Tyr Energy + Wärtsilä

Reference case

Gas power generation to support grid stability in Colorado

Tyr Energy is an investor and developer of North American independent power projects (IPPs). As such, Tyr Energy – a subsidiary of ITOCHU Corporation – currently owns and operates more than 15 IPPs all over North America. ITOCHU also have independent power facilities in Europe and Asia. In early 2013, the company acquired the state-of-the-art Plains End I & II power plant located close to Denver, Colorado, USA. The plant ensures grid stability and supports the regional renewable portfolio by providing peak load, standby and emergency operating modes for a large part of the Colorado area, extending out to surrounding states. The Plains End power plant provides a total combined output of 231 MW – from 20 Wärtsilä 18V34SG engines (Plains End I) and 14 Wärtsilä 20V34SG engines (Plains End II) –making it the world’s largest natural gas-fired peaking power plant with reciprocating engines.

The Plains End power plant is located at an altitude of 6150 feet (1845 m) above sea level with an average air temperature of 97°F (36°C). On top dealing with these ambient requirements, a second key factor in the purchase decision was that the new plant could cope with the sudden load swings which frequently occur due to the high proportion of intermittent winddriven generating capacity in the Colorado area.

Upgrading Plains End II to Wärtsilä’s 0.9% pre-chamber provided extra room for improved efficiency and stable emissions. In Wärtsilä 34SG engines, for example, pre-chambers are now an effective tool for optimising combustion dynamics, which can be seen in improved engine performance and a better balance between the heat rate and NOx emissions. Wärtsilä’s pre-chambers play a key role in providing efficient and reliable combustion. In Wärtsilä 34SG engines, for example, they are now an effective tool for optimising combustion dynamics, which can be seen in improved engine performance and a better balance between the heat rate and NOx emissions.

The new prechamber represents the latest design based upon advanced, three-dimensional, computerised fluid dynamics.

WhoTyr Energy Inc.
What231 MW Plains end I & II power plant
WhereColorado, USA
How20X18V34SG, 14X20V34SG

This is what we achieved


Of total combined output .


Of pre-chamber extra room for improved efficiency and stable emissions.


Reduction of urea consumption in SCR.

During breakfast and dinner hours demand increases and the plant follows this perfectly. This is the way. This is the future.

Kent L. Fickett former Senior Vice President of PG&E National Energy Group (NEGT’s predecessor)

How we did it

Challenge icon


  • Fluctuating output from wind generation
  • Harsh ambient conditions: high altitude and hot climate
  • Optimising return on investment
  • Stabilising engine raw emission levels without sacrificing heat rate
Solution icon


  • Internal combustion engines with excellent ramp rates
  • Adding low-pressure gas plant with extremely high availability (>99.4%) to the generation mix
  • Installation of upgraded prechambers on the engines
Benefit icon


  • Superb operational flexibility & increased revenue from selling balancing capacity
  • Grid black start capability at a very low cost & ability to keep plant online even when the quality of the gas supply suffers
  • Revenue from both the energy market and the ancillary service market – simultaneously
  • Reduced urea consumption in SCR by up to 25%, and  raw NOx emission
Plains End

The main details

CustomerTyr Energy Inc. 
TypeWärtsilä 34SG peak load/stand-by & emergency power plant
WhereColorado, USA
Total output231 MW
FuelNatural gas
ScopeEquipment, delivery (ED)
Delivery2001, 2006

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 brochure

Read our case study to get all the details.


Find your local office

Find a Wärtsilä office near you.

Related solutions and services

Trusted partner to the best companies in the world

Wärtsilä Energy. Let's connect.