Wärtsilä 34SG Balancer gas engine

The Wärtsilä 34SG Balancer is a four-stroke, spark-ignited, lean-burn gas engine generating set.

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Wärtsilä 34SG balancer gas engine for power plants

The Wärtsilä 34SG Balancer gas engine is optimised for balancing renewable power generation and provides flexible yet affordable peak demand generation and firming for energy systems with a high and growing share of renewables. It also offers unique fast-starting capability, which enables rapid response to fluctuations inherent to renewable generation. Wärtsilä engine power plants can be delivered both as EPC and Equipment Delivery contracts.

Key benefits of the Wärtsilä 34SG Balancer gas engine

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  • High power density for balancing and peaking applications
  • No start cost, limitations nor degradation in number of starts
  • Minimal water consumption
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  • Fast starting and loading capabilities: connects to grid in 30 seconds and reaches full load in 2 minutes
  • Runs on natural gas, biogas, synthetic methane and is capable of hydrogen blending
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Customer stories

  • Centrica, UK

    The rapid growth in renewable energy in the UK has increased the need for flexible power to balance the electricity grid. Wärtsilä has worked closely with energy and services company Centrica to provide the changing market with flexible energy, helping tackle the issues created by intermittent renewables and supporting the transition to a low-carbon energy system.

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    Centrica power plant aerial image.
  • Kraftwerke Mainz-Wiesbaden AG

    Flexible combined heat and power plant (CHP) in Germany –enabling KMW AG to operate profitably in the increasingly volatile power market and provide climate-friendly district heating to the community.

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Our proudest numbers

2 min

to full load


Electrical efficiency



Electrical power


Technical data for the Wärtsilä 34SG Balancer gas engine

Wärtsilä 34SG Balancer gas engine - Power generation set
Cylinder configurations 20 V
Cylinder bore 340 mm
Piston stroke 400 mm
Engine speed 750 rpm (50 Hz), 720 rpm (60 Hz)
Performance *
Rated electrical power (kW) 10 777 (50 Hz) 10 368 (60 Hz)
Electrical efficiency (%) 47.6 (50 Hz) 47.5 (60 Hz)
Heat rate kJ/kWh 7 560 (50 Hz) 7 586 (60 Hz)
Loading and unloading
  Connected to grid Full load
Regular start time (min) < 2 < 5
Fast start time (min:sec) 00:30 < 2:00
Stop time (min) 1
Ramp rate (hot, load/min) > 100%
* 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.

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Build your own power plant







> 500MW

Liquid fuels

Natural gas

Liquid fuels and gas

Flexible baseload (>6000 running hours annually)

Intermediate load (2000 - 6000 running hours annually)

Peaking and grid stability (<2000 running hours annually)


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