IN Brief:
- Electrica has signed the contract for an approximately 82MW electrical cogeneration plant serving Craiova.
- The scheme combines around 208MWt of thermal capacity with heat storage, fast-start gas engines, and black-start capability.
- The plant will replace a lignite-based heat source while providing controllable electricity alongside Electrica's renewable and storage portfolio.
Electrica has signed the development contract for a new high-efficiency cogeneration plant in Craiova, combining approximately 82MW of electricity generation with district-heating production, thermal storage, and system-restoration capability.
The Electrica Group plant will use natural-gas internal combustion engines and supply electricity to Romania’s National Power System while delivering heat to Craiova’s centralised district-heating network. The existing system serves approximately 53,000 households and public institutions and is currently supplied by ageing coal-based infrastructure.
Installed thermal capacity is expected to reach around 179Gcal/h, equivalent to approximately 208MWt, with additional peak-load and backup heat-generation equipment. The project will be implemented in two phases, beginning with hot-water boilers before the cogeneration engines enter service.
Electrica is designing the engines as flexible rather than continuous baseload units. They are expected to reach full output in approximately two minutes from start-up and synchronise with the grid in under 30 seconds, giving the plant the response characteristics needed to participate in balancing and ancillary-service markets as well as conventional electricity generation.
Thermal storage loosens the link with heat demand
District-heating cogeneration normally faces an operating constraint that does not apply to a stand-alone power station: electricity production creates heat at the same time, and the usefulness of that heat depends on demand across the local network.
Craiova’s thermal storage system is intended to loosen that connection. The engines will be able to operate when electricity-market conditions make generation attractive, store the heat produced simultaneously, and release it later as demand requires.
That changes the way the plant can interact with the power system. Without storage, engine dispatch would be tied more closely to immediate heating requirements. With an adequately sized thermal buffer, part of the generating schedule can instead respond to wholesale prices, balancing requirements, and variations in renewable output.
The arrangement does not turn heat storage into electrical storage; the two technologies perform different functions. It does, however, allow the electrical output of a combined heat and power plant to become more flexible because heat no longer has to be consumed at precisely the moment it is generated.
Electrica is also specifying black-start capability, allowing the plant to start without an external electricity supply and assist with restoration after a wider outage. That requirement tends to receive less attention than generating efficiency, but the withdrawal of older thermal plant forces system operators to consider where restoration services will come from as the generation fleet changes.
A plant capable of starting independently, synchronising rapidly, and supplying controllable output can provide capabilities that are not automatically delivered by inverter-connected renewable generation. The commercial value of those services depends on system-operator procurement arrangements, but designing them into a new asset preserves the option from commissioning.
Coal replacement retains controllable capacity
The new plant will replace an existing lignite-based source serving Craiova’s district-heating network. Electrica says the change will eliminate coal combustion from the city’s heat supply and reduce associated local pollution, while using high-efficiency cogeneration to extract useful electrical and thermal output from the same fuel input.
Natural gas still produces carbon emissions, and the project is therefore a fuel-switching and efficiency investment rather than zero-carbon generation. The engines are being designed to accept a hydrogen blend if hydrogen later becomes available at industrial scale, but the company has not presented the plant as operating on hydrogen from commissioning.
That distinction is important. Hydrogen capability can reduce the risk of specifying equipment around a permanently fixed fuel, but future emissions performance will depend on blend limits, hydrogen production, infrastructure, price, and availability. A technical provision in the engine does not by itself establish a future fuel supply.
Electrica approved a wider Craiova investment programme valued at up to €235 million on 20 August, covering both the district-heating project and a separate cogeneration objective associated with Ford Otosan Romania. The contract signed on 24 August moves the district-heating element from corporate approval into the development and delivery phase.
The project also sits alongside Electrica’s renewable generation and battery investments. Flexible thermal plant will increasingly operate in a system where wind and solar determine a larger proportion of energy production, changing the role of gas-fired capacity from continuous generation towards periods when heat demand, electricity prices, system balancing, or security requirements justify operation.
For Craiova, the immediate engineering task is more basic: replace an ageing heat source without losing reliable thermal supply to tens of thousands of customers. Adding thermal storage, rapid-start operation, and black-start capability means the replacement plant is being designed around electricity-system requirements at the same time.
That combination will be tested in operation rather than on the specification sheet. Efficiency, availability, heat-storage utilisation, market dispatch, and restoration performance will determine whether the plant functions as a genuinely flexible power-system asset or merely a newer source of district heat.
