Bright Idea

It is fair to say that building a new housing development is out of the ordinary for SSE (Scottish and Southern Energy, as one of the UK’s leading energy companies, but it hopes that its Greenwatt Way development in Chalvey, Slough, will prove to be a valuable research tool

SSSE has no desire to become a housebuilder, the aim of the development of 10 zero carbon homes – a mixture of two and three bedroom family houses, and one bedroom flats – is for the company to learn more about energy usage in such properties.

As Wendy Pringle, project executive, explains: “The previous Governmentannounced in 2007 that all new houses should be zero carbon from 2016 and the year after that our company set up a research department which I was a member of. My first report was on how zero carbon homes would impact an
energy company and one recommendation was to get involved in building some because there were so few about at that point and even less of them lived in.

“We felt that energy companies had to get better at being a builder or building companies had to get better at supplying energy solutions so somewhere along that line, we need to work together. So we thought if we build our own and get the builders involved we can find out exactly what they are up against.”

SSE is proud of its environmental credentials and is a leading generator of renewable energy in the UK offering green energy tariffs to customers, however the company has never built a zero carbon home before.

Very little is understood as to how much heat and power is needed for a zero carbon home and how occupants will use it and SSE is keen to explore the issue in greater detail. The company will also look at issues such as ventilation, air quality, noise and the environmental tolerance of a zero carbon home to the real people living in it.

Half of the properties have been constructed in masonary block while the remainder were built using Stewart Milne Timber Systems’ Sigma II Build System.

The closed panel timber frame construction helps to achieve maximum energy efficiency through the fabric and the properties were built in six working days from the foundations to the point of being structurally complete, insulated, sealed, weather proofed and air tight.

All of the properties feature integrated solar photovoltaic roof tiles generating up to 63kWp of electricity and the surplus electricity will be sold back to the National Grid. Each property also has a Mechanical Ventilation and Heat Recovery System, a Smart Meter, a Grey Water Recycling System which will use recycled bath and shower water to flush toilets and recover waste heat, and a Rainwater Harvesting system which will collect and store rainwater which will be used to flush toilets. The houses all have a private patio and vegetable plots but they also share a garden.

The development also boasts an energy centre, housing a mini district heat scheme supplying renewable heating and hot water to all of the properties. The water in the energy centre can be heated from four different renewable heat technologies – a ground source heat pump, a biomass boiler, an air source heat pump, solar thermal panels and a hydrogen fuel cell CHP is due to be installed soon.

The idea is to test each technology in turn and to monitor its effectivenessas Pringle explains: “We would never suggest that you put an energy centre like that in any housing scheme but we want to test each technology one at a time and see how well they perform. With the district heating you can heat up your water in different ways and it still gets to the house but if you tried different technologies in each house you would have to rip out each one each time and install a new one.

“We have to put them on for several months at a time so we would have todo a ground source heat pump in the winter versus an air source heat pump, we don’t chop and change daily.”

Energy use and consumption within the homes will be monitored by SSE over a two-year period and the tenants will be interviewed regularly about their dayto- day experiences of living in their homes.

SSE also holds monthly meetings with tenants to gain their feedback andtechnicians access the properties monthly for data collection to assess how well the renewable heating technology performs and how warm the houses actually are.

Pringle explains that the tenants – made up of SSE staff, their friends and families, Slough Borough Council staff and keyworkers, don’t have to be “stereotypical greenies”, as the idea is to find systems that “real people are happy with.”

The site also has a five seater Ford Connect electric car for the tenants to share and there is a charging point installed in the parking bay.

The results of the project still remain to be seen and while SSE won’t be giving up on its day job to become a developer, the company is keen to learn more about the practical use of renewable energies.

“We are going to prepare our company for the future,” says Pringle. “That is the main reason for this project to make sure that we are able to bring energy to customers in a sustainable way as their requirements change.”