“Here’s a multibillion-dollar question that could help determine the fate of the global climate: If a tree falls in a forest—and then it’s driven to a mill, where it’s chopped and chipped and compressed into wood pellets, which are then driven to a port and shipped across the ocean to be burned for electricity in European power plants—does it warm the planet?
Most scientists and environmentalists say yes: By definition, clear-cutting trees and combusting their carbon emits greenhouse gases that heat up the earth. But policymakers in the U.S. Congress and governments around the world have declared that no, burning wood for power isn’t a climate threat—it’s actually a green climate solution. In Europe, “biomass power,” as it’s technically called, is now counted and subsidized as zero-emissions renewable energy. As a result, European utilities now import tons of wood from U.S. forests every year—and Europe’s supposedly eco-friendly economy now generates more energy from burning wood than from wind and solar combined.”
“Nevertheless, the global transition away from fossil fuels has sparked a boom in the U.S. wood-pellet industry, which has built 23 mills throughout the South over the past decade, and is relentlessly trying to brand itself as a 21st-century green energy business. Its basic argument is that the carbon released while trees are burning shouldn’t count because it’s eventually offset by the carbon absorbed while other trees are growing. That is also currently the official position of the U.S. government, along with many other governments around the world.”
“critics of the industry have suggested an alternative climate strategy: Let trees grow and absorb carbon, then don’t burn them. Deforestation is a major driver of climate change, and the United Nations climate panel has warned that the world needs to end it worldwide to meet the ambitious Paris emissions targets for 2050.”
“European experience shows that general policies to promote renewables can spark a massive shift to wood-burning if biomass isn’t specifically excluded.”
“Enviva’s product would not exist without loggers who clear-cut forests into barren fields with motorized “feller-bunchers,” but the company tries to emphasize that its business is about growing trees as well as killing trees. Enviva requires the landowners who supply its wood to promise to replant their forests, and it uses GPS technology to track and trace every harvest to see if they comply. The company has also committed to help protect 35,000 acres of threatened bottomland hardwood forests and restore 5,000 acres of natural longleaf pine.”
“Jenkins wants the public to see the big picture: Southern forests are growing overall, with more trees being planted than cut, and Enviva’s demand for wood helps encourage landowners to keep their forests as forests. The Southeastern U.S. produces one-sixth of the world’s timber, and less than 4 percent of that harvest ends up as pellets.
“one thing both sides agree on is that it matters what kind of wood ends up in the pellet mills, and what would have happened to that wood otherwise. Policymakers and academics have made all kinds of theoretical assumptions, but it’s not hard to find the reality on the ground.”
“In the decade since Enviva started manufacturing pellets, the Dogwood Alliance has repeatedly exposed gaps between the company’s sustainability rhetoric and its actions. In 2018, for example, a Dutch TV station working with Dogwood followed some logs from another cypress swamp near the Virginia border back to Enviva’s mill. Smith and I returned to the scene three years later, and while the deforested high ground around the swamp had been recolonized by a thick tangle of grasses, bushes and scrub oak, there wasn’t much growing back in the low-lying wetlands, just some sad-looking stumps poking out of the murky water. Smith warns that if governments keep subsidizing the conversion of trees into energy, enormous swaths of environmentally valuable forests around the world will end up looking like that.
Enviva officials say they no longer accept any cypress wood at their mills, or for that matter any other wood harvested from ecologically sensitive areas. They say they now source only 3 percent of their wood from the increasingly rare bottomland hardwood forests that are such culturally resonant symbols of the South—and only from “non-sensitive” ones. But Jenkins admits the company made some questionable sourcing decisions in the past.”
