Slovenské Elektrárne plans to build a 9 MWh battery storage facility at its Mikšová hydroelectric power plant in north-western Slovakia. (source: Courtesy of Slovenské Elektrárne)
Last year witnessed the emergence of a remarkable phenomenon to the Slovak electricity market: traders were able to buy electricity at negative prices. This means that they were paid for removing excess electricity off the power grid, instead of being charged for it. Such a situation may have been due to a significant increase in electricity production from wind and photovoltaic power plants, opening a new niche in the energy sector – the production and usage of battery storage facilities. These can not only store electricity, but also help balance the national grid.
“Battery storage facilities as part of the grid are definitely the great future of the energy sector,” energy expert Andrej Hanzel told the Hospodárske Noviny daily. “They are very fast, and so negative prices can be very interesting for them.”
Mismatch on the electricity market
In 2023 Slovakia witnessed electricity purchases at negative prices up to 90 times. This is a relatively low number compared to other EU countries. For example, it happened 481 times in Finland, 300 times in Germany and 131 times in the neighbouring Czech Republic, the Slovak Sustainable Energy Association (SAPI – which until recently operated under the name the Slovak Association of Photovoltaic and Renewable Energy Industry) has reported.
