Monday, August 18, 2014

It Takes More Than Turbines

The Telegraph ran a brief story earlier this month about UK regulators paying wind farms in Scotland nearly £3.0M to not generate so much electricity for one day.  High winds due to the remnants of Hurricane Bertha coincided with a period with low local demand for electricity, and the grid lacked capacity to carry the available power elsewhere.  Such situations are neither new, nor confined to the UK: in both 2011 and 2012, the Bonneville Power Administration ordered wind generators in Oregon shut down to avoid oversupply problems.  The problems in both cases are not that the grid isn't smart enough to handle the intermittent nature of wind; the problem is that the grid lacks sheer bulk transport capability to move the excess wind power to someplace it could be used.

The map to the left is a portion of a graphic from an NPR story about the US power grid, showing the US portion of the Western Interconnect.  The bold orange lines represent a proposal by the American Wind Energy Association for an overlay high-level grid that would allow full use of wind when it is available in a geographically diverse set of sites.  This overlay grid passes "close" [1] to all of the major population centers in the West, as well as the best of the wind resources.

Building a reliable grid from intermittent renewable sources requires not just geographic diversity, but source diversity as well.  The AWEA overlay also happens to pass close to excellent solar resources in the desert Southwest, undeveloped hydro resources in the Northwest, geothermal resources in the Great Basin, and sites suitable for pumped hydro energy storage.  Balancing all of those resources against demand across eleven states (plus western Canada and a bit of Mexico) is a complex but doable task, given enough bulk transport.  Speaking broadly, the situation in Oregon with too much supply and not enough demand shouldn't happen.  If there really are no consumers for it, it ought to be pumping water uphill against future need.

The AWEA isn't the only group that draws proposals for overlay super grids [2].  In the Western Interconnect, they all tend to look similar.  As I've noted in other posts, geography plays a big role.  The people are concentrated in a small number of areas; the easy routes for transportation or transmission are few and obvious; the energy resources are where they are, many of them either close to one or more demand centers, or along one of the routes between those demand centers.  This is a good part of the reason that people can draw up nuts-and-bolts sorts of plans for a heavily-renewable power grid in the Western Interconnect.  The other parts of the country present a much more difficult challenge.  And as always, I raise the question of whether those other parts of the country will demand a single national energy policy that makes the West's efforts difficult or impossible.


[1] "Close" in the West can be rather different than close in other parts of the country.  As in, "it's only a hundred miles", or "it only has to cross one mountain range".

[2] The AWEA map does get used a lot, though.  Part of that is probably that it shows up in Wikipedia's Wikimedia Commons, unencumbered by copyright.  An interesting feature of the full national map is that it doesn't show any additions in the Southeast part of the country, where wind resources are rather poor.

Sunday, August 3, 2014

TABOR Conspiracy Theory

I let myself believe in conspiracy theories on alternate Tuesdays; that'll be relevent in a moment.

TABOR -- the Colorado Taxpayers Bill of Rights -- added a section to the Colorado state constitution in 1992 that, among other things, said the state legislature couldn't pass tax increases, they could only refer such measures to the voters.  In 2011, a group of state legislators sued the State of Colorado, asserting that setting tax rates is a fundamental job of government, and that by denying the state legislature that power, the state constitution was in violation of the Guarantee Clause of the US Constitution.  If it's been a while since you read the Constitution, that's the sentence which requires every state to have "a republican form of government."

The conventional wisdom at the time was that the suit would be short-lived.  To borrow from the defense's summary, the federal court would promptly find that this fell under the Supreme Court's political-question doctrine, that the plaintiffs lacked standing, and that the case would be dismissed.  Things have not, so far, worked out that way.  The district court judge ruled that the plaintiffs did have standing; this case differed from the political-question precedents; and the arguments should be made at trial rather than in a preliminary hearing.  The defense appealed.

A three-judge panel of the federal appeals court, arguing de novo, ruled the same way: sufficiently different from the precedents, plaintiffs had standing, and ordered the case returned to district court for trial.  The defense appealed to the entire court for a rehearing.  This past Tuesday, I read that the full appeals court declined to rehear the case, thereby affirming the ruling by the three-judge panel.  Presumably, the defense will now appeal to the Supreme Court, so it will be at least a few months before anything interesting can happen.  The quickest would be if the Supremes declined to hear the appeal, in which case the district court would schedule a trial date; the wheels of justice do grind slowly.

