I am finishing writing this blog on D-Day, Sunday, June 6th. This commemorates the day the Allied forces invaded Normandy on their way to liberating the rest of Western Europe from the Nazi menace. On April 13, 1945, they reached Farsleben—near the city of Magdeburg, in what’s now the German state of Saxony-Anhalt—and liberated me and my family. Today also happens to be an election day in this state. Many eyes around the world are focused on this election as an early indicator of the strength of the right-wing, anti-immigration party, AfD, ahead of the national German elections in September.
Due to pandemic precautions, this year’s celebrations of D-Day will be muted, similarly to those from last year. I hope that you will use the occasion to go to my last pre-pandemic D-Day entry (June 11, 2019) for my take of this important day. By the time that you read this blog, two days from now, we will all know the results of the German election in Saxony-Anhalt. Meanwhile, I am lighting a memorial candle to all the soldiers that took part in the invasion and wishing that these election results will not remind me too much of those from the early 1930s.
That aside, this blog post is about science. It will be the last blog in this series about factoring in electricity while calculating our energy use and the resulting carbon emissions.
I teach the same two general education courses almost every semester. One is focused on climate change on Earth, the other explores cosmology: what do we know about our universe and how do we know it? I emphasize the connection between the two topics. Per definition, the combination of the two covers a lot of territory. Stars are generally organized into galaxies. Rough estimates say there are about two trillion galaxies in total, with a “typical” number of more than a billion stars per galaxy.
Stars are defined in terms of conditions in their core that facilitate the fusion of hydrogen to helium, the act of which releases an enormous amount of energy. In other words, fusion runs the universe, including our existence. Our experience with fusion on Earth has mainly related to our use of our sun’s energy—which facilitates life here. We have also witnessed fusion’s destructive potential in the form of the hydrogen bomb. However, since the end of WWII, there has been an effort to recruit its enormous energy potential for peaceful and productive objectives to support human activities on this planet.
These activities have accelerated since we started to realize that our current main sources of energy are changing the chemistry of the atmosphere in a way that—in the not-so-distant future—will raise the temperature of this planet to unlivable conditions. We can look at the inhospitable surface temperature of our close neighbor Venus (around 425 oC = 800 oF) for a reminder of the most extreme possibilities. The only remedy is to replace our “dirty” energy sources with non-polluting ones. The ultimate hope in this transition is fusion energy.
Several years ago, I discussed the basic physics of fusion and the results of our attempts to utilize it in our energy transition (December 12, 2017). I strongly recommend that everyone reading through this blog revisit that earlier post on this topic (sorry about the extended homework in this blog). Meanwhile, I am borrowing one paragraph from that entry for those of you who don’t want to do all that work:
The ultimate solution to our energy problems is to learn how to use fusion as our source of energy. Since immediately after the Second World War, we have known how to use fusion in a destructive capacity (hydrogen bombs) and have been earnestly trying to learn how to use it for peaceful applications such as converting it into electrical power. It is difficult. To start with, if we want to imitate our sun, we have to create temperatures on the order of 100 million degrees Celsius. Before we can do that, we have to learn how to create or find materials that can be stable at such temperatures: all the materials that we know of will completely decompose in those circumstances. Figure 1 illustrates the facilities engaging in this research and their progress. We are now closer than we have ever been to maintaining a positive balance between energy input and energy output (ignition in the graph) but we are not there yet.
Today, I want to look at the largest coordinated global effort to learn how to fit fusion into the economy in a way that is both efficient and affordable. These qualities will help ensure its place as an important component in our energy transition. There is a facility dedicated to this study, called ITER (International Thermonuclear Experimental Reactor), which means “the way” in Latin. I mentioned ITER in the 2017 blog when I examined the rate of progress of energy transition efforts.
