Scottish and Southern Energy Scottish and Southern Energy Greenwatt Way Complete

Greenwatt Way had an ambition to set the standards for Zero Carbon homes and needed an innovative combination of biomass engine, district heating and smart metering solution to help them achieve their goal.

“Slough’s project is a glimpse into the future of how we could all be living in years to come. Homes in the UK account for more than a quarter of the UK’s carbon dioxide emissions so saving energy makes sense for the planet as well as the householders. With feed-in-tariffs, the micro-generation strategy, smart meters and the ‘green deal’, sustainable living will transform our community, create green jobs, cut emissions and fuel bills.”

Rt Hon Chris Huhne MP Secretary of State for Energy & Climate Change

Project Overview

Greenwatt Way in Chalvey, Slough, is setting the benchmark for zero carbon homes in the future by showing how four different renewable technologies – biomass, solar thermal panels, an air source heat pump and a ground source heat pump, can be implemented in an urban community. Vital Energi was chosen by SSE to play a pivotal role in the revolutionary project by designing, supplying and installing the community’s innovative energy centre, a biomass engine, a district heating scheme, hydraulic interface units and a smart metering system. 

The renewable technologies are significantly reducing the development’s CO2 levels, allowing it to achieve Level 6 in the Code for Sustainable Homes and helping SSE to meet its vision of being a ‘leading sustainable global utility’ by 2016. The pioneering eco community has already been recognised by the Combined Heat and Power Association (CHPA) with the prestigious Innovation Award.

The Challenge

The main aim of the project is to study energy usage and consumption in a zero carbon home and the findings will be used in studies by SSE, Reading University, the National House-Building Council (NHBC) and the Building Research Establishment (BRE). 

The information is being gathered from smart meters, which Vital Energi supplied and installed in each residence. Tenant feedback is also being gathered from monthly questionnaires that are being completed by the by SSE and Slough Borough Council members that are living in the 10 properties of Greenwatt Way with their families.

Vital Energi's Solution

At the heart of the development’s success is the unique Vital Energi energy centre which features a zero carbon 350kW wood pellet biomass boiler, with the three remaining forms of micro-generation situated externally to the energy centre. Vital Energi also installed a building management system (BMS) which all the micro-generation technologies on the development feed into. This is the first time these four different renewable technologies have been included on the same urban community, meaning that their effectiveness can be compared against each other. Studies have already shown that Vital Energi’s biomass boiler well exceeds the Dwelling Emission Rates (DER) required for a zero carbon community. In fact, when the biomass boiler is used independently to heat Greenwatt Way the DER emissions on a one bedroom flat are more than three times lower than the minimum requirement of Level 6 in the Code for Sustainable Homes. 

The low carbon heating and hot water that is generated by the micro-generators is supplied to the community through Vital Energi’s innovative district heating system which uses pre-insulated pipes. The system also features the ‘Band Muff’ fusion welded joint system which is exclusive to Vital Energi in the UK. The ‘Band Muff’ increases the pipes’ design life from 30 to 50 years and significantly reduces the pipes’ heat loss. Hot water and heating is available on demand to residents via the Vital Aqua Varm HIU’s which are installed in each property. To ensure that there is enough heat and water for peak times and that excess heat is not created during off peak periods Vital Energi installed a Building Management System (BMS) into the energy centre. The BMS controls all of the renewable technologies within the plant room to ensure energy efficiency.

Carbon emissions are also lowered by the enhanced insulation, triple glazed windows, grey water recycling and latest energy efficient appliances that are installed on each property in Greenwatt Way, helping them to achieve Level 6 in the Code for Sustainable Homes. The properties range from two and three bedroom family houses to one bedroom flats, with some properties built from masonry block and others from timber frame to reflect the different construction methods that are used in the UK’s urban developments, giving a vision of tomorrow’s green communities.


As the first energy company to design, install and supply renewable technologies in a zero carbon community in the UK, Vital Energi is leading the way in meeting the government’s aim of reducing CO2 emissions by 80% in 2050. Studies of Greenwatt Way are already illustrating how Vital Energi’s technologies can exceed the requirements of Level 6 in the Code for Sustainable Homes, meaning that the company already has the ability to meet more demanding sustainability policies and regulations in the future. Furthermore, with Vital Energi’s help SSE is taking a leap towards being a ‘leading sustainable global utility’ by 2016.


  • Project now complies with Level 6 of the Code For Sustainable Homes

  • Biomass Boiler meets Zero Carbon Dwelling standards

  • Winner of the Combined Heat and Power Association Innovation Award