A temple in Lyneham
Twenty kilowatts of solar and a forty-kilowatt-hour battery on a temple complex whose bills were being driven by the cost of heating it.
What the customer wrote
The Abbot is very pleased and wishes to pass on his appreciation and support to get this project delivered
System specifications
- Solar
- 20 kW
- Battery
- Three Tesla Powerwall 3
- Battery capacity
- 40.5 kWh
- Switchboard
- Meter board upgraded
About this job
The bill was a heating problem
The referral came from community members concerned about exceptionally high energy bills. The cause was the building: a large, draughty, energy-inefficient complex that is expensive to keep warm. That matters for the design. Heating load is concentrated in the cold months and in the early morning, the two times a rooftop array is least able to cover on its own.
What a battery does on a commercial tariff
A commercial site is usually billed twice for electricity. Once for the energy it uses, and once for the highest half-hour of demand in the period. A single peak sets that second charge. Forty kilowatt-hours held on site and released across the peak reduces a cost the solar alone cannot touch. Sizing a battery for a commercial site is about the shape of the demand curve.
The meter board came first
The switchboard is what decides whether a job of this size is possible, and on an older complex it is usually the first thing to be replaced. The meter board was upgraded as part of the works. Nothing about the array or the battery could be finalised until that was settled, which is the ordinary order of a commercial retrofit and the part most quotes leave out.
What came with it
Sunstak also donated a portable battery pack and arranged a detailed assessment with a certified energy assessor, so the temple has a list of the next things worth doing. On a building whose costs come from its fabric, an assessment is worth more than another kilowatt. Insulation and draught sealing have no inverter and no warranty. They change the load the system has to meet.
