Having not found an unambiguous answer to the question about the efficiency of solar panels in the latitudes and climate of the Moscow region and central Russia as a whole, we decided to test their work in practice.
Solar panels are placed on the roof with an inclination of 25 degrees, the slope is oriented to the South-West. Installed 3 panels with a nominal power of 216 W (648 W in total). No additional structures were used to improve the position in relation to the sun.
The data has been recorded since May 15, 2011.
The measurements made allow us to identify the instantaneous power , ie generated by the batteries at the current moment, as a percentage of the rated power; changes in power generation during the day; daily indicator of generated power accumulated in batteries; monthly rate in watts/hour.
1. Summertime energy production exceeds estimates based on weather statistics in the region, namely, each battery generated approximately 69 kWh (i.e. 106 kWh for a nominal 1 kW solar panel).
2. The average electricity generation per day was 2.3 kWh. Thus, the electricity generated during working days is quite enough, for example, to supply power to a country house on weekends, provided that lighting devices, a refrigerator, a TV are connected and short-term connections of electrical appliances with high power consumption.
3. All the time, the air conditioner was provided exclusively by a solar battery. Thus, the installation of a solar battery can be useful even when connecting the house to a stationary power grid. In addition, modern OutBack Inverters, such as Grid Interactive, do not waste the generated energy, even if there is no need to use backup energy, by dumping the energy received from solar panels into the grid.