Disabled sister needs help with electric bill

I recently found out that my sister has outrageous electric bills. Her bill is over $800 per month in a small house with a relatively new gas furnace in Ohio. However, she has COPD and requires an oxygen concentrator 24 hours, so this is probably driving the bill. She is on Medicaid, so there is no way she can afford these bills. How do you recommend we get help for these bills? The electric company referred us to a community aid organization, but I doubt they can help her at $800/month. Has someone else dealt with this situation? Can the doctor prescribe oxygen cannisters and avoid the cost to run the concentrator?