“what’s clear from talking to people in North Carolina, and from a few hours standing outside two Enviva mills watching logging trucks come and go, is that much of the wood that gets pelletized isn’t unmerchantable waste wood. It’s pulpwood—whole pine and hardwood trees as well as wood chips that could otherwise be sold to paper mills. It’s not thick or unblemished enough to turn into telephone poles, houses or high-quality furniture, but much of it is fine for Amazon boxes, toilet paper and the fluff inside diapers; one member of Enviva’s sustainability team described it as Walmart wood rather than Gucci wood. I later spent an hour outside a nearby paper mill watching what kind of wood arrived there, and the trucks were bringing in the same kind of logs they brought to Enviva.
That means Enviva isn’t just cleaning up around the edges of the logging industry—it’s increasing demand for wood in the South. And that means additional trees would need to be logged to feed the paper mills that are losing trees to Enviva; the increased demand for pulpwood will require an increased supply of pulpwood. Even if new trees are planted in their place, many studies suggest they will take decades, and in some cases centuries, to absorb enough carbon to “pay back” the carbon debt from burning the older trees. That’s a problem, because scientists don’t believe the world can wait decades, much less centuries, to cut emissions.”
“Over the past three decades, 30 states — red and blue alike — have passed laws requiring electric utilities to use more clean energy. Since 2015, 10 states have adopted 100 percent clean electricity standards, requiring the transition to fully 100 percent carbon-free power. And six more have committed to that goal. State laws are popping up so fast, it’s hard to keep track. Across the country, 170 cities have policies to get to 100 percent clean. As a result, more than one in three Americans already live in a place that’s committed to reaching 100 percent clean power.
We know this approach is technologically possible. Wind, solar, batteries, transmission lines, and other technologies can replace dirty fossil fuels. Google, one of the largest electricity consumers in the country, is aiming for 100 percent clean power, real-time at all its facilities by 2030.
With all this state and local leadership, it’s not surprising that this approach is popular with the public. In independent polls from both Data for Progress and the Yale Program on Climate Change Communication, run over the past few months, more than two-thirds of voters support the federal government moving the country to 100 percent clean power by 2035.
And once we implement this policy nationally, it should stay popular because clean energy saves customers money.”
“Many utilities continue to operate old, uneconomic coal plants. In just three years, these plants cost customers an additional $3.5 billion to keep open — and that’s before we add in all the extra hospital bills for folks breathing in their pollution day after day. Or the cost of destabilizing our climate. Replacing these dirty plants with clean power is not only good for our health; it’s also good for our wallets.”
“In our research for our report, we spent months talking with congressional offices, parliamentary experts, think tanks, climate advocates, and others, and have concluded that it is possible to pass a CES through the budget reconciliation process. In our report, we identify several ways a CES can fit with the Byrd Rule.”
“The researchers found that shifting to clean energy is feasible and easily pays for itself by eliminating the immediate and long-term harms from burning fossil fuels.
But they also placed a great deal of emphasis on making sure the costs and benefits of the shift to clean energy are spread equitably. This is essential, they conclude, to getting buy-in from a wide coalition for the major changes needed to eliminate greenhouse gas emissions. Otherwise, there could be strong resistance that would undermine progress.
The fear of consequences of the shift to clean energy has thwarted many proposals to address climate change over the years. For example, the cap and trade legislation that passed the House in 2009 and died in the Senate the next year was framed by opponents as a tax that would hamper the economy.”
“A clean energy transition is not simply a matter of replacing coal power plants with solar and wind energy. It is also about making sure that the communities that depend the most on fossil fuel industries are compensated for losses to their economies and that those who have suffered in the shadows of smokestacks have an opportunity to seize the light.”
” Households across Japan are likely to get hit by massive electric bills this month, after the price of wholesale electricity there spiked from about 13 cents per kilowatt-hour in December to an unprecedented peak of more than $1 on Jan. 7. ”
“The spike was partially a pandemic-related anomaly. But it was also an ominous sign of things to come for Asian countries working to curb their carbon footprints.
