Speaking as somebody who lived for two years in Southwest Virginia, I can testify that coal is filthy stuff.
It’s filthy when it burns, but it’s also filthy to dig up, filthy to process, filthy to transport, and it leaves behind filth in the ground, the water, the air and everybody’s lungs.
Coal made the Industrial Revolution possible, thank you very much, but we’ve outgrown it. Which leads us to Merrimack Station in Bow, the state’s biggest coal-fired power plant.
Merrimack Station is an efficient powerhouse of an electricity generator, providing power on demand in a way that wind and solar can’t, firing up whenever we need to top off the grid with fresh electrons.
Its 439 megawatts of baseload capability have become even more important to New England in recent years, what with the departure of other coal-fired plants, notably the Salem Harbor and Mount Tom plants in Massachusetts, and the Vermont Yankee and (soon) Pilgrim nuclear power plants.
But Merrimack Station’s future is up in the air thanks to the power system’s move toward less disgusting fuels. Since 2010, nearly one-third of the U.S. coal fleet has shut or has planned to shut, according to reports, which is the main reason that carbon pollution from the electric sector is projected to be lower than any time since 1995.
Merrimack Station also faced deregulation: Eversource wants to sell it, as New Hampshire finishes its long-delayed move away from the old way of structuring our utilities. Now’s the time to decide on its future.
But closing Merrimack Station would cause a lot of problems for New England’s grid, not to mention the roughly 100 people who work there and the town of Bow, which depends on its property taxes. How can we keep it operating?
So here’s my idea: Make it burn locally sourced wood instead of coal.
Eversource (in its PSNH days) did just this in 2006 at one of the three 50-megawatt units at Schiller Station in Portsmouth, which continues to burn chips today. Many coal-to-wood power plant conversions have happened in this country and overseas.
Instead of spending money on coal, we’ll give money to New England wood-product companies, and we’ll stop contributing to long-term climate change.
Brilliant, right? Only problem: It won’t work.
“You and I could create a scenario where this works very well, but if we tried to take it to the market, it would fall apart,” said Eric Kingsley, a partner at Innovative Natural Resource Solutions in Antrim, when I ran my scenario past him.
Part of the issue is technical, he explained.
Merrimack Station is a pulverized coal plant. The coal is crushed into a powder and sprayed into the furnace. Schiller has stoker grate technology in which coal is put in the plant and burned (if I may simplify outrageously).
Schiller Station can burn wood chips and certain other wood debris. Merrimack Station, however, would have to burn compressed wood that could be pulverized, meaning pellets.
“It’s like the pellets you buy in a bag at Home Depot. But it would be a huge bag,” Kingsley said.
Doing a “very back-of-envelope calculation,” Kingley estimated that turning just 10 percent of Merrimack Station’s output into wood (it’s common for power plants to burn both coal and wood at the same time) would require some 75,000 tons of pellets a year.
The state’s major pellet producer, New England Wood Pellet in Jaffrey, makes about 100,000 tons of pellets a year, so converting just a small part of Merrimack Station would basically use up all of the output, much to the irritation of its other customers.
So we’d have to import pellets, lots and lots of pellets.
“The bigger plants in Europe and Ontario have very long supply chains. They get their wood pellets delivered in bulk, in tanker ships or via rail,” said Kingsley.
That problems can be overcome, although it would be hard. The real deal-killer, Kinglsey said, is financial.
“Biomass stand-alone electric plants rely on REC certificates,” Kinglsey said, referring to Renewable Energy Certificates, which are given to non-fossil fuel and non-nuclear plants as a production incentive. RECs recognize the environmental benefits of clean energy and can be thought of as a reverse tax: Rather than putting a negative value on dirty power, it puts a positive value on clean generation.
RECs can be bought and sold and have proved a valuable tool in developing renewable energy industry, but that means their value is a function of supply and demand. Too many in the market at once drives down the value.
“In New Hampshire, there isn’t enough space in that market, for the next five years or so, to accommodate something like co-firing at Merrimack. They would all go to it, which would swamp the market and make them worthless for everyone,” he said.
As a result, nobody would finance the conversion, he said.
A more likely scenario is to convert Merrimack Station into a natural gas-fired plant using a pipeline nearby. Liquid fuels are already part of its mix, since the site has two 20-megawatt “peaker plants” which burn jet fuel to very quickly add power to the grid when shortages loom, and Merrimack Station itself burned oil before that got too expensive in the 1980s.
The Salem Harbor coal-fired plant is converting to gas at a cost of (gulp) $1 billion, while some folks are talking about turning the shut Vermont Yankee into a natural gas power plant, although that faces a lack of pipelines.
In short, it seems my idea of turning Merrimack Station into the source of livelihood for New Hampshire lumberjacks amid sustainable North County forests is woefully naive. We should continue to develop biomass energy to make use of a resource that Northern New England possesses in spades, but reality tends to be a lot more difficult than it looks from afar.
(David Brooks can be reached at 369-3313, dbrooks@cmonitor.com, or on Twitter @GraniteGeek.)
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Look at opg atikokan as a reference case. Pellets are made in the community causing secondary employment and enabling the 100 percent displacement of coal.
For the confused (like me), that refers to Atikokan station in Ontario.
