Can Renewable Biomass Power a Coal Plant?
In the prevailing quest for low emission renewable energy sources, a classic is making its way back into the mix. Man has been burning wood to cook food and keep warm for thousands of years, but wood and other forms of biomass lost favor in generating energy as fossil fuels like coal and oil powered the industrial revolution forward. Now, energy companies are rethinking biomass as perhaps a more desirable alternative in terms of emissions and regenerative capacity to run coal fired power plants.
United States utilities giant Dominion is actively planning to convert three of its aging Virginia coal plants to run on waste biomass sourced from local timber operations. The switch would boost the state of Virginia’s renewable capacity by 150 MW and increase the efficiency of two of the plants, allowing operation 90 percent of the day versus 25 percent while fueled with coal.
"The converted units will provide low-cost, renewable, base load energy, while promoting economic development through the use of a locally produced fuel," says Dominion Generation CEO David Christian.
In fact, Dominion’s transition to biomass from coal would create 250 direct and indirect jobs and cost ratepayers only 14 cents per month.
There are several reasons to make the switch to biomass. Economically, waste biomass can be significantly cheaper than coal, especially if the source is relatively nearby the power plant, thus reducing transportation costs. Also, EPA mercury and air toxin regulations currently exclude biomass, and with coal power under the regulators’ microscope, an energy source with less regulation is an obvious attraction to businesses. However, if biomass were substituted for coal on a nationwide scale, it is safe to assume that the regulations would catch up quickly.
The United States burns roughly 1 billion tons of coal each year. Since biomass has a lower BTU content than coal, it would require roughly 1.5 billion tons of biomass to completely transition coal to biomass. According to a 2005 study by the Department of Energy and Department of Agriculture, there are 368 million dry tons of forest resources and 998 million dry tons of agricultural resources that account for a total of 1.366 billion dry tons of biomass generated in the U.S. every year. Not quite enough to make a full transition, but certainly enough to consider incorporating biomass into the mix.
So what are the environmental advantages of using biomass over coal? Well, no more mountaintop removal for one. Biomass is regenerative, derived from plant matter. That doesn’t necessarily mean that forests will be cut down acre by acre to supply biomass for energy. Biomass can come from waste streams, such as food byproducts, timber operation leftovers (as sought by Dominion) and even landfill.
Over time, the use of biomass in place of fossil fuels can lower atmospheric greenhouse gas levels. Emissions from burning wood are initially higher than fossil fuels; however, the regrowing of biomass acts to sequester carbon, unlike fossil fuels. A 2010 study from the Manomet Center for Conservation Sciences revealed that the carbon debt of biomass takes more than 20 years to pay off. So essentially, biomass is better in the long-run than short term. However, when you factor in things like oil well blowouts, coal mountaintop removal, and polluted waterways, the environmental impact of biomass comes out on top comparatively.
The Oak Ridge National Laboratory claims that realistically, the United States could convert 26 gigawatts of coal capacity to renewable biomass by 2020. The most realistic implementation of biomass in coal plants will likely first be seen in the mixing of biofuels and coal in the same boiler. This maximizes overall efficiency versus solely utilizing biomass.
Biomass is not as clean as other renewable energy sources like solar or wind power; however, it is the renewable factor that places biomass well above coal. Coal reserves dug out of the ground will eventually run out, leaving abandoned mines and ravaged landscapes in the wake. Forests and plants, on the other hand, can be regrown. Even better, agricultural biomass, such as cornhusks, nutshells, and other non-edible plant matter can close the loop between the agricultural and energy sectors, providing both food and affordable electricity.
Carbon dioxide removal revenues worth £2bn a year by 2030
Carbon dioxide removal revenues could reach £2bn a year by 2030 in the UK with costs per megatonne totalling up to £400 million, according to the National Infrastructure Commission.
Engineered greenhouse gas removals will become "a major new infrastructure sector" in the coming decades - although costs are uncertain given removal technologies are in their infancy - and revenues could match that of the UK’s water sector by 2050. The Commission’s analysis suggests engineered removals technologies need to have capacity to remove five to ten megatonnes of carbon dioxide no later than 2030, and between 40 and 100 megatonnes by 2050.
