THE NEAT THING about solar cooking is that anyone can build one, design one, and even use one. All you have to do is just see the sun, and grow the food. Solar Cooking is not new. But what is new is that it is more "convenient" and "ergonomic". Worldwide there are about 60 or so patents in the field of solar cooking. There are all kind of designs, and people are inventing new ones all the time.
My friend Howard Donaghy, a bicycling ex-marine, is just such a person. One time I made a solar cooker out of just cardboard and reflective potato chip bags! He took it home. Presto, there was a power outage, and he was the only person in the apartment who had hot water. He then started to think and improve on the design. He recommended to me an adjustable grill, moving the solar cookware up and down to adjust for the focal area of the sun. He then got really inventive. He calls it "scrap yard" solar. He went to the local thrift store, got some clear suitcase covers, put "bubble packing wrap" in between, and presto, just the type of solar cooker a bicyclist would want.....just roll it up.
Solar cooking is neat in that it really reaches out to people in the "throw away" class. Energy of course is cheap....for the rich. A good definition of being rich, is having lots of energy to waste. People in the 'no energy class', well... don't have access to energy. Worldwide, the umbrella organization International Solar Cooking Association, has done a 'knockout job' of distributing solar cooking information, and even solar cookers to places like Somalia, India, South Africa....yep, there was a riot in downtown Kabul Afghanistan when they were first introduced. Increasingly, we hear over and over again, reports of people in third and fourth world nations that they would not have had a hot meal if it wasn't for this invention.
Solar cooking really is a good place to start to learn about solar technology. I contend the future of solar energy is 1) portable, 2) easy to use and understand systems, 3) assemble/disassemble, 4) light weight and shippable, 5) uses common materials and skills, 6) long lasting and quality. So far there isn't a 'solar restaurant in Seattle', but my engineered solar cookers are neat. Basically, I focus the sun's rays unto dishware (Pyrex or metal) placed inside a high temperature plastic bag, like Reynolds Turkey Bags. My patented designs are of the "grill type", where the sun's rays are focused onto a "grill" literally. On top of the grill is dishware, or my favorite .... solar cooked turkey! Ovens are different. They use glass. Grills work only on sunny clear days. Ovens are neat in that they can trap heat from the day, and cook at night. Ovens usually use glass, while grills don't. There is also another reason for the grill....to keep people's heads out of the focal area of the sun. Just like "don't stick your hand in the fire", the grill physically prevents the curious from sticking their eyes in concentrated sunlight. Plus, grills are a lesson learned from childhood... grills can be hot.
Still though earning the "Solar Cooking Boy Scout Merit Badge" is really a good place to start understanding the power of the sun. I find that my portable 2 footer can cook about 1 pound of food per hour. For example, three pounds of "solar burgers" would take 3 hours. An important rule of thumb for solar cooking....start before noon. The prime cooking times are between 10am and 2pm every sunny day. When the sun is highest in the sky, there is less atmosphere between you and the sun. At sundown there is much more atmosphere (making the sun look big) and a lot of the sun's energy is absorbed by the atmosphere. Solar cooking also works better at higher altitude than sea level, in part due to a thinner atmosphere.
I build my grills of various sizes. The two footer works like a crock-pot, while my 12 footer well fries! I have found that aluminum is the metal of choice....it is long lasting, highly reflective of sunlight, lightweight, and easier to machine (than say wood or steel). Each one is designed to be assembled/disassembled and packaged and shipped. (16 footers pull out nearly 700 to 900 degrees!).
So, if you are serious about integrating solar energy as part of your life (and utility bill!), start out with solar cooking.....great for kids.
Martin Nix
PO Box 95173
Seattle, WA 98145-2173
solarshack@earthlink.net