Hi
Interesting article that could be expounded upon quite a bit with regard to the fuel source side as well as technology integration at the Bow plant. There is a qualitative and quantitative side to this that is often overlooked in terms of sustainability as well as local ( regional ) sources of energy that insulate “us” from commodity markets often manipulated at great cost to the consumer. Biomass Combustion Systems is a Worcester MA based company that does all its manufacturing in NH so I feel very connected to the issue of NH energy security, which is greatly at risk currently. I appreciate your writing this article but also wish we could have more discussion about something just so utterly important to us now and for generations to come. I would love to offer any comment or dialogue you would feel beneficial to the objective of biomass conversions or the greater conversation of ” why not biomass in NH? “. I thank you in advance for taking the time to read this and respond.
Mark Arbeene
Biomass Combustion Systems.
Please forgive type-O on the website address. I corrected it with this post. Thanks.
David, You sure this is enough nat gas in the area to fire for 439 MWs. Nat gas does not produce as many btus as coal. So the boiler will have to fire harder to get the same steam generation for the turbine. However there isn’t a coal yard stock pile or dozers needed to push coal, no beltlines to move coal into the plant, no coal mills, no bag house or precip, no scrubber, no bottom ash or fly ash or an ash pile.
But there are prodigious amounts of CO2 emitted, totally uncontrolled and unsequestered, by natural gas-fired plants. Throw in significant amounts of NOx and fugitive releases of methane as well, and you have a witches’ brew of harmful effluents being thrown out into the air. Less than coal, sure, but if you go all-in on natural gas, which seems to be the path being taken by New England, you’re still going to be throwing out choking amounts of greenhouse gases.
Two points. First, I find it ironic in the extreme that biomass plants are allowed to issue RECs. Supposedly RECs are to encourage “clean energy” technology. Yet biomass plants have the highest carbon output per kwh of almost any technology. Advocates will make the “zero net carbon” argument but that ignores the very real issue of time constants. It takes a tree decades or even centuries to sequester the carbon it contains. Burning its wood in a biomass plant throws all of that carbon back into the biosphere in seconds. That builds up the amount of carbon in mobile form (CO2) to a much higher concentration over the short term, the rate of buildup being far faster than natural processes can re-absorb and sequester once again.
Second, I will agree with your point that conversion to natural gas is problematic because of the same issue plaguing New England in general, which is lack of pipeline capacity needed to meet demand, which is growing as the region seems to be putting all of its eggs into the natural gas basket. Burning more natural gas is the last thing you need. The best solution would be to keep Vermont Yankee and Pilgrim station operational. A fair PPA negotiated with each of them (Vermont Yankee offered one with power sold at below-market rates but all utilities in Vermont were ordered to refuse it), one that recognizes the value of 90+% capacity factor, unmatched reliability, and zero-carbon, zero-emissions, would return those plants to profitability. Doing so would require no construction of pipelines, no new transmission lines, no conversion of power plants, no increased emissions of damaging CO2 and methane. It would have the added benefit of keeping 1,200 of your fellow citizens employed and working in your area, paying taxes, and contributing to their communities. Sounds like a good deal to me.
If biomass replaces fossil fuel, IMHO, it is indeed clean energy. 20-30 years is not an unreasonable time scale to consider carbon cycles in the atmosphere, especially when compared to 20-30 million years for fossil fuels. You have to make sure that the harvesting doesn’t cause more problems than it solves, of course, but nobody tries mountaintop removal to get trees.
It depends on what kind of biomass replacement you are talking about. Certain kinds of biota are short-cycle, things like switchgrass and some kinds of trees. But I am guessing people in New England will not view favorably covering hundreds of square miles of natural fields and farmlands with switchgrass. Similarly, tree farms can grow some types of trees relatively quickly, but bear in mind that tree farms are not old-growth woodlands, and replacing natural forest with tree farms will likely result in a degraded environment.
There was a study done some time ago, I can’t remember if it was EAI or EPRI, one of those organizations anyway, that concluded if you tried to replace a significant fraction of electrical generating capacity with (wood) biomass, you’d end up cutting down all the forest lands in New England within a few years. Replacement times for old-growth forest are very long. Not as long as fossil fuels, but oil and coal at depth are not the CO2 sinks on the surface that native flora are. And remember there is a fairly firm consensus that a lot of the increased CO2 levels we are seeing in the atmosphere today are a combination of both emissions from combustion or carbon-based fuels, and the loss of CO2 absorption by trees and plants, which is caused by the destruction of forests by clear-cutting in third-world countries, some of which is to clear land, but some of it is to harvest fuel.
Oh, and contra Staghounds, netiher “shipped across the ocean” nor “island made of coal” are good counterarguments (shockingly).If there’s any bulk-hauler going across from the US to Britain/Europe empty, it makes more economic sense to make a pittance hauling pellets than to deadhead.Cargo vessels, both land and sea, always prefer even a low-paying cargo to running empty, because as I understand it even with sea vessels, the marginal difference in operating cost for empty vs. full is low enough to justify nearly any cargo.And coal is such nasty stuff to mine and burn from a real non-hippie-CO2-bullshit point of view that it’s probably good to replace it with wood in the interim required to build a lot of nuclear plants.(Again, see “why hippies ruin everything and are counterproductive” re. their opposition to nuclear power.)
I have a solution for Shiller and use of wood our firm has an order that can be the answer. We are looking into the auction specifically Shiller site.will be available to discuss with concerned citizens