Ultra efficient slow cooking

[lessenergymorefood]

Now here’s the thing. Contrary to popular belief slow cookers are not especially efficient. Typically they use more energy than a light-bulb – mine about 180 watts which is more like 9 high efficiency bulbs. That’s not the point of course; the point is that those figures do not give it an easy win over a highly efficient modern oven.
The big difference between the two is that an oven is thermostatically controlled; a slow-cooker is not, whatever the web blurb says. Now consider my latest friend – the Wonderbag; a fantastic idea which cooks really good food – go Google it. It is effectively a beanbag with a lid that can keep food simmering for 2 hours and hot for 6 and costs £30 and uses no energy!
Anyone who uses a slow cooker in the summer will tell you it’s not much fun as you will notice it heating up your kitchen like an Aga which means by definition it is very energy inefficient.
How about combining the two – a slow cooker with a thermostat in a beanbag? Not literally of course but give a slow-cooker a thermostat and some kind of heat sealing enclosure like the jacket of your hot water tank. In fact if I could find a slow-cooker with a thermostat I would put it in my Wonderbag (actually I think I will try cooking everything on low and put the slow-cooker in the Wonderbag).
There must be an engineer out there who could knock out a design based on these principles – it would make slow cooking enormously efficient …