I had several people ask me about putting a second row of solar panels on Ypsilanti’s City Hall. I’ve thought about it and always wondered where the next row would have to be place so it would not be in the shadow of the first row. Well yesterday was the summer solstices, the time of year when the sun is at it highest position in the sky. It was a nice sunny day, so I headed to City Hall with my camera around 1:00pm in the afternoon and took this picture.
Note how far down the wall the shadow reaches. If we ever do put a second row of solar panels on City Hall they would have to be about half way down the wall so they are not in the shade of the first row.
As you saw a couple of postings ago, we lost real time monitoring at the Ypsi Food Coop and River Street Bakery when the power company swapped out our meters with the newer smart meters. I thought this would be a good time to review the energy production at our four real time monitoring sites. Here are some pictures from the last 12 months.
Recall that if you hover your mouse over the monthly energy charts on the different webpages, it will show you the value for each portion of the bar chart. Doing this for the four locations and adding up the values, the Ypsi Food Coop produced 2739.1 KWH for the past 12 months, City Hall made 3015.8 KWH, the Bakery made 6616.6 KWH, and Adams School made 1886.6 for the past 9 months. If we divide these values by the rated values of these systems we see that the Ypsi Food Coop is running (2739.1/3328.8) 82.3% efficient, City Hall is (3015.8/3591.6) 84.0% efficient, the Bakery is (6616.6/8760) 75.5% efficient, and Adams School is (1886.6/2630) 71.7% efficient. It is not surprising that City Hall is the best, because it is located four stories up and has no issues with shading. Both the Ypsi Food Coop and Bakery have afternoon shading with the Bakery getting the most. The Adams School numbers are for only a partial year, and I suspect once we get a full years worth of data it’s percentage will go up.
If we divide that generated power by the total power consumed, we see the portion of the Ypsi Food Coop that is solar power was 38% solar powered, City Hall is 2.7% solar powered, the Bakery was 30% solar powered, and Adams School was about 1% solar powered. You may be wondering why the Bakery was not 100% solar power as we designed the system. You’ll notice that the first two months the bakery was doing great, but then drops off. In August last year, the Ypsi Food Coop installed some new coolers that used 3-phase electricity, but the store did not have 3-phase power, so they wired them into the Bakery. This created a much larger demand for power and dropped it’s percent solar powered. In May of this year, the store finally got their own 3-phase power, and the coolers were moved back to this circuit. In May you can see that the bakery is back to being mostly solar powered. Hopefully the next 12 months will show the Bakery 100% powered.
I didn’t post the graphs for the apartments on Huron street. We are collating real time data for those three apartments, but using a different method, we’re pulling data for only the generation directly from the EnPhase inverter’s website. We have data for the monthly charts, but the numbers don’t look correct and I’ll have to work with Nik to understand what’s going on. Hopefully we can just correct the numbers that are there and calculate an efficiency later.
In case anyone was wondering, we lost about a weeks worth of solar data from City Hall. The solar panels are fine and fully producing power, but we had a network issue with the laptop that collects the data from the utility meters. All is fixed and we’re collecting data again.
The panels are up! Go to SolarYpsi.org/index.php?siteDetails=cityhall to see all the pictures of the installation. Next step is to get the electrician over to City Hall to wire the power into the building’s electrical system. Should happen next week. Then a couple of inspections and a new DTE meter and we’ll be in business. The monitoring software will follow in a week or so after that.