Rolls-Royce’s SMR Needs 10,000 Times Less Land Than Wind Energy, Proves ‘Iron Law Of Power Density’

Last month, Rolls-Royce said that it expects to receive regulatory approval from the British government by 2024 for its 470-megawatt small modular reactor and that it will begin producing power on Britains’ electric grid by 2029.

Will that happen? Time will tell. Many nuclear projects and startups have blown past their projected in-service dates. But Rolls-Royce’s announcement is important for two reasons. First, it adds more credence to the notion that a global nuclear renaissance is, in fact, underway. Second, Rolls-Royce’s new 470-megawatt reactor design shows that due to its unsurpassed power density, nuclear energy is the only way we can produce electricity at scale while preserving the natural environment and reducing greenhouse gas emissions.

Why? The power density of the nuclear plants Rolls-Royce plans to build will need 10,000 times less land than a wind project and about 1,000 times less land than what will be required by a solar project. Due to their astonishingly high power density, the new nuclear plants will need far fewer resources like land, steel, neodymium, copper, and concrete which proves what I have dubbed the Iron Law of Power Density. More on that in a moment.

If you skipped physics in high school (I did), you may not understand why power density matters. No problem. Here’s a quick primer. Energy (measured in joules, or Btu) is the ability to do work. Power (measured in watts, or horsepower) is the rate at which work gets done. We don’t care about energy. What we want is power. We don’t necessarily care what form of energy (oil, sun, coal, or gas) that’s being used to move our car, run our television, or cook our filet mignon, we only care that we have the power we need to get our work done. And the corollary to that is also true: the more power we have, (computing power, heating power, motive power, cooking power) the more work we can do.

Power density is the measure of energy flow that can be harnessed from a given area, volume, or mass. That is, how many watts we are able to get per square meter, liter, or kilogram. And that leads back to the Iron Law of Power Density. I borrowed the Iron Law concept from author and University of Colorado professor Roger Pielke Jr., who coined the Iron Law of Climate, which says that when forced to choose between economic growth and climate action, politicians and decision-makers will always choose economic growth.

The Iron Law of Power Density is a cousin of Pielke’s edict. It says: the lower the power density, the higher the resource intensity. If you are relying on a low power-density source like corn ethanol (0.1 watt per square meter) or wind energy (1 watt per square meter) you have to counteract that paltry energy flow with big inputs of other resources. For ethanol, that means using lots of land, fertilizer, and diesel fuel to grow enough corn to produce meaningful amounts of liquid fuel. Last year, Dave Merrill, an ace reporter and data analyst at Bloomberg, reported that “Two-thirds of America’s total energy footprint is devoted to…corn grown for ethanol. It requires more land than all other power sources combined.” Merrill determined that biofuels (mainly corn ethanol) use about 80,000 square miles, an area bigger than the state of Nebraska.

Wind energy has the same problem as ethanol. To produce meaningful amounts of electricity, wind projects require vast tracts of land and staggering volumes of steel, concrete, copper, and rare earth elements. Those land-use requirements are one of the main reasons wind energy is meeting such fierce resistance across the country. As I show in the Renewable Rejection Database, some 331 communities across the country have rejected or restricted wind projects since 2013. The most recent rejection occurred on May 5 in Crawford County, Ohio, which rejected a wind project proposed by Apex Clean Energy, a firm that had seen fierce opposition to its projects including the now-dead Lighthouse Wind project in New York that was going to cover some 20,000 acres.

As I explain in my latest book, A Question of Power: Electricity and the Wealth of Nations, and in the graphic above, wind energy’s low power density means that to meet America’s existing electricity demand with wind turbines alone would require a land area twice the size of California. That’s an absurd amount of territory, particularly given that it’s nearly impossible to build wind energy in California.

What about solar energy? It has higher power density than ethanol or wind — about 10 watts per square meter — but it, too, requires lots of material inputs including polysilicon, steel, and copper. It also requires lots of land, which is why numerous communities across the country are rejecting Big Solar.

Now back to Rolls-Royce. The company’s 470-megawatt SMR will cost about $2.3 billion and will require a site of about 10 acres. That means the new power plant will have a power density of over 10,000 watts per square meter. Here’s the math: 470,000,000 watts divided by 40,489 square meters = 11,608 watts per square meter. If we assume a 90% capacity factor (meaning the plant will operate at full power 90% of the time) that works out to 10,447 watts per square meter. To be clear, that’s a very high number. As I show in the second graphic directly above, the power density of the recently shuttered Indian Point Energy Center in Buchanan was about 2,000 watts per square meter.

Rod Adams, a leading nuclear energy analyst and the publisher of Atomic Insights and host of the Atomic Show podcast, is bullish on the Rolls-Royce reactor. He said the company has the money and government backing that should allow it to succeed and get the new SMR built. “It’s a technically sophisticated company with decades of experience building complex machines including aircraft engines and nuclear power plants for submarines,” he told me on Thursday.

Another positive sign: British Prime Minister Boris Johnson is giving nuclear a big hug. Earlier this month, while visiting England’s Hartlepool nuclear power station he said nuclear is “absolutely crucial to weaning us off fossil fuels, including Russian oil and gas.” He also said the U.K will be building lots of reactors. “Instead of a new one every decade, we’re going to build one every year, powering homes with clean, safe, and reliable energy.”

To be sure, Boris says a lot of things. And yes, we’ve heard about the rebound in the global nuclear sector before. But this time, may, in fact, be different. Several factors, including soaring global prices for natural gas, and coal (the Newcastle benchmark is now at about $400 per ton), and huge uncertainty due to Putin’s invasion of Ukraine, are giving the nuclear energy sector a surge of hope and capital. But remember, it’s not just Rolls-Royce. Earlier this month, NuScale Power (ticker: SMR) went public on the New York Stock Exchange. France has said it will boost its nuclear industry.

These developments are good news for the natural environment, for our birds, bats, insects, and, yes, for people. Instead of the landscape-blighting energy sprawl that comes with wind and solar projects, the new nuclear era promises to deliver super-high-power-density reactors that spare nature and bring more zero-carbon juice to our electric grids. Rolls Royce doesn’t just have a technology that’s better than wind or solar. It has a technology that’s 10,000 times better.