Plains End I & II Colorado,
"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
Tyr Energy, a subsidiary of Itochu Corporation, is a major player in the energy market in the United States, focused on owning and operating power generating assets. Having evolved from providing risk management services for independent power producers to owning generation assets, it possesses a portfolio exceeding 7 GW of installed base. In early 2013, after acquiring the state-of-the-art Plains End I & II facility from Cogentrix, Tyr became the proud owner of the largest natural gas-fuelled combustion engine power plant in the USA.
When making the decision on which technology to utilise for Plains End I & II, the critical factor to take into account was the plant’s ability to operate at peak efficiency at high altitudes and temperatures. 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 of 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 wind driven generating capacity in the Colorado area. The growing list of demanding requirements brought the owners to Wärtsilä.
Not only the IPP Tyr Energy, but also the local utility, Xcel Energy, recognised the unique value offered by Wärtsilä solutions. Being able to operate efficiently at minimum plant output, Tyr has the opportunity to sell so-called ‘spinning reserve’ in the ancillary services market. The plant is also able to provide rapid up and down output regulation, which Xcel Energy has acknowledged as a great benefit provided by Plains End. The utility’s expectations of the plant’s grid balancing capacity routinely exceed changes of 20 MW/minute – which Plains End is able to compensate for by ramping from minimum load to full load and back again in record time.
The Plains End facility is also set up to make use of the supported ‘grid black start capability’ – at an exceptionally low cost compared to systems employing gas turbines. This capability is achieved by providing a very small amount of diesel-driven generating capacity (250 kW) that can supply the power required to start one Wärtsilä genset in the case of a transmission system blackout. The two Plains End plants can consequently feed their output into the grid to supply start-up power for other generators of more traditional design.
For most of the time, Plains End operates in non-spinning reserve mode. Should the need arise, the plant can reach full output in less than ten minutes. Its alternative mode of operation is spinning reserve, in which automatic signals from the grid dispatch centre commands the plant. In this mode the plant output is increased when the grid requires additional electricity, whereas a falling system demand triggers the plant to ramp down.
Annual operation time at Plains End totals 500-1500 hours. Both operating time and dispatch frequency are heavily dependent on the balancing requirements made by the Xcel Energy grid, and consequently also by the available wind power. The normal fluctuations that result from wind power generation are balanced by the Plains End regulation reserve service. Xcel’s generation mix also includes large coal plants, for which Plains End provides spinning and nonspinning reserve to cover any disturbances in supply.
The track record of Plains End is impressive. For example, in 2003, the monthly availability of Plains End I was between 99.4% and 99.9%, demonstrating the plant’s astonishingly high level of reliability. With these figures in mind, Xcel is relieved to know that the stability of their grid is in good hands. On top of their unrivalled reliability, should any issue arise in the natural gas supply, both Plains End plants can stay online significantly longer than other plants supplying the grid with power. This is due to the fact that even very low gas pressure (75 PSIG / 5 barg) is more than sufficient for Wärtsilä technology. Looking back at more than a decade of active service, as the biggest, most flexible gasfired wind chasing power plant in the USA, the Plains End I & II plant truly is a milestone in the history of power generation – for the owners, the utility and the manufacturer.
The owners of Plains End did not come back to Wärtsilä with an order for a second plant for no reason.
|| Tyr (IPP)
|| Wärtsilä 34DF grid stability
| Operating mode
|| Peak load / standby & emergency
|| 20 x Wärtsilä 18V34SG & 14 x Wärtsilä 20V34SG
| Total output
|| 231 MW
|| Natural gas
|| ED (equipment delivery)
|| 2001 & 2006
Read the success story in this brochure
Both these analyses show that there is value to increased flexibility resulting in system optimization...
Find in-depth info about our gas and multi-fuel power plant solutions in this brochure
If you want to know more about the Plains End I & II project, please contact
Business Development Manager
Energy Solutions, Wärtsilä North America Inc.
Tel: +1 720 360 9444