). You need 10 x 12V panels in series to get this voltage. That means you can deliver about 600W to the inverter. Usually smaller systems target 1KW as the power from the panels, using bigger panels, or 24V modules etc. The design starts with the total wattage of the panels, as this is the high cost item. A 1KW system may not export much power at all.

      I recommend you research this much further, or get some sort of consultancy with someone familiar with your region before you go ahead. There are plenty of references on the web. The wiring is at voltages similar to household voltages so you should get a suitably qualified electrician to do that work.

      I know it seems disappointing, but the power from a solar panel is small compared with household use, especially as the full power only occurs a few hours a day. For example, the standby power from your appliances alone will exceed the 60W rating of the panel, so it makes economic and environmental sense to eliminate that by turning things off at the wall outlet. This panel could perhaps power such a small thing as a network router on a 24 x 7 hour basis.

      Depending where you live, solar hot water may make more sense than an electrical system, as it represents more energy saving due to higher efficiency, and also is more practical for a DIY project.

      You may get government grants, Renewable Energy Certificates (RECs) etc. to offset the cost of some systems in some regions. Hope this helps.

  33. QUESTION:
    When buying a solar photovoltaic system, what does 3.0 kW mean?
    I know that kW means kilowatt but does 3kW mean it produces 3 kW per day or what? If my home uses 2-3 kW per day, does this mean a 3 kW system that is tied to the grid, would result in close to a zero electric bill for that month?

    • ANSWER:
      Using your numbers.

      You use 3 kWh per day on your home
      You install a 3 KW solar power sytem. If you only got 1 hour of sun a day you would zero out your electric bill. But normally we get more then one hour a day. It is all based on how many Peak Sun hours you get in your area. If you get 5 Peak Sun Hours a day in your area with the same 3kw system you would get 15 kWhs from the system.

      Read this link http://www.oynot.com/grid-tie-only-how-to.html

  34. QUESTION:
    help with making bibliography?
    sites:http://www.doe.gov/energysources/index.htm
    http://facts-about-solar-energy.com/solar-energy-history.html

    books:http://www.amazon.com/Got-Sun-Solar-Renewable-Grid-Tied/dp/0965809870/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1209616709&sr=1-2
    http://www.amazon.com/Goods-Living-Source-Book-Special-Anniversary/dp/0916571068/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1209690790&sr=1-2
    http://www.amazon.com/Dont-Know-About-Solar-System/dp/0064462307/ref=sr_1_44?ie=UTF8&s=books&qid=1209690882&sr=1-44

    i dont under a bit about bibliography organization and im too lazy :P thanks!

    • ANSWER:
      Use this: http://citationmachine.net/index.php?reqstyleid=1

      It's an internet site where you plug in your info and it creates a bibliography entry for you.

  35. QUESTION:
    Installing solar panels and wind turbines at home?
    I'm planning on installing both solar panels and wind turbines at my house over the next few years hoping to be more energy efficient. But, being the high cost of it I'm planning on doing it gradually as the money comes available to me. I use on average over a 12 month period about 800 kWh of electricity a month. I also live in Michigan where the average amount of sun is only about 3.5 hours a day year long and that's my reasoning for using both solar and wind. A grid tie inverter seems like it would be the most beneficial because it would eliminate the use of battery's and I think it would maximize the efficiency of the system over its life time. I'm an industrial electrician so I think I can figure out most of the installation my self. Can anyone give me some advice on what would be a good starting off point because this is all new to me? I don't have a problem working hard or doing more work to save some money as long as it wouldn't effect the efficiency of the project.

    Thank you for your time.

    • ANSWER:
      If you're looking to install your own renewable energy system, I would recommend taking some design and Installation classes. There are quite a few out there, but the ones that come to my head right away are....

      AltE University
      http://workshops.altestore.com/

      Solar Energy International
      http://solarenergy.org/

      Midwest Renewable Energy Association
      http://www.the-mrea.org/course_workshops…

      If you do a web search for Wind Turbine or Solar Panel Installation classes it should pull up plenty more options.

