Case study: Woking Borough Council

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Addressing sustainability concerns within the built environment often means dealing with a number of issues and undertaking multiple projects. Woking Borough Council has shown a genuine commitment to these concerns by undertaking numerous development projects encompassing energy-efficiency, sustainability and renewable energy over a number of years. Running multiple initiatives over time is increasingly becoming the norm for local authorities around the country, as more and more councils see the benefits of providing a wide range of renewable energy options, as opposed to just a single scheme or project.

To achieve its far-reaching sustainability aims, Woking Borough Council incorporated – as part of the DETR-funded Energy Saving Trust Energy Services Company (ESCO) Programme – the UK’s first energy and environmental services company (EESCO), Thamesway Energy Ltd. The company was created to realise the council’s sustainable development strategies and bring the projects to fruition through construction.

Entering into both public and private joint ventures, Thamesway allows the council to be ambitious with its environmental development strategies and achieve far more than would be possible without such a company.

Key elements of the sustainable and renewable energy development projects have been the utilisation of solar photovoltaics (PV) and combined heat and power (CHP) technologies, either as separate energy sources or working alongside each other.

Tim Lowe, Senior Policy Officer for Sustainability at Woking Borough Council, explained some of the benefits for the council in using these two technologies: “Photovoltaics and CHP were often the most appropriate technologies to be retrofitted on to the various buildings, as these systems often fit in well with the existing infrastructure. In terms of funding and availability, the technologies were also well suited to the council’s requirements.”

A flagship example of the council’s renewable energy strategy is Woking’s town centre combined heat and power plant: the first commercially operating energy station of its kind in the country, it distributes electricity through a private wire system, whilst heat and chilled water services are made available via private pipe networks.

Supplying energy to residential, business and public sector customers, a minimum of 30% surplus power (after satisfying its own electricity demands) is exported to other local buildings (as well as helping to power council offices) over public wires. Costing £4.2 million to install, the plant has an annual energy output of around 1352kW (equivalent to the power needs of approximately 1300 households), and was supported with an Energy Saving Trust grant.

Tim Lowe cites the town centre CHP plant as the council’s most significant energy-efficient building project so far: “It has a significantly better energy-efficiency level than what you would pay for through sourcing from the National Grid, and additionally, it also supplies power to a number of town centre locations. The technology has worked and it’s proved to be financially viable as well.”

In terms of energy-efficient retrofitting, the Brockhill housing complex shows Woking and Thamesway to be just as accomplished. A sheltered housing scheme for elderly residents comprising 52 residential units, the building was originally constructed in the mid-1980s, and was then retrofitted with the PV and CHP technologies in 1997/8 and 2001 respectively. These now provide year-round heating, hot water and electricity to Brockhill’s residents, and the PV panels on Brockhill save an estimated 26 tonnes of CO2 a year – equivalent to the emissions of approximately four households. The CHP system is also able to operate independently if a failure of the National Grid should occur. The installation cost for the two technologies was £162,820 for phase one and £194,700 for phase two.

In another project finished in 2003, the council also combined traditional CHP technology with a fuel cell, to create what was at the time the UK’s only commercially operational fuel cell CHP system.

In some respects, fuel cells work similarly to batteries and power generators, but pose some significant advantages over both. Essentially, the cells are fuelled by hydrogen (supplied to the anode) and oxygen (supplied to the cathode), producing electricity, and also water and heat as by-products. The Woking Park CHP fuel cell has an ‘integrated steam reformer’, allowing it to produce hydrogen from natural gas, whilst oxygen is captured from air. Fuel cell technology is seen as ‘clean technology’, working on high efficiency and giving off low levels of carbon and even lower levels of other pollutants.

Additionally, since fuel cells work on an electrochemical basis – and not a combustion process, like that of a traditional power generator – they are also a quiet form of energy generation, as well as being highly reliable (as its ‘fuel’ is constantly being fed into it), making it the perfect option for supplying electricity to the Woking Park leisure centre.

The fuel cell supplies 200kW of electricity to the centre through a private wire network and 264kW of thermal energy. Heat is provided to the centre through high grade heating circuits, and air conditioning via an absorption chiller, which stores excess heat created during warm summer months, allowing it to provide additional cooling and dehumidification. Low grade heat from the fuel cell is used to provide domestic hot water to the leisure lagoon. As with the town centre CHP, after meeting its own electrical requirements, the system can use excess electricity to provide for residential properties through an extended wire network.

With combined costs for installing both the fuel cell infrastructure and CHP at around £3 million, this was clearly not a project undertaken without considerable thought beforehand. However, as with so many energy projects, Woking Council and Thamesway’s sustainable development work has clearly been planned with long-term benefits and payback periods sensibly in mind; many Thamesway projects are structured around a 25-30-year business plan.

The council’s environmental efforts have not gone unnoticed, and it has received three Beacon awards for its work on sustainability and tackling climate change, including one for ‘promoting sustainable communities through the planning process’ in 2006/2007. It also received the prestigious Queen’s Award for Enterprise in 2001 (the first local authority to do so), for its work on sustainable development throughout the borough of Woking.