The Commission states technologies fit into two categories: extracting carbon dioxide directly out of the air; and bioenergy with carbon capture technology – processing biomass to recapture carbon dioxide absorbed as the fuel grew. In both cases, the captured CO2 is then stored permanently out of the atmosphere, typically under the seabed.
The report sets out how the engineered removal and storage of carbon dioxide offers the most realistic way to mitigate the final slice of emissions expected to remain by the 2040s from sources that don’t currently have a decarbonisation solution, like aviation and agriculture.
It stresses that the potential of these technologies is “not an excuse to delay necessary action elsewhere” and cannot replace efforts to reduce emissions from sectors like road transport or power, where removals would be a more expensive alternative.
The critical role these technologies will play in meeting climate targets means government must rapidly kick start the sector so that it becomes viable by the 2030s, according to the report, which was commissioned by government in November 2020.
Early movement by the UK to develop the expertise and capacity in greenhouse gas removal technologies could create a comparative advantage, with the prospect of other countries needing to procure the knowledge and skills the UK develops.
The Commission recommends that government should support the development of this new sector in the short term with policies that drive delivery of these technologies and create demand through obligations on polluting industries, which will over time enable a competitive market to develop. Robust independent regulation must also be put in place from the start to help build public and investor confidence.
While the burden of these costs could be shared by different parts of industries required to pay for removals or in part shared with government, the report acknowledges that, over the longer term, the aim should be to have polluting sectors pay for removals they need to reach carbon targets.
Polluting industries are likely to pass a proportion of the costs onto consumers. While those with bigger household expenditures will pay more than those on lower incomes, the report underlines that government will need to identify ways of protecting vulnerable consumers and to decide where in relevant industry supply chains the costs should fall.
Chair of the National Infrastructure Commission, Sir John Armitt, said taking steps to clean our air is something we’re going to have to get used to, just as we already manage our wastewater and household refuse.
"While engineered removals will not be everyone’s favourite device in the toolkit, they are there for the hardest jobs. And in the overall project of mitigating our impact on the planet for the sake of generations to come, we need every tool we can find," he said.
“But to get close to having the sector operating where and when we need it to, the government needs to get ahead of the game now. The adaptive approach to market building we recommend will create the best environment for emerging technologies to develop quickly and show their worth, avoiding the need for government to pick winners. We know from the dramatic fall in the cost of renewables that this approach works and we must apply the lessons learned to this novel, but necessary, technology.”
The Intergovernmental Panel on Climate Change and International Energy Agency estimate a global capacity for engineered removals of 2,000 to 16,000 megatonnes of carbon dioxide each year by 2050 will be needed in order to meet global reduction targets.
Yesterday Summit Carbon Solutions received "a strategic investment" from John Deere to advance a major CCUS project (click here). The project will accelerate decarbonisation efforts across the agriculture industry by enabling the production of low carbon ethanol, resulting in the production of more sustainable food, feed, and fuel. Summit Carbon Solutions has partnered with 31 biorefineries across the Midwest United States to capture and permanently sequester their CO2 emissions.
Cory Reed, President, Agriculture & Turf Division of John Deere, said: "Carbon neutral ethanol would have a positive impact on the environment and bolster the long-term sustainability of the agriculture industry. The work Summit Carbon Solutions is doing will be critical in delivering on these goals."
McKinsey highlights a number of CCUS methods which can drive CO2 to net zero:
- Today’s leader: Enhanced oil recovery Among CO2 uses by industry, enhanced oil recovery leads the field. It accounts for around 90 percent of all CO2 usage today
- Cementing in CO2 for the ages New processes could lock up CO2 permanently in concrete, “storing” CO2 in buildings, sidewalks, or anywhere else concrete is used
- Carbon neutral fuel for jets Technically, CO2 could be used to create virtually any type of fuel. Through a chemical reaction, CO2 captured from industry can be combined with hydrogen to create synthetic gasoline, jet fuel, and diesel
- Capturing CO2 from ambient air - anywhere Direct air capture (DAC) could push CO2 emissions into negative territory in a big way
- The biomass-energy cycle: CO2 neutral or even negative Bioenergy with carbon capture and storage relies on nature to remove CO2 from the atmosphere for use elsewhere