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Energy diversity: The Swindon site already uses solar power and now plans to invest in biomass too
Honda has applied to build a biomass combined-heat-and-power plant at its manufacturing site in Swindon.
If construction is approved by Swindon Borough Council, it will be the first combined-heat-and-power (CHP) plant fuelled by renewable feedstock at a UK factory.
The 4.5MWe and 1.5MWth capacity plant will use gasification technology to convert waste wood into syngas and provide baseload electricity and heat for the site’s manufacturing processes.
The Energy Centre, as it will be known, will consume 49,000 tonnes of wood a year to generate 30% of the site’s annual power requirement. It should reduce the factory’s CO2 emissions by 17,600 tonnes a year. Hot water will also be piped directly into the manufacturing operation.
In the process, chipped fuel is fed into the gasification chamber using hydraulic rams. Hot air is allowed to enter the chamber, causing the fuel to break down into syngas. The syngas is fed into a combustion chamber, which provides heat to raise steam in a boiler which drives the turbine and generator. Steam from the turbine is condensed and recirculated with heat exchanged into the Honda site’s water circuit. Flue gas is cleaned before it is dispersed.
A 5MWp solar photovoltaic ( PV ) farm already supplies electricity to the 370-acre site, and a further 10MWp scheme is under construction, but plans to build three wind turbines were rejected by the local council in 2011.
Julian Bliss, a senior staff engineer at Honda, said: “We are trying to manage energy costs and minimise our CO2 emissions. The Energy Centre will also give us security of supply because it is on site. Plus it complements the solar PV, supplying us baseload while the PV supplies during the day when we have peak demand.
Shopfloor benefit: Honda wants greater security of energy supply for its carmaking operation
“Honda is an innovative company and there are some examples of the technology we are proposing around the world, including one plant that has been operating in Italy for 12 months. It is also being promoted by the government.”
Around 2,700 people are employed at Honda Swindon and the site is said to support 12,000 local jobs.
Peter Rolton, chairman of engineering consultancy the Rolton Group, which is designing the plant for Honda, said: “There isn’t a biomass plant in the UK of the type we are building in Swindon up and running at the moment. Honda are ahead of the game – it’s the first time anyone has built a gasification plant with the intention of embedding it on a manufacturing site.
“It’s the equivalent of a large windfarm, but without the visual impact. The baseload electricity the plant provides has to have high rates of availability and we are targeting 95%.”
Rolton said his company was working on at least three similar projects and that there would be a large increase in the number of CHP gasification plants being built in the UK soon. “Today a plant buys energy at retail prices. If you generate on site you miss out on all the charges incurred from the wholesale-to-retail part of the chain. There are extra infrastructure costs, but you also gain much stronger security of supply and surety of price,” he said.
He added that even more manufacturing sites will add on-site generation if forthcoming changes to energy legislation are implemented by the government in a way that enables firms to retain carbon savings.
“When you claim a renewables obligation certificate currently you lose the carbon benefit to the energy company. Contracts for difference are a tariff support mechanism and if the government can make sure manufacturers can keep the carbon saving from them in accounting terms these plants will make even more economic sense,” he said.