In Sweden, municipal energy company Gislaved Energi AB has supplemented its heating plant with an additional Againity Organic Rankine Cycle (ORC) turbine and a new battery storage system. Together with the existing ORC turbine that has been in operation since 2021, this initiative paves the way for increased local electricity generation, island-mode operation, and new revenue opportunities in the ancillary services market.
Since 2021, Gislaved Energi has generated a portion of its own electricity using an ORC turbine from Againity.
In 2025, a second ORC turbine unit was installed at the biomass-fired heating plant, and together they generate nearly 1,100 MWh of electricity annually.
The ORC technology utilizes heat from the woodchip-fired boilers to generate electricity. This provides Gislaved Energi with local electricity generation directly at the heating plant and reduces the facility’s need to purchase electricity from the grid.
Battery storage enables island-mode operations
A battery storage system with a power output of 500 kW and a storage capacity of 1,000 kWh was also installed in 2025.
The battery can store electricity and rapidly increase or decrease the power fed into or drawn from the electrical grid.
A key objective of the initiative is to enable the heating plant to operate in “island mode”—that is, without support from the external power grid.
During island-mode operation, the ORC turbines generate the electricity required by the heating plant, while the battery storage system maintains stable voltage and frequency.
As long as the ORC turbines are running and fuel is available for the heating plant’s boilers, the facility can continue to produce both heat and electricity.
The aim is for the heating plant to function as a UPS and remain operational even during disturbances or outages in the external power grid.
Additional ancillary services revenue stream
The battery storage system can also generate economic benefits during daily operations.
Through electricity arbitrage, electricity can be stored when prices are low and used or sold when prices are high.
The battery can also shave peak loads and participate in ancillary service markets, thereby reducing costs and creating new revenue opportunities.
The capability for island mode operation is a key part of our efforts to strengthen resilience and ensure continuity during external disruptions. It is a positive outcome that the battery also generates revenue when not operating in island mode, said Rikard Bondéus, Technical Manager at Gislaved Energi.
Complementary technologies
The combination of ORC turbines and battery storage creates a local energy system in which the technologies complement each other.
The ORC turbines handle electricity generation, while the battery storage system stabilizes the grid and manages rapid fluctuations in production and consumption.
The first ORC turbine, supplied by Againity in 2021, has a generator capacity of 200 kW. The second was delivered in 2025 and has a generator capacity of 99.9 kW.
It is very exciting to continue developing our partnership with Gislaved Energi. Combining local electricity generation from the ORC turbines with the flexibility of the battery storage system creates entirely new possibilities—both for island-mode operation and for optimizing the facility based on the needs of the electricity market. This is a great example of how existing heating plants can play an even more important role in a robust and flexible energy system, commented Reine Lönn, Sales & Electrical Engineer at Againity.
The investment marks another step in Gislaved Energi’s efforts to develop the heating plant, strengthen preparedness, and create a more robust and flexible local energy supply.
