We love home shows. Meandering the aisles at the El Paso Convention Center. Browsing through all the latest neat stuff for the house. Getting quotes from multiple vendors selling like products and services. And, occasionally, you come out a winner. Right now, Ursula and I are feeling like winners.
Just before our last transatlantic adventure, and after we’d obtained the necessary approvals from our home owners’ association, we contracted for a solar generation system for the house. Unfortunately we were unable to get together everything we needed to install before embarkation, but within weeks of our return installation commenced.
The company is Border Solar. The system they installed is from SunPower—32 solar voltaic panels (E19 / 240) rated at 240 watts each. There are actually two installations here—one set of 18 panels over the back balcony, and another set of 14 panels installed over a south-facing roof visible only from the open-air courtyard around which our house is built. Since there are two sets of panels, the total system runs through two inverters (pictured below). Guaranteed annual output—a little over 13,700 kilowatt-hours (kWh), or somewhere between 95% to 97% of our home’s annual energy needs.
After weeks of planning, waiting, installation, waiting, more installation, and more waiting, the El Paso Electric Company gave their final seal of approval, installed a Net Power Meter and, on Thursday afternoon, the switch was thrown and power generation commenced.
So, how well is it all performing? Beyond my expectations, actually. SunPower’s system includes constant, internet accessible performance monitoring. At any time I can log on and check current production; daily, hourly, and even 5-minute-interval production; production by inverter; and even production on previous days. It’s sort of addictive checking to see how much energy you’re generating and, conversely, how much you’re saving on your electric bill.
On Friday, our first full day of generation we produced 51.54 kWh. Saturday, Sunday, and Monday saw 52.40, 50.74, and 49.84 kWh. If I’ve figured out our meters correctly, we’re using about 30.84 kWh per day and generating on average around 51.13 kWh a day for a net gain of some 20 kWh over and above our current usage. Those usage numbers won’t hold during the rapidly approaching triple-digit temperatures we can expect in June and early July, but at least we’re banking some reserve in anticipation of some heavy air conditioning usage (last June our home energy use topped out at over 1,600 kWh for the month).
A quick word about net metering. Net metering is a policy in use by some electric companies that gives you credit for excess power generated (which goes into their power grid). The electric company then applies that credit during those times that you draw power from their system. If your power company has such a policy, then that’s ideal for solar power. You give the electric company your excess power during the day—when demand is highest and the company most needs it—and at night when you’re no longer generating power, you “spend” those “banked” energy credits when you draw from the electric company’s power grid to pop some corn and play a Netflix Blu-ray of True Grit, X-Men: First Class, Thor, Captain America, Dark Shadows, 127 Hours, or Nordwand. How’s that for a shameless plug of my movie reviews?
The true test of course is billing, and June is historically our hottest month. Last June we had our worst electric bill ever—just shy of $300. This June is forecast to be just as stifling, perhaps even a bit hotter. Needless to say, this coming July is the first time in my life I’m actually looking forward to receiving a summer-time electric bill.
Now some numbers for the ecologically minded among my followers: During the period from Thursday afternoon through Monday evening we generated 228 kWh. That 4 ½ days the system reduced our home’s carbon footprint by 392 lbs. That’s the equivalent of planting four tree seedlings and growing them for ten years, or not driving the average car 373 miles.
Below is a (censored) photo-journal on the system and its installation: