Advance gasification is used to power the CHP system at Chatsworth. Credit: Creative Commons

Chatsworth House in Derbyshire, UK has commissioned the construction of a revolutionary new renewable energy generation system that is set to reduce its carbon emissions by 90%.

Work has already begun on the new system at Chatsworth House – which is being designed and constructed by UK-based low-carbon energy specialist, LowC Communities Ltd. Utilising only the low-value timber felled as part of the estate’s normal annual harvesting operations, the new system, which is known as Arbor ElectroGen, will convert the wood fuel into electricity via an advanced gasification process. This produces a clean, combustible gas that is used to power a combined heat and power (CHP) system – containing an engine similar to that found in large commercial vehicles – which in turn drives a generator to produce around 97% of Chatsworth’s annual electrical requirements.

Known as Arbor ElectroGen, this advanced gasification, biomass-fuelled CHP system delivers, low-carbon heat and power for a variety of applications. Fuelled by ‘woody’ biomass, it can be used by customers that have an on-site biomass resource – such as woodland, or easy access to a local feedstock.

The feedstock creation follows a few simple steps by taking newly cut, ‘small round wood’ or similar, chipping to the required specification, (much larger than traditional heat-only biomass boilers) drying in the warm extract air from the plant space and that used in the gas cooling process. There is no requirement for long-term storage or chip screening.

The Arbor ElectroGen system produces an almost equal amount of heat and electricity (in the ratio of 1.5:1), the system offers one of, if not the most cost-effective ways to meet the ever-more stringent demands of both the Code for Sustainable Homes and BREEAM. This heat-to-power ratio should be compared to a biomass steam boiler and turbine with a heat to power ratio of 5:1, a Stirling engine of 3:1 and a high-speed turbine of 3:1 therefore making it better suited to matching the power and thermal demands of a building, facility or community network without dumping heat.

Whilst the bulk of the delivery of the UK’s built environment continues to focus on producing renewable heat to meet the demands of planning requirements, the Arbor ElectroGen targets renewable electricity – a commodity that, if supplied from the national grid, emits around three times more carbon than the natural gas required to produce it – and additionally produces renewable heat

Nearly all of the heat created by the engine’s cooling system and exhaust will be recovered and used in a new district heating network to supply Chatsworth House, as well as its restaurant and garden glasshouses – providing around 72% of the annual requirements for space heating and hot water.

Nicholas Wood, land agent at Chatsworth commented: “This project perfectly illustrates our on-going commitment to sustainability at Chatsworth. There is normally a proportion of timber from our harvesting operations that is of poor quality and limited use – this will now be utilised on site as biomass. All felled areas are replanted, thus ensuring that our woodlands continue to be sustainable.” Annually, the new renewable energy centre will save around 1350 tonnes of carbon being emitted – in comparison to grid-supplied energy produced by fossil fuels.

“We considered many forms of renewable energy for the house – but the outstanding environmental and commercial credentials of the chosen technology far outweighed the alternatives.”

Indeed, it has been calculated that, to achieve the same level of carbon savings with solar photovoltaic panels, the estate would have needed to install around 24,000 square metres of panels – which would cover the same area as around 3.5 football pitches – something unthinkable in such an area famed for its outstanding beauty.

According to Richard Griffin, chief executive of LowC Communities: “We are truly delighted that Chatsworth will be taking a leading position in the fight against global warming and I would hope that it demonstrates that if a stately home can achieve carbon-neutral status, then this level of reduction is well within the reach of all other types of buildings regardless of their size or age.

“Although gasification technology can trace its roots back to the 1800s when it was first used to produce ‘town gas’ from coal, the major technological leap for us has been to refine the process sufficiently in order to produce gas that is clean enough to reliably power the engine. Many companies have tried to produce electrical power from biomass fuels, but they’ve either failed or only managed to achieve low levels of efficiency and reliability.

“Due to the efficiency of our process – coupled with use of a renewable fuel that’s absorbed carbon dioxide during its lifetime – the technology offers very low-carbon energy.

This technology could make a significant contribution towards the UK government’s targets for the year 2020 – cut ting carbon emissions by 34% and having the country deriving 15% of its total energy from renewable sources.”

This decentralised approach to power generation also ensures that energy is consumed locally – avoiding the inefficiencies and losses associated with transporting electricity long distances.

It also helps to overcome the increasing problem of balancing the grid by producing energy when and where it is required. Due to the high temperature of the gasification process, there is none of the air quality issues that are inherent in many other generation technologies and no visible smoke plume.

Education will also play an important role in Chatsworth’s on-going commitment to sustainability as its new Renewable Energy Centre and its purpose-built building will become part of the visitor experience. Members of the public will be actively encouraged to see at first-hand how the estate is generating its own renewable energy and learn more about the concept and how it fits in with the drive to reduce the estate’s environmental impact.

Innovation in energy goes back a long way at Chatsworth. In 1893, the Eigth Duke of Devonshire commissioned water-powered electricity generating turbines to harness the gravity-fed water system that was in place to feed the famous fountains. This hydropower system is still producing electricity today.

The Renewable Energy Centre at Chatsworth is the first in a series of advanced gasification projects that LowC Communities is developing in the UK. Previously, the company has pioneered an award-winning, low-carbon energy technology based on CHP – fuelled by UK-grown bioliquids such as rapeseed oil.

The idea of using CHP application in Britain’s stately homes is also a subject that is near to the hear of the Prince of Wales, who recently called for a major environmentally-friendly refurbishment of Britain’s historic buildings to “avert the climate crisis”.

In a new guide aimed at the owners of run-down estates, he said it was a “tragedy” to see such buildings abandoned, derelict or destroyed. Not only because of the loss of heritage but because of the “terrible waste of resources” as the country struggles to become more energy efficient. Prince Charles already uses ground source heat pumps and other forms of renewable energy on his wider estate.

He says historic buildings should be leading the way in the fight against climate change by insulating roofs, harvesting rainwater and even generating their own energy. The guide also recommends wind turbines where appropriate – despite the Prince’s well known hatred of modern attachments on older buildings.

Dr. Andrew Horsley is Managing Director of LowC Communities Ltd.

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