The immediate cause of the spike was bad weather. Japan was hit by an unseasonable cold spell, sending electricity demand in some regions to 10-year highs as homes and businesses cranked up electric heating systems. That in turn caused a sudden shortage of natural gas, which provides 20% of the country’s power and is entirely imported in liquid form (LNG) on ships. Despite the demand, several of Japan’s biggest utilities were forced to roll back power plant production, as the price of gas more than quadrupled from the beginning of December, hitting levels 1,000% higher than the record lows seen during pandemic lockdowns in May. A similar story played out in China and South Korea, turning the gas crunch into a regional issue.
The timing couldn’t have been worse: LNG was already tight as export facilities in several of the countries that normally supply it to Asia—particularly Australia, Qatar, Malaysia, and Indonesia—had experienced an unusual cluster of concurring outages in the preceding months.”
“as more Asian economies put more of their eggs in the LNG basket, they become increasingly exposed to sudden wild price swings. Supply disruptions in LNG exporting countries appear likely to continue in the near future as the global economy recovers from the pandemic”
“Part of the solution, Tsafos said, is for the Asian LNG market to embrace more steady, long-term contracts rather than the on-demand purchases that are the norm today. Delivering gas by ship on demand, instead of by a fixed pipeline, allows buyers and sellers more flexibility in theory, but becomes a problem when too many buyers are clamoring for the same shipment. Asian countries also need a better network for managing the regional flow of LNG, and will have to continue investing in alternative clean energy systems, including renewables and grid-scale energy storage, he said.
“There’s no real point, if you’re aiming for decarbonization, to go for an expensive, volatile fuel like gas,” Robertson said. “You’re better off looking at alternatives, and that’s the conclusion a lot of these countries will come to.””
“It’s not yet clear how many Texans died amid the cold, but several people died after they lost power, including an 11-year-old boy. Others died from carbon monoxide poisoning as they burned fuel indoors or ran their cars in desperate attempts to stay warm. Millions lost drinking water for days.
The blackouts cost the state economy upward of $130 billion in damages and losses, and some people who did have power saw their bills spike by thousands of dollars. Grid operators say that the situation could actually have been a lot worse, with the system minutes away from a monthslong blackout.
Texas politicians have not earned much sympathy from the ordeal. Texas Sen. Ted Cruz derided California’s “failed energy policies” when the Golden State suffered blackouts last year. Gov. Greg Abbott went on television to erroneously link the power outages to the Green New Deal. Other Texas politicos blamed iced-up wind turbines for the electricity shortfall when the majority of the power losses were from natural gas.
But this was a disaster that Texas should have seen coming. The state’s power grid has been creaking for years with underinvestment, despite previous winter outages, including one in 1989 and one in 2011 under very similar circumstances. And since 2011, the Texas population has grown by more than 4 million people to nearly 30 million residents, further increasing energy demand.”
“By now, the factors behind the Texas winter blackout are well-established: The coldest temperatures in 30 years triggered a sudden spike in wintertime energy demand, while the chilly weather led to coal piles freezing, a nuclear reactor tripping offline, and wind turbines icing up. Most importantly, the state’s largest source of electricity, natural gas, suffered shortfalls as wellheads froze, icy condensation blocked pipelines, and compressor stations shut down.
Much of the remaining gas was prioritized for heating rather than electricity. In total, about 34,000 megawatts of power generation shut down, more than 40 percent of peak winter demand.
Faced with such huge a mismatch between supply and demand, grid operators initiated blackouts to relieve the grid in the hope of staving off even more outages.”
“The Texas Public Utility Commission did issue guidance for making the state’s power grid more resilient to extreme weather, including severe cold, but the guidelines were voluntary and largely ignored.
Another issue for Texas is that the state’s electricity system is deregulated and almost entirely market-driven, unlike other states that have more specific rules about how the system should be run. In Texas, retail utilities buy electricity from power providers — companies that operate power plants — at fluctuating prices based on supply and demand and then sell them to customers.
The idea was that this would allow the power system to self-regulate and self-optimize while providing lower energy prices than a more regulated market. Periods of high electricity prices would spur generators to put more electrons on the grid and vice versa.
