A battery that pays for itself.

The same containers of cells can do entirely different jobs. The job decides the size, the connection, the contracts and who controls the battery.

• Behind a company's meter

  Cuts consumption peaks and reserved capacity, stores surplus from your own solar and provides backup.

• Beside a power plant

  Shifts midday output into the evening, when power is worth more, and makes better use of the connection the plant already has.

• Standalone on the grid

  Trades on the electricity market and provides balancing services to the transmission system operator.

• A combination

  One battery can do several things at once. What matters is which revenues add up and which exclude each other.

• We model revenues quarter-hour by quarter-hour from your data and market prices, with cell degradation and grid charges, and show what happens if prices move.
• We set power and capacity, the connection and metering, and who will control and trade the battery.
• With partners, we handle permits, the fire-safety design and the separation distances that authorities and fire services look at ever more closely for batteries.
• We write the specification, run the tender and help negotiate supply, service, guaranteed capacity and availability.
• As owner's engineer we oversee construction, testing and acceptance, the control system and its security included.
• Once it runs, we compare what the battery earned with what it could have earned, and keep the optimiser or aggregator honest.

• Grid-service revenues have fallen. The average price of aFRR+ reserve bought long term by ČEPS fell from EUR 20.8/MW/h in 2025 to EUR 10.8/MW/h in 2026. We therefore build the revenue model on a mix of trading and services, never on a single line.
• Banks are cautious. According to Seznam Zprávy, some Czech banks have not financed new standalone batteries since early 2026, or assess them case by case. In December 2025 Komerční banka cited at least 20 % equity and a tenor of about ten years.
• There is a queue for connection. ČEZ Distribuce received 4,414 storage connection requests totalling 47.1 GW in the first half of 2026. The order of applications is only one of the criteria, so it pays to apply at a realistic size, with a plan for carrying the non-refundable part of the connection contribution.
• The licence and the 1.2 rule. Storage above 100 kW connected to the grid needs an ERÚ licence for electricity storage. A generation licence holder may store through its plant without one if the storage's total installed power does not exceed 1.2 times the plant's installed power. Aggregation needs an electricity trading licence.
• Capacity has to be proven. The RES+ 1/2025 call required usable capacity to be proven by guarantee tests at commissioning. Even without a grant, we recommend accepting a battery on its measured capacity and efficiency.
• Tariffs from 2027. From 01/01/2027, customers at medium and high voltage will pay for their reserved input. A battery that shaves peaks lets you reduce it and save. Distributors need up to 30 days to change a connection contract.

Sources: oEnergetice, 10/06/2026, Seznam Zprávy, 01/07/2026, E15, 08/12/2025, ČEZ Distribuce, 22/07/2026, Energy Act, SFŽP, call RES+ 1/2025, ERÚ press release, 07/10/2026. As at 24/10/2026.

Lithium iron phosphate (LFP) cells are the default choice today. Where another technology makes sense, we assess it independently, including whether a bank will finance it yet.

• Sodium-ion batteries

  Similar uses to LFP. CATL says global commercial deliveries of its grid systems start in June 2027, and it is preparing the first large project in central and eastern Europe with Solarpro.

• Flow batteries

  For four to ten hours or more and deep daily cycling. In May 2026 delivery of a 20.7 MWh vanadium flow battery beside a solar plant was completed in the UK. Considerably more expensive to build than LFP.

• Sand heat storage

  Since June 2025, a 1 MW / 100 MWh sand battery has been the main heat source of the district heating network in Pornainen, Finland. Suited to smaller heat networks.

• Molten salt for steam

  Since October 2025, a 56 MWh store of salt heated above 400 °C has supplied process steam to a corn-processing plant in Hungary under a fifteen-year heat supply contract.

• Hot-water tanks

  Mature and inexpensive. Danish tanks installed since 2013 average about 5,000 m³; Aalborg built four of 50,000 m³ each.

• Hydrogen

  For seasonal storage, still at pilot stage. We assess small electrolysers of 1 to 5 MW, but in our view the business case in Czechia rarely works yet.

• Compressed and liquid air, gravity

  They need suitable geology or large scale. We do not consider them realistic for projects up to CZK 1 bn in Czechia today.

• Flywheels and supercapacitors

  Seconds to minutes, for power quality and fast response. Worthwhile as part of a hybrid system.

We do not develop pumped-storage hydro.

Sources: CnEVPost, 21/07/2026, Electrek, 11/05/2026, Polar Night Energy, 11/06/2025, Kyoto Group, 09/10/2025, Danish Energy Agency, 2026. As at 24/10/2026.

For a sense of scale, a few projects from the Czech market. These are not our projects.

Sources: oEnergetice, 18/08/2026, oEnergetice, 11/01/2026, Renewable Energy Industry, 03/06/2026. As at 24/10/2026.