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Energy Matters: Energy intensity matters


As you’ve probably noticed, we’re in the midst of a worldwide energy transition from carbon-emitting fuels to green renewables. In the midst of such upheaval, we shouldn’t be surprised by the effects of human resistance to change, and human doubts about successful change.

But when fear of change is coupled with the resistance of powerful industries and their political friends, the rhetoric can get out of hand. In times like these it’s especially important to analyze alarmist rhetoric quantitatively whenever possible.

One of the most popular arguments is that renewables simply cannot suffice to meet our needs.

We recently heard an interview with U.S. Congressman John Curtis (R. Utah.) in which he expressed just such skepticism. He claimed to have spoken to Singapore’s representatives at the U.N. climate summit: “They told me if they put a solar panel on every house, on every business, on every square empty piece of land, that would produce about 10% of the energy they need. So we can’t just say that’s the only answer.”

To understand the irrelevance of this observation to the worldwide potential of green renewable energy, we need to step back and look at a few simple concepts and numbers about the energy intensity of countries and power sources.

Singapore is a very densely populated, very small, and rich country. The question of how much area is needed to supply renewable energy to a country requires consideration of how much energy is used per square meter of the country, or its energy usage intensity.

In response to Curtis’s use of Singapore as an example, we decided to compile energy use data on every nation. Using the known sizes of those nations, we calculated their energy usage intensity on an area basis. At the top of the list was-–you guessed it—Singapore! So Rep. Curtis chose as an ostensibly typical example the nation that is the most difficult to power with wind and solar.

And it isn’t by a little bit. Singapore uses about 160 watts for every square meter (W/m²) of its own land area. Even the second-place nation of Qatar uses “only” 5.5 W/m², about 30 times less than Singapore. The US, because of its vast area, ends up in 41st place with only about 0.32 W/m², making Singapore literally 500 times more difficult to supply than the US. Australia is last on the list at 0.025 W/m², which is 6500 times less than Singapore’s use.

Because the energy intensity of renewables such as wind and solar is also calculated on an area basis, this number can give a sense of how much land area would be required in a given nation. For example, the intensity of solar energy in the US, on average, after efficiencies, darkness, and clouds are accounted for, is around 25 W/m².

If the US energy usage intensity is 0.32 W/m², then we have available 25/0.32 = 78 times as much available solar energy than we use. In other words, we need 1/78th, or about 1.3%, of our land to supply all of our energy if it were supplied by solar. (Note: this does not mean that we are advocating for all solar, or any specific mix of non-carbon energy sources. We are just trying to show where a relatively straightforward calculation can get you.)

So what about Singapore? They do have a difficult problem in shifting to renewables. They are also looking for solutions to that problem. For example, a proposed project would bring power from Australia to Singapore (Australia is last on the intensity list). A 45-square-mile solar array in NW Australia would be connected directly to Singapore by a massive 3100-mile undersea cable. While not the full answer to its energy needs, it could supply 15% of Singapore’s electricity. This is a very large solar array, but if you superimpose a square of this area onto a map of NW Australia, it looks quite small. (6.5 miles on a side.) Singapore is also separated from Malaysia by a narrow channel and could easily import power from there.

Energy intensity can pose big challenges, but there are always potential solutions. Even now, some nations struggle with inadequate domestic energy resources but work it out with international energy imports. So visualize such commerce – minus the toxic and polluting transportation accidents associated with oil tankers and pipelines!

As the shift to renewables gathers momentum, dire warnings from fossil fuel advocates increase in pitch and intensity. Some people seem easily convinced that our civilization will crumble if we stop burning oil – one such group burst into guffaws during the State of the Union address, at the President’s perceived understatement that we may remain reliant on fossil fuels for another decade or so.

But by applying a little quantitative analysis to the terrorizing rhetoric, we can vanquish the specters of scarcity. The numbers should give us the confidence to laugh right back at the never-ending stream of scary life-without-oil memes!

Paul Stancioff, PhD., is professor emeritus of physics at UMF. Cynthia Stancioff is a re-writer of her own and others’ prose. Email: [email protected] or [email protected] Previous columns can be found at https://paulandcynthiaenergymatters.blogspot.com/.

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