My impression is that the defense has been poorly prepared throughout.  That they were assuming that "political question, no standing, case dismissed" alone would carry the day.  When I read about the latest development, I was struck by the possibility that this was intentional and not just a matter of overconfidence.  Both parties have found themselves tied in knots by TABOR when they controlled the legislature following a recession: the Republicans following the 2000-01 recession, and the Democrats following the one in 2007-09.  The single-subject amendment to the Colorado constitution in 1994 makes it unlikely that TABOR could be removed in its entirety; it would have to be cleared a bit at a time (some experts think as many as 20 separate amendments would be necessary under the current rules).  "What," I thought on Tuesday, "if the secret plan is to lose the TABOR lawsuit and let the federal courts accomplish what the politicians can't?"

Nah, that's too crazy even for me on a Tuesday.

Monday, July 21, 2014

Migration

A while back at Ordinary Times, there was an interesting comment thread on the subject of defining the Midwest region of the US.  One of the thoughts that occurred to me while reading that was whether it was possible to define regions based on inter-state migration patterns.  The idea grew, I suppose, out of my own experience.  I lived and worked in New Jersey for ten years, but never really felt like I fit in there.  Eventually my wife and I moved to Colorado, to the suburbs of Denver, where we immediately felt right at home.  Most people, I thought, might have been brighter than we were and not moved to someplace so "different."

I've also encountered a variety of nifty data visualization tools that look at inter-state migration in the US, like this one and this one from Forbes.  State-level data for recent years turns out to be readily available from the Census Bureau.  We can define a simple distance measure: two states are close if a relatively large fraction of the population of each moves between them each year.  "Relatively" because states with large population have large absolute migration numbers in both directions.  For example, large numbers of people move between California and Texas -- in both directions -- because those states have lots of people who could move.  From Wyoming, not so many.  Given a distance measurement, it turns into a statistical problem in cluster analysis: partition the states into groups so that states within a group are close to each other.  Since there's only a distance measure, hierarchical clustering seems like a reasonable choice.

The map to the left shows the results of partitioning the 48 contiguous states into seven clusters.  The first thing I noticed about the partition is that states are grouped into contiguous blocks, without exception.  While that might be expected as a tendency [1], I thought there would be at least a couple of exceptions.  The resulting regions are more than a little familiar: there's the Northest, the Mid-Atlantic, the Southeast, the Midwest (in two parts), the West, and "Greater Texas".  There are a couple of other surprises after reading the discussion at Ordinary Times: Kentucky is grouped with the Midwest, and Missouri and Kansas with Greater Texas.  New Mexico clustered with Texas isn't surprising, but New Mexico with Louisiana and Arkansas?  Hierarchical clustering is subject to a chaining effect: New Mexico may be very close to Texas, and Louisiana also close to Texas, and they get put into the same cluster even though New Mexico and Louisiana aren't very close at all.

One way to test that possibility is to remove Texas from the set of states.  The result of doing that is shown to the left. As expected, New Mexico is now clustered with the other Rocky Mountain states and Louisiana with the Southeast.  Perhaps less expected is that the other four states -- Arkansas, Kansas, Missouri, and Oklahoma -- remain grouped together.  None of them is split off to go to other regions; the four are close to one another on the basis of the measure I'm using here.

Answers to random anticipated questions... I used seven clusters because that was the largest number possible before there was some cluster with only a single state in it [2].  The Northeast region has the greatest distance between it and any of the other regions.  If the country is split into two regions, the dividing line runs down the Mississippi River.  If into three, the Northeast gets split off from the rest of the East.  There are undoubtedly states that should be split, ie, western Missouri (dominated by Kansas City) and eastern Missouri (dominated by St. Louis); a future project might be to work with county-level data.


[1]  My implementation of hierarchical clustering works from the bottom up, starting with each state being its own cluster and merging clusters that are close.  Using the particular measure I defined, close pairs of states include Minnesota/North Dakota, California/Nevada, Massachusetts/New Hampshire, and Kansas/Missouri.  These agree with my perception of population flows.

[2]  The singleton when eight clusters are used is New Mexico.  When ten clusters are used, Michigan also becomes a singleton, and Ohio/Kentucky a stand-alone pair.

Sunday, July 6, 2014

An Update on the War on Coal

[A longer version of this post appeared at Ordinary Times.]

It's been a tough year for coal in the United States. I generally dislike the use of war-on-this and war-on-that. But if the intended meaning is "make it much more difficult and/or expensive to continue burning large quantities of coal to produce electricity," then the phrase is accurate. Where most people who use it are wrong though, is just who it is that's fighting the war. It's the federal courts, and to a lesser degree some of the individual states. The EPA is just the tool through which the courts are acting. Well, also ghosts of Congresses past, who left us with various environmental protection statutes in their current form. Since the SCOTUS hammered the coal side of the fight twice this just-concluded term, it seems like a good time to write a little status report.

