The energy crisis had many impacts. It made people more engaged with their energy use. But not in a good way. People feel powerless about the cost of power, and quite rightly.

One excellent way to rewire people’s emotions about energy is solar. Supporting people to generate their own clean power is a positive, economical step forward to achieving our climate targets as a country. It has a net benefit not only to net zero, but also towards putting people back in control of their energy costs.

Which is why the news that the government’s ‘rooftop revolution’, by ensuring new-build homes have solar panels by default, is so welcome.

Solar powering 1.17 million more homes 
With over 180,000 rooftop solar generator customers for whom we administer export and generation payments, Good Energy has a wealth of data on solar.

Prior to the general election last year, we ran the numbers on what introducing compulsory solar panels on the 1.5 million new-build properties the incoming Labour government proposed to build would mean. We found that, on average a domestic rooftop installation exports more electricity than is used in the home. This means that 1.5 million new domestic solar rooftops would, in fact, generate enough electricity to power an additional 1.17 million homes through surplus energy shared back with the grid.

We conducted calculations from smart meter readings from more than 900 of our domestic solar customers across the UK, over more than 12 months. They showed that the average UK home with solar panels on its roof shares an average of 60% of the electricity generated back to the grid for others to use.

Extrapolating this based on a conservatively sized average 4 kW solar array on each new home would collectively generate 5.25 TWh. This works out as more than 5% of the UK’s entire domestic electricity consumption in 2023. More than 3.1 TWh of this power would be shared back to the grid. A not insignificant contribution to the UK government’s Clean Power 2030 goal.

Untapped small-scale solar potential
We believe the UK has underestimated the potential impact of small-scale solar generation, which could make a significant contribution to the UK’s energy mix. Our home-grown renewables should be a core priority for the government, and we are reassured by this latest commitment as it represents an important and effective component in that energy mix.

Good Energy’s HomeGen scheme was the blueprint for the government’s feed-in-tariff (FiT) when it first launched in 2010, under Energy Minister, then and now, Ed Miliband. It was created to encourage people to become generators by paying them for all the energy they produce. However, FiT made an assumption about how much power microgenerators would use when it offered a 50% export payment for non-smart generators. This payment was made regardless of how much a solar household shares back with the grid or uses itself, and our data now shows it underestimated export.

Despite FiT closing to new registrants in 2019 and being replaced by the Smart Export Guarantee (SEG), it is still the largest scheme small-scale solar generators can be paid for their power. There remain over 870,000 FiT accredited generators in the UK, with a total capacity of just under 6.5 GW – about double the planned capacity of Hinkley Point C.

To underpin the new low-carbon heating trajectory the government is committing to, we need a range of measures to continue supporting the contribution that small-scale solar generation makes. For example, through our smart export tariff, for both FiT and non-FiT microgenerators, our customers receive a payment for the actual amount of electricity exported, rather than the 50% estimated. This gives people the opportunity to earn more for the power they export and a clearer picture of the value their feed plays into the national grid.

There remain over 870,000 feed-in tariff accredited generators in the UK, with a total capacity of just under 6.5 GW – about double the planned capacity of Hinkley Point C.

We now have a fantastic mechanism for almost guaranteeing solar on newbuild homes. But we could go further and faster for retrofits, especially lower-income households, as upfront costs are a major barrier. Further incentivising retrofits with grants and zero-interest loans would open up solar possibilities to millions more households. Rules that tether customers to the same company for both electricity and export do little to give customers the freedom of choice or the ability to access more competitive products.

The forthcoming new Future Homes Standard is a positive step towards helping homeowners save money on their bills and cut their carbon emissions, while enabling surplus energy to be sold back to the grid. It’s a win-win scenario, supporting the UK’s energy security with cleaner, homegrown power. Now let’s think about how we can make the ‘rooftop revolution’ happen even faster.

The views and opinions expressed in this article are strictly those of the author only and are not necessarily given or endorsed by or on behalf of the Energy Institute.

• Further reading: ‘Can renewables reduce energy poverty?’. How should the UK balance its net zero 2050 target with the pressing need to help citizens – especially vulnerable populations – to keep warm at home? What are the most urgent actions, and what are the most important actions? Should we offer support for fabric-first energy efficiency or prioritise decarbonisation? Findings from a Parliamentary report and pan-European energy poverty research may show the way.
• Most people think we should reduce the amount of energy it takes to heat our homes. However, most UK homeowners have never quite got round to tackling the issue. There are many contributing factors in this pernicious problem. What is it going to take for UK homeowners to improve energy efficiency?