Just over three years ago, SPEC installed a solar system on the roof of our office building in Sinton. Aside from generating renewable power, the purpose of the installation was to help SPEC learn more about solar power and provide better advice to members in regards to system prices and payback periods. Here’s what we’ve learned so far.
In September 2016, SPEC installed 22 solar panels on the south side of our office building 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.
In 2019 our panels generated 8,854 kWh of electricity. Still, that isn’t nearly enough to power the average home. In Texas, the average residential home uses 14,112 kWh of electricity per year, according to 2018 data from the U.S. Energy Information Administration.
As can be expected, our solar panels produce the most renewable electricity during the summer months. Our best month to date was in July 2017, when our panels generated 1,053 kWh of solar power. The system performed the worst in February 2018, generating just 398 kWh.
In its lifetime, our system has generated 28,921 kWh of renewable electricity. The difference in electricity generated by each type of panel was negligible. The 10-panel string inverters generated 14,603 kWh versus the 12-panel microinverters which generated 14,318 kWh.
The 22 solar panel system on our office building was purchased for $24,877. A residential consumer could expect to see a 26 percent federal tax credit on a like system through the end of 2020, bringing the initial cost to $18,409.
However, those costs increase when you factor in financing and maintenance. If you were to finance a similar system at 4 percent interest, over 20 years, the total system cost would increase by $8,364. Additionally, you could expect to spend approximately $500 on maintenance. In this scenario, the solar array would cost you almost $27,271.
Assuming the panels produce the same amount of electricity as SPEC’s panels to date, you would generate electricity at an average cost of 16.9 cents per kWh. SPEC’s average residential rate over the same period was 10.5 cents per kWh.
In other words, you would spend around $114 per month for your solar system, but reduce your bill from SPEC by an average of $78 per month.
While that’s a bit more expensive than is commonly promoted by solar retailers, we’ve found it to be realistic for our area based on the data we’ve collected. Keep in mind, however, that your costs for solar power could be lower if you’re able to purchase the solar panels outright, finance at a better rate or purchase less expense solar panels.
Of course, cost isn’t the only factor to consider. If you’re looking to be more environmentally friendly, a rooftop solar system could help keep your carbon footprint low.
Go Solar without Rooftop Panels
We know that renewable energy options are important to our members, but not everyone is able to put solar panels on their roof. That’s why we’ve been working on a community solar project with STEC, our generation and transmission cooperative.
Through that project, we will have 500 KW of solar power to offer our members, in addition to the wind and hydroelectric resources already in our energy mix. And we’re working to develop a renewable energy rate to make sure our environmentally conscious members have options when it comes to their energy sources. More information on the project will be available in the coming months.