Two generation firms were fined 39 million pounds (about 62 million U.S. dollars) for failing to meet environmental targets, the British energy watchdog Ofgem announced on Friday.
The North Yorkshire-based generator Drax Power was hit with a 28 million pounds penalty and another generation firm, InterGen, was fined 11 million pounds for their failing to meet environmental targets under the government's Community Energy Saving Programme (CESP).
Under CESP, generators as well as energy suppliers had to deliver energy saving measures to households in low-income areas by the end of December 2012.
Drax Power delivered 37.1 percent of its carbon emissions reduction target, according to the Ofgem.
Independent generator InterGen delivered 6.4 percent of its CESP obligation by the deadline. After additional measures it delivered 61.2 percent, remaining 38.8 percent short of its obligation.
Sarah Harrison, senior partner in charge of enforcement at Ofgem said that the punishments "reflects the seriousness of the consequences of these failings for consumers."
In May 2013, Ofgem launched investigations into six energy companies, including British Gas, SSE, Scottish Power, and GDF/Suez, who failed to deliver on time their obligations under CESP scheme.
The CESP was designed to lower carbon emissions through the delivery of energy saving measures, such as loft and cavity wall insulation free of charge, to households in low income areas.