A landmark new study from the National Renewable Energy Laboratory in the US finds that if the world’s biggest economy decarbonises its grid in just 13 years it would save up to $US1.2 trillion in avoided health and climate costs.
The new study, done in conjunction with the US Department of Energy, plots a range of scenarios on how to reach net zero emissions on the world’s biggest grid in just 13 years.
Three of the four scenarios require additional power systems costs of between $US330 billion and $US400 billion, while a fourth – limited by transmission constraints and amount of wind that can be deployed – requires more storage, and more nuclear, that doubles the cost to around $US740 billion.
But each of the scenarios delivers considerable more benefits in avoided health impacts and climate change because it shuts down the combustion of fossil fuels for electricity.
According to NREL, those savings from a net zero grid include avoiding 130,000 premature deaths, saving up to $US400 billion, with a further saving of more than $US1.2 trillion when factoring in the avoided cost of damage from the impacts of climate change.
“Decarbonizing the power system is a necessary step if the worst effects of climate change are to be avoided,” said Patrick Brown, an NREL analyst and co-author of the study.
“The benefits of a zero-carbon grid outweigh the costs in each of the more than 100 scenarios modeled in this study, and accelerated cost declines for renewable and clean energy technologies could lead to even larger benefits.”
The biggest challenge, according to the study, is finding a solution to the last 10 per cent to net zero.
The NREL says there is a growing body of research that shows that switching to high renewable energy power systems are possible and cost effective. But the “last 10 per cent challenge” is the part that adds significant costs because of the seasonal mismatch between variable renewables (wind and solar) and consumption.
NREL says it has been studying how to solve the last 10% challenge, including outlining key unresolved technical and economic considerations and modeling possible pathways and system costs to achieve 100% clean electricity.
Among the potential solutions cited by NREL are green hydrogen, advanced nuclear, price-responsive demand response, carbon capture and storage, direct air capture, and advanced grid controls. But they all require further R&D.
“There is no one single solution to transitioning the power sector to renewable and clean energy technologies,” said Paul Denholm, the principal investigator and lead author of the study.
“There are several key challenges that we still need to understand and will need to be addressed over the next decade to enable the speed and scale of deployment necessary to achieve the 2035 goal.”
(You can listen to a recent interview with Denholm on RenewEconomy’s popular Energy Insiders podcast here).
Still, it says the switch to renewables is likely to be accelerated by the new Inflation Reduction Act (IRA), which—in tandem with the Bipartisan Infrastructure Law (BIL)—which could slash grid emissions by 68 to 78 per cent below 2005 levels by 2030, according to a number of analyses.
The NREL study found that clean energy technologies must be deployed at an unprecedented scale and rate to achieve a net zero grid by 2035.
Wind and solar energy will provide 60 to 80 per cent of generation in the least-cost electricity mix in 2035, and will require a combined 2 terawatts of wind and solar, of an additional 70 to 150GW a year of wind capacity, and 40-90GW a year of solar capacity.
“That’s more than four times the current annual deployment levels for each technology,” the study finds.
“If there are challenges with siting and land use to be able to deploy this new generation capacity and associated transmission, nuclear capacity helps make up the difference and more than doubles today’s installed capacity by 2035.” But that also makes it significantly more expensive.
In each of the four scenarios, around 5 to 8GW of new hydropower and 3 to 5GW of new geothermal capacity are also deployed by 2035., and 120–350GW of “diurnal” storage is also deployed.
It says seasonal storage becomes important when clean electricity – mostly wind and solar – makes up about 80 per to 95 per cent of generation and there is a multiday-to-seasonal mismatch of variable renewable supply and demand.
Across the scenarios, seasonal storage capacity in 2035 ranges from about 100GW to 680GW. This will be long duration, although it does not specify the hours.
It also notes that emerging carbon removal technologies, such as direct air capture, could also play a big role in 2035 if they can achieve cost competitiveness.
“The U.S. can get to 80%–90% clean electricity with technologies that are available today, although it requires a massive acceleration in deployment rates,” another of the NREL researchers and co-authors, Brian Sergi, said.
“To get from there to 100%, there are many potentially important technologies that have not yet been deployed at scale, so there is uncertainty about the final mix of technologies that can fully decarbonize the power system.
“The technology mix that is ultimately achieved will depend on advances in R&D in further improving cost and performance as well as the pace and scale of investment.”
