For extra power, there are self doable, testded, durable, solar concentrator models, that can be made from commonly awailable parts. Like smaller versions of this one. For solar ovens, furnaces, and energy generators: Instructions from here: http://www.solarfire.org/
Vegetables for food can be grown in new permanent soil, that can be made from leftover materials of seaweeds that have been turned to fuel and energy: charcoal and plant nutrient slurry. Edible and sellable vegetables.