Permaculture defines energy in its broadest context. So not only do we see energy as wind, sun, and water but we see soil, plants and human effort as energy as well. What is important on your piece of land is that you identify all the possible opportunities to store or preserve energy. Once you have a list of those opportunities research possible techniques 
for capturing that energy. Sun can be captured through solar panels into batteries and of course the use of solar ovens. But Sun is also captured through plants. Plants use sunlight and turn it into chemical energy that feeds insects, animals, and humans. So plant as many trees, flowers, and edible plants as you can as you are storing energy for later use. Water is another source of energy. Water can be captured in dams, tanks and most importantly soil. Healthy soil stores a significant amount of water which plants can use to grow strong and healthy. The aim with water is to keep it on your property for as long as you can so this might mean creating swales or doing deep ripping in the paddocks so that water can seep in and nourish the earth.
Human effort is another form of energy, so a good Permaculture design will store the 
maximum amount of energy with the least amount of effort. Getting some mates over to help you on your block is a way of moving activities forward by using human energy. What would have taken weeks can now be done in a few hours. This highlights the importance of a community where we can harness and share human energy supporting each other to thrive. What comes with a tight-knit community is also a lot of other benefits such as friendship, caring, support, etc.
Other forms of storing or saving energy are preserving excess produce in the form of pickles, jams, etc., biogas, working dogs, your woodpile on the farm, a composting toilet that does not 
use water is a form of preserving energy and even redirecting grey water onto your orchard. On a personal level surrounding yourself with people who energise you and don’t drain your energy is also a way of ensuring energy preservation and good health.
Energy in all its forms is what sustains life, it needs to be preserved at all cost.