There are not many heating options available for a country property. These include a firewood stove or a solid-fuel boiler (burning either firewood or pellets), a gas boiler using liquefied petroleum gas, or one of several types of heat pumps: an air-to-air heat pump, an air-to-water heat pump combined with radiators or underfloor heating, and a ground-source heat pump, which is also connected to radiators or underfloor heating.
The Elektrum Energy Efficiency Centre has carried out calculations for a house with a heated area of 125 m2, which has a “B” energy efficiency rating (around 60 kWh/m2 per year), is inhabited by four people, and has an annual thermal energy consumption of 7,500 kWh for heating and 1,700 kWh for water.
Current electricity prices and average firewood and pellet prices from this autumn have been used for the calculations.
The cheapest option – ground heat
When evaluating fuel costs alone, a ground-source heat pump combined with underfloor heating is the most cost-effective. The average monthly heating cost during the heating season will be €110. In second place is firewood heating at €121, followed by a ground-source heat pump combined with radiators (€124 per month). Gas heating is the least economical option (€303 per month).
Of course, some might object that the efficiency coefficient of heat pumps is more than 100%. And that is correct. The energy produced by the equipment is greater than the energy consumed during its operation.
Installation costs must be taken into account
The picture changes slightly when taking into account not only the heating costs but also the initial investment required to install a heating system. Assuming the heating equipment has a 15-year operational cycle, the lowest monthly cost will be for firewood heating at €151. However, it should be noted that firewood heating has a number of significant disadvantages: the system cannot operate automatically, it requires constant supervision (someone has to tend the fire), it needs a lot of space for fuel storage, and procuring the fuel is only cost-effective if you own a forest where you can obtain this fuel by investing labour and resources.
Given the relatively low initial investment, the pellet boiler comes in second place at €195 per month. Heat pumps follow, and even with this calculation, gas heating remains the most expensive option (€338 per month) during the heating season...
Worth considering solar panels
However, the calculations do not model a scenario where solar panels are used to generate electricity. Of course, the initial investment becomes higher, but ongoing costs decrease rapidly. This is precisely the type of system being chosen more and more frequently in rural areas when renovating buildings and thinking about sustainable management and a greener lifestyle. Rural properties, in particular, offer the space needed for both solar panels and the underground loop for a ground-source heat pump.
The net metering principle ensures that when electricity is generated but not consumed by the house, it is fed into the public power grid and later retrieved from the grid. One must pay for the distribution network services and for the portion of electricity consumed above what was self-generated. In other words, one can generate electricity in the summer to power a ground-source heat pump in the winter.