Renewable energy sources such as solar, wind and geothermal do not cause air pollution and have low or no CO2 emissions. Another advantage is that the energy never runs out. This is in contrast to coal, oil and gas. The burning of these fossil fuels contributes to climate change.
There are quite a few options of renewable energy sources these days that are succesfully in use. These are:
Because of the ideal fit with underfloor heating, we will limit ourselves here in this article to Geothermal energy or Ground source heat.
Ground source heat pumps
Heat from the ground and the water in the soil is a renewable form of energy. Depending on the depth is called the Earth’s heat or ground heat. Geothermal energy is in hard to reach in Scotland and therefore very expensive. Ground heat is achievable and ends up as heating for the in mainly new homes.
Geothermal heat and ground source heat are eco-friendly alternatives to the burning of gas and coal. Because the use of Earth and soil heat will hardly pollute, or have any CO2 emissions and will therfore not influence climate change. Another environmental benefit is that geothermal heat will never run out, unlike fossil fuels.
To sum it up:
Sources of Earth and ground heat
Sunlight warms the soil and the groundwater (especially in summer). By circulation of ground water and by the distribution of heat by the soil, the Sun can heat up to several hundred meters deep in the Earth’s crust. The heat in the soil and water in the soil are both called ground source heat.
Nature core allows for geothermal
Geothermal energy comes from another source, namely, the hot core of the Earth. The temperature in the core is not exactly known, estimates range from 2.000 to 12,000 degrees Celsius. This form of heat is called geothermal, or geothermal heat.
The core heat spreads through the different layers to the Earth’s crust. Seen from the outside in, it is becoming warmer. Every kilometer we dig deeper, the temperature rises with 30 degree Celsius. Starting from 500 metres depth there is enough heat difference to be able to transport the heat to the surface.
How to extract ground source heat
The substracting of ground source heat to 100 meters deep in the Earth is done with so-called ground source heatpumps. Such a soil heat exchanger consists of a closed piping system that runs up to 100 meters deep in the soil. Pumped through the pipes is a liquid (usually water with antifreeze). The liquid flows through the warmer ground, heats up and flows through the tubes, back to the surface. On the surface the large heat pump systems take over the heat of the liquid in the heat exchangers, and transport it to the underfloor heating systems or other heating systems for domestic homes and industry.
Individual ground source heat pumps
In addition to large-scale heat pump systems, there are also individual heat pumps for the heating of interiors. They also use ground heat, but go much less deep into the ground.
Storage of heat and cold in the bottom
In theory there is over three times more energy available in the Scottish soil than Scotland needs on an annual bases. Nevertheless, Scotland still makes little use of geothermal energy. The UK Government has set a target of twenty percent of all energy consumption in the uk should come from sustainable sources by 2020 and has set up The Renewable Heat Incentive (RHI) to help boost this development . The scheme provides financial incentives to households and non domestic consumers.