By Chris Whitney, Senior Proposal Manager, Wärtsilä North America
In addition to the basic function of providing grid capacity and energy to their customers, some utilities have additional motivation behind their desire to build a new power plant, particularly as extreme weather, natural disasters, and geopolitical conflicts continue to threaten our power systems. Three recent cases where the added benefit of system or self-resiliency was a primary concern are described below.
Matanuska Electric Association (MEA), located in Palmer, Alaska, built a 170 MW power plant with ten Wärtsilä 18V50DF engines. A member of the Railbelt utilities, this was their first self-generation plant, having previously purchased and distributed power in the Railbelt network. Energy security and self-reliance are part of Alaska’s ‘belt and suspenders’ attitude towards life.
The plant is dual-fuel capable, with the primary fuel being natural gas, but also diesel fuel if the gas supply is interrupted. The plant was also designed and built to withstand high seismic forces in this earthquake prone area. The generator sets are fitted with seismic dampers, specialized flex connections and special generator bearings, and many other aspects of the plant are built extremely robust to withstand earthquakes.
This foresight was proven well-founded when in November 2018, the area experienced a 7.1 magnitude earthquake whose epicenter was located only 43 miles from the power plant. The facility experienced only minor damage, and MEA restored power to most of their territory in less than 24 hours.
Located in a much warmer place, Hawaiian Electric (HECO) serves 95% of Hawaii’s residents and has been in business for more than 100 years. Hawaii has one of the most aggressive goals towards achieving 100% renewable energy in the United States.
On the island of Oahu, HECO was able to combine a desire to provide a new, highly efficient, flexible 50 MW plant with the United States Army’s desire to provide increased energy security and resiliency for the Schofield Barracks Army Base. The result is the Schofield Generating Station, which has six Wärtsilä 20V34DF engines running on biodiesel fuel. The plant is located on land provided by the Army.
HECO is able to run this plant as part of their overall generation portfolio and dispatch it as needed when its grid requires it. However, should it be required, the Schofield Base has first call on the power in the event of a disruption in the grid.
As HECO’s website says, “In return for the value of the 35-year lease for the Schofield Generating Station project, Hawaiian Electric guarantees the Army energy security – ensuring it will be able to restore power to the three installations within two hours if they were to lose power. The lease requires Hawaiian Electric to conduct a one-time ‘full system test’ of this capability to prove it can be accomplished.” This test was performed in May 2021, when the microgrid serving the Base as an islanded load was successfully established and operated for 36 hours without any interruptions.
Another plant with recent real-world experience providing resiliency is owned by Entergy, a large utility serving parts of Arkansas, Louisiana, Mississippi, and Texas. Having been through several very serious hurricanes affecting New Orleans and South Louisiana, Entergy wished to replace a 1960’s era steam generation plant with a modern, highly efficient power plant located close to New Orleans. The utility chose to build a new plant consisting of seven Wärtsilä 18V50SG sets producing 128 MW. The New Orleans Power Station (NOPS) was designed to withstand the high wind and extreme rainfall present in hurricanes.
Once again, the designers proved to have good instincts, and Hurricane Ida struck South Louisiana on August 29, 2021. Ida proved to be the second most destructive hurricane to ever strike Louisiana, second only to Katrina, with sustained wind speeds of 150 mph. Entergy reported that within 48 hours, the NOPS plant was restarted and connected to the local grid.
Unfortunately, the damage to the local transmission and distribution system was so severe that full restoration of power to the New Orleans area took several days. However, some neighborhoods, and in particular, some critical facilities like hospitals and first responder facilities had power within 48 hours.
As extreme weather and natural disasters continue to shake our power systems, the need for resiliency is paramount. Adding in the variability of renewable power sources like wind and solar to extreme weather situations only increases the need for solutions that work when you need them.
All these plants had aspects built into them to meet the desire for resiliency – they can all “self-start” without external power, and they all have multiple generator sets such that if one is down for service, the remaining sets can still operate. Two plants have been tested in the real-life situations of an earthquake and a hurricane, and the third has successfully completed a realistic demonstration test.
When building resilient energy systems of the future, utilities and power providers should consider assets that possess characteristics described in these three examples: dispatchability, dual and multi-fuel capabilities, low minimum operating levels, zero minimum down times and run times, fast ramp speeds and the flexibility to keep the lights on when disaster strikes.
About the Author: Chris Whitney is a Mechanical Engineer who has worked for Wärtsilä for 35 years, first as a Project Manager for Power Plants, and currently as a Senior Proposal Manager. He worked initially for Schlumberger Offshore Services as a Field Engineer in the Gulf of Mexico, and following that as the Chief Engineer of a small independent oil company based in Lafayette, Louisiana. His current responsibilities include preparation of the technical specifications, performance data, and cost estimates for new offers produced by Wärtsilä for reciprocating engine power plants.
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