The Warm Home Discount Scheme can provide a rebate off your electricity bill. People on low incomes, including families, pensioners, as well as people with long term illness or disabilities, can qualify for a rebate of £140 from their energy supplier, which is paid in the spring.
If you have an income of below £16,010, or are on certain benefits, and have young children, you need to ring your electricity supplier to see if you qualify, and claim the discount. It is important that you do this as soon as possible, as this is a capped fund, and some suppliers have closed their applications already (Eon and Ovo).
Criteria vary from supplier to supplier, so check with them to see if you qualify. Please note that some suppliers offer the discount to low income families with children over 5 who are in full time education, whilst others extend it to below 8 years, or in full time education, or on free school meals.
See http://www.ccberks.org.uk/fuel-energy-advice for more information.