Wärtsilä 34SG gas engine

The Wärtsilä 34SG is a four-stroke, spark-ignited, lean-burn gas engine generating set. Its agility and flexibility make the Wärtsilä 34SG generating set an excellent choice for both flexible baseload and balancing renewables applications. It also offers a unique fast-starting capability, which enables rapid response to fluctuations inherent to renewable generation.

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Wärtsilä 34SG gas engine helps to provide an efficient, reliable and cost-efficient source of energy for power producers. It also provides enough spinning reserve for balancing whenever needed. The Wärtsilä 34SG engine generating set is extremely reliable as it is based on the well-proven Wärtsilä 32 engine, which has a track record from the mid-1990s. The Wärtsilä 34SG features a wide power output range from 5.6 to 9.8 MW, as it is available in 12V, 16V and 20V cylinder configurations. Wärtsilä engine power plants can be delivered both as EPC and Equipment Delivery contracts.

Key benefits of the Wärtsilä 34SG gas engine

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  • No start cost, limitations nor degradation in number of starts
  • Compact sizing enables transportation to demanding locations
  • Capable of operating in high altitude
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  • Runs on natural gas, biogas, synthetic methane and is capable of hydrogen blending
  • Minimal water consumption
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  • Longer maintenance intervals

Customer stories

  • Paras Energy, Nigeria

    Since deciding in 2009 that its three new power plants would operate with Wärtsilä gas engines rather than gas turbines, the conventional choice at that time in Nigeria, Paras Energy has continued to benefit from that decision.

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    Engineer working in Paras Energy power plant.
  • McArthur River Mine, Australia

    The McArthur River Mine in Australia, is one of the world’s largest providers of zinc in bulk concentrate form. Global energy producer EDL is responsible for supplying power to the mine. Wärtsilä has been a trusted partner for EDL for many years now, delivering gas engines and providing lifecycle services for condition-based maintenance to the power plant. The end result is better fuel efficiency, a low levelised cost of electricity, lower OPEX and guaranteed availability.

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  • Makuhari, Japan

    The growing demand for natural gas as fuel and the increasing importance of environmental values in Japan have encouraged investments in gas-fired power generation systems. The green point of view has also contributed to the rise of interest towards trigeneration energy sources.

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    Makuhari Power Plant, Japan

Our proudest numbers

2 min

to full load


Electrical efficiency

1 000

generating sets delivered

Technical data of the Wärtsilä 34SG gas engine

Wärtsilä 34SG gas engine generating set
Cylinder configurations12, 16, 20V
Cylinder bore340 mm
Piston stroke400 mm
Engine speed750 rpm (50 Hz), 720 rpm (60 Hz)
Performance *
Rated electrical power (kW)9 795 (50Hz) 9 388 (60Hz)7 830 (50Hz) 7 491 (60Hz)5 840 (50Hz) 5 580 (60Hz)
Electrical efficiency (%)48.9 (50Hz) 48.8 (60Hz)48.9 (50Hz) 48.7 (60Hz)48.0 (50Hz) 47.8 (60Hz)
Heat rate (kJ/kWh)7 363 (50Hz) 7 374 (60Hz)7367 (50Hz) 7396 (60Hz)7 501 (50Hz) 7 538 (60Hz)
Loading and unloading
 Connected to gridFull load
Regular start time (min:sec)00:30< 5
Fast start time (min:sec)00:30< 2
Stop time (min)1
Ramp rate (hot, load/min)> 100%
Minimum Load
Unit level10%
Plant level1%
* 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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