The Challenge of the Last Few Percent: Quantifying the Costs & Emissions Benefits of a 100% Renewable U.S. Electricity System
Only two decades ago, some scientists were skeptical we could integrate more than about 20% renewable energy generation on the U.S. power grid. But we hit that milestone in 2020 — so, these days, experts’ sights are set on finding pathways toward a fully renewable national power system. And according to new research published in Joule, the nation could get a long way toward 100% cost-effectively; it is only the final few percent of renewable generation that cause a nonlinear spike in costs to build and operate the power system.
In “Quantifying the Challenge of Reaching a 100% Renewable Energy Power System for the United States,” analysts from the U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL) and DOE’s Office of Energy Efficiency and Renewable Energy (EERE) evaluate possible pathways and quantify the system costs of transitioning to a 100% renewable power grid for the contiguous United States. The research was funded by EERE’s Strategic Analysis Team.
“Our goal was to robustly quantify the cost of a transition to a high-renewable power system in a way that provides electric-sector decision-makers with the information they need to assess the cost and value of pursuing such systems,” said Wesley Cole, NREL senior energy analyst and lead author of the paper.
Expanding on previous work to simulate the evolution of the U.S. power system at unprecedented scale, the authors quantify how various assumptions about how the power system might evolve can impact future system costs. They show how costs can increase nonlinearly for the last few percent toward 100%, which could drive interest in non-electric-sector investments that accomplish similar decarbonization objectives with a lower total tab.
“Our results highlight that getting all the way to 100% renewables is really challenging in terms of costs, but because the challenge is nonlinear, getting close to 100% is much easier,” Cole said. “We also show how innovations such as lower technology costs, or alternate definitions for 100% clean energy such as including nuclear or carbon capture, can lower the cost of reaching the target.”
Advanced Methods Expand Our Understanding of High-Renewable Grids
This work builds on another Joule article released last month exploring the key unresolved technical and economic challenges in achieving a 100% renewable U.S. electricity system. While some aspects of 100% renewable power grids are well established, there is much we do not know. And because 100% renewable grids do not exist at the scale of the entire United States, we rely on models to evaluate and understand possible future systems.
“With increasing reliance on energy storage technologies and variable wind and solar generation, modeling 100% renewable power systems is incredibly complex,” said Paul Denholm, NREL principal energy analyst and coauthor of the paper. “How storage was used yesterday impacts how it can be used today, and while the resolution of our renewable resource data has improved tremendously in recent years, we can’t precisely predict cloudy weather or calm winds.”
Integrated energy pathways modernizes our grid to support a broad selection of generation types, encourages consumer participation, and expands our options for transportation electrification.
Many prior studies have modeled high-renewable electricity systems for a variety of geographies, but not many examine the entire U.S. grid. And even fewer studies attempt to calculate the cost of transitioning to a 100% renewable U.S. grid — instead, they typically present snapshots of systems in a future year without considering the evolution needed to get there. This work expands on these prior studies with several important advances.
First, the team used detailed production cost modeling with unit commitment and economic dispatch to verify the results of the capacity expansion modeling performed with NREL’s publicly available Regional Energy Deployment System (ReEDS) model. The production cost model is Energy Exemplar’s PLEXOS, a commercial model widely used in the utility industry.
“Over the past couple of years we put a tremendous amount of effort into our modeling tools to give us confidence in their ability to capture the challenges inherent in 100% renewable energy power systems,” Cole said. “In addition, we also tried to consider a broad range of future conditions and definitions of the 100% requirement. The combination of these efforts enables us to quantify the cost of a transition to a 100% clean energy system far better than we could in the past.”
The analysis represents the power system with higher spatial and technology resolution than previous studies in order to better capture differences in technology types, renewable energy resource profiles, siting and land-use constraints, and transmission challenges. The analysis also uniquely captures the ability to retrofit existing fossil plants to serve needs under 100% renewable scenarios and assesses whether inertial response can be maintained in these futures.
What Drives System Costs? Transition Speed, Capital Costs, and How We Define 100%
The team simulated a total of 154 different scenarios for achieving up to 100% renewable electricity to determine how the resulting system cost changes under a wide range of future conditions, timeframes, and definitions for 100% — including with systems that allow nonrenewable low-carbon technologies to participate.