Not all the constituents of coal are combustible. Anywhere from 3% and up are not and are left behind as ash, and even 3% of a billion tons is a lot of ash. A bit more than 40% of coal ash is typically reused in various ways: some of it can replace Portland cement in the right circumstances, some it can be used as fill for roadbeds, etc. The remainder winds up in landfills or ash ponds. Ash ponds contain an ash/water slurry; the wet ash stays where it's put rather than being blown away by the wind. Ash pond spills are becoming more common. The federal EPA has not regulated ash ponds in the past; in January this year the DC District Court accepted a consent decree between the EPA and several plaintiffs that requires the EPA to issue final findings on ash pond problems by December. The expectation is that the findings will lead to significant new regulation, and increased spending on both existing and future ash ponds. Things are also happening at the state level. The North Carolina Senate unanimously approved a bill last week that would require the closure of all coal ash ponds in the state over the next 15 years. NC's not exactly one of your liberal Northeastern or Pacific Coast states.

Most of the visible pollutants that go up the flue at coal-fired plants have been eliminated. The picture to the left is the Intermountain generating station near Delta, Utah. The visible white stuff escaping from the stack is steam. Not visible are things like mercury compounds, sulfur and nitrous oxides, and extremely small particles of soot. Those are all precursors to haze, smog, low-level ozone and acid rain, as well as being direct eye, nose, throat and lung irritants. Some of these pollutants can travel significant distances in the open air. In April this year, a three-judge panel of the DC Circuit upheld a tougher rule for emissions of this type of pollutant (the MATS rule). Also in April, the SCOTUS approved the EPA's Cross State Air Pollution Rule that will result in tighter controls on this type of emission. Approval of the cross-state rule has been a long time coming, as EPA rules that would regulate cross-state sources made multiple trips up and down the court system. The courts have always held that the EPA should regulate cross-state pollutants; the problem has been finding a technical approach that would satisfy the courts. In EPA v. EME Homer in April, the SCOTUS reversed the DC Circuit, and the CSAPR will now go into effect.

Finally, last week the Supreme Court issued its opinion in the case of Utility Air Regulatory Group v. EPA. This opinion confirmed the Court's 2009 opinion in Massachusetts v. EPA that the EPA must regulate greenhouse gases. Massachusetts was a suit brought by several states against the Bush EPA, which had decided the carbon dioxide was not harmful. I think Utility is an odd opinion, cobbled together out of three different factions on the court (more about that in a moment). The opinion has three conclusions: (a) the EPA can and must regulate greenhouse gas emissions from stationary sources, (b) the EPA can only regulate greenhouse gas emissions from stationary sources if those sources would have been regulated for non-greenhouse emissions anyway, and (c) the somewhat controversial approach the EPA is taking to the regulation is acceptable. The last one seems to me to have been sort of an afterthought. OTOH, it's likely that we'll see a number of cases about it later when the states make the details of their individual plans known.

The results of the various court decisions are going to have very different effects on different states. Compare California and North Carolina, to pick two (not exactly at random). North Carolina has 43 coal ash ponds; California has none. North Carolina, despite being a much smaller state, generates more than 30 times as much electricity from coal as California; the MATS rule will require much more effort to meet in North Carolina. The CSAPR does not apply to California; but North Carolina power plants will be required to make reductions to improve air quality in downwind states. North Carolina has to reduce the CO2 intensity of its generating plants by more than the national average; California's required reduction is much less than the average, and decisions that California has already made at the state level will probably be sufficient to meet the EPA requirements. North Carolina's electricity rates are likely, it seems to me, to be noticeably higher in the future; California's rates will remain high and perhaps go higher, but aren't going to be driven by these decisions.

Monday, June 23, 2014

Infrastructure Needs - A Cartogram

From time to time you find articles that talk about how far behind the United States is in infrastructure spending.  The American Society of Civil Engineers maintains an entire web site dedicated to the topic.  I have often wondered whether there are geographic patterns to the infrastructure shortfalls.  One of the things that raises that question for me is the stuff I read about how the electric grid is falling apart.  In the Denver suburb where I have lived for the last 26 years, and the Front Range generally, there's been an enormous amount invested in the electric grid and service seems to be noticeably improved compared to what it was when I moved here.

