Wabbout a solar HW heater to take the a bit of the energy nut away? Can you create an attic access from the outside to accomade a roof top solar install. I hate voids in a house . They are always where the problems lie. The attic over the 12x12 ell was such a case until I made a cladboard hatch in the gable end.
Chris,you strike me as a capable guy. House carpentry isn't rocket surgery. It is mostly common sense.The more you DIY, the better off you will be. The battery plant that solar needs, presents you with a system, that allows to charge those batteries with regular electricity or a stand by genset. That is how a telephone central office powers their equipment. A CO can lose power and service will stay up until it is restored.May be a small scale plant could be fabbed that is dedicated to medical equipment , not the entire house?