Geothermal Renewable Energy

Geothermal renewable energy is heat energy generated from the ground. Geothermal heat pumps take advantage of the heat stored in the earth in order to heat buildings. Geothermal renewable energy heat pumps are also commonly referred to as ground source heat pumps.

Geothermal Renewable Energy

What are Ground Source Heat Pumps?

A Ground Source Heat Pump or ‘GSHP’ uses electricity to extract heat from the ground, convert it to a higher temperature and then transfer that heat into a building.

A GSHP has three main components: collector, heat pump and distributor.
The collector refers to the pipes which are buried under the ground in order to extract the heat energy from the ground they are commonly referred to as ‘slinkies’. The pipes contain a heat exchange liquid, and they are buried horizontally (at least 1.2m underground) or vertically (around 15-150m deep). The liquid in the pipes extracts the heat from the surrounding soil – this liquid, then moves through the pipes into the heat pump.

How the pipes are buried (e.g. Vertically or horizontally) depends on how much space is available at the property in question. This is something which an installation team will establish for you.

The liquid then moves through three parts of the heat pump. The first part is the evaporator; here the heat from the liquid meets the refrigerant. This forms a vapor, which is then fed into the compressor. The compressor causes the vapor temperature to rapidly increase; this vapor is then forced into the final part of the heat pump, the condenser. The condenser then passes this heat on to the heating system. The heating system or the ‘distributor’ is the final component of the GSHP, where the heat enters the building, either through under-floor heating or radiators.

Why chose a Ground Source Heat pump?

Once a GSHP is installed it makes no noise, requires little/no maintenance and will last, untouched for several years.

Not only is a GSHP low maintenance, but it is also energy efficient. For every unit of energy used to drive the pump around 4 units of heat are produced. Traditional boilers, on the other hand produce only one unit of heat per unit of geothermal electricity. This means you also save money on running costs.

So you save money on running costs, on heating bills and you are able to earn money through the RHI. With the domestic RHI now in place, homeowners need not be put off by the upfront cost of a GSHP system as they are guaranteed a long-term return and a fast payback. The RHI is available for both domestic and non-domestic installations.

How much does a GSHP cost?

On average, a GSHP costs between £11,000-£15,000. However, the price is dependent on the size of the property and the energy demand within that property.

GSHP are great investments, however, it is important to be aware of the costs before you decide to invest. This means that you should be provided with a detailed design of your system along with a breakdown of costs. For example, if your heat pump is going to be installed vertically, this will cost slightly more, and must be factored into the costs.

Therefore, it is important to be aware of what everything costs before you decide to go ahead with an installation.

What is the RHI?

The Renewable Heat Incentive is a tariff paid to the installation owner for the heat generated by the heat pump (similar to the FiT tariff paid for solar installations).Here are some simple facts you need to know:

– Tariff payments are calculated by multiplying the proposed tariff per KWH by the heat output of the system
– The current tariff per kWh for domestic systems is 18.8p/KWH
– The average payment for a 3-bed detached house is around £4,324
– The average ‘repayment time’ is 4 years
– The RHI will be paid to the installation owner for 20 years

Is my property suitable?

While there are so many benefits to installing a GSHP some properties are not suitable, and not all installations are done to the same standard.
When fitting to a GSHP to an existing building (i.e. Not a new-build) certain things must be taken into consideration. Installers must check your property to check it is compatible with a heat pump before it can be installed. GSHP installations are far more compatible with homes which are well insulated. Switch 2 Renewable and various other companies can check the insulation of your home before you decide to go ahead with installing a GSHP. This will ensure you are making a viable investment by choosing to install a GSHP.

Additionally, a large amount of garden space is required in order to bury the slinkier (as mentioned earlier) horizontally in the ground. Fortunately, there is still the option of digging a bore hole and placing the pipes vertically; however, this option is a little more expensive.

Also, if you are renting a property, only the owner of the property is eligible to receive the RHI payments.