Natural Gas and Nuclear: A Local View

The View from the Corner Office

This month, the CEO of Exelon and the CEO of Entergy both gave speeches about the future of nuclear power. As reported in Platts, John Rowe of Exelon spoke about the Exelon/Constellation merger and looked at the future of nuclear. These are his words:

The Calvert Cliffs-3 project is "utterly uneconomic," Rowe said after a speech at the Bipartisan Policy Center in Washington....

"At today's [natural] gas prices, a new nuclear power plant is out of the money by a factor of two," Rowe said, echoing one of the main points of his speech. ".... It's economically wrong. Gas trumps it," he said.

Well, okay, that's clear.

Meanwhile, Entergy President J. Wayne Leonard was honored by the National Wildlife Federation. National Wildlife Federation Honors J. Wayne Leonard with Achievement Award: Entergy CEO Honored for His Commitment to Gulf Coast Restoration, Addressing Climate Change. Some quotes from National Wildlife's description of that event:

With Leonard’s passion, leadership and strong points of view, Entergy has accomplished the following during his 10 years as CEO:

Entergy became the first US electric power company to establish a voluntary stabilization target for carbon pollution emissions and established a $30 million Environmental Initiatives Fund to support internal and external carbon pollution reduction projects. From 2001–2010, Entergy was 14% below its stabilization goals, achieving emission reductions which were 69 million tons below the goals.

The Time-Picayune reported the awards ceremony, partially reprinted by the National Wildlife Federation:

In an emotional speech to executives of the National Wildlife Federation on Friday night, Leonard said his controversial support for what would amount to a carbon tax stems from his attempt to face his own mortality...

"I can think of no time in history when the planet is in as much peril as it is today," he said. "We were not supposed to be facing the possibility of mass extinctions in anybody's lifetime ... but here we are."

These CEOs have very different views of the future of fossil fuel combustion! However, both Leonard and Rowe are CEOs, with CEO-type obligations. Rowe of Exelon faced building an expensive new nuclear plant, and he walked away from it. While he was walking away, he took the opportunity to lob a few cracks at nuclear. Meanwhile, Entergy is committed to low-carbon power, but Entergy recently announced it is going to buy a 550 MW natural gas plant in Rhode Island. Both Entergy and Exelon own fossil and nuclear units.

Such is the view from the corner office.

The View from the Peanut

My own office is a corner. It's a corner bedroom in my house. My view of fossil fuels and nuclear is more limited than the view of the CEOs, but it is also less constrained.

I have always admired George Washington Carver, a man who protected the soil of the South and prepared many products from peanuts, thereby partially weaning the South from cotton. Oh, and did I mention he was born a slave?

Carver said:“When I was young, I said to God, 'God, tell me the mystery of the universe.' But God answered, 'That knowledge is for me alone.' So I said, 'God, tell me the mystery of the peanut.' Then God said, 'Well George, that's more nearly your size.' And he told me.”

Inspired by Carver, I decided to look at two power plants as the examples of nuclear and natural gas: Vermont Yankee and a local combined cycle gas turbine (CCGT) plant in New Hampshire. Not a Big Picture, just two plants.

My blog post comparing the plants is posted at ANS Nuclear Cafe: Gas and Nuclear: A Comparison of Two Local Plants. The post grows out of the Energy Safari course that just finished. Here's a link to the course blog post about the natural gas plant. The course blog post has many excellent pictures, taken by Bob Hargraves.

The Peanut Draws Her Conclusions

Here are some conclusions about the two plants. For a more complete picture, please see the ANS post and the Energy Safari post.

• The natural gas plant is very new, clean and efficient.
• It doesn't take many people to operate a natural gas plant. This is good (efficiency) but also bad (not a good source of employment, unlike a nuclear plant.)
• The economic choice between natural gas and nuclear is not a slam-dunk, even if Mr. Rowe thinks it is.
• Despite the historically low price of natural gas, and the high thermal efficiency of the CCGT plant, the local gas plant is still forced to shut down more often than it would prefer. Its power is among the most expensive power on the grid. Many times, its break-even price is too high for the grid, and the grid operators don't buy its power.
• The CCGT is a good plant for load-following.
• Choosing between natural gas and nuclear is a false choice, anyhow. They are both reliable sources of electricity.
• Fossil fuels, including natural gas, contribute a lot more to global warming than nuclear does. Despite all the hoopla about global warming, this is not usually taken into account in power choices.

