This is a thermally insulated pressure cooker. We're not going to buy our way out of the environmental crisis, but certain purchases can make a big difference if they reduce our consumption of fossil fuels.
Pressure and Insulation for Efficiency
Pressure cooking is a super-efficient way to cook. A pressure cooker "can drop the consumption [of energy] by ... 68 percent ... compared to a flat-bottomed pot" (Stoyke, 2007, p. 80). It's so efficient because when it's under pressure, water can boil at a much higher temperature (about 120 degree Celcius), which makes the food cook faster.
Kuhn Rikon, a cookware company out of Switzerland, has introduced another concept to make cooking more efficient: insulated pots. As the picture above shows, the pot has double walls like a Thermos. The air between the walls insulates the pot, and heat stays in much longer. In fact, you can cook soups with this thermal cookware by bringing the ingredients to a boil, turning off the burner, and placing the pot on its insulated serving base. In two hours, the soup is fully cooked! It's similar in concept to a hay box cooker.
The Best of Both Worlds
Kuhn Rikon sells a product that is easily the most efficient way to cook: the Duromatic Thermal-cooker. It is a combination pressure cooker and thermal cooker. I bought mine right here in Edmonton at the Bosch Kitchen Centre at 9766-51 Avenue (they're the only Kuhn Rikon dealers in Edmonton). It was pretty expensive - around $350 - but you're buying two cookers in one, and they are built to last a lifetime.
I bought (and recommend) the 5-litre model. This thing is amazing. I can cook dried chickpeas in about 20 minutes, with the burner only turned on for 13 or 14 of those minutes. Chickpeas can easily take two hours of regular boiling to cook in a regular pot.
Once this baby comes up to pressure, it will stay at pressure for about 10 minutes without any more added heat because it's so well insulated. And if whatever you're cooking isn't cooked enough? Just place the pot on its insulated base, and wait 20-60 minutes. It will keep on cooking on its own due to the thermal properties of the pot.
Pressure cooking is a wonderful way to cook anything - it really infuses flavours together. I really recommend it for cooking beans from scratch (if you want to avoid the BPA in cans, for example). I bought Lorna Sass' book Great Vegetarian Cooking Under Pressure at the same time as my pressure/thermal cooker. Everything you need to know is in there, and the recipes are fantastic.
I recommend an investment in the Duromatic Thermal-cooker. It's a fun, green way to cook.