Bloomberg maintains an interesting collection of state-by-state numbers, including infrastructure needs.  They only consider a limited number of things: roads, drinking water, and airports.  I'd like to have figures that included more factors — ah, how pleasant it would be to have minionsgraduate students to do the grunt work — but Bloomberg is an easy-to-use starting point.  The cartogram at left — double-click in most browsers for a larger version — shows US states sized to reflect Bloomberg's figure for annual per-capita infrastructure spending needs for the period 2013-2017.  West Virginia has the largest value at $1,035; New Jersey has the lowest value at $78.  While there are lots of things that would be interesting to regress against the numbers, in this essay I'm just thinking about geography.

One of the obvious things that jumps out is that high-population states do better.  California, New York, Florida, and Illinois all fall into that group.  The most likely reason would seem to be that there are economies of scale involved in the things Bloomberg measures.  An airport can serve more people in a high-population state; highway lane-miles are used by more people; doubling the capacity of a water- or sewage-treatment plant doesn't mean that the cost of the plant will be doubled.

Another factor appears to be that states with high population growth over the last 20 years do better.  California, Colorado, Texas, Georgia and Florida are examples.  In this case, the likely reason would be that rapidly growing populations have made infrastructure spending a critical need.  To use Colorado as an anecdotal case, since I live here and pay some attention, Denver built a major new airport, my suburb greatly expanded its water-treatment plant, and I-25 along the Front Range has been subject to an entire series of improvements (if you drive its length, it's not whether part of it is under construction, it's a matter of how much).

Finally, some simple regional observations. Here's a standard map of the 48 contiguous states using an equal-area projection for comparison.  The 11 contiguous western states appear to be in much better shape than the country as a whole.   As might be expected, Wyoming and Montana, the two western states with the smallest populations, do the worst in that region by a wide margin.  With a caveat that this is state-level data, the upper Great Plains, New England, and Appalachia all do very poorly.  With a small number of exceptions, the East Coast looks particularly bad.

I think I'll just sum this up with the obvious statement: "There are new parts of the country, and old parts of the country, and the new parts tend to have more and shinier stuff per person."

Sunday, June 22, 2014

Western Secession 7 -- The Age of Electricity

Lots of people who believe that Civilization is Doomed because of energy constraints talk about this being the Age of Petroleum. As far as transportation goes, that's absolutely true. But it's not really the most critical aspect of our current high-tech society. This is really the Age of Electricity.

If petroleum were to slowly go away, eventually reaching zero, there are alternatives. Existing land transportation can become much more efficient: smaller vehicles, trains instead of trucks, etc. Alternate power sources are available, at least for some applications: smaller electric vehicles, electric trains instead of diesel, etc. Goods can be produced closer to where they are consumed in order to reduce the amount of transportation required to deliver them. Slower transportation and delivery of objects helps — delivering the small package by electric train and electric vehicle uses much less energy than flying the package overnight. More expensive synthetic alternatives to petroleum-based liquid fuels exist for situations where alternatives are impractical.

OTOH, we have reached a point where there is no substitute for electricity. This short essay was written on a computer; it was uploaded to Blogspot and copied into some number of their computers; the copy you're reading was downloaded from one of those servers. The non-electric alternative is paper and ink (since radio and television also require electricity in large quantities).  If that were the only medium available, chances are that you would never see this. Paper and ink distribution imposes serious limits on how many people's writing gets distributed widely.  I'm using "widely" in the sense of making it possible for many people in many locations to read it. Having the NY Times publish it would count, as the NY Times is popular enough to have nation-wide physical distribution (although without electricity, that may mean being a day or two behind).  Putting it up on a wall in a public place in Arvada, CO doesn't count.

Recall that the original "wire services" that distributed stories to local newspapers were called that because it was a description of what they did. Stories were collected and distruted by telegraph and later teletype, both of which require electricity. David Weber's popular Safehold series of science fiction novels, set on a world where the use of electricity is strictly forbidden, envisions a semaphore network instead. It's slow, it's even slower at night, it fails temporarily when the weather is bad enough, and it fails completely when the message has to cross a large enough body of water (discounting transcribing the content, moving it physically across the water, then putting it back on the semaphore network).  High-speed communication means electricity.

Electricity is a key consideration in developing countries as well, with China as the most interesting case. Their population is extremely large. As recently as three decades ago, that population was desperately poor. The government is working — at a pretty hectic pace — to urbanize and find non-farming work for what was an enormous peasant population. In order to do that, electricity is vital. As a result, if it will generate electricity, China is deploying lots of it. Coal, natural gas, nuclear, hydro, wind, solar... China's rate of growth in the use of all of those is among the very highest in the world.  India has been less aggressive about expanding its grid, leading the head of one of that country's software development firms to say, "Job one is acquiring the diesel fuel to power our private generators; job two is writing software, and doesn't happen if we fail at job one."

