19 August 2019

Coal-powered energy plants continue to close

As reported by Scientific American:
When the Navajo Generating Station in Arizona shuts down later this year, it will be one of the largest carbon emitters to ever close in American history.

The giant coal plant on Arizona’s high desert emitted almost 135 million metric tons of carbon dioxide between 2010 and 2017, according to an E&E News review of federal figures.

Its average annual emissions over that period are roughly equivalent to what 3.3 million passenger cars would pump into the atmosphere in a single year. Of all the coal plants to be retired in the United States in recent years, none has emitted more.

The Navajo Generating Station isn’t alone. It’s among a new wave of super-polluters headed for the scrap heap. Bruce Mansfield, a massive coal plant in Pennsylvania, emitted nearly 123 million tons between 2010 and 2017. It, too, will be retired by year’s end (Energywire, Aug. 12).

And in western Kentucky, the Paradise plant emitted some 102 million tons of carbon over that period. The Tennessee Valley Authority closed two of Paradise’s three units in 2017. It will close the last one next year (Greenwire, Feb. 14).

 “It’s just the economics keep moving in a direction that favors natural gas and renewables. Five years ago, it was about the older coal plants becoming uneconomic,” said Dan Bakal, senior director of electric power at Ceres, which works with businesses to transition to clean energy. “Now, it’s becoming about every coal unit, and it’s a question of how long they can survive.”..

There’s also this: The vast majority of super-polluters have no closure date in sight. That’s because massive coal plants generally benefit from large economies of scale. Because they crank out power around the clock, their cost of generating electricity is relatively cheap.

“The coal plants remaining have generally installed all the environmental controls,” Larsen said. “There are no additional regulatory threats, or they are cost-effective in a world where gas is $2.50 per MMBtu.”

7 comments:

  1. Good. Policy matters. The previous administration set out detailed policies to close these polluters down and replace them with wind and solar. The current administration can not be bothered with policy other than for headlines, so the underlying economic realities continue. Here the carelessness of the current administration is a good thing.

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  2. Hmm.. my reading of what is going on is somewhat what different.

    The Obama era EPA required state to phase out all coal (and eventually natural gas) with non-CO2 emitting sources of utility power and included specific targets for C02 emissions. That is, to start working to replace coal and natural gas with wind, solar and geothermal. However, in 2016 this was taken to the Supreme Court, which voided this rulling, since it exceeded the EPA's legal authority to implement "the best system of emission reduction" for pollutants (from the Clean Air Act). That is irregardless of if CO2 is a pollutant, which is a totally other question.

    So since 2016, there has been NO CO2 limits on utility power production.

    The EPA issued a new regulation last month, requiring states to implement the "best system of emission reduction", which has been interpreted as the best set of on-site efficiency improvements and emission controls. Note, this has gone from zero rules, to rules covering more than 600 coal power plants. If you go read the rgulations, they require a cut in CO2 emissions to 34% below 2005 levels, which is about the previous Ombama era regulations.

    Now, I'm not real happy with this regulation, but I think its a step in the right direction.

    What's going on now I think is that market forces are pushing coal out of the market. Coal plants are being replaced with natural gas which is having big impacts upon CO2 emission per kWh of power produced. According to the US Dept of Energy, Energy Information Admistration, energy-related CO2 emissions declined by 14% in the U.S. from 2005 to 2017 while increasing 21% globally. So we're heading on the right track.

    One of the problems we still need to resolve though is energy storage. There's a very well known curve of power needs as a function of time over the day -- it peaks in the afternoons, particularly on hot summer days (due to air conditioning and industrial power needs). However, wind power typically peaks in the evenings and mornings -- outof synch from the power needs. And both wind and sold are variable power sources -- the amoutn of power put out from a wind farm or solar field varies with time. So we either have to go for less efficient "peaking" power units which cycle up and down to match supply to demand for electricity, or come up with large-scale power storage systems. And regrettably, large scale power storage systems, other than large reservoirs and dams are still fairly speculative technology. People are working on it, but the available of large scale, fairly low cost systems aren't here yet.

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    Replies
    1. I stand corrected. You know the details better than I do.

      come up with large-scale power storage systems

      So, you are right that one thing that we still need a massive transformation on is a change in thinking on how power utilities work. Right now, power plants make power, put that on the net and homes and businesses can siphon of as needed. Changing the production from coal, nuclear and gas to wind and solar requires a fundamental change. Utilities need to change their thinking of just pushing power to consumers to managing power for consumers, because power will not just come from plants anymore. Urban consumers may have solar cells on their roof tops, and rural areas may have wind and solar farms all over the place.

      I have not seen how that change can be figured out properly. Sadly, many power companies really want to stay in the business of producing power and pushing it and they form a powerful lobby to stop any change.

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    2. Hi Nepkarel,

      I do have to comment on one minor thing here, which I think is related to the issue. You said:

      >Right now, power plants make power, put that on the net and homes and
      >businesses can siphon of as needed.

      That's not strictly true -- you can't put energy on the grid, unless there are homes and businesses which take power off the grid. You have to very closely match production and demand, on a second-by-second basis. If you dont' the grid can collapse and you have a huge power failure.

      That's a very complicated technical problem which people sort of gloss over. The way its handled (in a very simplistic explaination) is they can vary the frequency of the Alternativing Current (AC) on the grid a bit -- so if you turn off a light switch the power goes from 60 cycle AC to say 60.0001 and if you turn it on, it goes from 60 cycle to 59.999 cycles per second. However, you can't vary the frequency much, else things like electric motors wont work. The utilities and inter-system operators (ISOs -- who handle the distribution in states and regions of the country) are always juggling supply the demand -- shifting things around, to try to keep the grid stable

      >[...]Utilities need to change their thinking of just pushing power to
      >consumers to managing power for consumers, because power will not just
      >come from plants anymore. Urban consumers may have solar cells on
      >their roof tops, and rural areas may have wind and solar farms all
      >over the place.

      I've actually seen a lot of forwards thinking by some of the big utilities and ISOs. Part of is that they are in the business of doing this, so they want to stay in business --

      >I have not seen how that change can be figured out properly. Sadly,
      >many power companies really want to stay in the business of producing
      >power and pushing it and they form a powerful lobby to stop any
      >change.

      Remember also that most power companies are public utilities. That is, even if they are a private company they are heavily regulated in the prices they can charge and the profits they can make. This is because they are a "public monoply".

      For example, in San Francisco Pacific Gas & Electricity (PG&E) is the utility that hooks your house to the grid, and provides the grid electricity. In exchange for that, the state public utilities commission sets what rates they can charge for electricity, which puts a limit on any profit they can make. If they want to charge more, they have to have the rate increase approved through the state PUC. And since they also have shareholders who own the company and to whom they pay dividends for investing in them, they cant just decide push their profits up or down. If for example, PG&E wanted to invest in a large city scale storage system, it would probably cost billions -- but they would need the approval of their shareholders, and the PUC if this might affect their rates they would need to charge to customers.

      Delete
  3. And while we worry about coal...

    https://www.animalsaustralia.org/features/lets-talk-about-climate-change.php

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  4. The best part about the local coal powered electric generator is when it closed. That yellow grey haze that one would see on cold winter mornings went away. The plant was the top polluter in the state! We got to see the two cooling towers imploded. When built, they were the tallest structures in the state outside of Boston. They were in use for about seven years.

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