In practice, what this system meant was that when wind and solar power were abundant, they could undercut other power generators in price since wind and solar have no fuel cost and very low operating costs. Coal, nuclear, and gas power plants were then pushed to recoup their operating costs during periods of higher energy demand while also competing with each other, narrowing the windows where they could operate profitably. That left little incentive to build up extra electricity production capacity to deal with unexpected demand spikes or supply shortfalls.
“In fact, the incentives direct you to remove capacity from the market,” Hirs said. “If I add capacity to the market, I’m ensuring lower prices.”
The system worked when energy supply and demand followed predictable patterns. But when it deviated, like it did during Winter Storm Uri, it led to outages. As for customers, they ended up paying more. According to an analysis by the Wall Street Journal, Texas residential electricity customers under deregulated utilities paid $28 billion more than they would have under electricity rates charged by conventional regulated utilities in the state.
So the promise of greater reliability and lower costs did not materialize for millions of Texans under the state’s free-for-all, go-it-alone energy system. “This is a collision of naïve idealism and the real world,” Hirs said. ”
“While the Texas grid is unique in many respects, the problem of underinvestment in energy infrastructure is all too common throughout the US. Much of the power grid was built decades ago. In addition to the wear and tear that comes with age, the power grid is stressed by a growing population and its rising energy demands.”
“The broader problem is that every power system struggles to make the case to spend money on things that may never be used. The costs are upfront but the benefits are far away and theoretical. And that case doesn’t just have to be made to regulators, but to consumers.”
“Just like a blackout isn’t the result of any single point of failure, protecting the grid against them demands more than any single solution.
Faced with the prospect of more outages, there are a number of technical fixes: More energy storage, distributed power generation, interconnections across the major power grids, greater redundancy, microgrids, demand response, increasing energy efficiency, and hardening infrastructure.
But these things all cost money or eat into the margins of existing utilities. Trying to completely avoid all types of blackouts and grid disruptions stands to be prohibitively expensive, so part of the solution will also be managing failures and learning to bounce back after an outage.”
“it wasn’t as if those running the Texas energy system’s various fiefdoms—the grid, the power plants, the natural gas–production facilities—hadn’t been warned about the dangers of severe weather. Hell may not freeze over, but history suggests that Texas’s energy system does—and with some frequency. In 1989, in 2003, and in 2011, the state experienced, to varying degrees, simultaneous shutdowns of power plants and parts of its natural gas–producing infrastructure, as significant swaths of both of those critical systems were incapacitated by arctic temperatures, triggering blackouts.
The frigid weather during the first four days of February 2011 knocked off enough power generation throughout ERCOT—about 29,000 megawatts of capacity—that ERCOT initiated blackouts affecting about 3.2 million customers, according to a voluminous postmortem of the failure produced in August 2011 by the Federal Energy Regulatory Commission and the North American Electric Reliability Corp. That report suggested the state add teeth to its effort to gird its energy infrastructure for wintry weather. Among its policy recommendations was that in states in the Southwest, including Texas, legislatures require power companies to submit winterization plans and give their public-utility commissions the authority to require senior executives of power companies to sign off on those plans and the authority “to impose penalties for non-compliance.” Magness, the ERCOT chief, said that in the wake of the 2011 report he and others met with Texas power generators to suggest that they better winterize their facilities. He was asking, not telling. “It wasn’t a conversation like, `I’m your regulator and you have to do this,’” he recalled. “It was sharing those best practices.””
“Under the deregulation scheme passed by the Legislature more than two decades ago, Texas has a market design that allows generators to make money only by selling juice—not for investing in equipment that could help produce extra power in the event of an emergency. Critics contend that this approach, part and parcel of Texas’s aversion to regulation, makes the state’s energy system less reliable, even as it boosts profits for some market participants. Based on their biographies on the ERCOT website, at least eleven of the fifteen ERCOT board members have current or prior ties to the energy industry.”