“Here we use total cumulative system cost as the primary metric for assessing the challenge of increased renewable deployment for the contiguous U.S. power system,” said Trieu Mai, NREL senior energy analyst and coauthor of the paper. “This system cost is the sum of the cost of building and operating the bulk power system assets out to the year 2050, after accounting for the time value of money.”
To establish a reference case for comparison, the team modeled the system cost at increasing renewable energy deployment for base conditions, which use midrange projections for factors such as capital costs, fuel prices, and electricity demand growth. Under these conditions, the least-cost buildout grows renewable energy from 20% of generation today to 57% in 2050, with average levelized costs of $30 per megawatt-hour (MWh). Imposing a requirement to achieve 100% renewable generation by 2050 under these same conditions raises these costs by 29%, or less than $10 per MWh. System costs increase nonlinearly for the last few percent approaching 100%
Associated with the high renewable energy targets are substantial reductions in direct carbon dioxide (CO2) emissions. From the 57% least-cost scenario, the team translated the changes in system cost and CO2 emissions between scenarios into an average and incremental levelized CO2 abatement cost. The average value is the abatement cost relative to the 57% scenario, while the incremental value is the abatement cost between adjacent scenarios, e.g., between 80% and 90% renewables. In other words, the average value considers all the changes, while the incremental value considers only the change over the most recent increment.
Total bulk power system cost at a 5% discount rate (left) for the seven base scenarios and levelized average and incremental CO2 abatement cost (right) for those scenarios. The 2050 renewable (RE) generation level for each scenario is listed on the x-axis. The system costs in the left figure are subdivided into the four cost categories listed in the figure legend (O&M = operations and maintenance). The purple diamond on the y-axis in the left plot indicates the system cost for maintaining the current generation mix, which can be used to compare costs and indicates a system cost comparable to the 90% case.
Total bulk power system cost at a 5% discount rate (left) for the seven base scenarios and levelized average and incremental CO2 abatement cost (right) for those scenarios. The 2050 renewable (RE) generation level for each scenario is listed on the x-axis. The system costs in the left figure are subdivided into the four cost categories listed in the figure legend (O&M = operations and maintenance). The purple diamond on the y-axis in the left plot indicates the system cost for maintaining the current generation mix, which can be used to compare costs and indicates a system cost comparable to the 90% case. NREL
Notably, incremental abatement costs from 99% to 100% reach $930/ton, driven primarily by the need for firm renewable capacity — resources that can provide energy during periods of lower wind and solar generation, extremely high demand, and unplanned events like transmission line outages. In many scenarios, this firm capacity was supplied by renewable-energy-fueled combustion turbines, which could run on biodiesel, synthetic methane, hydrogen, or some other renewable energy resource to support reliable power system operation. The DOE Energy Earthshots Initiative recently announced by Secretary of Energy Jennifer M. Granholm includes the Hydrogen Shot, which seeks to reduce the cost of clean hydrogen by 80% to $1 per kilogram in one decade — an ambitious effort that could help reduce the cost of providing renewable firm capacity.
“When achieving a 100% renewable system, the costs are significantly lower if there is a cost-effective source of firm capacity that can qualify for the 100% definition,” Denholm said. “The last few percent cannot cost-effectively be satisfied using only wind, solar, and diurnal storage or load flexibility — so other resources that can bridge this gap become particularly important.”
Capital costs are the largest contributor to system costs at 100% renewable energy. Future changes in the capital costs of renewable technologies and storage can thus greatly impact the total system cost of 100% renewable grids. The speed of transition is also an important consideration for both cost and emission impacts. The scenarios with more rapid transitions to 100% renewable power were more costly but had greater cumulative emissions reductions.
“Looking at the low incremental system costs in scenarios that increase renewable generation levels somewhat beyond the reference solutions to 80%–90%, we see considerable low-cost abatement opportunities within the power sector,” Mai said. “The trade-off between power-sector emissions reductions and the associated costs of reducing those emissions should be considered in the context of non-power-sector opportunities to reduce emissions, which might have lower abatement costs — especially at the higher renewable generation levels.”
“The way the requirement is defined is an important aspect of understanding the costs of the requirement and associated emissions reduction,” Cole said. “For instance, if the 100% requirement is defined as a fraction of electricity sales, as it is with current state renewable polices, the cost and emissions of meeting that requirement are similar to those of the scenarios that have requirements of less than 100%.”
