The Petra Nova carbon capture and storage facility that captures CO₂ from a unit at the coal-fired WA Parish Generating Station in Texas, USA, has been mothballed, after being shut down in May. The key reason has been reported as being low oil prices, which made the enhanced oil recovery function of the facility uneconomic, but a Department of Energy report has detailed that the US$1 billion (€840 million) facility had been struggling with operational problems since its January 2017 inception. In the first three years of its operation, Petra Nova had experienced outages on 367 days, though issues to do with the capture part of the facility had only contributed to a quarter of those. During the same period it captured 3.45 million metric tonnes of CO₂, 17% less than expected; while this figure must been seen as a disappointment, it does not make the project a failure for its partners, NRG Energy and JX Nippon, nor the Kansai Mitsubishi Carbon Dioxide Recovery process the plant used. An NRG Energy spokesman said that the company is “proud of the work we have done to demonstrate that carbon capture could be installed on an existing coal-fired generating station and operated as designed.” The mothballing, however, demonstrates the difficulties carbon capture and storage as a whole will face to achieve operational stability and economic viability. The company may fire the plant back up when/if oil prices rise, and this ‘may’ says a lot about the operational difficulties experienced to date.