A solar farm in the sky
Solar farms are an efficient source of renewable energy, but they can be controversial and are, in the eyes of many, rather ugly. The 37 panel solar array at Copper Bottom is effectively an invisible solar farm that uses no land.
Our array is on the roof which slopes at 7 degrees and is behind a copper parapet on all four sides so that the roof and panels are not visible, except to passing birds. It was completed last week and we took advantage of the scaffolding and sunshine to take a tour. The panels looked rather beautiful set against the backdrop of the meadow and the views of Oxford on the horizon.
More importantly, this PV array will help Copper Bottom in its aspiration to be one of the most sustainable homes in the region.
Each of the panels has a peak capacity of 400Wp. Although they won’t ever quite achieve that performance, it is how they are calibrated for comparisons. With 37 panels the roof can produce 15,540Wp or 15.5kWp.
The panels feed a battery with a 24kWh capacity. So, if Copper Bottom uses an average of 1.5kW per hour, a fully charged battery will keep it running for 16 hours off-grid.
The battery can be charged directly from the solar panels on the roof, or from the AC mains via the inverter. It can therefore be charged from the mains at night, when power is cheaper, if necessary.
Once we are living at Copper Bottom, our solar panel supplier, AES, will monitor our power use and help us to maximise the efficiency of the system so that it ensures we use PV rather than the mains wherever possible. Of course, we will also aim to feed our renewable power back into the grid when we have a surplus in the summer.