Tuesday, December 30, 2008

On Clean Coal (Or the Lack Thereof)

[Reposted from University and State]

I have a confession. There's something that's been eating at me for a long time, and I need to get it off my chest before my soul caves in on itself and I break a television in a rabid fury. I HATE THIS COMMERCIAL:




I'm saying this up front: this post is going to be way longer than is reasonable for a response to a tiny commercial. But someone needs to say this, so I'm saying it.

Let's dig a little bit into what's going on here. This Is Reality is a collaborative project between a number of environmental advocacy organizations, but I think it's pretty clear who's ringleading this operation: Al Gore's advocacy group, the Alliance for Climate Protection. So because it would be impossible to direct my ire at all of the organizations behind this commercial (since they all have different positions), and because the website for This Is Reality is filled with links to other Alliance projects, I will point my comments at the Alliance.

The Alliance has two other projects besides This Is Reality which represent its constructive alternative to the use of coal technology to generate electricity: We Can Solve It and Repower America. But to understand what they're talking about, it will be necessary to get some background on how electricity is currently generated. So here it goes:

Electricity demand fluctuates on a daily basis, like this:

http://www.reliant.com/en_US/Platts/art/CEA_offices_fig1.gif
Source: http://www.reliant.com/en_US/Platts/art/CEA_offices_fig1.gif

That's not actually an observation of demand; in reality things are a lot choppier. But the basic point you should take from it is this: during the work day when people are running lots of electricity-intensive equipment (and particularly in the summer and winter, space heaters and air conditioners), there's a rise in the amount of electricity demanded. You'll notice that there's a minimum amount of electricity that is always needed but the grid at any time of day. This daily minimum amount of power is called the "base load." And there's also a cyclical daily hump in electricity demand, called the "peak load."

Currently, base load is predominantly generated by large, centralized coal and nuclear plants (and some hydroelectric plants). These are by far the cheapest fossil fuel plants to run in terms of marginal cost per unit of power generated. But they have an important and inherent limitation: they can't ramp their output up and down very quickly. So they just chug along, producing the daily minimum amount of power around the clock.

Peak load can't be met effectively by these large scale plants, and that's where we find "peaking" or "cycling" plants. These are predominantly natural gas plants with some diesel reciprocating engines thrown into the mix. Natural gas plants are like enormous jet engines, and reciprocating engines are like giant motors; they can both be ramped up and down relatively quickly, and are therefore better suited for handling intraday fluctuations in demand, even though they cost more to operate.

So remember: Base load is the electricity that the grid needs around the clock, and it's produced in huge coal and nuclear plants (as well as hydroelectric plants). Peak load is the electricity that the grid needs to meet intraday fluctuations in demand, and it's produced in smaller natural gas and diesel plants. It all works out so electricity generation comes out looking like this (chart from 2006):

http://upload.wikimedia.org/wikipedia/commons/d/d4/Sources_of_electricity_in_the_USA_2006.png
Source: http://upload.wikimedia.org/wikipedia/commons/d/d4/ Sources_of_electricity_in_the_USA_2006.png

As you can see, coal generation makes up about 50% of our current electricity production. So now I think we can turn to the Alliance's proposal, from its Repower America project: "100% clean electricity within 10 years." What's going on here? Exhibit A: There is no such thing as clean coal. Exhibit B: We want 100% clean electricity within 10 years. Exhibit C: America currently generates about 50% of its electricity from coal plants, and a large majority of its baseload power.

So how, exactly, do they plan to eliminate all of the coal generation capacity in America in 10 years (never mind all the other fossil fuel generation which likely gets the label of "unclean" as well)? Repower America has a four part plan. But before trotting it out, let's look at exactly what they're trying to do, using their own graphics:





...Yea. So here it goes:

Step 1: Energy Efficiency. Now, the Repower America authors rightly cite a Department of Energy document forecasting an increase in American electricity demand by about a quarter of current use over the next two decades. To counter this, the authors propose that 28% of future electricity demand be cancelled out by efficiency gains. Let's give them the benefit of the doubt (I don't feel like fact-checking this one), and suppose that this can be done. We're saying, then, that we can keep electricity demand essentially flat over the next decade while this transformation is supposed to take place. So now we're sort of at square one: we're supposing that energy efficiency will not make the problem any worse, but we haven't made things any better yet. I don't even want to begin to think about how much it would cost to eliminate 28% of American electricity demand with energy efficiency measures. We're not talking about changing light bulbs or installing better windows. But more power to them if they can do it. Okay then, we're at flat electricity demand for the next ten years; three steps left to replace coal!

