You have propane and gasoline generators on offer. The propane generators offer clean, eco-friendly emissions. On the other hand, the storage can be an issue when you opt for gasoline generators. The gasoline generators produce 125,000BTUs per gallon, whereas the propane generators produce 91,900 BTUs for each gallon. Make sure to add up the power requirement of each of your electrical appliances to understand the power the best-rated generators need to produce.