Changing the way buildings are made or kept warm is a starting point for reducing energy used to heat them. The UK has seen a great leap in numbers of homes fitted with loft and/or wall insulation over the last decade. This can bring great benefits very quickly, and is usually highly cost effective when reduced heating bills are taken into account. New buildings could be designed to bring even greater benefits – the concept of a ‘passive house’ , which is built in such a way that it can heat itself, is gaining acceptance by ambitious builders in some areas of the world. Other approaches, such as the ‘Energiesprong’ technique, allow much deeper reductions in heating demand than previous techniques. For now at least, fitting existing buildings with insulation and other measures reduces some, if not all, of a building’s heating demand.
Another very natural and relatively untechnical way of providing greater heating to homes is for the Sun to warm the hot water tank. Solar heating does exactly that, providing a simple solution. However, like its electric counterpart, this form of solar power is variable, and limited to when the Sun is shining.
Green gas and Biomass
Much in the same vein as biomass electricity and biofuels (see clean electricity and transport) biomass can provide heating in many forms. The most familiar is probably a crackling log fire, but biomass boilers, ‘green gas’ and other ideas might be less well known. Biomass boilers use wood pellets to provide heat for water and central heating, whilst green gas is gas made from biofuels. These examples provide much of the same benefits and drawbacks of its electricity and transport counterparts, but switching from conventional to green gas might be easier than a heat pump for many people.
Taking and converting natural heat from the surrounding environment can be a complete alternative to conventional heating systems. A heat pump is a device that does just that, working like the opposite of an air conditioner. There are two types, ground source and air source. Ground source heat pumps use underground heat, while air source heat pumps warm air around buildings. There are the same emission costs as vehicles in that they require electricity to run, and low carbon electricity to reduce emissions. A major drawback to heat pumps might well be the amount of electricity they require – it will require increased electricity demand if they are rolled out on a large scale. Also like electric vehicles, they are currently expensive, and will only decrease in costs if more are bought on a larger scale.
Creating large quantities of hydrogen, also a flammable gas, and injecting it into the gas grid to replace the current gas we use (methane) has been touted by some as an easier way of replacing our heating system. However, special hydrogen infrastructure and boilers would still need to be fitted to every home, like installing heat pumps or insulation, although it would be a more familiar way of heating houses to residents. Hydrogen is further behind in development than these other measures, but could be an effective option, especially if there are limits on how far heat pumps and home design can reduce heating emissions.