I think it'll be useful, before moving on, to quickly adjust the figures to take out the influence of energy efficiency, to normalize the contributions to actual energy produced (which should roughly match up with today's total demand). In the Repower America Scenario A, solar photovoltaics, biomass/municipal, and geothermal will be relied on for 4% of electricity production each, wind for 37.5%, and solar thermal with storage for 18%. Notice that today, these technologies combine for only 2.4% of total production. If the Alliance gets its way, we have a lot of work to do in 10 years, and it's going to be expensive! So on now to step two, where we find out how they're going to produce all that power without fossil fuels.

Step 2: Renewable Generation. And I quote: "Generate 100% of US electricity from truly clean carbon-free sources. Renewable energy generation technologies like solar thermal, photovoltaics, wind, geothermal and biomass have been adding clean reliable power to the grid for more than a decade...It is now time to dramatically ramp-up the contribution of renewables to the energy mix." Now, conspicuously absent from that list is hydroelectric power, and for good reason: there really isn't much potential for expansion there (and there are also some important environmental concerns associated with the dams that are used to generate it), and the authors accordingly hold hydroelectric generation constant in their analysis. Even more conspicuously absent is a word barely mentioned in the Repower America plan: "Nuclear." Even though nuclear electricity generation produces no CO2, is projected to increase substantially in coming years, and is currently the only major existing large-scale alternative to coal for baseload power, the authors hold nuclear generation constant as well.

We'll touch on this point again later, but for now, it will be useful to once again jiggle the calculations. So let's cancel out the influence of nuclear and hydroelectric generation, which account for roughly a quarter of total electricity production today and in the future according to the Repower America scenarios. What's left is the current influence of renewables and the fossil fuel generators: coal, natural gas, and petroleum; together they account for about three quarters of the total power generation, and we'll call this the "flexible space" (since apparently we're holding the other quarter fixed). In the future, renewables will ostensibly fill this entire space, even though they only fill about 3% of it now. Currently, the space is two-thirds filled by coal, a quarter filled by natural gas, rounded out by a 2% contribution from petroleum. In the Repower America plan, we get solar photovoltaics, biomass/munipal, and geothermal each on the hook for 6% of the flexible space, solar thermal for 26.5%, and wind for 55%.

I want to focus on the fact that "Other Renewables" make up a whopping 2.4% of electricity generation today. In spite of all the hype, this is not actually all that surprising, as there are three main hurdles facing renewable energy generation technologies today. 1) They are generally more expensive than conventional methods of generation; 2) It is often the case that the ideal places to generate electricity from renewable resources are not the places where people live, and it is expensive to build transmission lines that can carry electricity over long distances; and 3) The generation characteristics of many renewable technologies are such that electricity is either not produced consistently and reliably, or production cannot be coordinated to respond to demand. Because we're dealing with a one-dimensional analysis (that is, preventing climate change is clearly the only thing that matters to these people, no matter the cost), we'll just throw out (1) for now. Who cares what it costs! But how does Repower America respond to (2) and (3)? We need to go to the last two steps to find out.

Step 3: Build a Unified National Smart Grid. Because renewable energy is often produced far from demand centers, Repower America proposes to build a giant system of transmission lines across the entire country in order to ensure that renewable energy can be integrated into the grid. Remember, kids: cost is no object; we're fighting climate change! So now, and I quote: "It will allow us to connect solar power in Arizona with manufacturing centers in Ohio or allow us to use evening wind power on the East Coast to support late afternoon peak demand in Nevada." So what're we looking at for a price tag? American Electric Power drew up a proposal for something like this at the behest of a group of wind power advocates, and projected the cost at $60 billion (or about a half of a percent of US GDP, or six months in Iraq). But I should note that AEP's plan was based on producing enough transmission capacity to allow wind power to reach a 20% share of America's electricity needs; I'm not sure the transmission system they've described could handle the kinds of transfers that would be needed to make 100% renewable energy feasible. But remember, cost is no object, and this apparently can be done.

