The Challenge of the Last Few Percent: Quantifying the Costs & Emissions Benefits of a 100% Renewable U.S. Electricity System

Published

4 years ago

June 18, 2021

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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.

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

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Rumor: Polestar ($PSNY) planning reverse stock split to stay on NASDAQ

Published

3 hours ago

November 15, 2025

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Rumor: Polestar ($PSNY) planning reverse stock split to stay on NASDAQ

The automaker turned penny stock is doing a reverse stock split to stay listed on the Nasdaq

In a bid to get it above the $1.00/share NASDAQ-required minimum, fledgling EV brand Polestar ($PSNY) is rumored to be considering a 1:30 reverse stock split that could see the per-share price rocket up to nearly $16.

Geely-owned Volvo spinoff Polestar is working as hard as Tesla to prove that stock prices have little or nothing to do with traditional business fundamentals in 2025.

That’s because Polestar posted a 36.5% increase in retail sales and a heady 48.8% increase in revenue (to $2.17 billion) over the year before, Polestar’s share price has plummeted more than 35% in a matter of a few weeks – culminating in an unwelcome nastygram from NASDAQ threatening to delist the company’s shares from the NASDAQ if they didn’t climb back up above $1.

It looks bad

To goose the share price, CarScoops is reporting that Polestar aims to move forward with the reverse stock split before the end of 2025. The expected 1:30 reverse split would boost the PSNY price to an estimated $15.90 per share at current prices, keeping the brand well out of risk of a delisting.

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In a reverse stock split, each share of the company is converted into a fraction of a share – so, if a company announces a one for ten reverse stock split (1:10), every ten shares that you own will be converted into a single share. In a 1:30 reverse split like the one rumored here, every thirty shares in Polestar would become a single share.

The reverse split increases share price, but it’s not without risk:

A company may declare a reverse stock split in an effort to increase the trading price of its shares – for example, when it believes the trading price is too low to attract investors to purchase shares, or in an attempt to regain compliance with minimum bid price requirements of an exchange on which its shares trade … investors may lose money as a result of fluctuations in trading prices following reverse stock splits.

INVESTOR.ORG

That’s especially relevant because, despite the increased sales and revenue, the company is also posting increased losses. Through September, the brand posted a $1.56 billion net loss compared to an $867 million loss in the first nine months of 2024. The company is also getting hit hard by Trump-imposed tariffs in the US and increased downward pressure on pricing coming from aggressive post-tax credit discounts from rival brands like BMW and Kia.

If the split does happen, here’s hoping Polestar can make the most of their borrowed time and they don’t end up like Lordstown Motors or Faraday Future – two brands that have pulled similar reverse stock splits with dubious results.

Electrek’s Take

Make the switch to Polestar. Save up to $20,000 on a Polestar 3 lease as a Tesla owner. — Polestar showroom; via Polestar.

Product-wise, at least, Polestar’s future appears to be bright. The new 3 crossover is a viable competitor to the industry-leading Tesla Model Y, and the upcoming Polestar 4 and 5 models seem like winners, too. To drive that point home, Polestar is promoting up to $18,000 in lease incentives to lure Tesla buyers into their showrooms.

You can find out more about Polestar’s killer EV deals on the full range of Polestar models, from the 2 to the 4, below, then let us know what you think of the three-pointed star’s latest discount dash in the comments section at the bottom of the page.

SOURCE: CarScoops; images via Polestar.

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Maybe it really SHOULD have been the new Maxima: meet the Nissan N6 EREV

Published

4 hours ago

November 15, 2025

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Maybe it really SHOULD have been the new Maxima: meet the Nissan N6 EREV

Nissan’s New Hybrid Sedan Is As Big An Altima For Thousands Less Than A Versa

With its sleek, uncluttered styling and more than 100 miles of battery-electric range before the extended range electric sedan’s gas engine kicks on, maybe the new Nissan N6 really should have been the next Maxima!

Struggling Japanese carmaker Nissan is dealing with an aging lineup and a brand identity driven more by subprime financing than any suggestion of reliability or sportiness here in the US – but overseas? The brand is rolling out hit after hit, and the latest Nissan N6 plug-in sedan promises exactly the sort of entry-level panache that could change its American fortunes.

“Under our Re:Nissan plan, we are redefining what Nissan delivers today and beyond,” explains Nissan President and CEO Ivan Espinosa. “It’s about strengthening our core, reigniting Nissan’s heartbeat, and creating products that inspire excitement and trust. It is about a sharper, more focused product strategy, a stronger brand, and a renewed commitment to our customers. Integral to this transformation is China — an essential market whose speed, technological leadership, and customer insights are setting the pace for the global auto industry.”

