Solar power station in the Omurtag town

In May 2019, we installed a solar power station for a small house. The purpose of the client — to reduce electricity bills and ensure uninterrupted operation of electrical appliances during an emergency shutdown of an public grid.

For the solution of this task ideally suited hybrid solar power station, as it works together with the grid and batteries. The customer already had proper batteries, we had to do the rest.

The available roof area (the house is divided into two families) and the client’s budget, we decided to use 4 compact solar modules Sunsystem Mono 195 Wp. The total power of the photovoltaic modules is 780 Wp.

We also installed solar controller Victron Energy BlueSolar MPPT, battery balancer and a Venus GX device for remote monitoring and statistics collection.

The customer’s 12 volt GEL batteries are 140 A·h we connected in series to get 48 volts. The useful energy reserve in them at discharge up to 50% is 3.36 kW·h.

To convert DC voltage from the solar modules and batteries into alternating current for household electrical appliances meets inverter Victron Energy MultiPlus-II 3000. Its output power is 2.4 kW.

We set the inverter so that it can operate in fully autonomous mode at low power consumption and sufficient battery. As soon as the battery charge drops to 75% or the consumption starts to exceed 1.5 kW, help comes the public grid.

This chart clearly shows that in the last 30 days until the article was created (from July 12 to August 11, 2019) the grid was rarely included, providing 17% of total consumption. Accordingly, the electricity bill for this period has been reduced almost 6 times.

The host grandmother cannot believe that the refrigerator and the TV are working from the Sun even in cloudy weather. She says we are some wizards. But the real «wizards» — are Edmond Becquerel, Alexander Stoletov, Albert Einstein and many other scientists who have taught humanity to turn light into electricity.

Edmond Becquerel, Alexander Stoletov and Albert Einstein