Renewable and alternative energy sources are set to play an increasingly important role in providing the electricity, heat, cooling and fuels that society needs. There is a wide range of energy sources such as solar (both photovoltaic and solar thermal), wind, bio-fuels and biomass, hydro-electric, geothermal and heat pumps. - Description added by: David Lockie

A product or system is only as low carbon as the materials and components from which it is made. More and more, companies expect their suppliers to have strong corporate and social responsibility policies that meet their own high standards. A sustainable supply chain will ultimately increase profitability. - Description added by: David Lockie

A product or system is only as low carbon as the materials and components provided they do not increase during its life the overall environmental burden  with its maintenance and repair costs. - Description added by: Andrew Schofield