Wärtsilä 31SG gas power plant

The most efficient gas engine, Wärtsilä 31SG, is a four-stroke, spark-ignited, lean-burn gas engine generating set. With its world class open-cycle efficiency and unparalleled dynamic capabilities, it reduces environmental footprint and lowers the total cost of ownership.

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Wärtsilä 31SG is well suited for baseload production, balancing renewables and industrial applications where reducing carbon emissions while producing reliable power is crucial. Its capability of fast starting and stopping and ability to run on sustainable fuels secures low emissions and high efficiency. It also meets the specific needs of combined heat and power (CHP) plants, for example steam generation, hot or chilled water or a combination of the above. Wärtsilä engine power plants can be delivered both as EPC and Equipment Delivery contracts.

Key benefits

World-class open-cycle efficiency enabled by 2-stage turbocharging system
Synchronises with the grid within 30 seconds from start command

Adaptability for various gas qualities
Capable of hydrogen blending

Excellent load following capabilities
Cost efficient maintenance

Customer stories

Bremen, Germany

Wärtsilä and Uniper enable a revenue-adding transition from coal to gas for public utility swb Erzeugung in Bremen, Germany. When delivered in mid-2022, the flexible CHP power plant will decrease swb’s CO2 emissions by up to 75%.

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Benndale, Missisippi, USA

Enabling an increase in variable generation with more flexible capacity that can rapidly start up when needed.

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DREWAG, Germany

Wärtsilä’s state-of-the-art gas engine technology will provide flexibility and black start capability to DREWAG, the local utility company in Dresden, Germany. The combined heat and power (CHP) engine power plant will be the only power plant that can restart the Dresden grid in case of a power blackout.

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Our proudest numbers

30 sec

Power to grid

52.3%

Electrical efficiency

11.8MW

Electrical power

The details

Technical data

Engine generating set
Cylinder configurations	20 V
Cylinder bore	310 mm
Piston stroke	430 mm
Engine speed	750 rpm (50 Hz), 720 rpm (60 Hz)
Performance *
	WÄRTSILÄ 31SG	WÄRTSILÄ 31SG Efficiency optimised
Rated electrical power (kW)	11 777 (50 Hz) 11 377 (60 Hz)	10 798 (50 Hz) 10 396 (60 Hz)
Electrical efficiency (%)	51.5 (50 Hz) 51.6 (60 Hz)	52.2 (50 Hz) 52.3 (60 Hz)
Heat rate kJ/kWh	6 986 (50 Hz) 6 971 (60 Hz)	6 901 (50 Hz) 6 886 (60 H)
Loading and unloading
	Connected to grid	Full load
Regular start time (min:sec)	00:30	< 5
Fast start time (min:sec)	00:30	< 2
Stop time (min)	< 2
Ramp rate (hot, load/min)	> 100%
Minimun Load
Unit level	10%
Plant level	1%

* Rated electrical power and electrical efficiencies are given at generator terminals at 100kPa ambient pressure, 25°C suction air temperature and 30% relative humidity, and without engine driven pumps. Power factor 1.0 (site). Electrical efficiency with 5% tolerance. Site conditions, fuel and applicable emission limits may have an impact on performance figures. Please contact Wärtsilä for project-specific performance data. Emission figures for LBF must be evaluated case by case. Catalyst systems are designed based on project specific requirements. Certain fuel components are poisonous for catalyst elements. Maximum amount of these components to be limited in the fuel in applications where catalyst system is installed.

Disclaimer: The information contained herein is provided for informational purposes only and may not be incorporated, in whole or in part, into any agreement or proposal. No representation of any kind is made in respect of any information contained herein and Wärtsilä expressly disclaims any responsibility for, and does not guarantee, the correctness or the completeness of the information. The calculations and assumptions included in the information do not necessarily take into account all the factors that could be relevant in a particular case. Information herein shall not be construed as a guarantee or warranty of the performance of any Wärtsilä technology, equipment or installation.