“Texas lawmakers, as they investigate what went wrong this past week, ought to explore weatherization mandates.”
“better weatherizing power infrastructure, like inducing electricity producers to invest in extra generating capacity, likely would raise Texans’s electricity rates. “Is it worth the cost to consumers?” he asked. I asked him if ERCOT had any answer to that question. “I am not aware,” he said, “that we have ever conducted a real cost-benefit analysis on that topic.””
“the electricity blackout and frozen pipes in Texas had significantly curtailed the state’s production of oil and natural gas. IHS estimated that nearly 20 percent of natural-gas production, and perhaps an equal or greater percentage of oil production, in the continental U.S. in the first half of February had been shut in—and that the Permian Basin, the big oil-producing region that sits largely in West Texas, accounted for the biggest share of that production drop.
A couple of hours later, the governor, who earlier in the week had called for top ERCOT leaders to resign, issued an announcement. Years after Texas officials had been advised to do so, Abbott said he would ask the Legislature to mandate the winterization of power plants across the state—and to “ensure the necessary funding” for it.”
“In a sharp contrast to the Trump administration’s focus on increasing fossil fuel production, Biden’s orders will press pause on auctions of federal lands and waters to oil and gas companies, expand conservation protections for large swathes of federal land, create a new civilian conservation corps and promise to deliver economic help to coal-producing regions suffering from the industry’s decline.
Biden will still need Congress to accomplish his target of spending $2 trillion on climate change to help reach the goal of eliminating greenhouse gas emissions from the power sector by 2035 and across the economy by 2050. But the orders to be issued Wednesday show Biden taking aggressive steps to launch a government-wide effort toward tackling climate change.”
“Last week, on his first day in office, Biden signed an executive order calling for reconsidering methane emission rules from new oil and gas sources, reversing Trump rules that rolled back vehicles’ tailpipe carbon dioxide limits, and canceling a permit for the Keystone XL pipeline, the subject of pitched political battles for a decade.
Wednesday’s orders fill in many of the details left out of last week’s orders, including setting the date that Biden will convene a promised climate change summit with world leaders for April 22, Earth Day.
The new orders will also address “environmental justice” issues, such as by establishing new commissions to address the concerns of so-called fenceline communities that are disproportionately people of color or low-income families that live near pollution sources. Biden is also directing agencies to weigh the climate change effects of all their decisions, a move that could affect procurement strategies for government vehicle fleets or electricity production.”
“The order that has generated the sharpest opposition from oil companies is one that promises to re-write the relationship between the industry and public lands. The Biden administration will order an open-ended freeze on offering public land for oil and gas drilling and coal mining, pending reviews of whether such leases were in the public interest. Under that review, the administration is expected to consider whether to add language to new government lease agreements to tighten standards on greenhouse gas emissions and increase the royalties that companies must pay for minerals they produce on public land.”
“Wednesday’s move will not affect production currently underway or the oil and gas leases and permits that companies had stockpiled under Trump administration in expectation of new restrictions. That means oil and gas production on federal land, which contributes about one-fifth of overall U.S. production, will not stop immediately, with activity likely to continue for at least another year, energy analysts have said.”
“a pause on new activity could come back to take major bite out of some state budgets, especially those with an out-sized dependence on oil production for revenue, such as New Mexico, which gets more than 10 percent of it revenue from the activity.
New Mexico Chamber of Commerce President and Chief Executive Rob Black said the moratorium would simply lead companies to shift their operations to neighboring Texas, a state with little federal property and a state oil industry regulator who has called concerns about greenhouse gas emissions “misplaced.”
“It won’t further our shared goals on carbon emissions,” Black said during a call with reporters. “It would just cause production to move a few miles down the road to private oil and gas leases [in Texas] or will incentivize it to go overseas to Saudi Arabia and Russia.””
“The main problem facing renewable energy is that the biggest sources, wind and solar, are variable. Whereas fossil fuel power plants that run on coal and gas are “dispatchable” — they can be turned on and off on demand — wind and solar come and go with, well, the wind and sun.
Building an electricity system around wind and solar thus means filling in the gaps, finding sources, technologies, and practices that can jump in when wind and solar fall short (say, at night). And the electricity system needs to be extremely secure and robust, because decarbonizing means electrifying everything, moving transportation and heat over to electricity, which will substantially raise total electricity demand.
The big disputes in the clean energy world thus tend to be about how far wind, solar, and batteries can get on their own — 50 percent of total power demand? 80 percent? 100?) and what sources should be used to supplement them. (See this much-cited 2018 paper in the journal Joule on the need for “firm, low-carbon resources.”)
The answer currently favored by renewable energy advocates is more energy storage, but at least for now, storage remains far too expensive and limited to do the full job. The other top possibilities for “firming” electricity supply — nuclear power or fossil power with carbon capture and sequestration — have their own issues and passionate constituencies for and against.
Geothermal power, if it can be made to reliably and economically work in hotter, drier, and deeper rock, is a perfect complement to wind and solar. It is renewable and inexhaustible. It can run as baseload power around the clock, including at night, or “load follow” to complement renewables’ fluctuations. It is available almost everywhere in the world, a reliable source of domestic energy and jobs that, because it is largely underground, is resilient to most weather (and human) disasters. It can operate without pollution or greenhouse gases. The same source that makes the electricity can also be used to fuel district heating systems that decarbonize the building sector.
It checks all the boxes.”
“Tapping into it, though, turns out to be pretty tricky.”
“Though hydraulic fracturing as a technique has been around since the 19th century and the first commercial fracking for gas took place in the 1940s, the most recent fracking boom started in earnest around 2005. That’s when the rising prices of oil and gas forced energy companies to look for other sources, when related techniques like horizontal drilling and low-cost slickwater fracking matured, and new estimates revealed the gargantuan amounts of gas stored in formations like Marcellus Shale.
Fracking has now become the dominant technique for extracting oil and gas in the US.”
“During much of the fracking boom, the US economy grew and emissions declined. One study found that between 2005 and 2012, fracking created 725,000 jobs in the industry, not counting related supporting jobs. “This has been one of the most dynamic parts of the U.S. economy — you’re talking about millions of jobs,” Daniel Yergin, vice chairman of IHS Markit and founder of IHS Cambridge Energy Research Associates, told CNBC.
That’s largely due to natural gas from fracking displacing coal in electricity production. Natural gas emits about half of the greenhouse gas emissions of coal per unit of energy. It doesn’t have the massive land footprint that open pit mines or mountaintop removal coal mines do. While it has its own pollution problems, burning natural gas doesn’t produce pollutants like ash and mercury, which can pose health and environmental hazards for years.”
“Natural gas’s flexibility has also eased the integration of variable renewable energy sources like wind and solar power. When the breezes slow down and clouds form above, natural gas steps in. This has reduced the need for other ways to compensate for intermittency, like energy storage.”
“fracking has helped insulate the US from global economic shocks, particularly in oil markets. US shale oil has provided more than half the growth in global oil supplies, so rising tensions and disruptions in countries like Iran, Libya, and Venezuela have barely moved the needle at the gas pump.”
“natural gas obtained by fracking has reduced emissions, aided the economy, and helped clean energy rise, while costing less than dirtier fuels.”
“while low natural gas prices have helped knock dirty coal off the market, low oil prices driven in part by fracking have encouraged more travel. In fact, transportation is now the largest source of greenhouse gases in the US. And after years of decline, US emissions in 2018 rose by 3.4 percent.
Low oil prices have undermined the business case for cleaner transportation alternatives, like electric cars and fuel cell-powered buses. Instead, the United States has experienced a growing appetite for larger, thirstier cars and more air travel.
