Overstated production and peak sun hours

If you live in the Dallas-Fort Worth area, solar systems produce about 137.5 kilowatts per month for each kilowatt of system size; so, for example, a 10 KW system will produce about 1,375 kilowatts each month on average (after system losses, and assuming a normal roof tilt and acceptable azimuth; azimuth is just a fancy way of saying which way your house faces). Production increases out in places like El Paso and decreases down around Houston. The reason why the production varies is because of peak sun hours. Houston gets about 4.95 peak sun hours per day. Dallas-Fort Worth, Austin, and San Antonio receive about 5.4. El Paso receives over 6 peak sun hours per day.

Solar Watchdog routinely sees homeowners who are quoted systems that have a stated production that includes in its calculations 6 peak sun hours per day, regardless of where the homeowner lives. The fact of the matter is that companies or individuals who cannot give you a specific calculation about your peak sun hours for your home are either inexperienced or intentionally misleading you.

System Losses

Another area of concern for consumers is salespersons who do not allow for system losses. System losses should reduce the peak production of your system by about 15%. If you remember the 10 KW system we discussed in the first paragraph, that system will produce, before system losses, about 1,620 KW per month. When you subtract 15%, that is how we came up with the 1,375 kilowatts of production on average. Categories of system losses include soiling (dirt and foreign matter on the panels); shading; snow; electrical losses due to slight differences caused by manufacturing imperfections; resistive losses in the wiring and connectors; reductions in the system’s power during the first few months of its operation; inaccuracies by the manufacturer; age; and, scheduled and unscheduled system shutdown for maintenance, grid outages, and other operational factors. If your salesperson cannot explain to you what system losses are, then you need to look for another company from which to purchase your solar system.

The Myth About Refinancing Your System

Lots of companies out there sell you on the idea that you can easily refinance your system. What happens is that they tell you to take advantage of “no-payments” for a promotional period of time (e.g., 18 months); apply your 30% federal tax credit and all of your savings generated from your solar system; then, right before the no-payments period is up, go into your credit union or bank, and get a loan to refinance that package back down to a reasonable rate of interest. What they don’t tell you is that: (1) getting a loan to refinance your solar system is a whole lot easier said than done; (2) you’ve been accumulating interest the entire time you weren’t making payments; (3) your interest rate since Day One has been, say, 26.99%; and (4) even though they told you to call the company or your salesmen to help you with your refinance, the company has absolutely zero plan in place to help you. In fact, what happens is that these companies’ policies are “best of luck to you with that”. You know, sometimes, solar doesn’t pay for itself right off the bat. Companies do a poor job of solar making sense to consumers in any other way than the magical “it’s gonna pay for itself!” idea. Solar is an investment. Make sure it is an investment you can afford. Homeowners with credit scores lower than 780 find refinancing difficult. Moreover, the State of Texas has fairly stringent requirements for home equity loans. Again, it is way easier to tell consumers to get refinancing than it is for consumers to obtain refinancing options. The failure to refinance, often times, leaves homeowners with monthly payments of $800 –  $1,000.

Tax Credits versus Tax Rebates

You are gonna have lots of salespersons out there telling you that you have to make a decision today — that there is some kind of super-special promotion that is afforded to homeowners today and today only. That is just nonsense. They just are trying to get you to buy because lots of folks waste time by “kicking tires”, which is a salesperson’s worst nightmare. If you feel like you are a solar candidate, you need to talk to your tax professional about whether you actually will get your tax credit. The State of Texas gives each consumer who purchases anything in a home solicitation sale three days to cancel the transaction. Use that time to make sure you will be able to claim the residential energy credit. Solar Watchdog knows of countless situations wherein homeowners received so many other credits for things like child care credit that the residential energy credit was not available. We wish that it weren’t the case, but solar makes a whole lot more sense when you can actually take advantage of the residential energy credit (line 53 on IRS Form 1040). In any event, a tax credit is not a rebate. A rebate is a situation wherein you get a check back from the government for the 30% amount. A credit is a situation in which you receive a dollar-for-dollar reduction in your actual tax bill. If you don’t owe any taxes, you aren’t getting a tax credit. Under no circumstances should you believe that you are getting a check from the government for your solar system. You aren’t.

For more information about what incentives are available to you, please visit:  http://www.dsireusa.org/

Operations and Maintenance Agreements

Solar Watchdog is aware of a number of companies out there that promise a lifetime, bumper-to-bumper warranty on your system. Ask for that promise in a writing. Guess what? They will offer some flimsy excuse for why they don’t produce that in written form. The truth of the matter is that they won’t produce it in writing because it is a myth. It doesn’t exist. Any time you come across a salesperson or a company who isn’t willing to put their promises to you in a writing, you need to look elsewhere for a solar system.

Zero Bills or “Take You Off The Grid”

It takes a special system to eliminate your electric bill in its entirety. Usually, retail electric providers still assess you for meter fees and other line items that result in you paying something. Moreover, to take your electrical consumption down to zero kilowatts, you must have fairly reasonable consumption pre-solar installation with a system large enough to offset that consumption. Solar Watchdog strongly advises you take advantage of its quote evaluation before you believe claims of zero bills or systems that will take you off of the grid.

Temperature Coefficient

Okay, so, basically, this is some fancy way of telling you your panel isn’t going to produce as well in temperatures hotter than 77 degrees Fahrenheit. Solar panels are tested in climate-controlled factory conditions in what we call sweater weather in Texas, which is about 25 degrees Celsius.

Let’s say your 300 watt monocrystalline solar panel has a temperature coefficient of  -0.40.

The default analysis is that roofs in Texas reach 150 degrees Fahrenheit or 65 degrees Celsius.

The solar panel’s power loss can be calculated as follows:

65 degrees Celsius – 25 degrees Celsius = 40 degrees Celsius (remember that panels are tested at 25 degrees Celsius)

40 degrees Celsius x -0.40% (your panel’s temperature coefficient) = -16% reduction because of excess heat

Panel power loss = -16% x 300 watts = -48 watts

300 watts – 48 watts = 252 watts

Accordingly, your 300 watt panel during the summer months is only 84% effective because of the heat and is the equivalent of a 252 watt panel.