What is Geothermal Heating?

Find out everything there is to know about geothermal heating. Take a look at the cost of geothermal energy, find out how geothermal heating works and more below. 

Geothermal heating works by using naturally occurring heat from underground to warm your home. A geothermal system takes heat from the ground and uses it to heat pipes filled with water and antifreeze that are buried in your garden, this heat is then used to provide warmth to your home. 

In the UK there are three types of geothermal technology available: 

What is geothermal energy? 

Geothermal energy is heat that comes from below the earth’s surface. It is a form of renewable energy and has grown in popularity due to its low carbon footprint, especially in comparison to traditional fossil fuels. 

Geothermal energy is found within rocks and liquid under the earth’s surface and is accessed by digging down into the ground to access it. 

Traditionally geothermal energy would be accessed from deep underground, however, the term geothermal energy is often used to refer to ground source heat pumps too which can access heat from below the surface in your garden. 

What is geothermal heating and cooling how does it work? 

Geothermal systems can often be used for both heating and cooling your home. They are a great option if you want to keep your home at a comfortable temperature all year round.

Geothermal technology uses the temperature underground to help heat and cool your home in an energy-efficient and environmentally friendly way. 

Geothermal systems are the same as HVAC systems which allow you to both heat and cool your home. 

When you put your geothermal system onto cool it will reduce the heat in your home similar to an air conditioner. 

Geothermal energy can cool your home by basically doing the same process as heating but in reverse. To cool your property the geothermal system will start taking the heat out of the air in the room and transferring it into the fluid in the pipes and back into the earth.

Cold air is blown back into your home because heat is taken out of the air by the geothermal system, operating in reverse. 

Geothermal air conditioning is considered to be much more efficient than traditional air conditioning. This is because you aren’t wasting electricity pumping the hot air from inside your home into the heat outside, but instead, you are transferring the heat back into the cooler earth. 

Here is how to save energy with a heat pump.

How much is a geothermal heating system?

Before you decide whether a geothermal heat pump is right for you you’re probably going to be asking yourself, how much does a geothermal heat pump cost? 

The cost of geothermal energy can vary greatly, but it is likely to cost somewhere between £10,000 and £20,000 to install the system. The true cost will depend on things like the area size that you need to excavate and the type of ground you need to dig through. 

As with any large scale project, there will be a lot of variables like what system you are replacing and if there is any additional work that needs to be carried out alongside the installation like insulation or new radiators or underfloor heating. 

How much does geothermal energy cost per month? 

The running cost of a geothermal system is likely to be around £650 per year, however, the actual price will depend on the size of the home you are heating and how much you are using the heat pump. 

If you like to have your home toasty and warm all the time then it is likely to be more expensive than for someone who has the thermostat set a few degrees lower. 

Things like insulation and your home’s draught proofing will also impact how much the geothermal heat pump costs to run, as if you have a draughty home, the heating system will have to work harder to bring it up to your desired temperature. 

How well does geothermal heating work? 

Geothermal heating works well to keep your home at a consistent temperature year-round. This is because you have the option to both cool and heat your home meaning you can have your house nice and warm in the colder months, but kept cooler in the hotter months.

The efficiency of the heating system will also depend on your home’s efficiency rating. If you have good double glazing, well-insulated walls and no draughts then it is likely that geothermal heating will work well in your home. 

What are the pros and cons of geothermal heating?

Pros of geothermal heating

There are lots of benefits to geothermal heating, however, here are a few of them: 

  • Low carbon and environmentally friendly
  • Renewable energy 
  • Sustainable
  • Offers an uninterrupted heat supply
  • Cheap to run
  • Allows you to heat and cool your home
  • They require less maintenance than a normal boiler

Cons of geothermal heating

There are a few disadvantages that you need to be aware of when installing geothermal heating: 

  • You need to dig up your garden to install the pipework
  • You may need to invest in new radiators or underfloor heating 
  • Expensive upfront cost

Does Geothermal Heating Produce Any Emissions?

Geothermal energy is considered a renewable source of energy. The only energy that is used from geothermal heating is the electricity needed to power the compressor and the circulation pumps. 

If you get a green or renewable energy tariff you can ensure that you are cutting down your emissions as much as possible. 

If you are using traditional geothermal energy as opposed to a ground source heat pump there can be some other emissions. 

Geothermal energy can produce emissions like hydrogen sulphide and sulphur dioxide. 

Is geothermal heating and a ground source heat pump the same? 

Technically, Geothermal energy and ground source heat pumps are not the same, however, the two terms are often used interchangeably. 

Both ground source heat pumps and geothermal energy use heat from the ground to heat your home, however, the two systems are different. 

In its purest form, geothermal energy would be sourced from boreholes that were drilled between 500 and 2500 metres into the earth and filled with water. This water would then naturally heat and could be used to generate electricity. 

However, the word geothermal energy has become synonymous with ground source heat pumps. 

Ground source heat pumps do not need to be placed so deeply underground and use the heat from the matter below to transfer it into your property to run your heating and hot water system.  

Is geothermal energy popular in the UK? 

The UK as a whole isn’t considered to be a particularly geothermal county, however, there are parts of it where there is a lot of geothermal activity. 

Parts of Devon and Cornwall have high levels of geothermal gradients which means they offer the perfect conditions to use geothermal energy. 

How realistic is geothermal heating as an alternative energy source?

Installing geothermal heating is still possible in other areas of the country too, especially in areas high in granite and sedimentary basins. 

The use of geothermal energy would be possible across the majority of the UK with the use of special drills which would dig between 500 and 2500 metres deep to access rock temperatures that range between 30 and 100 degrees Celsius.