      Also, check out Homepower magazine. It is a fantastic resource.
      www.homepower.com

      -Dave

  36. QUESTION:
    How do I get a certain Voltage and a certain Amperage out of so many watts from solar power?
    I want to make a solar panel that is 12V D/C. I want all the amps i can get because my end goal is to power my house, or at least tie the power into the house. Here are the details as to what I (think I) know:

    A house runs off of 120V A/C and about 200 Amps. I know you can invert D/C to A/C, but i dont know what that does to effect total power. I know I could plug a 1000W inverter to a car battery and run a stereo or whatever. I have little knowledge on basic electronics, such as Amps X Volts=Watts, and watts = power. But when it comes down to series and parallel wiring, the only thing I think I know is that when you wire something in series, it doubles the voltage at each junction, and if you wire something in parallel, it doubles amperage. But maybe im wrong, maybe they dont double, but they increase, and depending on the resistance amount, will be the amount they increase.

    Anyway, I dont want to get into everything I know and dont know, I just want to try to find out how to get my goal voltage and aperage (120V A/C @ 200 Amps) from solar panels. Here is the data that i DO have:

    Each solar cell has a wattage rating of about 1.75W. This is with an output .5V @ about 3.5 amps through a multimeter. I was thinking of making a full panel consisting of 120 cells in rows of 10, columns of 12. Each vertical column (12 cells), when wired in series would output 6V D/C @ 3.5 amps, with a total of 10 columns. If every 2 columns were wired in series, it should be an output of 12V D/C @ 3.5 amps per 2 columns. Now I have 5 modules that are at a good voltage rating to input to an inverter, so i dont want to increase the voltage anymore, just the amps. So each of these 5 modules would then need to be wired in a parallel circuit which technically should add 3.5 amps for each module, totalling 17.5 amps and leaving the voltage at 12V. This should be the final output of the solar panel. 12V D/C @ 17.5 amps.

    Now, this is where i get lost (unless I have already, then someone needs to help me with my electricity knowledge)... I am also under the impression that amps are amps, no matter D/C or A/C. So i would guess that my next step would be to make enough 12V panels @ 17.5 amps each, to wire them parallel to equal 200 amps (household amperage). So this would be a little under 11.5 panels. Here in-lies another question, can I have more than 200 amps? Such as making it an even 12 panels to equal 210 amps? or does it have to be exactly 200? Alright, moving on, then I would have a total of 11.5 (or 12) panels equalling 12V D/C @ 200+/- Amps. This would be a total of 2.4kW or 2400 watts if I multiply voltage times amps, which would mean I would need at least a 2400W power inverter (grid tie inverter) for the system. But what confuses me is if I convert all that D/C power to A/C, what does that do to my voltage and amperage? I know it increases (or inverts I SHOULD say) the 12V D/C to 115-120V A/C, but do the amps honestly stay the same? They couldnt possibly, or it would make the wattage about 24,000W. Or is A/C amperage truly different than D/C and would it reduce it to 20Amps to keep the 120V x 20 Amps = 2400W equation correct?

    You can hopefully see where I am lacking knowledge and help me out, because I really just want to know how to convert all the DC power I can come up with (and I can make as many panels as I need), to an end result of 120V A/C @ 200 amps.

    Thanks for your time, I know this was a lengthy and somewhat drawn out question.
    Alright, if solar panels arent supposed to run a house, why not? You can get a 2.5kW Diesel Generator that can power a whole house, so why cant 2.5kW of solar power power a house? Watts are Watts right? just a matter of converting the energy to useful power??

    • ANSWER:

  37. QUESTION:
    Solar power unit for a house?
    I've been doing some research, and I found a company that would build a 2kw system for 00 in my city with an additional 2700$ off after the tax rebate. They could do this because of the electric company rebate of .43 per a watt.

    I determined the cost of materials from a seperate provider for a 2kw system that included the panels, tie grid power inverter, railing, and wiring to be about 00 but after rebates and credits pretty much free.

    Could I get an electrician to install my solar panels? Can I file my own permits? How much of the construction can I do?

    • ANSWER:
      You need to check your local building codes for those answers. Some/most city's require installation by certified licensed contractors that also have to register with the city to prevent fraud. Also, the local electric utility has requirements you must follow to tie into the grid.

  38. QUESTION:
    Has anyone ever had any real luck with Solar rebates, and credits.?
    After researching for years on a grid tie for my house, I saw CT offered a solar rebate of watt for the first 5000 watts. and .30 for the rest up to 10,000 watts total.

    It has now changed to and .50 based on above numbers.

    The problem is they require you to use one of their installers.

