Sun-powered rooftops could generate two nukes of electricity…if England follows Peterborough’s lead

If all English constituencies matched Peterborough, which has the highest proportion of homes with rooftop solar photovoltaic (PV) panels [1], the country’s solar capacity could be increased by around 7GW (gigawatts), [2] new analysis from the Energy and Climate Intelligence Unit (ECIU) has found.

The nuclear power station Hinkley C will have a capacity of around 3.2GW [3], so the capacity rooftop solar on domestic properties could be more than the capacity of two new nuclear power stations.

In the wake of the gas crisis, a record 120,000 homes have had solar panels installed so far this year [4], helping households reduce their electricity bills. Areas right across the country including Swindon, Exeter, Nottingham, Portsmouth, Tyneside and Liverpool are in the top ten areas for numbers of solar PV systems installed under government schemes which target social housing and those struggling most with bills [5].

Jess Ralston, Energy Analyst at the Energy and Climate Intelligence Unit said: “The gas crisis has taught some UK households a harsh lesson, with an 82% increase in solar panels installed in the first half of 2023 compared to last year. Brits are doing their bit to bring down bills and boost energy security by reducing the amount of gas we need the price of which is set to stay much higher than before the crisis. And solar is popular across the country, with government schemes helping to deliver solar into people’s homes to ease the cost of living crisis.

“The rest of the world is going gangbusters on rooftop solar too – installations grew by about half in 2022 – and neither the installation rates nor cost decreases show any sign of slowing down. More solar could improve energy security by lessening the UK’s reliance on gas for power.”

In addition, industry analysis shows that the capacity potential of solar on the roofs of commercial properties, such as warehouses, is 15GW [6]. Combined, Peterborough levels of domestic solar and industry estimates for commercial solar could deliver an additional 22GW capacity, which is the equivalent of the capacity of almost 7 nuclear power stations. However, industry has reported that it is currently difficult to get commercial roof top developments connected to the grid, with waits up to a decade or more, and it can be costly.

Under the 22GW solar capacity scenario, over 20TWh of electricity could be produced each year. The equivalent amount of gas needed for this amount of power generation would be around 40TWh, which is equal to around 50 LNG tankers’ worth of gas or gas used to heat over 3.5 million homes for a year [7]. As gas prices are expected to stay around two to three times higher than pre-crisis levels for the foreseeable future, this amount of solar generation could therefore save the UK buying around £450 million worth of gas each year, which adds up to savings of around £1,000 for each household by 2050 [8].

The UK Government has a target of 70GW solar power capacity by 2035 [9]. Today, there is around 15GW installed, so another 7GW would be around a 50% increase, taking the total capacity to around 22GW, which is approximately one-third (31%) of the Government’s 2035 target. In the more ambitious scenario where commercial rooftop solar is also installed at pace, total capacity could be up to around 35GW, which is half of the Government’s 2035 target.

According to Government data [1], Peterborough comes top among English constituencies for the number of domestic solar photovoltaic systems deployed, with 6,744 in total installed. This is the equivalent of rooftop solar on more than 1 in 6 (17%) of homes in the constituency [10]. Should the rest of England match this, 3 million homes could have rooftop solar overall.

In addition, data from the Microgeneration Certification Scheme (MCS) also shows that installations are continuing at pace outside of Government schemes, with 120,000 installed since the start of 2023 [4], which beats the previous record for installations, set in 2015 when the Government’s Feed-in Tariff scheme came to an end. This builds on a record year for rooftop solar in the previous year, as the gas crisis drove up bills and energy security concerns, with over 130,000 systems mounted in 2022, almost the same as the previous three years combined.

ENDS

Notes to editors:

[1] Domestic solar photovoltaic deployment by parliamentary constituency.

[2] The capacity of a power generation source like solar PV panels or a nuclear power station is the potential power that it could generate if it was running all the time. In reality, the power sources do not run all the time, with the time that it does operate for termed the ‘load factor’. Load factors are usually expressed as a percentage and are taken into account when estimating the actual power that is likely to be generated.

[3] Hinkley C has a capacity of 3.2GW, according to DESNZ.

[4] Microgeneration Certification Scheme data.

[5] Solar PV installed as part of the government schemes the Energy Company Obligation, Green Homes Grant Local Authority Delivery and Home Upgrade Grants.

[6] UK Warehouse Association.

[7] Assumes that households have Ofgem’s TDCV gas consumption of 12,000kWh per year and LNG tankers have a typical capacity of 870GWh LNG.

[8] Assumes that solar PV costs (£/MWh) fall from that secured under Contracts for Difference Auction Round 4 last year, corrected according to current inflation rates, in line with the Government‘s Electricity Generation Cost predictions out to 2050. Assumes that gas prices fall from today’s levels to £45/MWh, in line with industry projects in the medium term. Load factors used for solar PV and gas power stations are 11.4% and 50% respectively, as per Government and industry norms.

[9] The Government has set a target for 70GW solar generation capacity by 2035.

[10] Assumes solar PV is installed only on terraced, semi-detached and detached homes using data in 2021 Census, accommodation type.

For more information, please contact George Smeeton, Head of Communications: george.smeeton@eciu.net or 07894 571 153.