Bringing landfill into the 21st Century with solar power

The building of solar farms on agricultural land is a divisive subject.

Plans have recently been approved for one of the biggest solar plants in England. It will stretch across 2,965 acres (1,200 hectares) of land south and west of Wellingborough, north of Northampton and parts of Buckinghamshire.

Many people feel panels should be built on brownfield sites instead. Using former landfill sites is an option.

At Brogborough in Bedfordshire, one is currently being built on what Infinis, the company behind the work, said was "Europe's biggest landfill."

It said it was bringing "landfills into the 21st Century"

Work started earlier this year on the 450 acre (182 hectare) site which runs parallel to the A421. It is due to be switched on in spring 2027.

More than 62,000 panels are to be installed across 168 acres (68 hectares), creating about 40mwp of power - enough to fuel about 10,500 homes and the nearby Cranfield University.

The landfill site, previously a clay quarry and brickworks, operated from 1983 to 2028. It has since been covered with clay that was extracted from the same site.

As the buried waste decomposes, methane gas is produced which is turned into 9mw of renewable energy a year and fed straight into the national power grid.

Jason McGray, head of development of Northampton-based Infinis, said the solar site will also feed straight into the grid and a "private wire connection" will run to Cranfield, part of the Brogborough Clean Energy Hub.

He said the land cannot be used for anything else due to the "long-term management of gas and leakage liquids".

That gas is collected and fed through gas engines to generate a constant power.

He said: "It's constant, it's green energy but it's predictable and manageable.

"Combined with that we're now building solar so we've got the two sources of renewable energy both coming out of the same resource."

In the event that too much power is generated, McGray said there is also room on site for battery storage.

He said: "We've got planning permission, so we can then store power temporarily until it's needed on the grid."

McGray predicts managing the gas will go on longer than the 35-year expected life of the solar farm.

Ellie Goodchild is head of public affairs for Infinis. She said the land is owned by FCC, the energy is managed by Infinis and Akis Energy is the construction team behind the solar site.

She said the company wanted to "bring landfills into the 21st centry", turning a "legacy environmental issue into a productive energy asset"

Goodchild added: "Brogborough was formerly Europe's biggest landfill.

"This land would otherwise sit dormant, as the gas that comes out of landfills requires constant management to make sure that there are no environmental issues and issues for the local community, such as smells.

"This is about as brownfield as brownfield land comes."

The company also manages Stewartby landfill site across the A421. Here methane gas is also turned into power and planning permission has been granted for another solar farm to be built there.

A spokesperson for Cranfield University said it had been working with the company towards "securing a local zero carbon electricity supply".

They said: "This would underpin the University's progress towards achieving Net Zero carbon emissions by 2030."

Dr Pinar Karagoz is a lecturer in sustainability and smart environment at the school of engineering and innovation at The Open University, based in Milton Keynes.

She said: "In general terms capped landfill sites can be a sensible location for solar developments, offering important climate mitigation benefits.

"These sites also generally yield poor agricultural returns, even after fertiliser application."

However, Karagoz added that the benefits and potential trade-offs should be considered. She highlighted that solar panels can "alter soil moisture, temperature and airflow, creating wetter and drier zones across a site."

"Since solar panels can influence all three factors, the resulting effects may differ depending on drier or wetter regions, " she said.

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