We generated 1,018 kWh in August, up 5% from last month. That is our best month yet, and our best daily average of 32.8 kWh per day as compared to the last two month’s average of 31.3 kWh per day. Typically solar generation starts to decline in August, with decreasing sunlight hours, more clouds and more heat, but not this year.
Back in our June performance update, we mentioned that June was our first year anniversary for our solar PV system. In New York, the utility keeps track of the amount of power we use and generate (net-metering) over the course of a year and on the anniversary date credits the owner with any surplus power generated. We generated a surplus of 3,650 kWh from June 1, 2011 to June 1, 2012.
After several calls to customer service and waiting 75 days, we finally got our credit from the power company.
In our July performance post I stated that we were tracking our water usage and water pump usage to calculate the efficiency of the pump. Dan Gibson asked in a comment about our water usage, so I thought I’d cover that here. He says in his comment that there are not a lot of actual hard numbers on water usage and he’s definitely right. Most estimates I’ve seen online say 50 to 100 gallons per person, which seems both excessive and vague at the same time.
We installed water meters on the main line and the inlet to the hot water tank. We have usage data starting in January when we moved in.
We generated 970 kWh in July, up 3% from last month. That is our best month yet, but in line with last month’s daily average of 31.3 kWh. We used 319 kWh, 5% less per day on average than last month. We turned on the air conditioning for 3 days during a particularly humid run, and periodically for a few days the next week. We used 12 kWh for cooling / dehumidification, 8% of our month’s total usage. We generated a 651 kWh surplus this month, our 5th surplus month in a row and highest yet.
We ordered a radon test kit from the New York State Department of Health last month. The kit is small canister of charcoal that you open and place in the test area for several days. We let it sit for 4 days in our basement, then sent it off to the testing lab. The results came back about a week later.
June seemed to be in line with past year averages at least temperature-wise. (1 heating degree day less than the 10 year average, 52% less HDD than May, 8% more sun). We turned on the air conditioning for a couple of hours on three particularly hot and humid days. We’ve also started building a barn this month so that is starting to show up in our energy usage. This partially resulted in 5% higher energy usage in June. We used 0.36 kWh for space heating and 2.76 kWh for cooling. Our daily average usage was up 9% from May. We generated a 614 kWh surplus this month, our forth surplus month in a row and highest yet.
May was a warm and rainy month. (52% less heating degree days than April, 7% less sun). This partially resulted in 20% lower energy usage in May. We only used 4.8 kWh for space heating. Our daily average usage was down 23% from April. We generated a 558 kWh surplus this month, our third surplus month in a row.
Damaged belt causing the knocking soundFilter pad wedged between disc and unitDelaminated filter wedge after removal from disc
After a few months of flawless operation our UltimateAir RecoupAerator ventilation unit started to make a horrible squealing sound after we turned on the boost for a morning shower. I turn it off and grunted. No one likes a new piece of equipment to malfunction this early in their lifecycle.
April saw the return of weather normalcy. (12% less heating degree days than March but only 8% less than the 10 year average, 7% more sun). This partially resulted in 25% lower energy usage in April. We used 49 kWh just for space heating. We also installed a clothes line outside and used the clothes dryer less this month. Our daily average usage was down 22% from March. We generated a 538 kWh surplus in April, our second surplus month in a row.