I encourage you to read the ANS blog post, and tell me what you think of my view-from-the peanut.

Think locally, act locally, perhaps?

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Diagram of a turbo-electric COGAS power-plant. Such installations are used stationary and on some ships. 1. Electric generators. 2. Steam turbine. 3. Condensor. 4. Pump. 5. Boiler/heat exchanger. 6. Gas turbine. From Wikipedia article on combined cycle plants

George Washington Carver in his laboratory, photo from Wikipedia.

Biomass In Vermont: It Won't Replace Vermont Yankee

Biomass In Vermont's Future

On September 14, The Department of Public Service (DPS) released a 600 page Comprehensive Energy Plan (CEP) for Vermont. The plan was long, vague, and internally inconsistent.

Instead of tacking the whole thing, environmentalist Chris Matera studied a defined chunk: the plan's recommendations for increased use of biomass for electricity production. Matera wrote an opinion for the Bennington Banner titled Vermont's Plan Misses the Forest. He describes how burning wood for electricity causes air pollution, generates carbon dioxide, and causes deforestation. He asks: So how did increased cutting and burning of forests (called "deforestation" and "pollution" when it occurs in other countries) get re-branded as "green" energy..?."

The CEP sections on woody biomass were confusing. On some pages, the CEP seems to expect only about a 30% increase in electricity from woody biomass in the near future. On nearby pages, the CEP describes "25 x'25", a plan to produce 25% of Vermont's energy by biomass fuels by 2025.

Ignoring the Working Group

Two years ago, the state legislature convened a biomass working group. The group is supposed to report its results on biomass utilization to the legislature in 2012. It is typical of this administration that it is rushing to adopt the Comprehensive Energy Plan before receiving that report.

Is There Enough Biomass, Anyway?

Instead of trying to decipher the CEP statements on biomass, let's look at real examples of biomass plants, and what it would take to expand this type of electricity production in Vermont.

The Springfield Power LLC biomass plant in Springfield New Hampshire is visible to people who drive south on Interstate 89. It is located at exit 12A, not far from New London. The plant makes 19 MW of power, and runs most of the time, only shutting down for maintenance. It sells its power at about 5 cents per kWh, while paying around 4 cents per kWh for its wood. The Springfield plant is well-equipped with NOx and particulate control, and sells its fly ash as a garden amendment.

It also sells Renewable Energy Certificates, and therefore is profitable to run. I visited it with the Energy Safari class. Bob Hargraves wrote a very comprehensive blog post on our visit.

The Springfield plant burns 200,000 tons of wood to make 20 MW of electricity. This about 100,000 cords of wet wood (2 tons per cord).). Chuck Theall, the plant manager, says that the plant calls the grid operator daily, and promises to supply energy. The grid counts on his energy, and if the plant does not operate, it has to pay for replacement power.

Wood-burning plants are heat engines, which means they can be reliable baseload plants, like Springfield Power. The ability of a wood-burning plant to supply baseload power is in sharp contrast to solar and wind renewables, and makes expansion of wood-burning very attractive for an all-renewable energy plan.

How Much Forest Per Megawatt?

In terms of power production, the Springfield plant is tiny. Vermont Yankee makes 620 MW of power. It would require 31 Springfield Power plants to replace Vermont Yankee on the grid. How much forest would this require?

I did research on sustainable forest yields. I could not find answers in a book, so I asked local foresters: "What is the sustainable yield of firewood for an acre of Vermont forest?"

I learned that foresters hate to answer general questions about "Vermont forests" because "Every bit of forest is different." Eventually, I found an approximate consensus: One-half cord per acre is a sustainable yield for most of our forests. As a child, I learned the mantra that you could harvest a cord of wood each year from an acre of forest. Vermont foresters agree that that number was too high.

Half of the Green Mountain Forest for 20 MW

A quick calculation (100,000 cords per year, half a cord per acre) shows that the yield from 200,000 acres is required for a 20 MW plant. To give some context to this number, the entire Green Mountain National Forest is 400,000 acres, and the state of Vermont is 6,000,000 acres. It takes the equivalent of half the harvest of the Green Mountain Forest to make 20 MW of electricity. To make 31 times this amount of electricity, to replace 620 MW of Vermont Yankee with woody biomass power plants--this would mean the entire state would be devoted to raising wood to burn. Six million acres wouldn't even be quite enough.

