The most important groups of fuels are fossil fuels, bio-fuels, hydrogen and nuclear fuel (uranium). Of these fuels, only bio-fuels and hydrogen are strictly renewable, but in both cases, this really depends on the energy source used to produce it. We have traditionally been heavily dependent on fossil fuels (first coal, then oil and now natural gas) and more recently on nuclear power. In the future, we will need a more sustainable range of fuels for all potential uses. New technologies such as fuel cells may require a wider range of fuels (e.g. hydrogen) and widen the range of applications for which fuels may be used (e.g. methanol-fuelled fuel cells to power laptops). There are many controversial topics surrounding fuels, from carbon emissions and climate change through the potential for bio-fuel crops to compete with food crops to the whole debate around nuclear power generation. - Description added by: David Lockie

Appliances, whether domestic, commercial or industrial, are consumers of electricity. A low carbon economy requires that these appliances be very energy efficient, both in use and when on standby. However, there are embedded carbon costs in appliances, from their manufacture and transport. These also needs to be considered when choosing an appliance. - Description added by: David Lockie