Biomass power
Biomass power is renewable energy produced from organic material. This can include plant or animal waste (i.e. rice husks, manure, or slaughterhouse waste), or plants grown specifically for the purpose of fuel.
Biomass can be turned into energy in the form of heat or electricity by burning it, converting it into gas (called gasifying), charring it into charcoal (called pyrolisis) or processing it into cooking fuel.
Organizations working in biomass fell into 5 areas:
- Biodiesel
- Biogas Digesters
- Biomass Briquettes and Biochar
- Biomass Gasification
- Efficient Burning Stoves
Biodiesel
Biodiesel is engine fuel made from plant oils. It is seen as a cheaper and greener alternative to fossil fuel diesel. Normal diesel engines can run on up to 20% plant oil unmodified, and 100% if retrofitted. While many plants can be used, the most well-known is jatropha curcas. Surveyed organizations using biodiesel are focused on either engines or fuel. Organizations focused on engines are developing or promoting biodiesel engines for farmers so that they can grow or collect their own fuel sources. Organizations focused on fuel promote how growing biodiesel fuels can increase the productivity of wasteland and farmland.
Biogas Digesters
Biogas digesters use bacteria to process plant or animal waste (manure or slaughterhouse waste), which contains methane gas, into burnable fuel, which can be used for cooking or to power turbines and generate electricity. A solid residue is also left which can be used as a fertilizer. This can be processed into a more portable form through worm-composting.16 million households worldwide have small-scale biogas digesters processing manure or plant waste. If not processed into burnable form, methane is 23 times more potent than CO2 in releasing carbon into the atmosphere. Therefore methane biogas digestion also has major climate benefits.
Biomass Briquettes and Biochar
To make biomass briquette fuel, plant waste is heated and compressed in a machine or kiln into solid charcoal or fuel briquettes, which can then be burned as cooking fuel. The fuel is carbon neutral because the initial growth of the plants used as feedstock removed carbon from the atmosphere equivalent to that released by its burning. Briquettes can be a cheaper replacement for liquified petroleum gas (LPG/propane), but must be used in stoves designed for them. Biochar can replace charcoal in normal burners.
Biochar can also be used as carbon-negative fertilizer, and some organizations, such as re:char, promote this as their primary use.
Biomass Gasification
Biomass gasifiers turn biomass waste (rice husks, pine needles or other dry material) into a burnable carbon monoxide/hydrogen gas which can be used for cooking or generating electricity. Generally used to make productive use of waste material that was previously burned or left to rot. One of the lowest-cost per kW methods of generating off-grid electricity. Plants generating over 100kW can light 10,000 homes, and cost under US $100,000. Community level plants usually range between 35-120 kW and require staff to run and maintain them. Plants in rural areas without large populations sometimes face challenges finding enough demand for the power generated. Small-scale gasifiers can also be used at the household level to fuel inexpensive, clean cooking.
Efficient Burning Stoves
Efficient Burning Stoves improve the efficiency of traditional fuel sources by reducing smoke, cooking time, and fuel use. They are sold as a replacement for traditional stoves that many people across the developing world use to cook every day. Efficient Burning Stoves are relatively inexpensive and save users time and money spent collecting fuel. They also produce 40-50% fewer emissions than traditional stoves, which is beneficial to health and the environment.