Renewable energy in cities comes down to three things: generating electricity on rooftops and car parks, supplying heat through shared networks rather than individual boilers, and planning rules that decide where each goes. Cities matter because they account for about 75% of global energy use and about 70% of greenhouse gas emissions, according to the International Energy Agency (IEA, 2024).
In UK cities, the biggest question is heat rather than electricity. Heat networks and heat pumps are doing more of the work than rooftop wind turbines ever did, and new rules on zoning, regulation and new homes are changing how urban energy is planned.
How it works
Rooftop solar and on-site generation
Solar panels are the most visible form of urban renewable energy. Cities have large areas of roof, car parks and commercial buildings close to where the electricity is used. The government’s Clean Power 2030 Action Plan (December 2024) aims for 45–47 GW of solar across Great Britain by 2030, up from 16.6 GW, and mentions rooftop solar alongside home batteries and solar canopies over car parks.
Heat networks
A heat network (also called district heating) pipes hot water from a central energy centre to many buildings. The heat can come from a gas plant, a large heat pump or waste heat from industry or transport. Because a network can change its heat source without every building replacing its own boiler, it is a way to cut emissions across a whole neighbourhood at once.
Heat networks supply only about 3% of UK heat today. The government expects that to grow to around a fifth by 2050, which is an ambition rather than a binding target. According to a 2023 government and Ofgem consultation, there are about 14,000 heat networks serving about 500,000 customers, around 12,000 of them small communal systems serving a single building.
Planning and zoning
The Energy Act 2023 gives powers to designate heat network zones in England, where certain buildings will be required to connect. These requirements are not in force yet. A pilot tested the zoning model in 28 English towns and cities, and the government responded to its consultation on 21 January 2026, saying some pilot areas are now being taken forward as the first zones ahead of the legislation coming into force.
Real-world examples
Bunhill heat network, Islington
Bunhill began in 2012 from an energy centre on Central Street, using a gas combined heat and power (CHP) engine and a 115 m³ hot water store. According to Islington Council, it first served 600 homes on three estates and two leisure centres, and more than 200 further homes were added later.
From 2016 the network was extended from a second energy centre on City Road. There, a large heat pump takes waste heat from warm air in the Northern line tunnels through a ventilation shaft, adding 550 homes on the King’s Square Estate and Moreland Primary School. The council has not published carbon or price figures for the scheme.
London’s solar ambitions
The Mayor’s Solar Action Plan (2018) set an ambition of 1 GW of solar in London by 2030 and 2 GW by 2050, from a base of about 95 MW at the time. The Greater London Authority’s Local Energy Accelerator, a £6 million programme, aimed to help deliver 3 MW of renewables and save 20,000 tonnes of CO2e a year by summer 2023. We could not find a reliable current total for solar capacity in London.
Manchester’s Civic Quarter Heat Network
Manchester City Council owns this network, which Vital Energi built and is contracted to run for 30 years. The scheme cost about £20 million, including a £2.87 million grant from the government’s Heat Network Investment Project. Its energy centre near Bridgewater Hall houses a 3.3 MWe gas CHP engine and two 12 MW gas boilers, feeding about 2 km of pipes. Connected buildings include Manchester Central, the Town Hall Extension, Central Library, Bridgewater Hall and Manchester Art Gallery.
This network runs on gas today. It is lower-carbon than separate boilers in each building, because the CHP engine makes electricity and heat together, but it is not renewable. Published estimates of its carbon savings have also varied.
Copenhagen: a target that slipped
Copenhagen was long cited for its pledge to become carbon-neutral by 2025. In August 2022 the city abandoned that target. The ARC Amager Bakke waste-to-energy plant had failed to qualify for state funding for carbon capture, and in November 2021 the city had already admitted errors in its emissions accounting.
The city had still cut its emissions by about 80%, as reported at the time, and set a new aim to be climate-positive by 2035 at the latest. The lesson is that large, real reductions through measures such as district heating are achievable, but a promise of full carbon neutrality by a set date is fragile.
