[caption id="attachment_214721" align="alignnone" width="1000"] NRG planned on closing its plant in May 2022, but the PJM is exploring options to maintain reliable service for its customers. That may mean it could be open a little longer.| DBT PHOTO BY ERIC CROSSAN[/caption] DAGSBORO  — Delaware’s last coal-fired plant may be open a little longer, as plant operators and the regional power grid operator are working out how closing it may impact service reliability for customers. NRG Energy announced earlier this summer that it would close its 410-megawatt Indian River Generating Station in May 2022, eliminating 50 jobs. But the regional power grid operator PJM announced that in order for the transmission system to carry the weight of the Dagsboro plant, it would need to update its services. Those upgrades are estimated to be complete by 2026 or 2027. “PJM’s most important job is maintaining grid reliability ... PJM is currently exploring all options, including the possibility of requesting the unit owner to retain the unit in operation until all upgrades are in-service,” PJM Interconnection spokesman Jeffrey Shields told the Delaware Business Times. The regional power grid operator cannot compel NRG to keep the Indian River plant in-service, but it can request NRG keep it in operation to support reliability. That process allows the plant to stay in-service and recover operating costs until all transmission upgrades are in place, Shield added. PJM and NRG and the local transmission utility have until Sept. 28 to come up with a mitigation plan for the area that will ensure continued reliability for users. A detailed report will be sent to the Delaware Public Service Commission.  “We continue to work collaboratively with PJM to support reliability in the region. How long the unit might remain operating will depend on the duration of transmission upgrades needed to relieve reliability impacts and the terms of any potential ‘reliability must run’ arrangement,” NRG spokesman Dave Schrader said. NRG purchased the Indian River plant from Delmarva Power in 2001, after Delmarva Power developed the site in the mid-1950s and operated with two coal-fired units. By the 1980s, Delmarva Power doubled the unit numbers. But in the new millennium, NRG oversaw closing down the units, starting in 2010, leaving the final unit running today. The Indian River plant generates enough power for roughly 328,800 homes today. In 2009, NRG invested $360 million to upgrade the plant to meet higher emission standards. Other improvements included the installation of a scrubber and selective catalytic reduction system to further reduce emissions in 2011. Shields noted that the PJM’s deactivation study process is designed to ensure that any retirement of plants keeps the lights on for its customers. The process has been able to successfully shepherd more than 40,000 megawatts of generation to close over the last decade while keeping service reliable. “PJM’s analysis shows wholesale electricity prices associated with the [Indian River plant] deactivation appear to remain relatively unchanged so long as the appropriate transmission system upgrades are completed and all other factors remain constant,” Shields said.