Expanding our current wood-fired electricity production will be difficult, but not impossible. Replacing Vermont Yankee with wood-fired plants is impossible. Going "25% by 2025" for electricity through woody biomass is close to impossible, especially since power plants must compete with homes and schools for firewood.

The Bigger Picture in the Woods

In the long run, our forests are our joy. Our forests are our foliage season. Our forests eat carbon dioxide from the air, and even sustainable harvest will affect this to some extent. We can add some wood-fired electricity in Vermont, but not much. We cannot get one-fourth of our electricity from our forests. We need to be mindful of competing uses for our woodlands.

And so, we return at last what Matera said in his op-ed: So how did increased cutting and burning of forests (called "deforestation" and "pollution" when it occurs in other countries) get re-branded as "green" energy..?"

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Picture of Chuck Theall of Springfield Power, and Neil Daniels, retired engineer, courtesy of Bob Hargraves, from his post on the ILEAD visit to the Springfield plant.

True North Reports published a more complete version of this article. I thank Rob Roper and True North Reports for the opportunity to reprint the article on my blog.

Picture at upper left is part of the wood pile: approximately two weeks worth of logs, and logs are approximately 1/3 of the wood used. The rest of the wood is delivered as chips.

This post also grew out of an earlier Yes VY post about the biomass plant, specifically from the comment section of that post.

Energy Safari: Energy Efficient Life Sciences Building At Dartmouth

An LEED Building at Dartmouth: Conserving Energy

On October 11, the ILEAD Energy Safari Class visited the new Life Sciences Building at Dartmouth, to see Energy Conservation as well as Energy Production. As usual, Robert Hargraves has an excellent blog post on our visit.

Our tour was led by Joe Broemel, senior project manager at Dartmouth, and Ken Merrow, project manager at Trumbull-Nelson, a construction company. They were knowledgeable and very patient. They had to be patient, because we asked so many questions.

The building is beautiful, and one of its most lovely features is its careful management of run-off rainwater. Roof gardens help cool the building, and a rain garden (shown above right) is part of the run-off-capture system. Captured rainwater will feed the toilet water, the Reverse Osmosis/Deionized Water system that provides lab water, and cooling tower make-up water. The run-off system is expected to save one million gallons of water a year.

Another beautiful feature is the use of daylight lighting when possible. The labs have large windows, providing daylight deep into the lab space. Adjustable lighting makes up for cloudy weather, rather than the "lights on/lights off" format of most buildings.

I thought back to some of the labs I have worked in during my life: well, they just seemed squalid in comparison!

Air Exchanges

It was a truly gorgeous, energy-efficient building, but it seemed to be such uphill work to make it efficient.

For example most energy-efficient buildings have a tight building envelope, and aim at three air exchanges per hour for ventilation. This building also has a tight envelope, but the labs require twelve air exchanges per hour for safety. That twelve-exchange figure does not include the air exhaust demands of the fume hoods: each square foot of fume hood opening requires 100 cubic feet per minute of air flow to protect the workers.

The building deals with the air-exchange problem well, with an enthalpy wheel (air-air heat exchanger) to capture much of the heat from the air the building needs to vent. The enthalpy wheel is shown at left. (I am not sure how big it is, but it seems about two stories tall.) Enthalpy wheels are a relatively new technology, capable of recapturing 80% of the heat in outflowing air. They also control humidity, and they keep the indoor atmosphere pleasantly humidified. Indoor humidity becomes important in below-zero weather, when the dry air inside a building can lead to cracked skin and nosebleeds. I think enthalpy wheels can make an important contribution to energy conservation. They are used in other buildings on the Dartmouth campus.

Being Cranky About Cost-Effectiveness

However, somehow, I was not as happy with the whole thing as I might have been. All those air exchanges, for example. The building has a very tight envelope, but inside it has has fume hoods and rapid air exchanges in the lab space. I wasn't sure that the carefully built envelope and triple glazed windows were important, considering all the air exchanges. On the other hand, the enthalpy wheel at least mitigated the exchange problem.

Let me first admit I am being completely unfair. The Life Sciences Center is wonderful. It is well designed, and will be an ornament to the Dartmouth campus for at least a century. It has a pleasantly "organic" feel due to the roof gardens, the sweeping views from the large windows, and the use of local wood in the interior design. It's really a marvel.

So, what was my problem? I guess I wish more local buildings had simple efficiency retrofits, rather than this one shining example of every possible type of energy efficiency. If I think of the building as an experiment, then I love it. It shows what can be done. If I think like an energy-committee member (which I am), I can't help but worry about cost-effectiveness.

