Biomass energy sources

It’s year 2506. A group of robots are visiting The Museum of Energy Sources. Here we see one of the oldest examples of humans using energy. Humans discovered that some things such as wood release light and heat when they burn. These are two forms of energy.

This picture from 2015 shows a much later example of two little humans using the same source of energy in a similar situation. They are using natural material containing atoms of carbon - ORGANIC MATTER. We can also say that organic matter is anything that comes from living or recently living organisms, such as animals, plants or algae. Energy from the sun is trapped inside organic matter in the form of chemical bonds. Once we burn materials made of organic matter, chemical reactions take place and energy is released, along with steam and carbon dioxide.

When organic matter is used as a source of energy it’s called BIOMASS. We get biomass in two different ways. We can collect LEFTOVER ORGANIC MATTER, such as dead plants and animals, used cooking oils, or food waste. We can also grow new plants with the purpose of converting them into energy. We call them ENERGY CROPS.

There are different ways to produce energy from biomass. Solid biomass such as wood, garbage, or dry animal droppings can be burned directly to heat buildings, or water we use in our houses. Biomass can also be converted into liquids or gases first, which can be burned to produce energy. These are FUELS. Fuels made from biomass are called BIOFUELS.

Examples of liquid biofuels made from biomass are BIOETHANOL or BIODIESEL. Bioethanol and biodiesel can be used to power engines, for example in cars. Gas biofuels are created when bacteria decompose organic matter and produce a gas called METHANE. Examples of gas biofuels are BIOGAS and LANDFILL GAS. Gas biofuels can be burned to produce heat.

Living organisms create organic waste all the time. Plants also grow continuously - they absorb energy from the sun, and carbon dioxide from the air. Most of the biomass grows at about the same rate as we use it and it does not reduce the amount of natural resources available. That’s why biomass is a RENEWABLE ENERGY RESOURCE. There is one special type of biomass which can be used as a fuel but is not renewable.

Sometimes, dead organic matter doesn’t decompose completely, especially if there is not enough oxygen. Then, it might turn into PEAT. Peat forms very slowly, so we use it much faster than it takes to renew. It might also release harmful substances when it burns. Therefore peat is not a biofuel but a BIOMASS FUEL.

We also use peat as well as solid and gas biofuels to produce electricity in POWER PLANTS. Solid biofuels and peat are burned inside a furnace. When they burn, they release energy which heats up the water. The water turns into steam and moves a turbine, which drives an electricity generator. Biogas and landfill gas can also power engines which generate electricity by converting movement of engine parts into electrical energy.

For robots, biomass energy sources might seem like a very odd concept. But for us, it is a great way to use waste and produce energy in a way that doesn’t harm our planet.