In March 2017, Mitsubishi Hitachi Power Systems (MHPS) and Carnegie Mellon University announced the results of its Power Sector Carbon Index, which provides a comprehensive picture of the environmental impact of electricity production on emissions and its contribution to the U.S. power grid.
In celebration of “Bring Your Child to Work Day”, Paul Browning, CEO of MHPS, part of the Mitsubishi Heavy Industries Group, visited his freshmen daughter, Molly, who is studying engineering at Carnegie Mellon University where he answered her questions regarding the Index and what it means for the future of energy.
Paul – I’m more nervous for this interview than any interview I’ve ever done, because it’s with my own daughter. We are doing this in part because we are at your school and the Carnegie Mellon Carbon Intensity Index is something that we have sponsored with Carnie Mellon. And then we’re doing it in part because it’s “Bring Your Child to Work Day” – so instead of bringing you to my work, they brought me to you at the University.
Molly – You came to my work.
Paul – I came to yours, that’s right.
Molly – Dad, I was wondering if you could explain what the Carnie Mellon Carbon Intensity Index is?
Paul – Well, the Carnegie Mellon Carbon Intensity Index is something my company, Mitsubishi Hitachi Power Systems, is sponsoring, and the reason we sponsored it was because we wanted to make sure that a really important message is getting out there to the general public. This is that the carbon intensity of power generation in the United States has fallen dramatically over the last 12 years or so.
Everybody, rightfully so, is very concerned about climate change and sometimes I think we feel that the world’s not making any progress. Here in the United States, in the power sector we’ve actually made a lot of progress and we asked Carnegie Mellon, as an independent research institute, to study the data and put out this report on how the U.S. is doing in the power sector and decarbonizing it.
Molly – And why are things changing?
Paul – Well, what Carnie Mellon reported in this first Index report, is that since 2005 the carbon emissions from the U.S. power sector are down by 23%, and that’s a pretty remarkable number, that’s something I don’t think a lot of people realize. And then furthermore, they went to the next level down to work out why it is down by 23%.
One reason is the overall carbon intensity, which is the amount of carbon per megawatt hour of electricity produced, has dropped by 24%. So, if you produce a megawatt today versus 2005, it emits 24% less carbon dioxide. The reason the total emissions are down by 23% is because our electrical usage between 2005 and today has been pretty constant. So for about the same amount of megawatt hours, we’ve reduced 24% in intensity which is 23% in total emissions.
And then when they break that down, they can work out why is that happening. 53% of that reduction is because the United States has been switching from coal-fired power generation, this is the older 30-40 year old inefficient coal-fired power plants to natural gas fired power generation. There’s less carbon in a methane molecule than there is in coal and so you get about a 50% reduction just because there’s less carbon in methane. Furthermore, a natural gas power plant is more fuel efficient than a coal fired power plant, so you actually get about a 65% reduction from a modern natural gas power plant versus an older inefficient coal-fired power plant. 53% is a result of that switch from coal to natural gas, 4% is due to natural gas plants are getting more efficient. 53 + 4, is 57%, and then 40% of the change is because there’s more renewables that have been built out since 2005.
So, basically, the whole story is that in the United States power sector we’re switching from older inefficient coal-fired power generation to a combination of efficient natural gas and renewables.
Molly – Is that the same story worldwide, or is that a U.S. specific story?
Paul – It’s specific to the US in one way, we have a new abundance of natural gas in the United States that’s due to new drilling technologies, which has dropped the cost of natural gas from about 7 dollars a million BTUs a decade ago to 3 dollars a million BTUs today. This actually makes it cheaper than coal and so there’s a real economic driver to switching from coal to natural gas in the United States. That same driver doesn’t exist in some other parts of the world, for example, in Asia, where they have to import all their natural gas, natural gas there today is about 12 dollars a million BTUs so it’s actually cheaper to burn coal in Asian that natural gas.
Molly – What do you think the power plant of the future will look like?
Paul – What’s being sold right now in the United States is this combination of really efficient natural gas and renewables and that’s displacing some older, less efficient coal-fired power generation. What we think the power plant of the future is going to be, in the near future, is more of the same. More natural gas power plants along with renewables replacing older inefficient coal-fired power generation. If we look out beyond that, we’re really starting to concentrate on the idea of ‘dispatchable’ clean power.
The idea that we need to have clean power sources that remove the problem of intermittency that we have with renewables, or clean power sources that remove the problem of carbon emissions that we have right now with fossil fuel powered generation. So that means either renewables plus batteries or it means fossil fuel power generation with carbon capture and sequestration. And the reality is, we think the power plant of the future is probably going to be some combination of both of those.
Molly – What do you see as the place for engineers in the energy sector, especially for engineering students who are my age and a little older?
Paul – For an engineer that’s a freshman in college like you, I think you’re just starting to learn these tools. The more that you can turn what you’re learning into ideas, and turn those ideas into reality and just practice doing that again and again and again. No matter what you end up doing with your engineering degree, that’s great training and great progress to get you ready to go change the world.
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