Wärtsilä 31DF multi-fuel engine

The most efficient Wärtsilä 31DF, is a four-stroke multi-fuel engine generating set.

Download leaflet



Wärtsilä 31DF multi-fuel engine generating set

The record-breaking efficiency and fuel adaptability of Wärtsilä 31DF multi-fuel engine has been designed for applications where energy security is significantly important and where the gas network is still forthcoming. Its modular design ensures easy adaption for the engine to run on renewable fuels. Wärtsilä engine power plants can be delivered both as EPC and Equipment Delivery contracts.

Key benefits of the Wärtsilä 31DF multi-fuel engine

Key benefits icon star
  • World-class open-cycle efficiency
  • Synchronises with the grid within 30 seconds from start command
Key benefits icon star
  • Ensures energy security in operation through fuel flexibility and seamless switching between fuels
  • Can be easily adapted to run on synthetic renewable fuels
Key benefits icon star
  • Supports off-grid operation and provides fast black start capabilities
  • Unparalleled load following capabilities and high part load efficiency

Our proudest numbers

2 min

to full load


Electrical efficiency


million running hours with Wärtsilä dual fuel technology

The details

Technical data


Engine generating set
Cylinder configurations 20 V
Cylinder bore310 mm
Piston stroke430 mm
Engine speed750 rpm (50 Hz), 720 rpm (60 Hz)
Performance *
Rated electrical power (kW)11 779 (50 Hz) 11 377 (60 Hz)11 779 (50 Hz) 11 377 (60 Hz)
Electrical efficiency (%)50.2 (50 Hz) 50.2 (60 Hz)47.9 (50 Hz) 47.9 (60 Hz)
Heat rate (kJ/kWh)7 170 (50 Hz) 7 175 (60 Hz)7 510 (50 Hz) 7 515 (60 Hz)
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) < 2
Ramp rate (hot, load/min)> 100%
Minimun Load
Unit level 20%
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 and heat rate 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. 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.


Would you like to know more?

Contact us.

Contact us

Fill in a contact form and our experts aim to be in contact within 1-2 business days. Contact us »


Read our leaflet

Read our product brochure to get all the details. Download leaflet »

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)


By checking this box you agree to receive communications for marketing purposes. You can unsubscribe at any time.

Read more about how we process data in our Legal & Privacy Notice

Related solutions and services

Insights - news and articles

Boy on train
21 Nov 2023 · Article
5 min read
Every Second Counts for our flexible energy future
It’s now or never to meet climate goals.
24 Oct 2023 · Article
10 min read
How shorter time resolution is the key to decarbonising energy markets
Solutions banner
24 Oct 2023 · Article
10 min read
Why proper procurement of ancillary services is key to increasing the use of renewable power
Wärtsilä Energy. Let's connect.