Photovoltaic panels are becoming more and more popular. However, their installation requires quite large investment outlays. In turn, the return on investment is faster the more electricity a household uses. KOSPEL produces electric boilers that work perfectly with PV installations.
Photovoltaic installations installed in households usually have a power of up to 10 kWp, which in the Polish climate allows for obtaining up to 10,000 kWh of energy per year. The average energy consumption for lighting, household appliances and electronics is 3,000 kWh/year. The use of an electric boiler in the heating system allows you to use the remaining free energy from the sun to heat water and the house.
A photovoltaic installation working with an electric boiler allows you to heat your home comfortably and almost free of charge. But what if the energy from photovoltaics is not enough for heating purposes and for heating domestic water? How much will it cost to heat your house then?
See Kospel electric boilers in Onninen
The costs of heating your home depend on many factors. The price of energy itself is only one of them, and not the most important one. It is worth knowing what to take care of and what to do to reduce heating costs even several times.
How to reduce heating costs?
Technology and standard of building insulation
The building technology has the greatest impact on reducing heating costs. The approximate demand for usable energy for heating and ventilation is presented in the table below.
| Demand for usable energy for heating and ventilation | |
|---|---|
| Old building - poor thermal insulation | approx. 200 kWh/m 2 /year |
| The building after thermal modernization | approx. 70 kWh/m 2 /year |
| New building – good thermal insulation | approx. 35 kWh/m 2 /year |
This means that to heat an old building with poor thermal insulation with an area of 120 m2 may require over 24,000 kWh of energy per year. Thermal modernization (insulation of walls, roof, ceiling and replacement of windows and doors) will reduce consumption to 8,400 kWh per year. A house with the same area, built in accordance with the latest standards, equipped with heat recovery, requires only 4,200 kWh per year.
Heating domestic water
It can be assumed that the consumption of hot water by a family of 4 is approximately 6 m3 per month, and approximately 35 kWh is needed to heat 1 m3 (from 10 to 40oC). Therefore, 2,500 kWh of energy is needed annually to heat water, after taking into account the losses of the tank and installation, it will be approximately 3,200 kWh.
Economical energy tariff
Heating costs also depend on the appropriate selection of the electricity tariff. Fees vary depending on the energy seller. On average in Poland, according to prices from October 2019 in the G11 24-hour tariff, the cost of 1 kWh is PLN 0.55.
For heating purposes, it is best to choose the G12 or G12w (weekend) tariff. In the case of the G12 tariff, cheaper energy can be used between: 22:00–6:00 and 13:00–15:00, i.e. 42% of the time, which gives an average price for 1 kWh of PLN 0.49. In order to optimally use the cheaper tariff, a heat accumulation buffer should be installed, thanks to which the average price of 1 kWh can drop to as much as PLN 0.33.
The use of an electric boiler with a heat accumulation buffer ensures comfortable and inexpensive heating with relatively low investment costs. For heating a house with an area of 120 m2 with the demand for usable energy for heating at the level of 70 kWh/m2/year, in the case of underfloor heating, a buffer with a capacity of at least 500 l and a 16 kW boiler should be selected, and in the case of radiator heating (55/45oC) a buffer of 800 l and a 24 kW boiler kW.
Approximately 11,600 kWh of energy is needed to heat a well-insulated house and water for a family of 4, which will cost PLN 3,800 per year using the G12 tariff. In the case of a new house, it will only be 7,400 kWh of energy, or only PLN 2,450 per year!
Kospel electric boilers
Electric boilers are advanced heating devices that ensure maintenance-free operation and comfortable operation (EKCO.MN3 and EKD.M3 can be remotely controlled via the Internet). Thanks to the use of cheaper energy tariffs, they are cheap to operate, and in cooperation with a photovoltaic installation, heating costs can be reduced to almost PLN 0.
Electric boilers do not produce low emissions and do not emit exhaust gases - they provide clean and ecological heating.