Trials and Tribulations of Biomass Energy

In the May 2019 GSGF Newsletter article “Waste to Energy, Slips, Trips and Falls”, I wrote about the investment risks in WTE plants and their Achilles heel in operations (waste stream sorting, moisture reduction, combustion process and thermal cycling). In this article, I present biomass energy (not as a part of a WTE stream mix), but as a sustainable fuel source (wood feedstock) for power generation/energy production and examine its current status.

 Biomass (biomass/biogas) electricity generation in the USA began with gusto 15 years ago and was termed as a “near carbon-neutral source” with a stabilizing, dispatchable sustainable power, to the otherwise intermittent wind/solar power. However, its take-up has been paltry, compared to the progress of solar/wind power, despite good sustainable availability of biomass. The USA Energy Information Admin. (EIA) notes the statistic for 2018[1]. Per the EIA, only about 50% of biomass plants are in operation as of 2018.

 I think the biomass energy demise in the USA is due to a combination of several factors, i.e. (1) low natural gas prices and gas plant O&M costs; (2) removal of biomass subsidies and minimum quota; (3) recent policy debate on the net benefits of biomass emissions relative to natural gas; and (4) falling wind/solar prices (and now battery energy storage prices). All this taken together, makes biomass energy industry, not be seen in a favorable light by the regulatory/policy makers to promote it. In a recent (“Power Magazine”) article by Jim Romeo (Writer/Contributor), he captures it well in a statement, “biomass power is simply not, what it was hoped to be”.

 This is however, not the case elsewhere in the world (developed and the developing countries). Countries that import fossil fuels at a high cost burden (or with hard currencies) or have a high carbon tax, can hedge their intermittent wind/solar plants (particularly seasonal variations) with distributed biomass/biogas CHP plants. 

 For example, in the Nordic countries, biomass energy has been nurtured and is now a viable industry (sustainable wood harvest, efficient combustion technologies and much cleaner particulate emissions). China too has successfully implemented MW scale biomass (waste and municipal waste) plants in its cities. Canada converted its 230 MW Atikokan coal plant into a wood-pellet fired plant to become the largest biomass power plant globally, but is currently under reduced generation due to lack of power demand in NW Ontario. 

 In my opinion, small distributed biomass energy (both heat and power), offers a good value and domestic fuel flexibility in developing countries, particularly in Asia, Latin America and Southern Africa, where fossil fuel is imported in hard currency and sustainable forest harvest can be developed. In other larger countries such as Australia and Canada, annual forest fires render hundreds of acres of such partially damaged wood as local biomass resource. In a recent study undertaken in Yukon (northern Canada), it was estimated that local biomass was a cheaper fuel to heat large buildings than transporting oil from far away. 

 In establishing such distributed and small biomass CHP plants, a few considerations provide much better financial and operational leverage. These views are entirely mine (from examining these) and are outlined below:

 1.     Smaller capacities (10– 200KW). are best for biomass power and most appropriate in energy access applications (rural and remote areas where distribution wires are expensive or unavailable). They also are viable where intermittent solar PV needs to be stabilized. The closer such plants are to both the wood supply and the point of consumption, the better the value.

 2.     Small power generation is best done with biogas production (from the biomass) at the point of generation, using gasifiers (cleaner burn, better efficiency and better part-load control). Excess gas can be stored locally and used for other distributed uses. Also, the biochar produced offers excellent soil nutrition value. In many such cases, these smaller units are mobile and can be moved around.

 3.     Chipped biomass feed is problematic in steam boilers (size and moisture content). In such cases wood pellets (albeit higher cost), is preferable. In steam systems, it is better to pre-mix biomass varieties (average calorific value), than to keep varying the boiler controls to match feedlots (bad for the boiler).  

 4.     Combined Heat and Power (CHP) or simply just heat energy is best use of such sources and should be leveraged for other community necessities (boiled water for drinking, hot water for cooking/bathing, sanitation, economic development, etc.). Its higher capital cost needs to be offset with local (otherwise unavailable benefits).  

 5.     Biomass energy policy directions should not be halted or reversed. It plays a vital role in the natural CO2 cycle neutralization and are almost GHG neutral (traditional fossil fuels are net GHG emitters). 

 Simply put, let us not bundle biomass energy along with other traditional fuels and simply look at economics. It needs tender-care just as solar and wind energy do. Investor confidence will come if built on the above principles.

[1] https://www.eia.gov/electricity/annual/html/epa_04_03.html