For your 12v DC system, you might check with an RV dealer for DC equipment. Also RV DC equipment online, like small refridgerators, lights, etc. Don't know how much firewood you have available, but it can be used for heating, water heating, and cooking. Solar, even homemade solar is good for water heating and heating with a hot water system. You can buy and/or make a solar slow cooker. Works kind of like a crockpot. You can put a stew in a cast iron Dutch oven and surround it with aluminum foil covered cardboard from a box and aim the sunlight to the pot. It can cook a stew in a few hours.
Heating and air conditioning are your biggest users of energy. Air conditioning will be the hardest to solve. Even 3' underground stays about 60 degrees, and with body heat, cooking, showers, lights, TV's, computers, etc, put off heat.
The next largest user is for water heating. Solar is cheap, but you do need a cloudy day backup.
Refrigeration is next, and they do make DC and propane refrigerators.