THERMAL energy is the total potential and kinetic energy associated with the random motions of the molecules of a material. OK, that’s the definition, but what does it mean? Energy’s editor first encountered thermal energy at the age of eight in New Zealand, where the family was living way back in the 1950s. Fairly near the town of Rotorua, which is famous for its hot springs and boiling mud pools, we travelled past what, as it later transpired, was the world’s first thermal energy power station.
Basically, it harnessed steam from below ground to spin a turbine that drove an alternator to generate electricity.
They use thermal energy in Iceland, where it is available in abundance, while in much of northern Europe, bore holes are drilled into the rock in order to harvest heat below ground to keep buildings warm. Ground source heat, as it is often called, is only now catching on in Britain and is very expensive, even though the energy source itself is free for the taking.
Then there is the massive amount of energy held in the oceans. Here in Britain, we feel the impact of ocean energy every day. It’s called the Gulf Stream – a conveyor of warm water that travels from the tropics northwards towards Europe. Without it we would probably be living in another ice age.
The ocean resource is incredible, bearing in mind that the seas cover a little more than 70% of the Earth’s surface.
This makes them the world’s largest solar energy collector and energy storage system. On an average day, 60million sq km (23million square miles) of tropical seas absorb an amount of solar radiation equal in heat content to about 250billion barrels of oil.
If less than 0.1% of this stored solar energy could be converted into electric power, it would supply about 15 times the total amount of electricity consumed in Europe every day.
Useful reference points include
. gov/kids/energyfacts/sources/ renewable/ ocean.html