In 2010, with tough climate change targets facing the UK’s housing market, SSE set out to deliver 10 of the UK’s first zero-carbon homes, in a development called Greenwatt Way, to understand better the needs of its customers in a low-carbon world
Three years on, our period of monitoring is complete and has yielded some interesting results.
The average Greenwatt Way home used 5% less electricity, 20% less hot water and a staggering 395%morespace heating than calculations predicted. However, even with the higher than predicted heating load, energy bills at Greenwatt Way averaged at around £575 pa, which is less than half of the national average.
Just as importantly, residents enjoyed living in their zero carbon homes. Kathy Jakeman, who moved in when the housing development first opened said: “I love living a ‘normal’ life while still doing my bit for the environment and saving on my energy costs too.”
Wendy Pringle-MacIntyre, Project Manager for Greenwatt Way, said: “We are pleased with the findings from our zero carbon home study. While the build costs are higher, these homes are comfortable places to live with significantly lower utility bills.
“The challenge now facing policy makers and the housing market is to find the right balance. Ideally this will include builders being obligated to build homes which actually use less energy in reality, particularly heat, rather than simply focusing on programmes to upgrade homes once they have been built.”
Did we achieve zero carbon living?
The scheme could have been entirely zero carbon if we had managed to reduce the heat load of the homes or switched the running regime of the on-site renewable energy centre to include more biomass. The homes used four times more heat than predicted and the vast majority of heat and hot water was supplied via a ground source heat pump, which runs on electricity. The electricity used was slightly more than the amount of electricity that was generated by the on-site solar panels.
Energy Performance Gap
The in-house energy usage information gathered at Greenwatt Way will be made available to the Zero Carbon Hub to assist with ‘The Performance Challenge’ – a programme to close the gap between designed and as-built performance in low-carbon homes.
Retrofitting Existing Homes
While improved energy efficiency and low-carbon technologies should limit the growing carbon emissions related to future homes, the real challenge is reducing the carbon associated with the estimated 20 million existing homes that will still be standing in 2050. With this in mind, SSE has set up a series of energy monitoring studies in homes where we have retrofitted energy efficiency measures to understand better the energy savings in reality. These include homes with district heating, external wall insulation, fuel switching from oil or old electric heating to gas, and electric heating upgrades.
For a look inside a zero-carbon home at Greenwatt Way, see the video below: