Explainer: Warming planet, failing grid: The myriad ways that heat wreaks havoc on our power system–and society — @Land_Desk #ActOnClimate

Photo credit: Jonathan P. Thompson/The Land Desk

Click the link to read the article on The Land Desk website (Jonathan P. Thompson):

A scorcher has settled over the entire Southwestern United States, with highs expected to hit the triple digits for several days in a row from Bakersfield to Las Vegas to Grand Junction. Phoenicians will be doing the Summer Solstice Swelter during that long day and short night—the minimum temperature is sticking at just below 90 degrees, to give even those used-to-be-cool predawn hours an ovenlike ambience.

That type of heat can cause the human body to go haywire, short-circuiting the renal system, causing the brain to swell, blood pressure to drop, heart-rate to increase, blood clots to form. Last year this heat-caused cascading failure proved fatal for more than 300 people in greater Phoenix.

Heat-associated deaths by year in Maricopa County, Arizona. Source: Maricopa County Public Health.

Now, the electricity grid is not a living organism, but it can behave like one in a variety of ways. And just as excessive heat can ripple through the vital organs of the body, so too can it trigger chain reactions and feedback loops in the power system that keeps society churning along. Which is why during heatwaves like this one—that threatens to drag on in varying degrees of intensity throughout the summer—the power often goes out, right when folks need it most to keep their homes habitable.

To continue with the body metaphor, the grid has a heart, made up of all of the generators such as power plants and wind farms and so forth; a circulation system made up of arteries (high voltage transmission lines) and capillaries (distribution lines that carry power to your home or business); and organs, or the electricity consumers. The supply of power generated must always be equal to the collective demand. If demand kicks up, then the grid operators (the brain) have to increase the output of the “heart” accordingly.

In the West, we get our power from the Western Interconnect, which is actually broken up into about 38 separate grids, each with its own heart and brain and organs.

On a summer’s afternoon, as the temperature rises, thermostats signal air-conditioners to start running in order to keep homes and businesses comfortable and—in some cases—survivable. Cooling space requires a lot of energy. A 2013 study found that during extreme heat events, about half of all electricity use goes toward space-cooling of some sort. So when some 18 million residential AC units, plus all of the commercial units, kick in across the West, it increases the demand—or load—on the respective electricity grids significantly.

Some of that sudden increase in demand is offset by a corresponding uptick in solar generation, if available on the grid, and wind power—assuming the wind’s blowing at the time. The problem is, solar generation tends to peak in the early afternoon, but temperatures—and therefore AC-related demand—peak a few hours later. Grid operators need to turn to other resources in order to match that late afternoon peak.

Probably the best source of “peaking” power is a hydroelectric dam, which is essentially a big battery in that it stores energy in the form of water that can be run through turbines to generate power at the flip of a switch. Except, well, in the hottest, driest years, just when that hydropower is most needed, hydroelectricity is in short supply thanks to shrinking reservoirs.

Meanwhile, the nuclear reactors that are currently in service can’t be ramped up or down to “follow the load.” The same goes for coal power plants. Still, those sources provide important baseload, a fairly constant stream of power. Yet many thermal power plants run less efficiently when the ambient temperature is high, and nearly all of them—whether nuclear, coal, or natural gas (steam, not turbine)—need billions of gallons of water per year for cooling and steam-generation purposes, another problem during drought. And the warmer that water is, the less effective it is: Nuclear plants have been forced to shut down because the cooling water is too warm.

Since grid operators have no control over wind or solar generation and there aren’t enough batteries online yet, they have little choice but to turn to natural gas peaker plants, which can be cranked up quickly but are also expensive to run and emit more pollutants than conventional plants, including greenhouse gases that warm the climate and exacerbate heat waves and drought. Sometimes even that’s not enough to meet demand and grid operators must “shed load,” or do rolling power outages.

But usually all that power being pumped out of the giant, multi-generator heart of the grid is sent across the deserts in high-voltage transmission lines, where we once again run into heat-related problems: Power lines work less efficiently in high heat, causing them to sag, break, and come into contact with vegetation, which can ignite wildfires. And wildfires, in turn, can bring down transmission lines, thereby triggering chain reactions that can ripple through the entire grid and kill power—and air conditioning—for millions.