So now we're a little closer to seeing how coal could be replaced, but there's still an important hurdle: many renewable energy sources are either inconsistent and unreliable, or don't produce energy at the same time that it's demanded.

A little more background is needed here. As I said before, some of the biggest problems with renewable electricity generation from technologies like wind and solar have been about timing and control. For example, photovoltaic solar generators only produce energy during the day, and they can't really be adjusted to produce only the electricity that you need. During the summer and winter, when there's a lot of space heating or air conditioning going on, that doesn't matter too much. Most electricity use happens during the day anyway, and grids can pretty much use whatever electricity they can get during those times. But in the spring and fall, when intraday fluctuations are smaller, those operating characteristics aren't particularly helpful. From one study exploring the impacts of large-scale use of solar generation:

http://www.nrel.gov/pv/pdfs/39683.pdf
Source: http://www.nrel.gov/pv/pdfs/39683.pdf


http://www.nrel.gov/pv/pdfs/39683.pdf
Source: http://www.nrel.gov/pv/pdfs/39683.pdf

As you can see, in the second chart, the contribution of solar energy drops the residual peak demand (that is, the demand during peak demand periods after the impact of the contribution from the solar generator) significantly below the normal daily minimum level. If this electricity were going to be used by the system, the baseload plants would need to be ramped down to the new minimum levels, and expensive peaking plants would need to fill in the gaps. Needless to say, this wouldn't happen; utilities would just dump the extra power. This means that if solar power were going to be implemented on a very large scale, it would need to be profitable even with the use of only a portion of the electricity generated by the systems. Looking at wind generation, one can see that the problem is exacerbated by the fact that wind generation doesn't necessarily line up with the peak demand period for a grid. One example from New York yielded this result:

http://www.nyiso.com/public/webdocs/documents/white_papers/wind_management_whitepaper_11202008.pdf

Source: http://www.nyiso.com/public/webdocs/documents/white_papers/ wind_management_whitepaper_11202008.pdf


At least part of the rationale for the National Unified Smart Grid seems to be the idea that power can be sent from areas with unneeded excess generation to those where the electricity can be used, so that something along the lines of a "law of averages" approach would help to ensure a more stable grid system. But can wind power really be relied on the carry the burden of base load? I'm not sure. Remember, of the flexible space in the area of generation, big baseload coal takes up about two thirds of the generation we need to replace. Solar thermal, which apparently can be effectively (if expensively) utilized for baseload power when combined with storage technology, is being relied on for 26.5% of the space. The 6% each taken up by biomass/municipal and geothermal could ostensibly go towards base load requirements as well. But we need to acknowledge that wind is being asked to do a whole lot of work here, and I'm not entirely sure if that's realistic.

And unlike natural gas and diesel plants, it appears to me that none of these technologies can be dispatched on the scale that would be necessary to completely address jumps in peak demand. You simply can't just demand that the wind blow harder or the sun shine brighter. If a heat wave comes along and the wind is dead along the West Coast while people are blasting their air conditioners like there's no tomorrow, we need a source of on demand power. Natural gas currently serves a very important role in bringing flexibility to the grid. It doesn't appear to me that there's any generation technology with that characteristic in the Repower America portfolio.

A piece of the solution to this problem is provided by the "Smart Grid" component of the "Unified National Smart Grid" plan. This basically mirrors the Department of Energy's vision of the future of the electricity grid, and involves the use of smart metering technologies and communication between utilities and end-users of electricity to allow for "demand response" programs. This would allow utilities to tell their customers in times of system stress or unexpectedly high demand that they should reduce their electricity consumption. Utilities would generally pay customers to do this, and some plans include the ability for utilities to remotely control some of the appliances in their customers' facilities in order to initiate these drops in demand instantaneously. But there's a limit to how effective a demand response program can be. Ultimately, it's an important part of the job of a utility to be able to provide electricity on demand, and relying on customers to put up with unavailability of electricity is simply not a feasible option.