Developed by the Nissan Dongfeng JV in China, the new N6 is more compact that the well-received N7 BEV. In fact, the new Nissan N6, at 190.1″ long, compares nicely to the 192.8″ length of the most recent (and largest-ever) US Maxima, discontinued in 2023. Like the Maxima, the top-shelf version features modern, near-luxe features like soft, leather-like surfaces, LED mood lighting, multi-way adjustable seats, and mimosas or something.

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Mimosas or something

The four or five passengers inside the N6 are propelled down the road exclusively by the car’s 208 hp electric motor, which is efficient enough to take you 112 miles on a full charge of its 21.1 kWh LFP battery. Once that charge is depleted, a 1.5L gas engine kicks on as a high-efficiency generator to keep the good times rolling.

Nissan says the N6′ exterior design, “features a V-Motion signature grille and expressive LED lighting at the front and rear.” And says that the car’s crisp lines give it, “a confident, dynamic presence.”

All of which sounds good on its own, but sounds absolutely miraculous when you consider the car’s Chinese price: ¥106,900 – or about $15,000 US for the base Nissan N6 180 Pro, as I type this.

Even with a nearly 100% markup to give it a $29,990 price tag in the US, I think the N6 would be a huge hit in the North American market. And – good news! – thanks to Canada’s apparent willingness to give Chinese carmakers a shot, we might find out if I’m right somewhat sooner than later.

Check out the Nissan N6 image gallery, below, then let us know what you think of the car’s US and Canadian appeal in the comments.

Nissan N6 gallery

SOURCE | IMAGES: Nissan.

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BLUETTI just dropped new home backup power stations – and slashed prices up to 65% for Black Friday

Published

7 hours ago

November 15, 2025

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BLUETTI just dropped new home backup power stations – and slashed prices up to 65% for Black Friday

Whether you’re prepping for winter power outages, loading up the RV for a long-haul trip, or want clean, reliable power anywhere you go, BLUETTI has a portable power option for every need. And right now, the clean energy experts are offering up to 65% off their most popular products for Black Friday – plus they’ve just dropped two major new releases: the Elite 400 and B500K expansion battery.

Here’s a complete guide to what’s new, what’s on sale, and how to pick the model that fits your lifestyle best. There are also some special deals just for Electrek readers, so don’t miss out!

For home backup + outdoor adventures: Elite 200 V2 and all-new Elite 400

Elite 200 V2 – Best value for backup, camping, and van life

BLUETTI’s Elite 200 V2 is designed for power users who need versatility. It’s nicknamed the “Swiss Army Knife” of portable power stations because it powers everything from your fridge to your laptop — whether you’re off the grid or just want to keep the lights on during a storm.

Key specs:

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Battery capacity: 2,073.6Wh
Continuous power output: 2,600W (3,900W surge)
9 output ports: AC, DC, USB-C, and more
Recharges to 80% in just over one hour
Ultra-quiet 16 dB operation
LiFePO₄ battery with a 17-year lifespan (3,500+ cycles)

Who it’s for:

RVers, weekend campers, off-grid explorers, small cabin owners
Homeowners looking for dependable backup power

Commonly powered devices: Mini-fridges, coffee makers, power tools, microwaves, kettles, electric blankets, laptops, LED lights, wifi routers

Its compact profile makes it easy to tuck away in an RV cabinet, trunk, or apartment closet.

Elite 200 V2 Portable Power Station is regularly priced at $1,699, and it’s on sale for the record-low price of $699 – that’s a 59% discount for Black Friday and Cyber Monday.

Elite 400 Rolling Power Station — New and optimized for home

Launching November 15, the Elite 400 is a powerful 3.8kWh portable station designed with mobility and backup readiness in mind. With built-in wheels, a telescoping handle, and side grips, you can roll it anywhere – even if you’re flying solo.

Key specs:

Battery capacity: 3,840Wh
Continuous power output: 2,600W (3,900W lifting power)
9 output ports for simultaneous device charging
15ms UPS switchover during power outages
Recharges to 80% in 70 minutes using AC + solar
Low standby energy use (3W) with app-control wakeup and timers

Who it’s for:

Homeowners needing serious backup power
Outdoor event hosts, road trippers, off-grid enthusiasts

Commonly powered devices: Full-size refrigerators, sump pumps, CPAP machines, space heaters, power tools, projectors, outdoor cooking appliances, large TVs

Whether you’re powering your home in a blackout or running a campsite movie night, the Elite 400 delivers enough capacity to handle just about anything.

The new Elite 400 Portable Power Station is regularly priced at $2,999, and it’s making its debut on November 15 for $1,499 – that’s a 50% discount for Black Friday and Cyber Monday.

For whole-home power and off-grid living: Meet the new B500K expansion battery

If you’re looking for a system that grows with your energy needs, the B500K expansion battery delivers massive storage potential at a competitive cost of around $0.33/Wh – making it an excellent choice for users seeking higher capacity than the well-acclaimed B300K. Paired with the Apex 300, it also qualifies for the soon-to-end 30% Federal Tax Credit. Designed to integrate seamlessly into BLUETTI’s modular ecosystem, it’s ideal for home battery backup or off-grid setups.

Key specs:

Supports up to 100 kWh storage (paired with Apex 300 system)
Compatible with BLUETTI’s SolarX 4K, B300K, Hub D1, and more
Acts as both standalone power or an expansion battery
Future-proof with long-term ecosystem integration

The new B500K expansion battery is regularly priced at $2,999, and it’s making its debut on November 15 for $1,699 – that’s a 43% discount for Black Friday and Cyber Monday.

Ideal bundles:

Apex 300 + B500K: Best for large homes, off-grid living, and whole-home backup. With a larger individual capacity, the B500K enables a plug-and-play power system that can be expanded to a massive 100 kWh with the Apex 300. It provides 3.8 kW of power output and 7,884.8 Wh of capacity in total.
The Apex 300 + B500K Home Battery Backup is priced at $4,998, and it’s on sale for Black Friday for $3,098 – that’s a 38% discount.

Apex 300 + B300K: The Apex 300, paired with the B300K, provides 5.5 kWh of capacity and up to 3.8kW of power output, offering smaller households or remote cabins reliable off-grid energy with room to scale. It’s an ideal way to support essential loads, such as refrigerators, lights, fans, and wifi routers, without the need to invest in a larger setup.
The Apex 300 + B300K is normally priced at $4,098, and it’s on sale for Black Friday for $2,299 –that’s a 44% discount.

Plus! Both bundles are fully eligible for the 30% federal Residential Clean Energy Credit through December 2025.

For everyday portability: Elite 30 V2 and the new Elite 10

Elite 30 V2 – now in EcoTide colors

If you need lightweight, flexible power for camping, car trips, desk-side charging, or college dorm use, the Elite 30 V2 is the sweet spot. Weighing just 4.3 kg, it’s a portable backup that fits in your backpack or on a small shelf. Plus, it comes in six fun colors.

Key specs:

Battery capacity: 288Wh
Continuous power output: 600W (1,500W surge)
9 output ports including 140W USB-C PD
Charges to 80% in 45 minutes
Quiet operation under 30 dB
10-year LiFePO₄ battery lifespan, with a 5-year warranty

Ideal for powering: Laptops, DSLR cameras, portable fans, smartphones, drones, modems, LED lighting, external hard drives

It’s perfect for digital nomads, travelers, or anyone who needs reliable backup power without adding bulk.

Elite 30 V2 Portable Power Station is regularly priced at $304, and it’s on sale for $199 – that’s a 35% discount for Black Friday and Cyber Monday. You can buy it on BLUETTI’s website here and on Amazon here.

Sneak preview: The new Elite 10 – pocket-sized power

Launching on November 20, the palm-sized Elite 10 is BLUETTI’s most compact power station yet. It’s the perfect in-between if a power bank won’t cut it, but you don’t want a full-sized power station.

Key specs:

Battery capacity: 128Wh
Power output: 200W AC (300W peak, 400W surge)
5 DC outlets + 200W AC outlet
Fully recharges in 70 minutes
LED light modes: reading, warm, SOS

Perfect for powering: Bluetooth speakers, portable fans, DSLR cameras, tablets, Chromebooks, routers, handheld consoles, mini-fridges

Small enough to slip into a tote, train bag, or glovebox, the Elite 10 is built for everyday carry and quick power access.

The Elite 10 launches next week and is said to be the best budget-friendly option yet – available for under $150, and rumored to go even lower. You’ll be able to grab it on BLUETTI’s website and on Amazon here starting November 20.

Electrek exclusive discounts

In addition to the fantastic Black Friday Cyber Monday sale prices, up to 65% off, BLUETTI is offering a special discount code just for Electrek readers!

95% of BLUETTI products qualify for an extra 5% off with code: ELECTREK5OFF
The new Elite 400 and all Apex 300 series products qualify for 6% off with code: ELECTREK6OFF

Now is the best time to invest in a power system that’s quiet, clean, and ready whenever you need it – at home or beyond the grid.

The trusted name offers a full lineup of portable power stations to keep you charged – whether a winter storm hits or you’re enjoying outdoor adventures – and stay charged, no matter where life takes you.

Follow BLUETTI on Twitter/X here and on Facebook here.

All photos: BLUETTI

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