Renewable industry campaign group Our Solar Future called on the government to abandon its plans for additional cuts to feed in tariff (FIT) subsidies.
An MP said it was unacceptable that 20,400 householders in his constituency live in under-heated homes. Dan Jarvis confirmed that he would be raising the issue in parliament.
The government has appeared to back-track from plans that energy firms will be impelled to give all customers the lowest tariff. However, a minister said the details had still to be worked out.