Have you determined the make/model and install cost from a local dealer? Permits, fuel source, electrical work? You have a very achievable goal, so define it exactly. Then ask the dealer for a charitable discount, talk to your bank manager about their community grant program, talk to the rotary club, and then you could have half covered. Ask everyone for referrals, and consider hitting up the local newspaper for a short article outlining need and ask people to donate directly.