Meanwhile, low natural gas prices have had some collateral damage for nuclear power, the largest source of clean electricity in the US. Some of the nuclear power plants that have announced early retirements are likely to see their capacity replaced by natural gas. So while replacing coal with natural gas often leads to a reduction in emissions, replacing nuclear energy leads to an increase.
Natural gas itself can also become a climate problem. Methane, the dominant component of natural gas, produces less carbon dioxide than coal when burned. But if methane leaks, which it often does in some quantity during normal gas extraction operations, it becomes a potent greenhouse gas. Over 100 years, a quantity of methane traps more than 25 times the amount of heat compared to a similar amount of carbon dioxide.”
“then there’s the technique of fracking itself. It requires a massive volume of water. Wells can release toxic chemicals like benzene into the air. Fracking sites can experience explosions and fires. They can contaminate drinking water. More than 17 million people in the US live within a mile of an active fracking well, and research shows that fracking can lead to low birth weight in infants born in that radius.
Many of these environmental risks, on balance, are less than those associated with mining and burning coal. However, the sudden surge in fracking means many people are being confronted with its impacts for the first time, making it a more vivid political concern. That’s in contrast to coal hazards, which are mostly familiar to the public consciousness.”
“when it comes to limiting climate change, a key factor is time. Methane leaked from gas wells can stay in the atmosphere for a decade. Carbon dioxide from burning it can linger for a century. So it is imperative to ramp down greenhouse gas emissions as quickly as possible. Yet every new natural gas power plant represents a decades-long commitment to continue using the fuel. That means gas plants will have to install carbon capture systems, which would add to their operating costs and worsen the business case further, or some poor investor is going to be left holding the bag.”
“To a first approximation, the question of whether renewables will be able to get to 100 percent reduces to the question of whether storage will get cheap enough. With cheap-enough storage, we can add a ton of it to the grid and absorb just about any fluctuations.
But how cheap is cheap enough?
That question is the subject of a fascinating recent bit of research out of an MIT lab run by researcher Jessika Trancik (I’ve written about Trancik’s work before), just released in the journal Joule.
To spoil the ending: The answer is $20 per kilowatt hour in energy capacity costs. That’s how cheap storage would have to get for renewables to get to 100 percent. That’s around a 90 percent drop from today’s costs. While that is entirely within the realm of the possible, there is wide disagreement over when it might happen; few expect it by 2030.”
“It’s important to test renewable energy over longer time spans. In addition to daily and weekly fluctuations in solar and wind, there can be yearly or even multi-year fluctuations. And indeed, by looking back over 20 years, the team found several rare events in which wind and solar were both unusually low for an unusually long time. These rare events represent a spike in the amount of storage needed. Planning for them substantially increases the cost of a pure-renewables system.”
“these researchers set an extremely high bar: a system with all-renewable energy, with flexibility handled entirely by storage, adequate to meet demand at every hour of every day for 20 years.
Soften any of these restraints even a little and the cost target that storage must meet rises to something far more tractable.
First and most notably, loosen the amount of time that the system must meet demand and things get much easier for storage. And a 100 percent EAF is a little crazy anyway; the existing power system is not up and available 100 percent of the time. There are brownouts and blackouts, after all. No power system is 100 percent reliable.
Trancik’s team found that if the EAF target is lowered from 100 to 95 percent, the cost target that storage must hit rises to $150/kWh. (More specifically, lowering the EAF reduced the total cost of energy storage by 25 percent for the first tier of storage technologies and 48 percent for the second tier.) That’s a much more tractable number, within reach of existing technologies.
Why does lowering the EAF so little ease the pressure on storage so much? The explanation is in those rare meteorological events of extended low wind and sun. They don’t happen often over a 20-year span, but building enough storage to deal with them when they do happen makes the last few percent of EAF exponentially more expensive. To lower the EAF to 95 percent is to say, “something else can handle those rare events.””