Additional Research Can Help the Power Sector Understand the Path Forward
While this work relies on state-of-the-art modeling capabilities, additional research is needed to help fill gaps in our understanding of the technical solutions that could be implemented to achieve higher levels of renewable generation, and their impact on system cost. Future work could focus on key considerations such as the scaling up supply chains, social or environmental factors that could impact real-world deployment, the future role of distributed energy resources, or how increased levels of demand flexibility could reduce costs, to name a few.
“While there is much left to explore, given the energy community’s frequent focus on using the electricity sector as the foundation for economy-wide decarbonization, we believe this work extends our collective understanding of what it might take to get to 100%,” Cole said.
Learn more about NREL’s energy analysis and grid modernization research.
Article courtesy of the NREL, the U.S. Department of Energy
Rivian and VW have recently opened a partnership, despite the brands have very similar upcoming electric adventure vehicles with the Rivian R2 and VW Scout. But at a roundtable discussion with Rivian’s CEO RJ Scaringe, he said there’s more than enough room for the brands to coexist with each other.
Recent news about Rivian and VW’s software partnership, with VW investing over $5 billion into Rivian and forming a joint venture to adopt Rivian’s zonal architecture for the underpinnings of VW’s vehicle communications, has led to some interesting questions about how the details of the partnership would work out.
At the top of many people’s minds has been: isn’t it a little weird that the Rivian-like Scout brand will now essentially be competing with itself for the adventure EV market?
The question has been answered before – or perhaps more specifically non-answered – in press conferences around the official opening of the joint venture last week.
Generally, comments ran along the line of Rivian working to bring its software expertise to bear across VW’s brands, though the two companies have been a little shy to confirm whether Scout specifically would use Rivian’s software. After all, Scout is a bit of a spinoff from VW, and seems interested in showing some independence on that front, so it could be possible that they work on their own.
But in comments at a roundtable which Electrek attended today ahead of the LA Auto Show, it certainly seemed that Rivian will be working on Scout vehicles. Scaringe said that “we’re going to be supporting their full portfolio of brands – Porsche, Audi, Volkswagen, Scout.”
However, more importantly, Scaringe said that he’s “amused” by the focus that many have had on Scout, or those who consider it a potential threat to Rivian.
Scaringe estimates that there are “less than five” compelling EVs available for under $50k in the market today – and that’s perhaps being charitable. Meanwhile, if you go over to the gas world, there are gobs of choices out there for consumers, and yet they all manage to coexist without issue.
So Rivian has worked hard to distinguish itself from Tesla, for example, and thinks that even if Scout is inspired by Rivian, there’s still room for similar vehicles to coexist.
After all, there are many competing vehicles in many categories – some of which do indeed share underpinnings from separate companies. Just in the EV space, the Kia EV6 and Hyundai Ioniq 5 share a platform, and the Subaru Solterra and Toyota bZ4X are basically identical vehicles. So there has been plenty of history of companies working together to come out with similar or near-identical (rebadged) cars.
That’s not the case here, as Scout and Rivian will be very different in terms of platform and manufacturing. But sharing software shouldn’t be much of an issue – and even if we assume that Scout could cannibalize a segment of the market that Rivian otherwise had a good hold on, Rivian can still benefit from the partnership regardlessl.
Rivian’s main focus in recent years has been getting costs down. The story is that Rivian began scaling production in an extremely difficult time – trying to organize supply contracts at the historical peak of the auto industry (~2018), trying to start a manufacturing program during a global pandemic (2020/2021), and having little clout available to get on the better side of those contracts.
Now, Scaringe said, the situation is better: not only can Rivian show that it has a dominant position in its class – selling more premium SUVs than other EV and even gas brands – but it can also tout that it has support from one of the most established auto manufacturers in the world, Volkswagen. If VW – the second-largest automaker in the world – has enough faith in Rivian to invest $5.8 billion, then surely a supplier can trust that Rivian will stick around long enough to buy more than one set of parts.
Not only that, but the companies could potentially leverage their combined size for larger supply contracts. Say a certain microcontroller is needed for vehicle architecture across Rivian and also VW’s brands, then perhaps the joint venture could recognize much larger economies of scale.
The question also came up over whether Rivian might try to see if VW’s global sales network could help them to sell Rivians, but Scaringe shut that down, saying there is “no interest” in doing so. Rivian would rather stick to its plans of setting up its own stores and doing direct sales.
