Powering the World with its Own Waste

As the world continues to develop, energy demand continues to increase, yet we are finding it more difficult and more expensive to develop new sources of energy. One source of energy that already exists, and is not taken advantage of, is waste. It has been estimated that increasing efficiency or using disposed waste could create an extra 100 gigawatts of electricity capacity in the US alone.

There exist various forms of capturing waste to convert it into useable energy, but here we will consider three companies, reviewed in a Popsci article, that offer completely different forms of waste-to-energy technology.

The US currently holds around 70,000 tonnes of spent nuclear fuel, which will remain dangerously radioactive for tens of thousands of years, and must be carefully stored at a cost. Transatomic Power has designed a reactor that can run off spent nuclear fuel, and claim that the current stockpile of waste will be enough to provide the entire nations energy needs for 70 years.

The two cofounders, both PhD students at MIT, made modifications to plans used to develop a fluoride molten salt reactor at the Oak Ridge National Laboratory in the 1960s. Their 500MW Waste Annihilating Molten Salt Reactor (WAMSR) is 20 times smaller than the original, and is able to capture 98% of the stored energy in the spent nuclear fuel pellets. 50% of the waste produced by this nuclear reactor will then become inert after only a couple of hundred years, making storage much cheaper.

Related article: As Climate Change Worsens, US Corn Ethanol becomes Uneconomical

Biofuel is typically developed from a feedstock that uses precious land and water resources, and often prevents those resources being used to grow food crops; technically however, biomass fuel can be produced from any source of carbon.

Fulcrum BioEnergy plans to build a power plant in Nevada that will convert 160,000 tonnes of municipal waste into 10 million gallons of transportation biofuel each year; at a cost of just 70 cents a gallon. The waste will be shredded into small pellets, and then left in a gasifier, which siphons off the natural gases released by the decomposing waste, and converts it into ethanol.

Factories in the US release around 13 quadrillion BTUs of heat each year into the atmosphere, and that represents an enormous amount of lost energy. Alphabet Energy intends to recapture some of that lost heat and convert it into useable electricity. Their product consists of a thermoelectric material that they position between two pipes; one containing hot exhaust gas, and the other a coolant. The thermoelectric material then uses the temperature gradient to generate electricity.

By. James Burgess of Oilprice.com