Decarbonisation is a catch-all phrase covering anything that reduces, or stops altogether, the carbon emissions produced by our daily activities. These activities are, for the most part, hardwired to the burning of fossil fuels, such as driving a car and heating our homes, which are mainly powered by oil and gas respectively. In the past, electricity was generated by predominantly coal-fired power stations emitting a high proportion of CO2 per unit of electricity produced. The UK’s ‘dash for gas’ in the 90s, together with increased investment in renewables, has since reduced the amount of CO2 released in electricity production, making electricity the preferred energy source when working towards decarbonising a building. 

The government has made a commitment to fully decarbonise the electricity grid over the next 30 years or so, but it is unclear how that will be achieved. There are several mature technologies available, for example wind, solar and nuclear. Whatever the technology it will not be without financial or environmental impact, so we should be looking to reduce our energy consumption whatever its source.

 

The most efficient way to heat a building with electricity is by using a heat pump, which takes heat from a cold heat source (for example the outside air, or the ground) and boosts it to a temperature high enough to heat a building. Using this technology, the heat generated will be two to four times greater than the amount of electricity used. The closer the temperature the cold heat source is to the heating temperature, the more efficient the heat pump is - but the bigger the heat emitter is (e.g. radiator). Any building can be heated in this way, but the bigger the heat loss, the bigger the heat pump. 

 

New builds should be well enough insulated to be easily heated with a heat pump. However, improving the fabric of an existing building to reduce heat loss is often seen as an expensive process which can be off-putting, but there are some inexpensive improvements that can be made, such as loft insulation and draft stripping. More expensive interventions, such as solid wall insulation and upgraded windows, are desirable and such improvements can be done at any time and will save energy and reduce the running costs of a building.

 

Of course, turning down the thermostat and switching off the lights will reduce the energy usage with no expenditure at all!

 

Examples of exemplar decarbonisation projects include Wolfson College - University of Oxford, Harper Adams University (pictured below) and Manchester Science & Industry Museum.

Image Credit: Harper Adams University