Electricity storage facilities
In times of development of energy from renewable sources, the dynamics of power grids are slowly changing. Large-scale energy storage can help a lot to ensure that electricity distribution runs smoothly. How do they work and why are they needed at all? We explain!
Renewable energy introduces unforeseen changes
Energy from the sun and wind is a great solution for ecology. However, it cannot operate at the same efficiency level all the time. It is obvious that to produce electricity it needs appropriate weather, which changes even every few minutes. As more and more of these installations are connected to the electricity grid, the supply of energy production fluctuates more and more. It is the highest during windy and sunny days, and practically nil during windless nights. This changes the electrical balance in the entire network.
Since the dawn of energy industry, there has been a problem of balancing consumption and production. The demand for electricity across the country varies throughout the day - it is almost always lower at night. Production, however, is often a continuous process. For technical reasons, both the startup and shutdown of coal-fired power plants take a very long time. The solution was hydro-pumped storage power plants, which work in both directions. They can supply energy during times of higher demand and take it out when it is lower - they then pump water masses upwards. Thanks to this, they are not energy producers, but rather a kind of battery, where electricity is converted into potential energy. It pays off financially when you sell more expensive electricity during the day and buy cheaper electricity at night.
The construction of such power plants generates certain problems. Usually, a huge dam is necessary to dam up the mass of water into an entire lake. The terrain must allow for this, and this always means sacrificing some area for flooding. Meanwhile, the development of solar energy means that more and more energy surpluses will be produced. Hydro-pumped storage power plants are simply not enough. That's why a new concept has emerged: energy storage.
Renewable energy sources need storage
Most solar farms and wind turbine complexes are focused on selling electricity to the national grid. Therefore, they have a grid connection point (GCP) through which energy can be output. This is the output point through which electricity is received from the power plant and transferred to the network, specifically to the transformer station. It has a set of devices for controlling, signalling and measuring the operation of generators, most often automated and not requiring constant supervision.
The grid connection point (GCP) is the supervisory, central node of the power plant, so it is the best point to place the energy storage. What is it basically? Theoretically, it's simple - a battery assembly. An example is currently the largest Polish warehouse of the Energa Wytwarzanie company - the Bystra hybrid warehouse in the Pomeranian Voivodeship (2023). It serves a nearby wind farm. It has lead-acid and lithium-ion battery packs, hence the term hybrid. It has a total power of 6 MW and a capacity of 27.37 MWh.
Green electricity storage
The future of renewable energy is related to energy storage
Currently, many Polish energy sector companies have extensive plans for energy storage. Grid connection points (GCP) of newly built solar and wind farms will additionally have a network balancing function. Experts from Polskie Sieci Elektroenergetyczne say clearly:
In practice, the development of electricity storage is a necessary condition for further effective development of renewable energy sources. Even now, despite the existence of adequate network transmission capacity, renewable energy sources may not be able to produce energy in periods of high availability of primary energy from the sun and wind, because their production potential exceeds the demand for their production at that time.
This is particularly visible during the annual capacity market auctions, when prices and obligations to supply electricity from various suppliers are set several years in advance. In December 2022, the warehouses were contracted and are to be operational in 2027. Five companies took part in the auction: Columbus Energy, OX2, Battery ESS-1, Energa Wytwarzanie and the PKE Pomorze team, Hynfra Energy Storage and Heyka Capital Markets Group. It was then announced that storage facilities with a total capacity of 165 MW would be built!
Such a large increase in the demand for energy storage is a natural consequence of the transition to ecological solutions. Only experts could predict this in advance, but after a little consideration, energy storage is a logical solution in GPO. Energy can then be extracted from them with almost any dynamics, adapted to the changing demand of consumers. All to meet the ever-growing electricity needs of consumers.