    For people like myself who have built additions, wired subpanels, and done electrical work, and are general do it yourselfers, we lose out..

    For a 00 Mitsubishi system COMPLETE with top of the line parts, I could get one for about .35 /watt for the panels, and ,000 for the grid tie invertor,,

    With the CT rebate I would pay about ,000 to ,000 for this system.

    But going through one of their required installer means I am paying ,000+

    It's 2 days worth if install.
    So ,000 for labor sounds rediculous.
    Also, the rebate doesn't even go to the consumer, it goes directly to the installer.
    Of course the installer is going to price it to make it look like your getting some sort of deal, but it still will cost you about as much as if you just purchased the system on your own..

    CT clean energy fund is a scam.

    Just wondering if anyone else has better luck or experiences with this elsewhere...
    I meant 6500 watt Mitsubishi system.. not ,500

    • ANSWER:
      You may want to look in to what it takes to becoming a certified installer; it sounds like they have a good scam going. In WI we have a similar problem of having to use only Focus on Energy certified installers to get the rebate, but the owner gets the check. When I called them they told me that too many people with little or no skill tried to install themselves and ended up with a pile of useless junk. Personally, I agree with you that the wrong people are getting rich off of people who are trying to do the right thing. I was lucky enough to have some on sue for the right to self install wind systems in WI and still get the cash back reward so I went that route.

  39. QUESTION:
    Is Solar Power really an option for most homeowners?
    I see a lot of Solar advocates here and in the media. I looked into it and found it impossible for me because of cost. I looked at a simple 3 Kilowatt, 16 Panel system which is tied to my electric company grid so all I produce just reduces my bill. The cost installed is about ,000.

    I did some research on life of equipment, hours of sunlight, etc., and figure I can only reliably get a max. of about 20 Kilowatt-Hours (KWH) a day 70-80 percent of the time, or about 5000-6000 KWH a year. I assumed a 10 year life of the equipment.

    I pay about 10 cents/ KWH for my power, so the system will save me maybe 0/year.

    This is rediculous. The system cost me 00/year (2000 depreciation and 1000 interest @ 5%). The system will never pay itself off. Even if I cut the cost in half, it will not come close to reasonable power costs.

    How can anyone promote this as a viable alternative? Maybe it will when power costs on the grid quadruple or more.

    • ANSWER:
      For ordinary people like yourself its a waist of money . The price tag is way to high . For guys like me the solar cell is sent from heaven . I build my panels from scrap broken cells and build small wind mills from junk i have a few pics in my blog . For the average guy it is ridiculous to pay that much . Your best off holding off until they come out with a better solution for energy .

  40. QUESTION:
    If I installed 20, 100 watt solar panels and 20 12v batteries for power storage?
    how much of my power needs would this generate? This system would be not be tied to the grid unless there's a benefit. We use about 600kw monthly and receive 5.5 hours of sun light daily. Thank you for any help. Chris

    • ANSWER:
      Location, weather, shading, and de-rating would be factors, but a rough estimate would be about 230 kWh per month, or just over 35% of your usage. There are benefits to being tied to the grid, but it really depends on what your motivations are for doing solar. Contact me at the E-mail below if you would like a detailed list of pros and cons.

      Be advised you will also need racking, a charge controller, a combiner box, an inverter, fuses, disconnects, switchgear, and properly-sized wiring. Please do not try to do this project alone unless you are comfortable and familiar with these items.

  41. QUESTION:
    How much would it cost after tax credits to install solar on my house in Phoenix, Arizona?
    I would want a system that could run my entire house of electricity needs. The most electricity I ever use is in July and August, about 2000kWh and in the cooler months I use 800kWh or more. I live in Phoenix, AZ. and have a 2300 Sq ft 2-story home. I know we get "6 full sun hours" here and I want to be Grid-Tied. I really don't need the battery back up if that costs much more.

    What kind of a system would I need as far as solar Panels and what could I expect it to cost. I will be calling a solar company soon and get a quote from them but just starting to do my research now.

    • ANSWER:
      Speaking very crudely, that sounds like a 6 kW system. You have good sun in Phoenix, but the heat reduces the efficiency of the panels.

      Ask your question on this forum:

      http://www.wind-sun.com/ForumVB/index.php

      Northern Arizona Wind and Sun is in your state.

      There will be tons of solar installers in your area looking for work. I'd suggest getting free analyses and bids from a few of them.

