There's a new gadget called the "Microwave Regenerative Converter" from Nihon Dengyo Kosaku Co Ltd that can harvest the wasted electromagnetic energy from your microwave's efforts to heat up last night's leftovers, and turn that energy into useful electricity.
TechOn reports, "The new product is much smaller than the other products in the series. It can be used for harvesting microwave oven's or industrial microwave heating machine's electromagnetic energy that does not contribute to heating food or materials and is discarded."
The device is a rectenna, a combination of an antenna and rectifier, and its regeneration efficiency (ηt) is based on how efficient your microwave is at warming up foods -- the efficiency of which is determined by what the food actually is. TechOn notes we can use this formula:
ηt = ηm x (1 - ηh) x (1 - LC) x ηr x ηC
In this formula, ηm is the efficiency of converting alternating-current power into microwaves with a microwave oven, etc. ηh (heating efficiency) is the ratio of the energy used for heating food or materials to the energy of the generated microwaves. LC is the loss of the transmission circuit. ηr is the efficiency of the rectifier, and ηC is the efficiency of the boost circuit or superposed circuit.
Among those parameters, ηh (heating efficiency) fluctuates most because it depends on food or materials. It ranges from 0 to 90%.
The less water the reheating food has in it, the more efficient your microwave is. So if you're heating up a mug of tea, you'll probably be able to convert more wasted energy into electricity.
Dengyo plans on promoting this household use of a rectenna as it puts this new product out in the market. Exactly how well it will work and how useful it will be to someone busy cooking up Hot Pockets is to be determined. Either way, we're glad they aren't sticking with the name "rectenna" and going with something slightly less unfortunate sounding with "Microwave Regenerative Converter."