This is my absolute FAVORITE: solar thermal panels on your roof can heat your house, your water, and generate no-transmission-loss electricity . . . even on a cloudy day! This technology is a game changer!
DIY Homemade Solar Furnace -- Solar energy is free, and is always begging us to make use of it. Here is another great way you could make use of solar in your house. Why not build this diy homemade solar furnace to help heat your home this winter. Most of the materials for this project can be re-purposed or picked up at dump yards. The reminder should not cost you more than $50 at your local hardware store.
Excellent method for heating your water off the grid. This method is not only very efficient as it uses what would otherwise be waste heat being directed out through the stack, but it also works in much the same way as a hot water on demand system or a solar water heating system. This concept can even be directly incorporated into your current solar water heating system or as a separate stand-alone in the kitchen or workshop. Keep your mind open and remember to improvise!