  42. QUESTION:
    When will solar rebates actually benefit the DYI'er?
    In CT we had a nice rebate program that used to pay /watt upto 2500 watts
    It's since dropped to the .30 range.

    The rebate only goes to the installer.

    So my 5K Mitsubishi grid tie could cost me about K doing it myself, if I got the rebate, but instead will cost me about ,000 without it.

    Likewise if I used one of CT's handpicked installers and they used the rebate, that same system will STILL cost me ,000.

    You see my point?

    If the country is really concerned about people going green, perhaps they should offer benefits that actually work

    Anyone else have any luck with rebates?
    Didnt realize fed rebate went up, good news there.
    From the examples i saw from other consumers, they didnt get any deals.
    Installers are claiming slim margins, but to me it reeks of ripoff.
    The rebate is the only reason installers do what they do
    Personally after doing the math on a few examples, people paid about ,000 for labor. Sounds pretty high for a 3 day install.

    • ANSWER:
      All I can suggest is that you check carefully with the authorities to see whether there isn't some provision for you to get the rebate standing as your own installer.

      I did a self-install here in California, and the state was happy to send me the check. I was still subject to all permits and inspections, of course, as I would be if I was building, say, my own addition to my house.

      Perhaps the installer's lobby is strong in CT, and influenced the structure of the rebate to shut out DIY'ers.

  43. QUESTION:
    Need advice from an electrician?
    I'm installing a solar backup power system in my home.
    It's not grid - tied or anything complicated.
    Just a cheap inverter connected to deep cycle batteries and the required solar charging stuff.
    I'll be running the inverter to a separate set of receptacles throughout the house for convenience. They will be isolated and connected to the inverter only.

    My question regards grounding the system.
    The inverter states that in a standalone configuration, the ground terminal of the inverter should be bound to the negative terminal. Fair enough - done.
    BUT, on the resulting three prong plug, I don't have a "real" ground. Is this a problem? Should I separate the ground on the receptacles and wire it up the to a pipe or something? Does it matter?

    How about the panels? They have only + and - leads, but should I ground the frame for safety? They won't be on a roof, only on a back deck.

    Thanks in advance.
    + from battery goes to + on inverter
    - from battery goes to - on inverter

    - from battery goes to Ground on inverter (as per manufacturer).

    Inverter does have a 3 prong outlet build it, which I extend through a string of outlets (a glorified extension cord). But that third prong can't be a "real" ground right?

    • ANSWER:
      Last first - the panels are only putting out 12 (or 24) volts to charge the batteries, so there is no safety factor in grounding the frame.
      To answer your main question completely would require knowing the circuit. It seems like the inverter might have a ground connection through it. The inverter I had in my school bus camper had outlet mounted on it, so there was no consideration of extending the circuits. I think you have got to get the manufacturer to tell you otherwise there is a risk of high voltage in the wrong places. I would think the DC ground should be separate from the panel/neutral/safety ground.

  44. QUESTION:
    Calculus Word Problem Help?
    [Residential Solar Array] Ann Arbor resident Albert Anderson wants to put
    solar panels on his roof. He has gotten quotes for the full installation from a
    reputable contractor. The solar panels cost 00 per kW and the other equip-
    ment needed to tie into the power grid costs 00. For the labor to install the
    system, the contractor charges 00 per kW for the first two kW and 00
    per kW for any additional panels beyond two kW. Note that fractional kW in-
    stallations are possible in this problem (and in real life).

    a) Write a function C which outputs the cost of the system for a given in-
    put k, the total number of kW in the system (Hint: Your function should be piecewise)

    b) Calculate C′
    at k = 1.5, k = 2 and k = 4. Give an interpretation of these
    derivatives.

    The federal government gives a 30% rebate on the total cost of the system and
    DTE (the electric company) gives a rebate of 00 per kW installed.

    Write a function N which outputs the net cost of the system after the two installation rebates for a given k.

    • ANSWER:
      If you don't know how to define those functions, then you need to sit down with a tutor who can help you work through it step-by-step. It would be pretty hard for anybody to write down the whole explanation of how to solve it without actually handing you the answer.

      You wouldn't want anybody to just hand you the answer, would you? 'Cause you're just wasting your time and money by going to school if you do.

      You probably can get help from your prof during office hours, or if not, then you probably can get help from one of your classmates.


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