What the numbers say
- Cities’ share: about 75% of global energy use and about 70% of emissions (IEA, 2024). The urban share of the world’s population is expected to rise from 56% today to about 70% by 2050.
- Cooling: the IEA expects global space cooling capacity to nearly double by 2030 from 850 GW, a bigger issue for hot cities than for the UK.
- UK heat networks: about 3% of heat today, around 20% hoped for by 2050; about 14,000 networks serving about 500,000 customers.
- Solar: 45–47 GW targeted across Great Britain by 2030, from 16.6 GW (Clean Power 2030 Action Plan, 2024); London’s own ambition is 1 GW by 2030.
- Costs: Manchester’s Civic Quarter network cost about £20 million (2019). For households, costs of solar or a heat network connection depend on the home and tariff, so check current scheme rules on GOV.UK or with an MCS-certified installer. This is general information, not advice.
You can see how much of Britain’s electricity comes from solar and wind at any moment on our live GB electricity mix page.
Limitations and honest assessment
- Not every heat network is renewable. Manchester’s runs on gas, and Bunhill started on gas CHP before adding its tunnel heat pump. A network makes a low-carbon switch easier later; it does not guarantee one.
- Targets can slip. Copenhagen’s experience shows that accounting errors and missed funding can undo a headline date even when real progress has been made.
- Roofs vary. Shading, orientation and roof structure limit what rooftop solar can produce in a dense city.
- Urban wind is weak. Small turbines on city buildings are sometimes promoted, but we found no well-documented UK example producing meaningful output.
- Heat networks are monopolies. A customer cannot switch heat supplier the way they can switch electricity supplier, and Ofgem regulation began only in 2026.
Remote communities face a different version of the same challenge, with no grid to fall back on; see our article on renewable energy for remote locations.
The UK angle: heat, zoning and new homes
Heat network zoning
Beyond the 28-place pilot, councils including Leeds, Plymouth, Bristol, Sheffield and Stockport have worked with the Department for Energy Security and Net Zero on its Advanced Zoning Programme to prepare early zones. The City of London ran a consultation on its proposed heat network zone boundary from 29 June to 12 August 2026. Until zoning legislation comes into force, no building is required to connect.
Consumer protection
Ofgem became the regulator for heat networks on 27 January 2026. Its rules cover billing, customer service, complaints and support for vulnerable customers, and existing operators have to register through Ofgem’s digital service.
Future Homes Standard
The Future Homes Standard for England was published on 24 March 2026, with most changes applying from 24 March 2027 after a transition period. Under it, almost all new homes will need on-site renewable generation such as solar panels, with rare exceptions such as heavily shaded sites. On-site generation will then be built into new homes from the start, rather than retrofitted later. For the wider case for and against switching, see why switch to renewable energy.
Frequently asked questions
How is renewable energy used in cities?
Mainly through rooftop and car park solar, heat networks that supply many buildings from one energy centre, and heat pumps that use local sources of warmth, such as the Northern line tunnel heat used by Islington’s Bunhill network.
What is a heat network?
A system of insulated pipes carrying hot water from a central energy centre to homes and other buildings. About 14,000 operate in the UK, supplying about 3% of the country’s heat.
Are heat networks renewable?
Not always. Many run on gas, including Manchester’s Civic Quarter network. Some use renewable or waste heat, such as Bunhill’s heat pump that recovers heat from the London Underground.
What is heat network zoning?
A planning tool in England, created by the Energy Act 2023, that will let authorities designate zones where certain buildings must connect to a heat network. The first zones are being prepared, but the requirement is not yet in force.
Is Copenhagen carbon neutral?
No. Copenhagen dropped its target of carbon neutrality by 2025 in August 2022. It now aims to be climate-positive by 2035 at the latest.
Will all new homes have solar panels?
Almost all new homes in England will need on-site renewable generation, such as solar panels, under the Future Homes Standard, with most changes applying from March 2027. There are rare exceptions, such as heavily shaded sites.