“the team is modeling a system in which storage is doing almost all the flexibility work. In fact, there are other sources of grid flexibility. My favorite candidate for flexibility dark horse is “load flexibility,” demand-side programs that can shift energy consumption around in time. Another source of flexibility is enhanced long-distance transmission, to carry renewable energy from regions that produce it to regions that need it. Another is dispatchable renewables like run-of-the-river hydro and advanced geothermal.
All of those sources of flexibility will grow and help to smooth out renewables. Storage won’t have to do all the work on its own. That, too, should ease the price pressure.”
“a renewables+storage system also gets easier if renewables get cheaper. The numbers that Trancik’s team use for renewables are quite conservative. (For instance, $1/Watt solar costs are already being beat routinely in the US.) If renewable energy continues to defy expectations and plunge in cost, it would become cheaper and easier to oversize renewables and curtail the excess energy. That in turn would ease pressure on storage.”
“the headline $20/kWh cost target for energy storage is almost certainly more stringent than what will be required in the real world. Even the $150/kWh target required for an EAF of 95 percent is likely too stringent. In the real world, storage will be assisted by other forms of grid flexibility like long-distance transmission, load flexibility, and microgrids, along with regulatory and legislative reforms. And renewables will probably continue to get cheaper faster than anyone predicts.
So let’s call the target $150-$200, or thereabouts. Can storage hit that?”
“There are two key characteristics of a storage technology: power capacity and energy capacity. Roughly speaking, power capacity refers to how fast you can get energy out of it, measured in kW; energy capacity refers to how much energy you can store in it, measured in kWh. Each is priced separately, power capacity costs and energy capacity costs. The latter is the number we’ve been using for targets”
“It expects, by 2030, “a drop in the total installed cost for Li-ion batteries for stationary applications to between USD 145 per kilowatt-hour (kWh) and USD 480/kWh, depending on battery chemistry.” Hey, $145 is well within our target range!
Nonetheless, lithium-ion batteries are limited. Researchers generally treat the raw materials costs of a storage technology as the lower possible bound of its total costs. Manufacturing and transportation costs can be lowered with scale, but materials costs are stubborn, and the materials involved in Li-ion batteries alone are costly enough that they will likely never hit $20/kWh. In the $150 range, though — that’s doable.”
“How about flow batteries? “The two main flow battery technologies — vanadium redox flow and zinc bromine flow — had total installation costs in 2016 of between USD 315 and USD 1,680/kWh,” IRENA reports. “By 2030, the cost is expected to come down to between USD 108 and USD 576/kWh.” Yes, $108 is well within our target range. (Note that there are flow battery companies already claiming to beat that.)
High-temperature sodium sulphur (NaS) and sodium nickel chloride batteries have been around for a while, but they are also expected to get much cheaper. “Cost reductions of up to 75% could be achieved by 2030, with NaS battery installation cost decreasing to between USD 120 and USD 330/kWh,” says IRENA. “In parallel, the energy installation cost of the sodium nickel chloride high-temperature battery could fall from the current USD 315 to USD 490/kWh to between USD 130 and USD 200/kWh by 2030.” Again, at the lower end, well within our target range.
CAES costs are extremely site-specific, as they depend on a reservoir in which to pump the air. “The typical installation cost is estimated to be approximately USD 50/kWh,” says IRENA, “possibly dropping to USD 40/kWh if an existing reservoir is available.”
Then there are thermal-storage options, like the increasingly popular option of storing electricity as heat in molten salt, with claims of energy capacity costs as low as $50/kWh.”
“Storage is rapidly evolving, diversifying, and falling in cost, to the point that wind and solar power plants coupled with storage are beginning to compete directly with fossil fuel power plants on cost. That’s only going to accelerate as both renewables and storage get cheaper. Providing all of US power, all day every day, will require oversizing renewables and installing an enormous amount of storage, but if they get cheap enough, that’s what we’ll do.
To put that more plainly: A US energy grid run entirely on renewable energy (at least 95 percent of the time), leaning primarily on energy storage to provide grid flexibility, may be more realistic, and closer to hand, than conventional wisdom has it.”