Dependency on electricity has been greatly increased by the integrated circuit revolution. The common design approach for an enormous range of things is now a processor, a batch of sensors (some as simple as push buttons), and a handful of actuators. All of the difficult parts are implemented using software. Television is now digital, and depends on billion-transistor integrated circuits for every step from source to final viewing by the consumer. Film has disappeared. Music is (at least the vast majority is) delivered in digital formats dependent on those same integrated circuits. The banking system depends on computers to run the check clearing house, the stock markets are all electronic, the Post Office depends on computers to read addresses and route mail...  I told my bosses at Bell Labs that it was a software world back in the late 1970s; it has only become more so.


All of this may seem trivially obvious, but any plan to ensure that modern technology continues on into the future depends on maintaining robust reliable supplies of electricity.  The next post in this series will look at where the US gets its electricity today.

Monday, June 16, 2014

A Thought on the EPA's New CO2 Rule

Recently, the US EPA announced its proposed regulation of CO2 emitted by existing power plants.  The proposed rule follows as a consequence of (a) the Supreme Court's finding that greenhouse gases are an air pollutant under the language of the Clean Air Act, and that the EPA is therefore required to regulate it if it is harmful, and (b) the DC Circuit Court's subsequent finding that greenhouse gases are harmful.  Everyone knows that the matter will wind up back in the courts.  Ben Adler at Grist provides a nice summary of the potential legal vulnerabilities of the proposed rule.

As described in an earlier Grist piece, each state will have its own target for reduction of CO2 emissions, and each state will be allowed to develop its own plan for achieving the necessary reduction.  Washington will have to reduce its emissions by about 70%; North Dakota will only have to reduce its emissions by about 10%.  The EPA formula(s) (PDF) for calculating the required emissions targets are complicated and consider a number of factors.

One of the factors that is not included is where the electricity is consumed.  Some states produce more electricity than they consume, others produce less.  The graph to the left shows the approximate net exports for each state, in megawatt-hours [1].  California is at the top, with a negative value indicating they are a large importer of electricity.  Pennsylvania is at the other end of the chart and is the largest exporter.

Tracking exports and imports in more detail can be difficult.  Some cases are relatively straightforward.  Xcel Energy owns the coal-fired Comanche power plant in Pueblo, CO and sells the electricity generated there to consumers up and down the Front Range.  The 1.9 GW coal-fired Intermountain power plant in Utah is owned by utilities in California and Utah.  75% of the plant's output goes by HVDC transmission directly to San Bernardino County, CA; the remainder goes to utilities and electricity cooperatives in Utah.  The coal-fired Jim Bridger power plant in Wyoming is owned by Berkshire Hathaway and sells its output to two utilities operating across six states.  Oregon is one of those states.  Oregon is a net exporter of electricity, primarily hydro electricity sold to utilities in California.  Oregon generates a modest amount of in-state power from coal and imports coal-fired electricity from Wyoming and Utah.

Reducing CO2 emissions will require that money be spent on coal-fired power plants -- on sequestration technology, or on efficiency improvements [2], or on fuel conversions.  That money will eventually be collected from the pocketbooks of electricity consumers.  The fact that there are states that are exporters and importers of electricity would seem, at least to me, to create an opportunity for a certain amount of mischief.  That is, a state's plan for reducing CO2 emissions might be structured so that, as far as is possible, out-of-state consumers pay for the necessary changes.  From the examples in the preceding paragraph, Wyoming and Utah have an interest in getting California and Oregon to foot as much of the bills as possible.  In addition to Ben Adler's list of reasons that the EPA's final rule will end up in court, look for the distinct possibility of some states (and interstate companies) suing other states over their plans.

Myself, I'm in the camp that says, "A carbon tax would have been enormously simpler."  Reality, though, forces me to acknowledge that politics is the art of the possible, that such a tax would be DOA in Congress, and that not allowing Congress to delegate taxes and tax rates to the EPA is a good thing.


[1] Data from the EIA's state electricity profiles for calendar year 2012, total net generation minus total retail sales.  For the US as a whole, net generation exceeds retail sales by about 10%.  Each state's generation figure is scaled down by the US ratio so that the US Total exports comes out zero.

[2] An older conventional coal-fired plant may have 30% thermal efficiency.  That is, 30% of the heat energy released by burning the coal is converted to electricity.  New technology may achieve 45% thermal efficiency.  Such technology would lower CO2 emissions by 33% for the same amount of electricity.