How Does Waste-to-Energy Work?

Waste-to-energy is the process of transforming organic plant matter into usable energy. Much like a coal burning plant that creates electricity by burning coal, a waste-to-energy plant burns primarily organic waste and turns it into the electricity. Not only does this procedure create energy from garbage, but it ultimately reduces the amount of garbage that goes into landfills. It therefore has a two-fold beneficial effect. The basic process of transforming waste into energy is relatively simple and more than a little fascinating.

Waste to Energy

The process of turning waste into energy works something like this: mostly organic waste consisting of paper products, plant matter and corn-based plastics is gathered at an industrial plant, where it is burned. The burning of the waste produces heat which–because the burning process is done in a boiler–turns water into steam. The steam then is used to power turbines, which in turn generate electricity. The electricity that is produced as a result is then transferred to power plants and then distribute it across the power grid. Essentially, the process of turning waste into energy is as simple as that.

Reduced Landfill Waste

Whereas all of that waste would have normally been dumped into a landfill, at a waste-to-energy plant the vast majority of it is burned and converted into electricity. Therefore, the landfill is spared the additional contents. Of course, there is a byproduct from burning all that waste. Of every 100 tons of waste burned to make energy, approximately 15-20% of it remains as ash. Thus, a landfill will ultimately only receive 15-20 tons of waste rather than 100 tons.

Energy Produced

The energy that can be produced from burning organic waste and converting it into electricity is approximated to be 500 kilowatt-hours for every 1000 kilograms of waste. That means that it produces 500 kilowatts of power that can be used for an hour. Considering that a city like New York uses 50 million megawatts annually, that is a drop in the bucket, but it is still notable. In the aggregate, burning organic waste to make energy produces more power because far more than 1000 kilograms are burned.

Use of Ash

In addition, it is theoretically possible to use the ash byproduct from the burned organic waste. This would require, though, that the waste thus burned be totally organic. If this was the case, the organic ash could be used as an input in organic fertilizers, among other things. The cycle would be complete. Organic plant matter is collected, compiled and burned. The immediate result of this is the production of heat, which turns water into steam. The steam powers turbines that in turn make electricity. The 15-20% of ash that remains could then be put to other uses, like an ingredient in composts and fertilizers, and even soap.