Charge your electric vehicle at home using rooftop solar panels. Find a reliable and competitively priced solar installer near you on EnergySage, for free. They have pre-vetted installers competing for your business, ensuring high-quality solutions and 20-30% savings. It’s free, with no sales calls until you choose an installer. Compare personalized solar quotes online and receive guidance from unbiased Energy Advisers. Get started here. – ad*
FTC: We use income earning auto affiliate links. More.
Hyundai has officially debuted its Ioniq 9 in advance of the LA Auto Show, with a concept car-like interior that lets you swivel the 2nd row seats and turn your car into a living room.
We’ve been hearing about the Ioniq 9 for some time now, and the time has finally come for its release.
In an event in advance of the LA Auto Show, starting this Friday and with a media preview day tomorrow (which Electrek will be in attendance for), Hyundai showed off the Ioniq 9 which will officially be unveiled at the Auto Show (you can watch via livestream) on the morning of Nov 21st.
The car is what we expected – a large, 3-row SUV, much like the EV9, the Ioniq 9’s cousin that is built on the same platform by Hyundai’s sister company, Kia.
But it also has some features we didn’t expect – like a little more clarity on that “lounge-like” interior we heard about, which turns out not to just be marketing fluff at all. It actually is like a lounge, complete with la-z-boy style footrests and swiveling seats so you can face your friends. More on that in a bit.
The Ioniq 9 comes with a perhaps excessively-large 110.3kWh battery (that extra 300Wh makes a big difference), offering up to 335 miles of range on the Long-Range RWD model with 19-inch wheels. 20- and 21-inch wheels are also available, we imagine with lower ranges.
The large battery will retain the E-GMP platform’s excellent DC charging performance, with the ability to charge from 10-80% in 24 minutes, assuming you’re connected to a capable charger (Hyundai says 350kW “under optimal conditions”).
The Long-Range model will have a 160kW (215hp) rear motor, and an additional 70kW (94hp) front motor if you get the AWD model. Performance AWD will be available with 160kW motors on both axles.
The long range RWD model will do 0-100km/h (0-62mph) in 9.4 seconds, AWD in 6.7 seconds, and Performance AWD in 5.2 seconds (or, if you prefer 0-60, the Performance model can do it in 4.9).
The vehicle is large, as you’d expect out of a 3-row SUV, at 5,060mm (199.2in) long, 1,980mm (78in) wide and 1,790mm (70.5in) high. This is 2 inches longer than its sister car the EV9, and 1 inch less long than the Rivian R1S.
Exterior design keeps some of the design language of the (excellent) Ioniq 5, but larger and more rounded-off. In particular, it keeps some of the dot-matrix/pixel aesthetic of the lights.
I have to say I don’t love the roundedness of it – the design of the Ioniq 5 feels extremely consistent with a lot of straight lines throughout, whereas the rounded hood and extended rear end of the 9 spoil that consistency to some extent (and speaking of the rear… it almost seems a little hearse-like, to me).
Incidentally, with the Ioniq 5 and EV6, one is more boxy and the other is more rounded – and the same thing has happened with the Ioniq 9 and EV9, only in reverse. The Ioniq 9 is more rounded and the EV9 is more boxy. So, once again, these two similar vehicles have differentiated themselves enough that we expect the market will be split, with many customers liking one and disliking the other, meaning little cannibalization between the two.
The interior seems incredibly spacious, though so far we haven’t had a chance to experience it ourselves. Most 3-row SUVs in this size class do have somewhat cramped third rows, so we’re curious if Hyundai has managed to do some sort of magic in that respect.
And in addition to rear and frunk storage (with a frunk capable of holding 88L in RWD and 52L in AWD models), the center console offers a large amount of storage inside (18.2L, split between an upper and lower tray), and can be slid back and forth to allow easier movement between front or rear seats.
And speaking of magic, Hyundai has actually done something new here – an interior with swiveling middle seats, to turn the car into a lounge.
We’ve seen similar interiors on countless concept cars, but understandably they never make it to production. It’s definitely an attention-grabbing feature, but who really uses their vehicles like that?
Well, Hyundai thinks that people will, so it’s offered swiveling 2nd-row seats to allow for this. However, it says that these seats will be available “in selected markets only,” and it has declined to say exactly which markets those are yet. We also imagine this will only apply to the 6-seat configuration, rather than 7-seat.
The seats don’t just swivel though, they also recline and have a leg rest. Hyundai is calling these its “Relaxation Seats,” and the first and second row seats will both be capable of this feat. It says this will be particularly useful for people who want to get comfortable during vehicle charging (though, on an optimal 350kW charger, 24 minutes is hardly much time for a nap).
