What is Biothermal Energy

Biothermal energy is a type of renewable energy derived from the composting of organic material. It often uses waste byproducts of agriculture, such as the fibrous matter that remains from sugarcane after the sucrose extraction. It is considered a viable alternative form of energy but is still in its early stages of development.

BREAKING DOWN Biothermal Energy

Biothermal energy, first developed and popularized by the French inventor and farmer Jean Pain in the 1970s, is gaining attention as a renewable energy resource. Pain created 10-foot-high mounds of compost from macerated underbrush that generated enough heat and methane gas to supply all his household hot water and electricity needs, plus run a small van.

Methane gas is known as a biogas biofuel. Biofuels are most useful in liquid or gas, easy to transport, and burn cleanly. These fuels are those derived from renewable plant and animal materials. 

  • Ethanol often made from corn in the United States and sugarcane in Brazil
  • Biodiesel from vegetable oils and liquid animal fats
  • Green diesel, biodiesel, derived from algae and other plant sources, animal fats, or recycled restaurant grease
  • Biogas or methane from animal manure and other broken-down organic material

A renewable resource has the ability for replenishment in the same, or less, time as it takes to draw the supply down. Some renewable resources have a virtually endless supply, such as solar energy, wind energy, and geothermal pressure. Other still carry the identifier even though time or effort must go into the resource's renewal, such as wood, oxygen, leather, and fish.

Investors may invest in an alternative energy ETF which invests in companies engaged in industries serving alternative energy production and research. Some of the businesses in the ETF basket participate only in alternative or clean energy production.

Rot Makes Hot Biothermal Energy

The process came to be known as Jean Pain Composting and relied on the principle that rotting vegetation creates heat and gases. Micro-organisms, which assist in the breaking down of organic material through anaerobic digestion, create heat, methane, carbon dioxide and other gases. These byproducts are useful in a variety of applications.

By running hundreds of feet of water tubing through his compost piles, Pain was able to heat his household water to 140 degrees. The collection of off-gasses, which he put into old truck tire inner-tubes, was cleaned and compressed into usable methane gas. A methane-fueled combustion engine generated electricity, and the gas also powered his cookstove and van. Pain estimated 88 pounds of brushwood provided the equivalent energy of a gallon of gasoline.

Large-Scale Biothermal Applications

Pain’s experiments seemed quixotic to some because his efficiencies that have proven difficult to reproduce. However, biothermal energy has gained significant followers, and advances in the technology continue. In particular, the field of methane and ethanol gas production from compost matter has been both lucrative and environmentally beneficial. This environmental benefit is especially valid when using energy is derived from animal waste. Some sewage plants are even harvesting methane gas from human waste.

Biothermal energy requires large areas for composting functions. Its application is primarily in substantial agricultural environments. For example, many farms are now using the power generated from compost piles to heat greenhouses. Further innovations may make it possible to use biothermal energy as a large-scale supplement for home heating or to capture methane and other biogases for use in place of natural gas. 

One promising technology converts the chemical energy stored in wastewater directly into electricity. However, so far it is not economically viable. Meanwhile, other companies are experimenting with creating so-called biopolymers from organic waste, which is plastic made from compost.