Meanwhile, sales of batteries and heat pumps doubled over the same period. According to the Czech Solar Energy Association, the main type of solar energy production in the Czech Republic is through small roof solar panels. Martin SEDL á K, project director of the Modern Energy Union, a non-governmental organization supporting green, said: "what the Czech Republic is most interested in is buying solar panels and batteries to maximize the potential of photovoltaic systems“"The most typical system costs about CZK 500000, but a cheaper system can also be found at a price of about CZK 430000.