Passive Residence with PVs located in Dąbrowa Chotomowska, a small village nearly 30 km away from Warsaw (geographic coordinates Lat/Lon: 52.426281/20.877025). This private building was built at the beginning of 2016 as a result of the owner’s dream – he created the idea of zero-energy consumption house and turned it into reality. In the residential building lives a family of four persons. The house has 204.23 m2 floor space. Energy demand for heating / cooling – 12.6 kWh/m2a. The house was equipped with high-efficient heat pump as a source of heat, cool, hot water and mechanical ventilation with recuperation system. PV installation was placed on the roof of the house and fits perfectly into passive house appearance.
The passive Residence was designed by Passive M2 Office and achieved positive verification of NF15 (accordingly National Fund for Environmental Protection and Water Management) and at the moment is waiting for verification by Passive House Institute in DARMSTADT.
The purpose of PV installation was to cover total residence’s electricity needs on an annual basis. Nowadays, support scheme in Poland gives prosumers opportunity to fully cover electricity demand by PV systems. The state supports prosumers (individual consumers of energy who generate electricity in small installations) in production for own purposes (and not for profits). There is no fixed tariff, but the prosumers are allowed to exchange the surplus of energy produced by favourable conditions for gaps in energy production in relation 1 to 0.8 in the case of micro-installations with capacity up to 10 kW and 1 to 0.7 in the case of micro-installations with capacity above 10 kW (but below 40 kW). The prosumer signs a complex agreement with the energy seller. The seller calculates the difference between the produced and consumed energy. Net metering has one-year period accounting.
Due to current regulations, PV system of 9.75 kW was integrated to the distribution grid, which has a function of “energy storage” accordingly to support scheme’s idea. All PV modules were installed in a tilt angle of 40° facing south. The total energy consumption of Passive Residence is roughly 9 MWh last year, while total electricity production provided by PV system was 10.3MWh. However not the whole amount of energy produced was self-consumed. Self-consumed rate was nearly 23%, the excess of the energy was filled into the grid. However, support scheme gives prosumers the opportunity to receive up to 80% of energy filled for installations of capacity up to 10 kW. Last year, Passive Residence fed grid with 7.95MWh. Thus, the owner had “a discount” for receiving 6.36MWh without any additional costs, but he had to buy 303 kWh in order to cover the whole energy demand. Due to above info the owner was obliged to pay for 303 kWh and fixed fees.