When I say "innovations" I don't necessarily mean NEW ideas. As you know, there's nothing new under the sun. But there are definitely ideas that are new to the masses, and new to our post-industrial society, which has become so completely dependent on our intricately linked, fossil fueled lifestyle and infrastructure.
When I say "save the world", I mean hopefully, help us transition to a lower energy society without too much pain and suffering.
So without further ado, here is the completely unauthorized and unprioritized list of exceptionally useful post-peak innovations.
1. Passive Solar Design-
Structures which are properly designed, facing south, and with appropriate amounts of glass, insulation, and thermal mass, require hardly any heating. If integrated when the structure is built, it should cost nothing extra but yield massive payback.
2. Bikes -
Proven to expand the range of the human 3.5 times without increased effort, they require little energy to maintain and none to fuel.
3. Clotheslines -
The original solar appliance, it replaces the energy hogging clothes dryer and improves the smell of your clothes without nasty chemicals. Also works when the power grid is down.
4. Permaculture -
The design system that reduces energy consumption, integrates nature's inputs, and multiplies your return for the same amount of effort. A powerful tool which integrates the other innovations.
5. The Solar Oven -
The gift that keeps on giving, it cooks your food with no fossil fuels or wood required, and no pollution emitted.
6. Vegetable Gardening -
A revolutionary act in this day and age, producing your own food means that you know how it was grown, where it came from, and that it required little to no fossil fuel energy to grow.
7. Root cellars -
A very common sight throughout history, humans produced food during the growing season and saved it for winter consumption by placing it in cool underground conditions. Root cellars, both traditionally styled and newly designed, have the potential to replace one of our most energy intensive appliances (refrigerators).
8. Fermentation -
Another food preservation method, humans have used natural fermentation to both extend the life of food and to increase it's nutritional value. Familiar fermented products include beer, wine, yogurt, and sauerkraut.
9. Solar Hot Water -
A wonderful luxury, hot water makes hygiene pleasant. Solar water heaters are simple, have few moving parts, and replace the #2 user of fossil fuels in the home. They usually have a 5-7 year payback at current fuel prices, and could pay back much quicker when rates rise.
10. Preventive and Herbal Medicine -
After a brief experimentation with utterly invasive and pathologically blinded pharmaco-hospito-insurance - based medicine, many people are rediscovering the benefits of nutritious food, excercise, and ancient forms of non-energy intensive health care, such as chiropractic, herbs, acupuncture, and massage.
Submit your own ideas for the list! Innovations should be proven, affordable, no or low energy usage, and extremely useful ;).