Biogas Power Generation

Ever since 1752, when Ben Franklin flew his kite in a thunderstorm, electricity has powered most of the major industrial and technological innovations in common use today. Consequently, the more widely electricity applications spread, the more intense the exploration for — and exploitation of — natural resources to fuel electrical generation. A century of this expansive exertion, however, took a toll on the health of the global atmosphere: the burning of fossil fuels yielded the massive release of carbon dioxide that may destructively affect our climate. A promising solution to this worrisome phenomenon is a greater emphasis on biogas power generation.

Power Usage in the U.S. and the World

Over the last half-century, global electricity consumption has more than tripled, according to statistics compiled by the World Bank. Broken down by nation-state, the northern climate states use far more electrical power than those closer to the Equator, with Iceland ahead of all — 53,832 kilowatt-hours per capita in 2014. In the United States of America, Texas leads in terms of net generation: 483,201,031 kilowatt-hours in 2019 per the U.S. Energy Information Administration. With electric cars and other battery-sourced technology on the horizon, the demand for electrical energy will likely rise further.

Fossil Fuels and Power Generation

Presently, the vast majority of electricity produced in the United States is done so by means of fossil fuels. In 2019, 62 percent of electrical output was credited to fossil fuel — 38 percent from natural gas; 23 percent from coal; and one percent from petroleum. The remaining electricity is derived with nuclear power (20 percent) and renewable sources (17 percent). Conversion from fossil fuel to electricity is usually achieved through the mechanical energy of steam and/or gas turbines. Diesel oil is combusted in diesel generators.

Renewables and Power Generation

Of the 17 percent of electricity made with renewable sources as the converted fuel, hydro-electric and wind power produce the lion’s share of it. Lagging behind are solar power, biomass and geo-thermal forms. Each of these is an important component in the effort to reduce fossil fuel emissions; each possesses advantages and challenges. They are all positive in terms of carbon dioxide release. Hydro-electric is also up to the task of meeting energy demands when at their peak. At the same time, infrastructure for water power is an often cost-prohibitive initial investment. On the other hand, wind energy saves water and demonstrates the lowest enviroinmental impact among the renewables. Unfortunately it is not always available when needed most.

How Biogas is Different

In understanding biogas power generation, it is important to draw a distinction between biogas and biomass. Both originate with organic matter — wood chips, crops, vegetation, compost and waste, e.g. Whereas biomass produces energy through the direct combustion of such materials, however, the biogas process of gas production is multi-stepped and more gradual. When organic matter is cut off from oxygen, it is subject to anaerobic digestion. This happens as very specific bacteria begin to break down the chemical compounds and form new ones. In subsequent chemical reactions, the end-product gases of carbon dioxide (CO2) and methane (CH4) are formed. The resulting CH4 is — after purification and processing — the combustible component.

What, then, makes biogas an attractive alternative to the other alternative sources in terms of electricity creation? Like the others, it is friendly to both atmosphere and environment. Meanwhile, the financial investment associated with biogas manufacturing is relatively modest, particularly since projects can exist at both grand and modest scales. Unlike wind and solar processes, anaerobic digestion of manure, fallen foliage, food scraps and gleaned crops — to name a few — enjoys a constant and endless supply of organic materials upon which to draw. As long as things grow and die, evacuate waste, and discard food and fiber, a reliable inventory of locked-up methane remains available for liberation.

Getting Electricity from Biogas

Electricity from biogas can be generated in much the same way it is from natural gas. A combustion engine burns it as fuel, producing mechanical energy. Based upon the principle of electromagentic induction, the mechanical movement is converted into electricity when a magnetic field is formed through the interaction of moving and stationary components. Although the biogas is consumed like a fossil fuel, there is no new CO2 released. This is because it emits only CO2 that would have been released by the organic matter were it is simply left on its own to decompose. Furthermore, the remaining digestate, i.e. that leftover matter at the end of the biogas generation process is in demand as a rich and nutritious fertilizer for agricultural crops. Needless to say, these virtues promote biogas as a superior means of producing electricity while preserving the environment.

In Summary

Electricity consumption is widespread and growing, both in the United States and around the world. As cultures and governments grow more concerned about the effects of fossil fuel combustion as a precursor to electricity generation, renewable forms of energy take on increased importance. While there are several alternative sources of energy being developed, each carrying both promise and problems, biogas is one substance that offers very few downsides. Best of all, it never runs out.


AirFacts Magazine