What's needed to make this plan technologically feasible is an effective form of energy storage. This would allow grid operators to build up energy reserves to respond to unexpected changes in supply or demand which could not be remedied by the almost nonexistent responsive capacity of a generation portfolio pretty much entirely dependent on resources which can't ramp production quickly up and down when needed. And that's where the final step comes in.

Step 4: Clean Plug-in Cars. When I saw this, I first thought, "Here is where, as they say, the plan jumps the proverbial shark."



The way that Repower America apparently expects to provide added stability to the electricity grid of the future is to basically use plug-in electric hybrids as batteries which can be charged when excess electricity is available, and drawn upon when electricity is needed by the grid. Now, a lot of people are talking about this as an important part of our energy future, and I'm one of them. I think plug in cars are a great idea. But the authors at Repower America are nuts if they think that the adoption of plug-in hybrid cars widespread enough to bring about this kind of energy storage capability would be consistent with their use of the Department of Energy's projection of electricity demand! A large plug-in hybrid fleet (in addition to taking longer than 10 years to materialize) would put an enormous strain on the electricity grid, forcing the already tenuous production of electricity from only renewables to somehow come up with thousands or millions more gigawatts of electricity. Perhaps it could be done; after all, we're not taking cost into account, remember?

But it's at this point where we really have to step back for a moment and ask ourselves, is this really what we think is going to happen? Even if we really want to stop climate change, does it make sense to try to completely eliminate fossil fuel technologies from the electricity generation landscape? Should we really just close the doors on billions upon billions of dollars in infrastructure investment? Is it really the best idea to try to force utilities to stop using coal, natural gas, and diesel to power their grids (or to offer them the money to convince them to do it voluntarily)? OF COURSE NOT!

So now we can finally get to why I hate that frikkin' commercial. There is such a thing as CLEANER coal technology, and we'd better darned well be ready to work towards implementing it! And we'd better keep an open mind towards expanding the use of cleaner natural gas and petroleum generation (which can be more energy efficient than coal) as well! And we SURE AS HELL better start building nuclear plants!

Smaller, decentralized coal plants can be used to provide heat to nearby buildings and homes, typically producing energy efficiencies much higher than can be achieved at large, centralized plants. Natural gas turbines typically operate at higher efficiencies as well, and they can be harnessed for combined heat and power too. By gasifying coal, petroleum coke, and other carboniferous feedstocks for use in Integrated Gasification Combined Cycle (IGCC) plants, we can also increase energy efficiency, even if we don't use the more concentrated resulting CO2 exhaust stream for Carbon Capture and Sequestration projects. Higher energy efficiency means less CO2 emitted, and doesn't necessarily force us to completely abandon cost-effectiveness. Looking for synergies for the use of waste CO2 could also be part of a solution. By burying our heads under the sand with a proposal to completely eliminate fossil fuel technologies, we draw attention away from these critical possibilities, and ultimately obstruct their development and implementation.

Nuclear power is CO2-free, and also needs to be a part of the answer. We simply can't expect to replace all of our baseload coal capacity without relying on nuclear power to help fill in the gap. To be sure, the increased use of renewable resources will need to be a huge and central part of our energy future. But to expect it to be the only part is flat out ridiculous, and trying to convince the American people otherwise is simply unreasonable and counterproductive.

Like it or not, we need fossil fuel technologies to meet our energy demands. And in addition to the technological feasibility we've discussed so far, and the monetary cost, that's because we're not going to employ the entire frikkin' country and its resources producing renewable generation facilities for the sole purpose of preventing climate change. Perhaps the most grating part of the Repower America plan is its repeated focus on job creation.

