What does ground source heating cost?

In recent decades, as the technology and equipment have evolved, the costs of ground source heat have decreased significantly from what they used to be e.g. in the 1990s. The costs of ground source heat are always site-specific, and largely depend on the system installed.

The costs of ground source heating are affected by:

• The costs of implementing the brine circuit, i.e. usually the cost of drilling a ground source heat well
• The costs of the ground source heating system (the size of the property to be heated and the demand for domestic hot water)
• The costs of installing the ground source heating system

In renovation projects, additional costs may incur from e.g. electrical alterations or the possible dismantling of the old system.

Drilling a ground source heat well affects the costs of ground source heating

The costs of drilling a ground source heat well is determined by the depth of the well, which in turn is determined by the property’s demand of heating energy – the larger the house to be heated, the deeper the well needs to be. Drilling the ground source heat well is a significant expense, so the dimensioning of the well must be sufficient also in the long run. For large apartment block projects, several wells will be needed, in which case the well field must be large enough in order to obtain sufficient thermal energy.

A heat well produces about 100 kWh of energy per metre per year. Therefore, a 200-metre heat well produces roughly 20,000 kWh of energy, and in addition, the amount of electrical energy consumed by the compressor will be obtained for heating the property.

The depth of a heat well, and thus also the costs of ground source heating, is also affected by the soil type. When drilling a ground source heat well, a steel protection pipe must be installed in the soft soil above the bedrock to prevent loose soil from collapsing and clogging the well. Ground drilling is slower than rock drilling and, in addition, the steel pipe rods must be welded together, making ground drilling more expensive than rock drilling.

Horizontal piping between the well and the technical room

The horizontal pipes and their installation between the heat well and the technical room are usually included in the price of the heat well. If the amount needed exceeds the amount stated in the quote, the excess amount will be invoiced separately at the price per metre stated.

Installation of a brine circuit in the ground or a body of water

The brine circuit can also be installed in the ground or in a body of water near the property. Installing a ground source heat brine circuit in a horizontal position does not require drilling, but a trench about a metre deep is excavated for the brine circuit.

Moist clay soil is better for a ground source heat brine circuit than sandy soil because sand does not transfer energy as effectively as moist clay does. The brine circuit can also be installed in a body of water found near the property, with weights attached to the pipes in order to immerse them at the bottom.

The price of a ground source heat pump

The efficiency of the ground source heat pump, and subsequently, its price, is affected by the demand for heating energy and domestic hot water. The larger the property, the higher the capacity of the ground source heat pump must be.

The costs of ground source heat in a detached house

A new detached house of 180 square metres for a family of four, with a room height of 2.5 metres, would require 13,950–18,900 kWh per year for heating and 5,000 kWh per year for domestic hot water. For a detached house, the costs of a ground source heating system vary between €15,000 and €25,000.

The costs of ground source heat in a terraced house

In addition to detached houses, many terraced housing companies have decided to switch to a more energy-efficient and cost-effective form of heating. The costs of ground source heat in terraced houses depends on e.g. the demand of heating power, the heating output of underfloor heating or radiators, and the demand for domestic hot water.

The costs of ground source heat in an apartment building

Ground source heat is also an increasingly popular form of heating even for large residential properties, as it makes controlling heating costs easier. The required supplied power must also be considered already at the design stage, since the installation of the ground source heating system may require increasing the electricity connections.

Full power or partial power?

Full power dimensioning of a ground source heating system means that the system is intended to cover 100% of the peak power demand, without the help of any electric heaters, even during the harshest and coldest winter conditions. A full power ground source heating system is a slightly more expensive investment, but the operating costs during the coldest time of the year are lower than those of a partial power system.

The partial power system is intended to cover 60–85% of the peak power demand, meaning the electric heaters of the ground source heat pump switch on during the coldest time of winter. The investment costs of a partial power system are slightly smaller, but the operating costs will be higher during the coldest winter.

Installation costs of a ground source heat pump

The installation price of a ground source heat pump includes the hauling of the heat pump into the technical room as well as connecting the heat pump into the brine circuit, the heating network, and a possible accumulator or buffer tank. Upon request, Gebwell Ltd.’s dealers can offer turnkey ground source heating solutions, which include the drilling of the heat well and a fully installed, ready-to-use ground source heating system.

Replacing oil heating with a ground source heating system

Are you considering switching from oil heating to ground source heating? Many others have, too, as the price of heating oil has increased and made ground source heating an increasingly attractive option. In many cases, even just the installation of a ground source heating system alongside the old oil heating system will be profitable, as it will significantly reduce oil consumption.

Installation of a ground source heating system entitles you to claim tax credit for household expenses

Installing a ground source heating system in an old house entitles you to claim tax credit for household expenses in Finland. NOTE: For the drilling of the heat well, about 90% of the price is installation work that you can claim tax credit for. In addition to the drilling, the installation of the ground source heat pump is also considered work that you can claim tax credit for.

Costs of ground source heating

Ground source heating is the most cost-effective form of heating if free fuel, such as firewood from your own forest for wood heating, is not available. The ground source heat pump produces at least 3 kW of heat energy per kilowatt hour it consumes. Here is an indicative calculation example for annual heating costs of a medium-sized detached house (150 square meters) for a family of four:

• Electric heating: €2,500/year
• Oil heating: €2,400/year
• Ground source heating: €680/year
• Savings / year: €1,500–2,000

Plus, a cooling system practically free of charge

When considering switching to ground source heating, it is worth considering the practically free possibility of cooling the property as well. The heat well can be used for cooling during the summer. Gebwell heat pumps have a built-in readiness for cooling connection, which means that all that is needed in addition is a circulator pump.