It has been just over 2 years since San Patricio Electric Cooperative installed a solar system on the south side of our office building in Sinton. We now have 26 months of solar generation data, and have learned a lot about how well the system produces renewable electricity in our area.

Output Statistics

In September 2016, SPEC installed 22 solar panels on the south side of our office building in Sinton with capacity to generate 6.5 KW of renewable electricity. There are 10 panels with string inverters, each with a capacity of 310 watts. And 12 panels with microinverters that have a capacity of 270 watts.

Together, the two systems generated 9,018 kWh of electricity in 2018. That’s slightly less than the 9,777 kWh produced in 2017. And it isn’t nearly enough to power the average home. In Texas, the average residential home uses 13,334 kWh of electricity per year, according to 2017 data from the U.S. Energy Information Administration.

In the 26 full months we have collected data from our solar panels, the system generated 20,074 kWh. As can be expected, solar generation has been highest during the summer months. In the time we’ve been tracking data from our solar array, the best month for solar generation was in July of 2017 when our panels produced 1,053 kWh of electricity. It performed the worst in December of 2016, producing just 368 kWh.

There is some difference between how much renewable electricity each type of panel generates, but not by a significant amount. Over the last two years, the 12 microinverter panels produced 10,161 kWh, whereas the 10 panels with string inverters produced 9,913 kWh.

Financial Breakdown

The 22 solar panel system on our office building was purchased for $24,877. A residential consumer could expect to see a 30 percent federal tax credit on a like system through the end of 2019, bringing the initial cost to $17,414.

However, those costs go back up when you factor in financing and maintenance. Financing the system for 20 years, at 4 percent interest will add another $7,912 to the total system cost. Additionally, you could reasonably expect to spend about $500 in maintenance.

In this scenario, the solar array would cost approximately $25,825. Assuming the solar panels produce the same amount of electricity as SPEC’s panels to date, you would generate electricity at a cost of 14.75 cents per kWh. SPEC’s average rate for residential members over the same time period was 10.51 cents per kWh.

That means you would spend around $108 per month for your solar system, but reduce your bill from SPEC by an average of $81 per month.

However, keep in mind that your costs for solar power could be lower if you’re able to purchase less expensive solar panels or finance at a better interest rate. You may also consider that solar power could help you hedge against future costs of electricity. If the price of electricity was to rise over the years, your fixed price for solar power could help keep your electricity costs down.

It’s also important to note that the financial aspect of solar power isn’t the only factor to consider. You may also want to install solar power for environmental reasons. Having your own solar panels ensures that the electricity you use is renewable and keeps your carbon footprint low.

If you decide to install solar power at your residence, please give us a call at 361-364-2220 so we can be a part of the process with you.