I am bringing all of this up so I can amplify the importance of both knowing that electricity needs to be calculated as a secondary energy source (including the multiple alternative names that we discussed in the last two blogs: Scope 2, heat rate, and, here, the distinction between Q-physics and Q-engineering) and understanding how to make those calculations. Grant Hill wrote an insightful piece a few weeks ago for WHYY, a Philadelphia educational channel of PBS, that addresses how crucial communication can be. I have emphasized some pieces that I find especially important:
A fusion experiment promised to be the next step in solving humanity’s energy crisis. It’s a big claim to live up to
It’s called the International Thermonuclear Experimental Reactor, ITER for short. Still under construction in the south of France, the huge doughnut-shaped test reactor is often labeled the world’s largest science experiment, and the next step in the journey to fusion energy. (The Latin word “iter” means “way” or “journey.”)
ITER is a product of diplomacy. In the 1980s, two longtime foes, the United States and the former Soviet Union, came together with a common mission: to harness this seemingly magical power source for something other than mutual annihilation. By then, the idea of working together was a more novel concept than fusion power itself.
ITER’s design wasn’t finalized until 2001, but its approval carried a big punch: a promise to create 10 times more energy than it consumed. At that point, 35 countries had joined the project to split the cost (and benefits) of such an achievement. The final price tag is still up for debate. If you ask ITER, the bill will run around $25 billion. The U.S. Department of Energy puts it at nearly $65 billion.
ITER’s made a bold promise: to produce 10 times the amount of energy it consumed. Even though ITER was only a test reactor that would never actually connect to the grid and produce electricity, such a result would be a record-smashing number for fusion reactors compared to its predecessor, a reactor called JET in the U.K. That one couldn’t even break-even — meaning it produced less power than it consumed.
ITER’s remarkable energy-production upgrade is thanks to the reactor’s scaled-up design. When it comes to doughnut-shaped fusion reactors called tokamaks, such as ITER and JET, size is a limiting factor. It is ITER’s enormous magnitude, nearly 240 feet tall and weighing 23,000 tons, that allows the organization to make such big claims. And the ITER organization has done so, frequently touting its 10-times power gain number, often called the Q ratio.
But when Krivit needed to double-check some figures for a book he was writing, a closer look at the Q ratio ITER promised revealed something concerning, he said.
“I assumed that everybody knew the rate of power that went into these reactors. But the scientists that I spoke to said, ‘Well, actually, we don’t measure the rate of power that goes into the fusion reactors.’ And I’m going, `What are you talking about?’” Krivit said. “We all thought that the rate of power that you talked about from the JET reactor was a comparison of the power coming out versus the power coming in. And they said, ‘No.’ That power ratio doesn’t compare the rate of power coming out versus power coming in. It only compares the ratio of the power that’s used to heat the fuel versus the thermal power that’s produced by the fuel.”
In reality, the Q ratio only speaks to what happens deep inside the reactor when fusion occurs, not the total amount of energy it takes to run the whole operation, or the actual usable electricity the fusion reaction could produce.
According to Henderson, physicists and non-physicists think of Q differently.
“For me to put in 50 megawatts of power, I need to pull from the grid about 150 megawatts. And so an engineer would say, ‘Well, Mark, wait a minute, you know, you’re pulling 150 megawatts from the grid, you convert it to 50 megawatts, it gives me 500 megawatts out, but then those 500 megawatts are going to heat water that turns a turbine that then generates electricity that would put back to the grid roughly 150 megawatts,’” he said. “So from an engineer’s perspective, if ITER was a [commercial] fusion reactor, it would be giving a Q-engineering roughly of about one.”
A Q-physics ratio of 10, but a Q-engineering ratio of one. Henderson doubted whether actual engineers who work on fusion sites correctly understood this difference, let alone the public. But it’s an important difference, nonetheless.
“That means the ITER reactor is effectively a zero-power reactor,” Krivit said. “If the design works as expected, we’re going to get the same rate of power coming out as the power going in. Zero extra power that would be available to use for any practical purposes.”
Since we are starting to pay not only for our electricity energy use but also for the carbon emissions that result from that electricity’s production, it is high time that we include secondary energy sourcing in our educational objectives. We need to know both the monetary and environmental costs of the electricity that shapes the world we live in.
*Update: it looks like my candle worked—the right-wing, anti-immigration party, AfD, lost resoundingly in the German state’s election!
nice post. thanks for sharing