Here's something to chew on: When people consume their income, they consume goods and services that are produced by everyone else. If a substantial percentage of people are employed removing our existing infrastructure and replacing it with new infrastructure that serves exactly the same needs as the stuff that was there before, then it means that the people whose products are being consumed by the "green workers" are getting nothing in return for what they created. Imagine that Tom, Dick, and Harry are an economy. Tom produces food, Dick produces liquor, and Harry produces dirty magazines. At the end of the period, Tom, Dick, and Harry each have enough from selling to the others to end up with enough food, booze, and porn to go home happy. Now in period two, the government hires Harry to replace Tom's and Dick's doors with new doors that are no different from the old doors, except they're better for some reason which doesn't directly impact Tom or Dick. Tom and Dick still produce their food and booze, and the government taxes them to pay Harry for his services. Harry ends up with some food and some booze, but not as much as before, and Tom and Dick are in similar situations. And no one has any porn! What a terrible shame! So we can talk about jobs all we want, but what's really important is that at the end of the day, what goes around is what people produce. And if people are producing stuff that doesn't do anyone any good, everyone ends up worse off for it.

Now, it will immediately be countered that talking about costs is well and good when we're thinking about what to make for dinner, but climate change is a matter of justice. And while that would shift the debate away from my objection, which was that it's infuriating that Repowering America keeps harping about its plan's potential for job creation when it's undoubtedly going to make people generally worse off, I'll grant the point. The debate about climate change ultimately does come down to a question of ethics. But as Tom Athanasiou and Paul Baer point out in their book, Dead Heat: Global Justice and Global Warming, "The real issue, even ethically, is what will work..." (118). And this plan being pushed by the Alliance simply won't work.

Going a step farther, I defy anyone to give me a legitimate ethical argument which ends in the conclusion, "...and therefore, we must repower America with 100% clean energy in ten years, or else we will neglect our moral duty." I can't believe I'm about to sound like Bjorn Lomborg (*shudder*), but I'm not stopping myself. Watch:

Much of the climate change we can expect in the future is already in the pipeline. Taking a slower approach to reducing emissions, and embracing our need to maintain some carbon-intensive generation, would produce enormous efficiency gains and seriously accelerate progress in other areas of our economy. If we took some of the hundreds of billions or trillions of dollars that we would save by not implementing Al Gore's plan, and put it towards fighting malaria, restoring the rainforests, researching AIDS, promoting better energy efficiency in the developing world, and helping those who will need to adapt to the now inevitable impacts of climate change, we could likely do a lot more good in the world, even from the perspective of dealing with the impacts of climate change. Further, our descendents would likely be richer and better able to deal with their changing climate, and to help those who were not brought along by the rising tide of economic prosperity.

I'm not saying that nothing should be done to fight climate change. But driving our entire economy into the ground in order to fight a problem which is already partly out of our control doesn't seem like it's the best answer from anyone's perspective: even the victims', and even the environment's. We can be more energy efficient. We can use less coal and natural gas and oil. We can learn to harness the sun and the wind and the soil. We can learn to live as responsible members of the biotic community. But we have to learn to do that. And everyone will be better off if we don't rush ourselves into a more impoverished lifestyle to make it happen. Remember, before we were comfortable and well taken care of, the environment was the last thing on anyone's mind; look at China.

And remember, we're saving the world for future generations. Imagine if the industrial revolution had been stopped to prevent mercury poisoning. 'Nuff said.

So in closing, I hate that commercial because it represents a loss of perspective. It takes an important issue and reduces it to a set of overly simplistic talking points. We need to address climate change, to be sure. And that means a shift away from CO2-intensive electricity generation and towards renewables and clean technologies. But taking half of the most reasonable and important responses entirely off the table is irresponsible and counterproductive. It makes it so I end up talking to people who say, "No! No new coal plants!" instead of, "Is the plant going to produce combined heat and power?" And that's a problem, because if they scream about wind and solar, the utilities are going to laugh at them, whereas if they scream about capturing the heat stream for the benefit of the community, they might actually end up having an impact. The commercial makes it so the people who care most about fighting global warming get the absolute wrong idea of how to go about doing that. And that's a darned shame.


Update:

For anyone interested, the current breakdown for electricity generated from renewable resources by technology is as follows: Biomass electricity accounts for about 1.1%, wind for 0.6%, geothermal for 0.3%, and solar for about 0.01%. Hopefully that puts the Alliance's plan in a little better perspective.

2 comments:

Michael said...

Have you read Julian Simon's "Ultimate Resource 2"?

He gives strong arguments why resources (including energy) are practically infinite.

Danny Shahar said...

I haven't read it, but I'm not sure I understand the point. I wasn't arguing that we were going to run out of resources.

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