Exploring Energy: Woody Biomass

Elena Bilheimer, EcoNews Journalist

Continuing along the journey of exploring energy, bioenergy, or biomass energy, is another power source that is oftentimes framed as a bridge to a world powered solely by renewables. Although biomass is sometimes considered renewable because it utilizes waste products, or sources that can be replanted, concerns about the carbon accounting system, community health, and air quality make it a controversial energy source for many people. Biomass is an important topic in Humboldt, as it currently provides a significant amount of energy for the county. 

A Brief Primer of How Biomass Energy Works

Biomass refers to a range of organic fuels and matter that can be used to generate  electricity. Unlike fossil fuels, which come from long dead life forms, biomass comes from recently living organisms. It can include wood and wood processing wastes, agricultural crops, organic waste from industry and households, human sewage, and animal manure. 

This organic matter can be converted to energy through various processes, including burning, bacterial decomposition, or conversion to a gas or liquid fuel. Burning and the direct combustion of woody biomass is the most common form of releasing this energy, and thus the focus of this article. Through the process of photosynthesis, plants convert radiant energy from the sun in combination with water and carbon dioxide to form glucose — a form of chemical energy. This energy is then released when the plant is burned or transformed. In order to achieve this, matter is burned in a boiler to produce a steam that rotates turbine blades and ultimately drives a generator to produce electricity. Wood pellets, made up of compacted lumber and wood waste, are the matter frequently utilized in this process. According to the Partnership for Policy Integrity, burning woody biomass releases stored carbon into the atmosphere, emitting more greenhouse gas emissions than coal. 

A Brief History of Woody Biomass

Up until around 1870, wood was the dominant source of energy and heat for people in the United States. However, issues related to deforestation and the widespread introduction of coal led to its replacement of biofuels as the dominant source of energy. By the 1950s, electricity and natural gas replaced the role that wood had previously played in American homes. Before the Clean Air Act — which introduced more stringent air pollution control regulations — open burning of mill waste was prevalent.  

In the United States, biomass has had a resurgence in recent years, due to concerns about the negative impact of fossil fuels on the environment. It is becoming increasingly popular in Europe, because of its label as a green and renewable energy source. The burning of wood pellets is now replacing coal in many European countries, with the United States serving as a net exporter of biomass energy, meaning that it exports more of this material than it imports. In 2021, biomass provided around 5 percent of the total primary energy consumption in the United States. The global biomass power market is projected to exhibit a compound annual growth rate (CAGR) of 6 percent from 2022 to 2030.

History of Woody Biomass in Humboldt

There is only one currently running biomass power plant in Humboldt, located in Scotia and run by the Humboldt Sawmill Company. Under a Redwood Coast Energy Authority (RCEA) Power Purchase Agreement, the power generated from the plant is sold to Pacific Gas and Electric (PG&E). The project was commissioned in 1988, and has been running continuously since then. The biomass fuel used comes from the waste produced by the local lumber manufacturing economy that has been operating for more than 100 years. 

According to a summary entitled “Biomass Power in Humboldt County” prepared by Michael J. Furniss as part of the bioenergy strategies included in RCEA’s 2019 RePower Humboldt strategic plan update, “The local electric power provided by biomass plants would otherwise come from the PG&E natural gas plant in King Salmon until additional local renewable generation is built and brought online.” The RePower Humboldt plan was originally prepared by Cal Poly Humboldt’s Schatz Energy Center for RCEA in 2013. This plan and its 2019 update have since guided the Community Choice Energy (CCE) board’s decisions about Humboldt County’s energy mix. The original plan was created to develop local energy resources, with biomass factoring heavily into this agenda due to its abundance and ability to generate electricity on demand. Whether or not this is the right course of action has been a matter of significant debate for the community.

Why It’s Championed

Like nuclear power, proponents argue that biomass power can be a bridge solution for climate change, helping in the intermittent period before solar and wind power are more developed. It is often considered a net-zero transaction regardless of source, as woody waste would release carbon during its natural decomposition anyway, and live trees that are cut and burned can be replaced by new vegetation that would theoretically be able to absorb the same quantity of carbon dioxide released during the process. Proponents also assert that with increasing wildfires, woody waste that is left in the forest can act as fuel. For this reason, proponents believe burning the waste for energy is a more helpful and safe option. Additionally, because biomass matter can be continuously replanted, it is considered reliable and renewable by some entities. 

Why It’s Controversial

Although sometimes framed as carbon neutral, concerns about deforestation and the carbon accounting system developed under the 1997 Kyoto Protocol have many environmentalists questioning the sustainability and cleanness of woody biomass energy. In a research paper by the Chatham House looking at the impacts of this source on the global climate, author Duncan Brack wrote, “In order to ensure consistency and avoid double-counting, the IPCC determined that countries should report emissions from biomass combustion only in their land-use sectors. It is this categorization of emissions that has led many policymakers to perceive biomass as a carbon-neutral energy source (although this was not the IPCC’s intention).” 

Although proponents claim that most lumber waste and residue is unusable and would decompose and release carbon anyway, critics say that the timeline of these processes is not taken into account. While these materials would release carbon dioxide by decomposing naturally, this process would normally occur over a much longer period of time, with a portion of the released carbon becoming incorporated into the soil. Reforestation also takes a significant amount of time, as young trees take decades to potentially offset the carbon that was released by their predecessors. 

Additionally, biomass energy has also been criticized for the harmful pollutants that can be released by the power plants. EcoNews contributor Wendy Ring wrote about the negative health effects of the Scotia plant in the February issue, expressing concern about the health costs and the lack of enforcement of regulations that are supposed to protect the community. Although respiratory issues are an obvious concern associated with breathing in harmful pollutants, heart attacks, birth defects, and neurodegenerative diseases can also be associated risks. Humboldt Sawmill Company has since published a response to Rings’ article, making alternative claims about their compliance and the effects of the emissions on the community. 

There are also concerns that the RePower plan developed in 2013 is outdated, as energy technologies and markets have advanced, making bioenergy less necessary to fill any gap. RCEA released an updated RePower plan in 2019, reaffirming their goal to procure local biomass energy. However, they also included their desire to investigate the impacts of biomass emissions.

Composting mill waste has been proposed as an alternative to burning it, because proponents assert that it is cheaper and the net emissions are significantly less. In 2021, 500 scientists wrote a letter to global leaders that urged them “…not to undermine both climate goals and the world’s biodiversity by shifting from burning fossil fuels to burning trees to generate energy.”

These scientists suggest solar and wind as alternatives to truly decrease warming, both of which will be explored in future articles in this series.