Engine power plants generate electricity and, often, additional thermal energy. It is a solid and reliable technology, with very short start-up and ramp-up times, and extremely flexible when it comes to the types of fuel or gas used.

The various engine types available on the market cover a broad output range, from small 6 kW systems supplying heat and power to individual apartment blocks and public buildings to large 21 MW engines, used in balancing plants for grid stability.

Typical engine power plants have three main components:

• The internal combustion engine (ICE) – the heart of the plant
• The alternator, which generates electricity
• The heat exchanger used to capture the heat

The internal combustion engine can either be a spark ignition engine (a “gas engine”) or a compression engine (a “diesel engine”). Smaller engine power plants often use modified car and truck engines, while larger plants above 1 MW generally use modified ship engines.

The alternator transforms the mechanical energy into electricity. By using a supercharger a larger amount of compressed air can be supplied to the engine and thus the power output increased.

Cogeneration – what is it?

Combustion is a chemical reaction where a fuel is combined with oxygen, producing thermal energy (heat). While a major part of that heat is used to produce electricity, some of it remains unused.

To avoid this loss of heat (and thus of energy) engine power plants often run as cogeneration plants, using the un-used heat from the engine and the exhaust for space heating or in industrial processes.