Still, the world needs shining examples as much as it needs insulated walls in modest homes. This building certainly is such an example, and I am very grateful for Dartmouth for arranging our tour.

Energy Safari Visits Woodchip Plant

On October 4, the Energy Safari class visited Springfield Power LLC, a wood-burning power plant in Springfield New Hampshire. The plant is very visible from Interstate 89, at Exit 12A, Georges Mills. It is rated for 19 MW, and usually makes that amount.

As usual, I recommend Bob Hargraves excellent blog post on the visit. His post contains videos of logs being fed into the chipper, chips on a conveyor belt to the silo, and a semi-truck load of chips being emptied into a chip pile, from which they will be loaded into the conveyor belt. (I include that video below.) The plant buys about one-third of its wood as logs and chips them on site. The other two-thirds of its fuel is purchased as chips.

They use trees that are not good for other uses, such as furniture or firewood.Most of the trees they use are small pines. This is the first powerplant I have every visited that smelled wonderful, like a Christmas tree or a pine forest. Nothing like having tons of pine chips around for a truly pleasant odor. The plant burns 200,000 tons of wood chips per year. Our host, Chuck Theall, was incredibly patient and completely knowledgeable. I include one of Bob's videos.

Okay, I admit it. I was very comfortable in this environment, because it was a "regular" power plant, and Theall is a man who was in the Nuclear Navy. Somehow, I expect power plants to be run by Nuclear Navy people. Shows something about me, I guess!

It's a Heat Engine

This wood chip plant is a heat engine, which means they have to keep fuel on hand. The picture below shows their current log pile, which is about two weeks supply of logs.

During mud season, there are weight limits posted on the local roads, and logging trucks have a hard time traveling. Theall builds up a six weeks supply of wood and chips in preparation for mud season.

We Keep Running

I found the fact that this plant keeps running very reassuring. The exact figures are proprietary, but Theall said the plant gets paid about 5 cents/kWh, but his fuel costs are about 4 cents/kWh. These are in the price range of power from other types of plants, unlike the 24 cents and 30 cents/kWh of the solar farm, for example. Theall said that the sale of RECs (Renewable Energy Certificates) was an important part of the plant's ability to be profitable. He also pointed out that all the plant's fuel expenses are paid out to local people. The money goes right into the local communities, to loggers, land-owners, and their families.

Every day, the plant tells ISO-NE (the grid operator) whether it is on-line or having a problem. (It is usually on-line, with one or two weeks off per year for inspection and repair.) After that call to ISO-NE, the plant contracts to supply a certain amount of power to the grid that day. If it can't supply that power, it has to pay ISO-NE for replacement power. I found this type of contract and requirement a change from the discussion of capacity factors (14% at solar, 35% at wind) in the other facilities.

Pollution Control and By-Products

The plant has excellent pollution control equipment for fly-ash and NOx.

Electrostatic precipitators catch the fly-ash: you can see the big ash-hopper below. The ash is sold as a soil amendment. It brings alkalinity and minerals to the soil. They also sell tree-bark to landscapers.

The plant burns hot (1600 F) enough to make some NOx. It controls NOx with a selective catalytic reduction control system with an ammonia feed. I could include a picture, but I think a picture of a tank of anhydrous ammonia is somewhat boring.

Lovely, but Not Enough

I was impressed by the plant, by the pollution control equipment, by professionalism of those who ran it, by the sweet smell of pine. Alas, I was more surprised than impressed by the turbine hall. It's a perfectly nice turbine, but it is only 19 MW, which looks tiny to people like me who are used to coal or nuclear plants. At twenty MW, it would take 31 plants like this to make as much power as Vermont Yankee.

Turbine below.

This is a serious, well-run plant that lives up to its committments to supply power. It is a benefit to its community and I am very glad I visited it. All in all, I got a very positive impression of biomass.

Krista Langlois of the Valley News wrote a front-page article about our trip in the Valley News October 5. The article is not on-line, but I will quote the final paragraphs:

While those in the ILEAD class are serious about getting reputable information in an industry in which misinformation abounds, one draw of the class is likely the field trips.

As Hartford resident Meredith Angwin summed it up: "I just like power plants."

It's true. I like power plants. I like electricity. I feel privileged to have spent so much of my lifetime in the electricity business, which is so important to human health and happiness.

All pictures are my own. Video from Robert Hargraves.

