There is tremendous debate and controversy over biomass, and in some locations there is significant grassroots opposition to biopower projects. A recurring question is whether utilization of biomass for energy production is carbon neutral. What are the actual benefits for helping solve the global warming crisis? Scientific research is continually refining our understanding of these questions. With each new study or paper, we get a clearer picture of just where and how biomass is good for the climate. We at SACE constantly track the latest news and information, because when biomass doesn’t actually help the climate, it’s not worth our efforts.
Visiting with relatives over the holidays, I was asked, “is biomass electricity a smart thing to do?”
Related to this question, an interesting news item caught my attention a few weeks ago.
Well, just what is it about renewable biomass energy that is spurring these “brainy” cities to support its development? Here’s a few of our thoughts:
Stored Solar Energy? Valuable.
Several of these cities use biomass energy for district heating – a highly efficient use of renewable biomass. Because trees and other plants store solar energy in the form of biomass as they grow, district heating is a smart way to release the sun’s warmth when you need it (such as during cloudy winters in Seattle, WA or St Paul, MN). Combined production of heat and power (CHP) is a similarly efficient use of biomass.
Here in the South, though, we don’t have as much use for all that heat-energy. Southerners use much more energy on cooling and refrigeration than heating. While it is certainly possible to use biomass to drive chillers, additional research and testing is needed to asses the economics of biomass-fired combined heat, power, and chilling.
Biomass-heating and biomass-CHP are clearly helpful in fighting climate change — even in places where trees grow very slowly. Both technologies were highlighted in the recent Manomet study as being useful in the fight against climate change, with very short timelines before “payback of the carbon debt.”
Healthy Forests, Ecosystems, and Soils? Precious.
There is also value in the intelligent and careful use of biomass for improving the health of our Southeastern forests, special ecosystem restoration, and in improving the health of soil. If done right, creating new markets for biomass for energy can help in all three of these areas.
Consider our Southeastern forests. Tens of millions of acres of private woodlands in NC, SC, GA, FL, and TN are in degraded condition. Woodland owners describe decades of shortsighted management, where – for example – the very best, strongest, tallest trees have been cut, leaving behind the worst specimens. This practice of “high-grading” is like the Bizarro world‘s version of Darwin’s natural selection: The least vigorous specimens are left to multiply, and we are left with the worst genetics possible. This means the landowner is left with stands of timber having little economic value; If the landowner can’t keep the land in production of marketable wood, the pressure to sell-out for development is increased. Having new energy markets for low-value biomass will help heal the history of poor management.
Ecologists and wildlife specialists tell me of restoration projects they hope to undertake – like expanding the majestic longleaf pine ecosystems. These are projects that will necessitate removal of the un-sellable trees, brush, and invasive plants. This “junk” may not have high ecological value, and it may be worthless to the local pulp-mills and lumber mills, but it does have value for energy. Long-standing biomass energy facilities like Burlington, VT’s McNeil Generating Station have delivered decades of value to their communities by providing an incremental economic boost to woodland ownership and struggling wood products industries. That’s smart (and another reason it’s on the list!).
Biomass is also valuable in that it can feasibly sequester carbon while releasing energy. That’s right, biomass can go carbon negative. This is where the biomass is heated to release the energy, while creating a durable form of charcoal that has value as a soil amendment, called biochar. It’s a pre-commercial technology that still needs lots of work, but it’s already showing impressive benefits to soils, increasing crop productivity, and reducing nitrous oxide emissions from soils. Nitrous oxide is a greenhouse gas 300 times more powerful than carbon dioxide at forcing climate change, so slowing these emissions is extremely valuable to our planet.
Pushing Aside Fossil Fuels? Priceless!
Biomass is also valuable in that it can immediately displace coal when co-fired in power plants. One recent study collaborated by Duke University and NCSU researchers showed “biomass can achieve significant greenhouse gas reductions” by maximizing woody waste cofiring with coal in the Southeastern United States.
In addition to cofiring, we think that smartly designed new-built biomass power plants will play a role in meeting strong goals for renewable energy. Biopower can also be a direct substitute for coal- and natural gas-fired electricity — as smart grid technology is developed and refined to manage the variability of solar photovoltaic and wind power.
The ability to displace fossil fuels in the near term is one of the greatest values of biomass, as reinforced by the famous climate scientist, Dr James Hansen, in this recent quote:
An important part of a diverse energy mix
As we transition towards a cleaner, lower-carbon economy, biomass is also valuable as one part of a diverse mix of energy sources, including efficiency (first and foremost). From the perspective of the electric utilities, the value of biomass electricity is the fact that it can be dispatched, and that it has high availability. To “dispatch” a generator means you can turn a biopower plant off and on when you need it, and “availability” means it runs reliably, between 85% and 90% of the hours of the year. Among renewables, this is valuable because biomass can then provide support for the time when the wind is not blowing and the sun is not bright.
The Hard Choices
Today very few electric utilities in our region have a practical understanding of utilizing a smart grid that allows solar and wind to play major roles. The utilities’ job is to constantly balance generation sources with changing demand. Each day, as millions of people arrive at work, flick on the lights, turn-on computers, crank up the machines, adjust the thermostat, etc., demand for electricity changes. And even if the blowing of the wind or the shining of the sun do not coincide with these demands, the electric utility must still deliver electrons into the grid.
In very simple terms, utilities rely upon massive centralized generators to meet the all-day electricity demands, such as factories, office lighting, heating and air conditioning. These are demands that tend to remain level over time, and these demands are typically met today with coal-fired electricity, nuclear power, and hydroelectric dams.
As the utilities learn how to run a smart grid, and once they begin building it (both things easier said than done), we will be able to use lots of solar and wind power. Afterall, the wind is always blowing somewhere. And as the utilities and electricity consumers begin serious investments in energy efficiency, we can reduce demand for all baseload electricity (coal, nuclear, hydroelectric, and biopower).
But in the meantime, in order to shut-down the most polluting coal plants — the old ones built in the 1950’s and 1960’s — then we need new baseload generation to replace them.
Smart bioenergy can have an important role in meeting that demand. In the Southeast, scientists tell us that biomass is an abundantly renewable resource. This is why SACE is working hard to learn (and help others learn) the complexities of sustainable bioenergy. We’ve got to ensure we do it right and maximize the benefits, as these “brainiest” cities are doing.
The magnitude of the challenge is enormous. Even reaching the goal of 25% electricity from renewables by 2025 is ambitious. Based on our analysis we’re convinced that reaching this goal will be much more difficult and expensive without biomass electricity. One day, we humans will provide for 100% of our energy needs using renewables. And perhaps someday we will achieve this without biopower. Until then, is smart bioenergy right for your smart city’s energy mix?