The second Permaculture Principle is called "Catch and Store Energy." As with most of the Principles, if you look for it in the Eightfold Path, it pretty much falls under Right Doing and Right Livelihood. Livelihood is not necessarily a job; if your house warms in the sunshine during the winter day and keeps you warm for at least part of the night, that captured sunshine is income to you, and therefore part of your livelihood. Designing the house to do that is acting according to both Buddhist and Permaculture ideals, since sunshine is not stolen from anyone (unlike petroleum, quite a lot of which has been stolen through the judicious use of lawyers, politicians, and militaries). Growing your own fuelwood or using a ram pump to lift water to the homestead from a stream on the property would also fit this pattern. So would investing together in a community solar power system or wind turbine. These have issues of hidden costs of manufacture, but it could be argued that they may be preferable to remaining grid-tied to coal or nuclear.
Energy efficiency is also income. By caulking, insulating and otherwise retrofitting a home, one reduces payout to the utility companies, freeing up income toward, saying, paying down a mortgage early.
Powering down is also "powering up." Assuming you are within range of whatever you need transportation to reach, and in reasonable physical condition, trading in the car for a bicycle eliminates car payments, fuel costs, the higher level of maintenance required by a car, associated governmental costs such as license plates, registration and smog inspection, and insurance payments, thus paying the mortgage even faster.
The image at the top of this post shows a solar hot water pre-heater. With a little tweaking, it could provide all hot water half the year, even at 44 degrees North where it resides. It's a salvaged hot water heater with half its jacket removed, painted black, surrounded by an insulated cold frame built onto the well's pumphouse. Currently all it does is heat well water before the water goes to the household electric hot water heater, passively collecting sunshine as income.
There are gigabytes of such projects, mostly in PDF form, at this link: http://www.cd3wd.com/cd3wd_40/cd3wd/index.htm
Principle 2: Catch and store energy: “Make hay while the sun shines.” By developing systems that collect resources when they are abundant, we can use them in times of need.