Myths about biopower abound: from the fear that it is deforesting the US, to the exaggeration of how fast it really grows. Does bioenergy hold potential as a global warming solution? In this first installment of three on bioenergy, Ben Paulos looks for the facts.
As the world grapples with ways to prevent catastrophic global warming, all eyes are looking toward renewable energy as a solution. While wind and solar power are making rapid progress, and have enormous potential, there is ongoing debate about whether they are sufficient by themselves to displace fossil fuels in power production, transportation, heat, and all the other things we do with energy.
While there is much discussion about nuclear power and energy storage, less is said about energy from biomass. Bioenergy is still the largest source of renewable energy, leading hydro, wind and solar, but it is probably the most controversial and least understood form of renewable energy.
To remedy the situation, we will explore the status of bioenergy and its potential as a global warming solution. It’s a complicated topic, so it will take three installments to cover. In the first, we address the many myths about bioenergy, and seek the facts. The most complicated and contentious issue will be the subject of the second installment: how to measure the global warming impacts of bioenergy. We will conclude by exploring the future of bioenergy.
Our goal is not to argue for or against biopower, but to present an understanding of the constraints, the barriers, and the pitfalls of bioenergy – as well as the potential and the benefits.
While wind and solar energy attract daily headlines due to their rapid growth, recent developments have brought increased attention to the slow-moving biomass power industry. Increased exports of wood pellets from the US to Europe for energy production have raised concerns by forest protection groups in the Southeast, while a proposal in the US Senate about carbon accounting for biopower has fired up national green groups.
This opposition has promoted a number of myths about biopower: that it is big now and rapidly growing, that it is deforesting America, and that it has worse carbon emissions than coal power.
The truth is simpler in some ways – and in the case of carbon emission accounting, much more complex. (We will discuss the complicated issues around carbon accounting in the next installment in this series.)
To judge whether biopower is good or bad we must first understand how the industry operates, where the feedstocks come from, and the economic potential for growth in the future.
Basic facts about Bioenergy
Bioenergy consists of many different feedstocks, processing technologies, and end products, including heat, electricity, and motor fuels. According to REN 21, bioenergy makes up 14 percent of total global energy consumption, with 12.6 percent for heat and almost 9 percent from “traditional” sources, such as cooking and heating in the developing world.
Biomass for electricity production (biopower) is small, only 2 percent of world production, and only 1.6 percent in the US.
Myth: Biopower is deforesting America
Biomass critics warn that the biopower industry is deforesting America, often showing photos of recent clear cuts. The truth is that biopower has been for decades the waste disposal arm of the wood products industry. Loggers sell their wood for lumber, furniture, and paper, much higher value products, with residues burned for energy. Only recently, with the advent of pellet production for export to Europe, have trees been cut specifically for electricity production.
Because the byproducts are used for power production, rather than wasted or burned in the field, they displace coal, gas, and oil, thus reducing carbon emissions.
In fact, two-thirds of electricity from biomass is made by wood mills for their own use, with most of the rest by independent power producers in forest and farming regions with ready access to waste streams. Biopower must use low-cost wastes, since even with free fuel it is expensive compared to natural gas, wind, and even solar power.
Recently, falling demand for paper and a slowdown in new construction due to the housing market collapse have cut demand for wood, creating a build-up of forest inventory. In other words, trees are growing faster than they are being cut in most regions of the US.
Recycling rates for corrugated cardboard, newspaper, and miscellaneous mixed paper such as office paper have doubled since 1990, now accounting for two-thirds of US paper production. At the same time, the growth of electronic communications has cut total demand for paper from over 100 million to less than 80 million tons. As a result, virgin paper production has been cut in half over the last 25 years.
And as fewer trees are cut, there are fewer residues that can be used for energy, cutting off supplies for US biopower plants.
The only part of the industry that is expanding is producing wood pellets to export to Europe, for use in heat and power systems. The lack of market for timber and paper, and the resulting wood glut, is leading some forest owners to cut trees specifically for the pellet market.
According to a study by Forest2Market, an industry consultant, pellet exports from the Southeast in 2014 amounted to 3.6 million tons, produced by taking 6.1 million tons of wood out of Southern forests, about 3.8 percent of all wood cut in the region that year.
Meanwhile, Southern forest inventory increased by 1.2 billion tons between 2000 and 2014. Fourteen pulp and paper mills closed, replaced by 19 new pellet export mills.
The South accounted for 40 percent of Europe’s demand for imported pellets. The study estimates that if demand increased to meet EU renewable energy goals, pellet exports from the South could rise to over 10 million tons per year by 2025, thus requiring 25 million tons of harvest, or 10 percent of total logging in the region.
That would be equal to harvesting around 90,000 hectares of pine plantations per year, or the net annual growth from 2.1 million hectares, according to a recent report commissioned by the EU. The Southeast has 89 million hectares of forested land, the same as it has had since the 1940s, according to the report.
Myth: Biopower is rapidly growing
To make the case for the imminent threat of forest damage, some bioenergy critics say that biopower is a rapidly growing energy source in the US too, pointing to forecasts from the US Department of Energy. They argue that biomass tax credits should be repealed and biopower should be excluded from state renewable energy standards.
