Green tech savings
How much can you save with solar panels, battery and a heat pump?
Green tech savings for a typical three-bedroom house
Using data from hundreds of solar, battery and heat pump installations, we estimate an average household could save £1491.65 a year on their energy bills by installing solar panels, battery storage and a heat pump. Read on for our workings.
Typical savings from installing green technologies
| 10 solar panels + export tariff | £943.30 |
| 10kWh Battery | £467.35 |
| Heat pump vs gas heating | £81 |
| Total | £1491.65 |
About our example average household
Our average 3 bedroom household has a electricity consumption of 2700kWh a year, and a heating demand of 11,500kWh a year – the national averages defined by Ofgem.
We have based our modelling on installing a 10 panel 4.75kWp solar panel system, a 10kWh battery and an 8kW heat pump. These are realistic upgrades for homes of this size.
See our workings
Click into the accordions below to see how we have calculated total bill savings and earnings from green technologies.
Good Energy installs highly efficient 475W solar panels, meaning a 10-panel solar array will have a total installed capacity of 4.75kW.
A south facing system in the South of England with no shading and an average 30° pitched roof is estimated to generate up to 5997kWh per year. East or west-facing systems are estimated to generate up to 4822kWh.
Using our internal data, we estimate that our average household would use around 2,000kWh of their solar power as its produced, instead of drawing power from the grid at 26p / kWh (the current average energy price cap). Assuming they have east / west facing panels, they would export around 2,822 kWh a year at 15p / kWh.
| Solar power generated | Unit rate saved / earned | Financial saving | |
| Electricity bill savings | 2,000 kWh | 0.26 / kWh | £520 |
| Export tariff earnings | 2,822 kWh | 0.15 / kWh
|
£423.30 |
| Total solar bill savings | 4822 kWh | £943.30 |
Customers that install solar panels and a battery with Good Energy are also eligible for an exclusive export tariff paying 25p / kWh for a year – further boosting earnings.
Combining a battery with a smart time of use tariff is an effective way to lower energy bills. We estimate it could save the average household with a 10kWh battery around £467.35 over the course of a year. Here’s how:
We analysed anonymised half-hourly smart meter data from 400 customers to understand their typical usage patterns – and noticed that typical customers were using around 6.6kWh of electricity in the afternoons and evenings (when their power is less likely to be covered by solar panels).
If these customers scheduled a battery to store power at a cheap overnight rate of 6.6p / kWh; and then used it to cover this peak time usage, they would save £1.28 a day, adding up to £467.35 over the course of a year.
| Off peak rate | Price cap | Financial savings from storing 6.6 kWh off peak power | |
| Daily savings | 6.6p | 26p | £1.28 |
| Annual savings | £467.35 |
Customers that install solar panels and a battery with Good Energy are also eligible for an exclusive export tariff paying 25p / kWh for a year – further boosting earnings.
Our real-world data of 102 heat pump installations shows that our heat pumps have an average efficiency (SCOP) of 3.57. This means that for every one unit of electricity they use, they generate 3.57 units of heat.
We’ve calculated that a home with average heat demand of 11,500kWh switching from a modern gas boiler to a Good Energy heat pump could save £81 a year. This includes the bill savings from the higher efficiency heating method, plus savings from no longer paying the gas standing charge.
| Annual heat demand | Unit rate | Efficiency | Gas standing charge | Annual heating bill | |
| Gas heating | 11,500 kWh | 6.29p / unit | 0.9 | 34.03p / day | £928 |
| Heat pump | 11,500 kWh | 26p / kWh | 3.57 | n/a | £847 |
| Saving | £81 |
(Heat demand of 11,500kWh / efficiency of 0.9 * gas rate + standing charge * 365) – (Heat demand of 11,500kWh / average scop * electricity rate * 365)
Higher savings for customers with larger installs
The example above evidences the savings that a UK-average 3 bedroom home could achieve from installing solar panels, battery storage and a heat pump.
Good Energy often installs much larger solar and battery systems for customers, resulting in much larger savings. Here are some real-world savings from our larger installations.
The average install size for Good Energy’s supply customers between January 2024 and the present is 10.02kWh – roughly equivalent to 22 panels.
This system would generate roughly 8,500kWh a year; with these customers using on average 58.3% of their power at home.
This lead to energy bill savings of £1,288 a year from avoided import electricity purchases.
We’ve analysed real payments made to 2,128 Good Energy customers in 2024 on our solar savings tariff. We can see our median customer earns £416.72 through export of excess energy, and our top 10% earn in excess of £963.59 a year.