Lempster Wind Farm

Approaching the Wind Farm

Yesterday, the Energy Safari course went to Lempster Wind Farm in Lempster, NH. We went on a lovely sunny day, which would have been great for the solar farm visit last week. Unfortunately, we went to the solar farm in the rain, and the wind farm on a clear, sunny day with almost no wind!

Bob Hargraves did an excellent blog post on our visit at the Energy Safari site. I am just adding my impressions.

The picture above shows the entrance to the wind facility. (If you enlarge it, you can see one of the turbines.) Unlike the solar farm, which is just a short walk from a few houses, with no locked gate, the wind facility is more heavily protected. There are moving parts overhead (it's all a hard-hat area) and people are not allowed to wander around it by themselves.

Several landowners still live within the wind farm boundaries, and I assume they can do as they choose about hard hats. (They probably signed something about liability. I am just guessing.) We were tourists, and we were well guided. Ed Cherian was the construction manager for the project, and he was our knowledgeable, patient and gracious host.

I admit I am rather fond of the photo on the right. We are standing at the base of one wind turbine, looking over at another wind turbine, and in between is a solar array to run a private communications tower.

Inside the Turbine Building

We had a great time and lots of access at the wind facility. At the left, you can see that they allowed us inside the turbine building. There's a readout there of the power production for the turbine. "Our turbine" went from negative production to positive production while we were there, as the wind picked up. Readout below.

Money

However, I did find it frustrating that the owners would not tell us the price at which they sold their power. They don't have to tell us, I know. They are a private company, and have every right to their trade secrets. Bigger companies, like Hydro Quebec, also do not share that information. We don't have any right to have that information.

However, we are the "energy safari" course and it just makes it harder to assess the success of the first wind project in New Hampshire. In contrast, the solar farm sells their power according to the Vermont SPEED program. The solar farm people were quite straightforward about their production and prices.

Safety

It was a beautiful sunny day, and we had an excellent visit. We were allowed to see everything, everything was explained to us, and many aspects of the site were very impressive. For example, Iberdrola is very careful about safety. Everything is done from within the tower, or on the nacelle. Nobody is ever up there on scaffolding. If they need to work outside, like lowering a damaged rotor, they hire a crane. When the facility was under construction, they had helicopter landing pads in place to take any injured workers to the hospital. (The pads were not needed or used.)

The wind turbine base is sunk with 40 foot bolts into solid bedrock. The turbine itself is bolted to the concrete base. The bolts are covered with black plastic because otherwise they tend to collect minerals and salt, and therefore they attract moose. There's a lot of wildlife around the windfarm.

Factoid time: Why are wind turbines white or light grey? It's an FAA rule for pilot safety.

Jolly Group

I will finish with the obligatory picture of the jolly group! For a more complete assessment of the visit, please go to Bob Hargraves excellent write-up. We are grateful to Iberdrola Renewables for the opportunity to visit their facility. Out on a hillside on a sunny autumn day in New Hampshire! It hardly gets better than this!

All pictures are my own. Click on any picture to enlarge it.

Update on Energy Safari: The Solar Farm

In the picture above, Andrew Savage of All Earth Renewables explains the Williston solar farm to our ILEAD class, Energy Safari. The All Earth Renewables website includes real-time energy production, showing excellent honesty and transparency.

For a more complete explanation, including notes on capacity factors and so forth, I recommend Robert Hargraves post on the class blog. I don't have too much to add.

I'll just make a short list of things that surprised me:

• Somehow, I didn't expect the solar farm to be in a suburban neighborhood. I don't know why not, I just didn't expect it. You get to the installation on a lane off a typical suburban cul-de-sac.
• The sun trackers are quite intricate, and they move every ten minutes or so. The slight noise of the movement is the only sound. This is the quietest power plant I have ever visited!
• Most of the parts of the suntrackers (the things that hold and move the panels) are made in Vermont. The panels themselves are made in China, but the panels are less than half the cost of the installations.
• People walk their dogs around the edges of the solar field. It is still very much "part of the neighborhood."
• Each suntracker has an anemometer on it (easily visible in this picture of a suntracker panel in the horizontal position for an on-going test.) When the wind speed is above 30 mph, the panels are placed in a horizontal position to avoid damage. As Andrew Savage noted, however, high wind speeds are associated with storms and clouds. Therefore, moving the panels flat during high-wind incidents does not affect their long-range performance very much.

We are grateful to All Earth Renewables for hosting us, and also for their complete transparency on energy production.