I love my solar cooker! I use it as often as is practical, and I find that the investment in a purchased Sun Oven was well worth the money. I get a lot of satisfaction out of saving energy and showing off the Sun Oven to friends, family and the blogging community :).
But is solar cooking worth it to YOU? Is it worth purchasing one and learning how to use it? Or is it worth the time to figure out how to build one? Whether solar cooking is right for you depends on several factors:
1. Geographical location
2. Location for your solar cooker
3. Your goals
4. What you want to cook
5. Your schedule and adaptability
Your geographical location
If you live in Southern California, Arizona, New Mexico, Texas, Colorado, Nevado, Utah or Oklahoma, look no further. You are in prime solar cooking-ville. In fact, any place south of the 40 degree latitude has around 150 prime cooking days. The authors of Cooking with Sunshine report that you can use a solar cooker if you live between the 60th parallels of latitude on Planet Earth :).
The best places for cooking are, obviously, ones with many sunny days. Surprise! Oklahoma City is the 11th sunniest major city in the United States!
Personally, I have found that in June and July it is possible to cook 2 - 3 different things (bread, lunch and dinner) on sunny days in OKC, which I have found to be 4 - 5 times per week on average. I'm sure this will decrease as the days grow shorter, and in the winter I will probably have to cook dinner at lunchtime. I'll report on that later...
Location for your Solar Cooker
As a guideline, your solar cooker/ Sun Oven will usually need at least 4 hours in an unshaded location between 10 am and 4 pm in the spring, autumn, and winter; and as few as 2 - 3 hours between 9 am and 6 pm in the summer (depending on your cooker and what you are cooking). I find it easy to cook in my Sun Oven because it is located right outside my back door and I can pop out to check on food or adjust the cooker in just a few seconds.
Why do you want a solar cooker? Here are a few common reasons:
1. You want to decrease your environmental impact by using less energy (natural gas, electricity, wood, etc.)
2. You want a back up option in the case that your usual energy source is not available. For instance, many peak oil theorists predict rolling blackouts or grid crashes as energy becomes more scarce or rationed.
3. You want a way to cook during camping, park cookouts, or at a remote, non-grid location, such as a cabin.
4. You want to avoid heating up the house in summer. (As a bonus, your food is already cooked by the evening, when your house is getting the hottest!)
5. You want to hedge your bets against rising energy prices by reducing your energy usage now.
6. You want a cool way to demonstrate Earth-friendly technologies to your doubting family or friends. You want an easy way to get people talking about reducing energy use or preparing for the peak oil future.
What you want to cook
Keep in mind, you can solar cook both "oven" food and "cooktop" food (although maybe not sauteeing). The fastest foods to cook are fish, chicken, egg and cheese dishes, rice, some grains (like quinoa and couscous), fruit, beans from a can, pizzas, non-root veggies, sweet potatoes, and warming up leftovers. You can cook these in 1 - 2 hours, so it is easy in even marginal areas. I have found that I can cook foods like enchiladas, quesadilla stacks, and lasagna in 2 hours as well.
Foods that take a little longer (3-4 hours) include bread, root veggies (potatoes, carrots), lentils, and meats. I have to note that with my Global Sun Oven, I have found that I can cook banana bread in under 2 hours in prime conditions. If you cut up potatoes you may be able to cook them in a shorter time.
Foods that take the longest (5 - 8 hours) include large roasts, soups, and dried beans. I haven't even tried these yet, so I can't comment.
Your Schedule and Adaptability
Solar cooking is a little different - you have to cook during daylight hours and allow enough time to get the food cooked. According to some sources, you can put dinner in the solar cooker (facing due South) in the morning and come back home to a cooked meal. However, I have not tried that. I have always monitored the cooker and adjusted it as the sun moved. Maybe I should try it - it sounds pretty darn easy.
Basically, if you live in a prime solar cooking area and have any of the goals listed above, you might at least try making your own solar cooker. Although I do love my Global Sun Oven, there are cheaper ways to solar cook.
If you want to cook mostly fast-cooking dishes, you should consider getting or making a solar cooker, even if you live in a somewhat marginal area.
If you only cook dried beans and you live in Alaska, don't even bother :).