And that charging will be accomplished via a NACS port – making this, we think, the first non-Tesla vehicle to debut and be sold with only a NACS port at any time in the model’s existence. Other E-GMP vehicles are switching over to NACS, but the Ioniq 5 for example has been out for many years now, so there are lots of CCS Ioniq 5s out there, but that won’t be the case for the Ioniq 9.
Like other E-GMP vehicles, it will be able to discharge the battery via vehicle-to-load (V2L) to power devices, though we didn’t get clarity on how much total output it will have. Other E-GMP cars usually top out around 1.8kW, so enough to run some regular outlets, but not enough to power a house.
The Hyundai Ioniq 9 will be available in Korea and the US in the first half of 2025, and then will come to Europe and other markets later. The US version will be built at Hyundai’s plant in Georgia – another example of a car brought to the US by the domestic sourcing provisions of President Biden’s EV push (and which could be put into Jeopardy if Dumb & Dumber get their way in attempting to kill this boon for US manufacturing).
We don’t have pricing or all tech specs yet, so stay tuned as there’s still more to come.
Also, you can watch the official debut livestream over at Hyundai’s website, starting at 9:10am PST November 21st. And Electrek will be at the LA Auto Show to ask around and see if we can get any lingering questions answered.
Charge your electric vehicle at home using rooftop solar panels. Find a reliable and competitively priced solar installer near you on EnergySage, for free. They have pre-vetted installers competing for your business, ensuring high-quality solutions and 20-30% savings. It’s free, with no sales calls until you choose an installer. Compare personalized solar quotes online and receive guidance from unbiased Energy Advisers. Get started here. – ad*
FTC: We use income earning auto affiliate links. More.
Honda has been promising to unlock the power of all-solid-state EV batteries for several years. Today, we are getting our first look at the progress. Honda unveiled a demonstration production line as it continues to advance promising new battery technology.
By 2050, Honda wants all its products and corporate activities to be carbon neutral. Although electric vehicles are essential to this mission, Honda believes improvements are needed.
Since the battery is such a critical component for EVs, the company aims to unlock more driving range at a lower cost with new chemistries.
Honda is developing all-solid-state EV batteries in-house to power up its next-gen vehicles. It’s not “merely trying to establish a lab-level technology,” Honda is eyeing mass production in the coming years.
On Wednesday, Honda unveiled its demonstration production line for all-solid-state EV batteries, giving us our first look at the progress.
The line is located at Honda’s R&D facility in Sakura City, Tochigi Prefecture, Japan. Honda will use the demo line as a preface for mass production while determining the basic specifications of the battery cells.
Honda is launching EVs with all-solid-state batteries
Honda plans to launch electric models with the new all-solid-state battery tech in the “second half of the 2020s.”
The new demo line replicates the processes required for mass production. It covers around 295,000 ft2 (27,400 m2) and is already equipped with the tools to verify each production process, including weighing and mixing electrode materials, coating, and roll pressing electrode assemblies. The line also supports the formation of cells and the assembly of the module.
After the new facility was completed this spring, all the equipment needed for verification is now in place.
Honda plans to begin production on the new demo line in January 2025. With a highly efficient production process and a wide range of use cases, including automobiles, motorcycles, and aircraft, Honda aims to slash battery costs.
To speed up development, Honda is conducting “speedy research” in two main areas: material specifications and manufacturing methods.
The company plans to start mass producing all-solid-state EV batteries in the second half of the 2020s.
Ahead of its 2050 carbon neutrality target, Honda aims for 100% of global vehicle sales to be EV or FCEV by 2040. Honda believes the new battery tech will be its differentiator.
FTC: We use income earning auto affiliate links. More.
-
Sports2 years ago‘Storybook stuff’: Inside the night Bryce Harper sent the Phillies to the World Series
-
Sports8 months agoStory injured on diving stop, exits Red Sox game
-
Sports2 years agoMLB Rank 2023: Ranking baseball’s top 100 players
-
Sports1 year agoGame 1 of WS least-watched in recorded history
-
Sports3 years ago
Team Europe easily wins 4th straight Laver Cup
-
Environment2 years agoJapan and South Korea have a lot at stake in a free and open South China Sea
-
Environment2 years agoGame-changing Lectric XPedition launched as affordable electric cargo bike
-
Business2 years agoBank of England’s extraordinary response to government policy is almost unthinkable | Ed Conway