Francesco Mazzagatti: Bioenergy: The Hidden Giant of Renewable Energy
In the field of renewable energy, it can often seem that wind and solar power hold supreme. They certainly gain far more public attention in the search to change from a hydro-carbon based energy system to a green energy system, at least compared to any other form of renewable energy. As such, it may be surprising to discover that, by quite some margin, the energy output of both these power sources together is out produced by bioenergy.
By 2023, it is forecast that bioenergy will make up fully half of renewable energy produced globally. The reason that bioenergy makes up such a greater share of energy production than other forms of renewable energy is its considerable use in heating and transport, which make up 80% of total energy consumption. Bioenergy is predicted to make up 30% of the growth in renewable energy consumption from 2018–2023, and as long as governments ensure that a sustainable framework is maintained for bioenergy production, its share of global energy use will only continue to grow.
But how is bioenergy created? The fuel itself is the chemical energy contained in biomass, converted into solid, liquid or gaseous form. The most common sources of biomass for energy production are agricultural crops, animal and plant wastes, algae and organic residential/ industrial waste. These are then broken down through different forms of thermal degradation, and kept as liquid or gaseous fuel depending on the temperature and heat source used in refining.
Biofuels such as wood can also be ‘directly combusted’, burnt as fuel, but bioenergy plants which use this method tend to be far less efficient than those which refine their biomass, operating at 20–35% and 85% percent efficiency respectively. The creation of biofuel is a far less flashy process than that of generating solar or wind power, and not nearly as eye catching. It is reliant on much finer tolerances in scrubbing greenhouses gases and tars from its bio-products. Despite this, and despite the area of land needed for generating biomass, in comparison to building wind turbines or installing solar panels it is a much more effective way of expanding renewable energy production.
The primary use of biofuel is in direct use for heating and transport, rather than in generating power which is then used for other purposes. The heat sector, including heating for industry, will account for the biggest overall share of renewables in meeting energy demand in 2023. Renewable heat consumption is expected to increase by 20%, reaching a share of 12% of total heating sector demand by 2023. Renewables in transport have a much lower contribution to power generation compared to heat, with its share predicted to grow only minimally from 3.4% in 2017 to 3.8% in 2023. Renewables cover only a small portion of all energy demand in transport because of ongoing petroleum product consumption. In this then can be seen the path which governments and companies can take to make travel more sustainable. There is already an effective model in using biofuel to power transport, much more so than wind or solar energy. The use of biofuel in directly generating thermal energy is an accepted path. What needs to happen alongside this is a similar culture shift in regards to petrol.
Bioenergy is efficient to create, develop and use. It does not grab headlines in the way wind and solar power do, but its potential cannot be overlooked as a source of renewable energy, and one which is already surging in its share of power generation.