And that smoke? It’s not so good for solar power: Smoke from wildfires was so thick last summer that it blotted out the sun and diminished solar power generation in California, which meant grid operators had to scramble to make up for the loss.

Even when the power does make it to the air conditioners without triggering disasters, troubles remain. Air conditioners work by pulling heat from indoors and blowing it outside, as anyone who has walked past an AC vent when its running has experienced. Multiply that phenomenon by hundreds of thousands and you’ll get an increase in nighttime temperatures and exacerbate the urban heat island effect, according to a study by an Arizona State University researcher. Not only are the emissions from generating power to run the air conditioners heating things up, but so is running the air conditioners, themselves.

And heat doesn’t affect everyone equally. Various studies have found that heat disproportionately affects people of color and those who live in lower-income neighborhoods. That’s in part because those neighborhoods don’t have as many trees or green-spaces, which mitigate the urban heat islands. And it’s also due to the fact that they are less likely to be able to afford air conditioning equipment or the electricity to run them. It’s just another way in which wealth inequality ripples throughout society, creating health inequality, quality of life inequality, opportunity inequality, and so forth.

The first priority is to help the people who are most affected by the heat and the resulting grid failures, while also reducing greenhouse gas emissions so as not to exacerbate the heat even further. And we need to pursue solutions for the grid, by installing more batteries and energy storage, breaking down the divisions between the balkanized grids in the West, expanding transmission in some places to enable moving clean power across big distances so that solar and wind from the Interior can match up with California’s demand peak, while also focusing on micro-grids for fire-prone areas and rooftop solar paired with batteries—for everyone, not just the wealthy—so that the grid becomes somewhat redundant.

It’s a massive challenge, but we have to take it on before it’s too late.

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And on the lighter side, please witness comedian Blair Erskine’s impression of a spokesperson for the Texas grid:

Paper: #Drought impacts on the electricity system, emissions, and air quality in the western United States — PNAS

Glen Canyon Dam from the east side. Photo credit: Allen Best/Big Pivots

Click the link to access the report on the PNAS website (Minghao QiuNathan RatledgeInés M. L. Azevedo,  and Marshall Burke):

Significance

Climate-driven changes in drought could disrupt electricity systems that depend heavily on hydropower, potentially increasing generation from fossil fuel sources. Impacts from the associated emissions and air pollution could represent a large and unaccounted-for social cost of climate change. We empirically quantify the impacts of drought on fossil fuel power plants in the western United States and the consequent effects on emissions and air quality. Damages through these channels are estimated to be 1.2 to 2.5x the increase in direct economic cost of drought-induced fossil fuel electricity generation. Under future climate, these drought-induced impacts likely remain large due to increasing drought risks, and we find that even rapid expansion of renewable energy has limited ability to curb these impacts.

Abstract

The western United States has experienced severe drought in recent decades, and climate models project increased drought risk in the future. This increased drying could have important implications for the region’s interconnected, hydropower-dependent electricity systems. Using power-plant level generation and emissions data from 2001 to 2021, we quantify the impacts of drought on the operation of fossil fuel plants and the associated impacts on greenhouse gas (GHG) emissions, air quality, and human health. We find that under extreme drought, electricity generation from individual fossil fuel plants can increase up to 65% relative to average conditions, mainly due to the need to substitute for reduced hydropower. Over 54% of this drought-induced generation is transboundary, with drought in one electricity region leading to net imports of electricity and thus increased pollutant emissions from power plants in other regions. These drought-induced emission increases have detectable impacts on local air quality, as measured by proximate pollution monitors. We estimate that the monetized costs of excess mortality and GHG emissions from drought-induced fossil generation are 1.2 to 2.5x the reported direct economic costs from lost hydro production and increased demand. Combining climate model estimates of future drying with stylized energy-transition scenarios suggests that these drought-induced impacts are likely to remain large even under aggressive renewables expansion, suggesting that more ambitious and targeted measures are needed to mitigate the emissions and health burden from the electricity sector during drought.