Renewable heat
Almost half of the final energy consumed in the UK (49%) was in the form of heat, of which 70% was used by households and in commercial and public buildings.
[3]: 165 In those countries, such as Sweden, Denmark and Finland, where government intervention has been closest to a technology-neutral form of carbon valuation (i.e. carbon and energy taxes), renewable heat has played the leading role in a very substantial renewable contribution to final energy consumption.
Geothermal energy is an enormous, underused heat and power resource that is clean (emits little or no greenhouse gases), reliable (average system availability of 95%), and homegrown (making populations less dependent on oil).
The ground temperature remains constant at a point of 42 to 100 °F (6 to 38 °C) all year round depending on where you live on earth.
Though capital intensive, heat pumps are economical to run and can be powered by renewable electricity.
Solid wood fuel requires a large amount of dedicated storage space, and the specialized heating systems can be expensive (though grant schemes are available in many European countries to offset this capital cost.)
Low fuel costs mean that wood fuelled heating in Europe is frequently able to achieve a payback period of less than 3 to 5 years.
Burning wood fuel in an open fire is both extremely inefficient (0-20%) and polluting due to low temperature partial combustion.
In the same way that a drafty building loses heat through loss of warm air through poor sealing, an open fire is responsible for large heat losses by drawing very large volumes of warm air out of the building.
A heater with average wood consumption of 4 tonnes per year therefore emits 37.6 kg of PM2.5, i.e. particles less than 2.5 micrometers.
A recent European study[16] identified PM2.5 as the most health-hazardous air pollutant, causing an estimated 492,000 premature deaths.
Because of the problems with pollution, the Australian Lung Foundation recommends using alternative means for climate control.
Converting a wood-burning fireplace or stove to use either natural gas or propane will eliminate exposure to the dangerous toxins wood burning generates including dioxin, arsenic and formaldehyde.
A recent peer-reviewed paper found that, even if burning firewood from a sustainable supply, methane emissions from a typical Australian wood heater satisfying the current standard cause more global warming than heating the same house with gas.
Major consumption of hot water is sinks, showers, baths, dishwashers, and clothes washers.
