A good question; for me personally, there are two areas that I have a particular interest in:-
• Organic vegetable growing, and
• Renewable energy.
With regard to the first, we are almost self-sufficient in vegetables (except potatoes) from what I grow in our back garden organically (as a hobby). Our back garden is about 333 square yards, of which about 10% (33 square yards) I devote to the vegetable plot.
All kitchen and garden waste is composted to enrich the soil; and by working with nature no chemicals are used as either fertiliser or for pest control. Our vegetable plot supplies us with all the vegetables we need 12 months of the year (except for potatoes), all organically grown; saving us about $600 per year on our food bill.
I also devote another 10% of our back garden for growing fruit, raspberries, blueberries, strawberries, blackcurrants, apples, pears, plumbs, cherry’s and peaches; which provides us with a surplus of fruits for 3 months of the year.
As a vegetarian, if I devoted the whole of our modest sized back garden to growing organically we could be almost self-sustaining for food (including potatoes) in all but dairy products.
As regards renewable energy, my interest stems from admiring the goals and achievements of the EU to become self-reliant on sustainable (renewable) energy by 20% by 2020, 30% by 2030 and 80% by 2050.