The truth is that biopower production has been largely flat in the US for 30 years, even as wind and solar have boomed, and new forecasts predict more of the same.
Recent data from EIA show that solar surpassed biomass power for the first time in May 2016, while wind passed it in 2008. Prices continue to drop for wind and solar, making it dubious that biopower will see significant growth in the future as they compete for market share and to meet state renewable power standards (RPS).
While wind and solar growth has been driven by state and federal policies, biopower shows little positive interest from policymakers. The federal production tax credit for biopower is worth only half of what it is for wind. And when wind and solar credits were extended last year by Congress, biopower, geothermal, and other renewable sources were left out. While every state RPS allows some form of biopower, Massachusetts made typical biopower plants ineligible for their standard, forcing the shutdown of two plants in Maine.
A significant problem is that the non-energy benefits of biopower are typically not given any value by public policies. While state and federal agencies spent $1.2 billion on fire suppression in California forests over the last three years, there are no systematic programs or incentives to enable power plants to play a role in that process.
The California forest crisis did finally spur action this year. An estimated 102 million trees have died due to drought and beetle infestations in the state, creating a huge risk for catastrophic forest fires. New legislation approved in October will support 125 MW of existing power plants that were at risk of shutting down. Research by UC Berkeley shows that burning this wood in power plants would drastically reduce particulates, nitrogen oxides, and other pollutants compared to open burning or even the portable incinerators currently used by the forest service.
Indeed, the most common story in biopower is that plants built in the 1980s, under a federal law known as PURPA, are shutting down as their contracts expire and they are no longer competitive. This is exacerbated in some regions by the financial problems of the US wood products industry, driven by lower demand for lumber and paper. As wood mills shut down, their waste stream ends, cutting off fuel to power plants.
California, the state with the most biopower production, hit a peak of 66 plants in the early 1990s, but has only about 30 operating now. Farmers are concerned that the loss of biopower plants, combined with strict limits on open burning, will leave them with no options for dealing with orchard trimmings and other ag waste in the polluted Central Valley.
Almost no new plants are being built, according to the Biomass Power Association, and prospects are not good for reopening the ones that have closed. America’s largest independent biopower producer, Covanta, got out of biopower altogether earlier this year, shutting down the last of their eight plants.
Myth: Biopower will grow rapidly in the future
The grim reality in the industry today stands in stark contrast to the many years of optimistic projections by the US Energy Information Administration, the forecasting and data collection arm of DOE.
In their Annual Energy Outlook, EIA consistently predicted steady growth in biopower, largely in response to state RPS laws. But the stellar results for biopower were largely due to assumptions EIA used in the model, according to Steve Clemmer, director of energy research for the Union of Concerned Scientists.
“EIA’s model had a number of features that limited wind and solar growth,” he explains. “They assumed much higher costs for wind and solar than we’ve seen, and that wind costs would rise over time as the best locations are developed. In reality, wind and solar costs have seen huge price drops.”
“So because the model had to choose renewables to meet state laws, and the costs of wind and solar were inflated, it picked a lot of biopower – much more than we think is realistic.”
Indeed, EIA has been ratcheting down expectations for biopower in recent years (see graph), and improving their treatment of wind and solar. In the 2010 Outlook, EIA expected biopower to increase eight-fold, but lowered the forecast in each successive year. The most recent Outlook sees no growth through 2035, in line with actual trends over the past decade.
“The capital cost of new biopower plants is too high, about twice as much as utility scale wind and solar,” adds Clemmer. “Even existing biopower plants using low cost wood waste and other residues are having trouble competing due to low natural gas prices.”
The industry used to dream of expanding beyond waste streams by using dedicated energy crops like switchgrass and fast growing trees, but high costs have put that out of reach.
The picture in Europe is different, however, as biopower has doubled in the past ten years. European energy policies are more comprehensive, covering renewable heat as well as power. The large number of district heating systems, paired with high efficiency combined heat and power (CHP) plants, are good candidates to convert from coal and oil to biomass.
RPS programs in America don’t differentiate between wind, biomass, and other bulk generators (though do sometimes offer higher credit prices for solar), so low cost wind has dominated compliance.
Only a handful of US states have policies encouraging renewable or low carbon heat sources, a significant gap in US climate policy. District heating systems are also uncommon in the US, while CHP plants tend to run on low-priced natural gas, making conversion to biomass expensive. It is interesting to note that when Massachusetts cut back on their policy support for biomass electricity, they increased support for heat from biomass.
The new concern from biomass opponents is that the Clean Power Plan, the Obama Administration’s plan to regulate carbon emissions in the power sector, will drive a new wave of biopower development in the US. This is especially true if EPA counts biopower as “carbon neutral,” where the smokestack emissions are perfectly offset by regrowing trees.
The complicated issue of carbon accounting will be covered in the next installment in this series, while the future of biopower will be covered in the third.
Bentham Paulos is an energy consultant and writer based in California. His views are his own, and don’t necessarily represent those of any of his clients.