The US could shift to a 90% clean electricity supply within just 15 years, a new study has shown, and reduce wholesale power prices by up to 10 per cent in the process.
The study, published by the University of California Berkeley and EnergyLab, finds that a combination of strong government policies and increasingly cheap solar, wind and battery storage technologies could feasibly deliver a 90% clean electricity share by 2035.
Setting this course would also see all the US’s existing coal plants retired by 2035, reduce natural gas generation by 70%, and prevent up to 85,000 premature deaths by 2050.
The report bases all this on what it describes as the “plummeting” costs for wind and solar energy – which it says many other studies have failed to keep pace with, and which have dramatically changed the prospects for rapid, cost-effective expansion of renewables.
“Previous studies concluded either we need to wait until 2050 to decarbonise or the bills will go up if you decarbonise,” said co-author Amol Phadke on a call with reporters. “I think we really need to revisit these conclusions because of the dramatic decline in costs.”
At the same time, it notes, battery energy storage has also become a viable option for cost-effectively integrating high levels of wind and solar generation into electricity grids.
Still, the task is a big one. To get to the 90% mark by 2035, the report estimates that 1,100 GW of new wind and solar generation would have to be built, averaging about 70GW per year.
The study points to precedents for natural gas and wind/solar expansion which suggest a renewable energy buildout of this magnitude would be “challenging but feasible,” particularly considering new renewables can already be built cost-effectively in all regions of the country.
“On the path to 90% over the next 15 years, we can inject $US1.7 trillion into the economy, support a net increase of more than half a million energy sector jobs each year, and reduce economy-wide emissions by 27%,” the report says.
The study also answers inevitable questions around the reliability of a grid so high in shares of solar and wind.
It says that by retaining existing hydropower and nuclear capacity (after accounting for planned retirements), and much of the existing natural gas capacity combined with new battery storage, national electricity demand will be met dependably with a 90 per cent clean grid.
“Under the 90% Clean case, all existing coal plants are retired by 2035, and no new fossil fuel plants are built,” the report explains.
“During normal periods of generation and demand, wind, solar, and batteries provide 70% of annual generation, while hydropower and nuclear provide 20%.
“During periods of very high demand and/or very low renewable generation, existing natural gas, hydropower, and nuclear plants combined with battery storage cost-effectively compensate for mismatches between demand and wind/solar generation.
“Generation from natural gas plants constitutes about 10% of total annual electricity generation, which is about 70% lower than their generation in 2019.”
But, as is the case in Australia, this sort of a transition simply won’t happen without strong government policy support – a No New Policy case also modelled by the researchers achieves just 55% clean electricity in 2035. Not bad, but not nearly good enough.
“The United States can achieve 90% clean, carbon-free electricity nationwide by 2035, dependably, at no extra cost to consumers, and without new fossil fuel plants. But without robust policy reforms, most of the potential to reduce emissions and increase jobs will be lost,” the researchers said.
And for the benefit of governments like the US Trump administration and Australia’s Morrison Coalition, the report goes on to explain why ambitious, pre-2050 targets are so important.
“Establishing a target year of 2035, rather than the typical 2050 target, helps align expectations for power-sector decarbonisation with climate realities while informing the policy dialogue needed to achieve such an ambitious goal,” it says.
“Aiming for 90% clean electricity – rather than 100% – by 2035 is also important for envisioning rapid, cost-effective decarbonisation,” it goes on to explain.
“By 2035, emerging technologies such as firm, low-carbon power should be mature enough to begin to replace the remaining natural gas generation as the nation accelerates toward 100%, cross- sector decarbonisation.
And there are plenty of other up-sides.
“On the path to 90 per cent over the next 15 years, we can inject $US1.7 trillion into the economy, support a net increase of more than half a million energy sector jobs each year, and reduce economy-wide emissions by 27%,” the researchers note.
It would also all-but eliminate emissions from the U.S. power sector by 2035 and, through associated health and environment benefits prevent up to 85,000 premature deaths by 2050.
And finally, the icing on the cake, is cheaper power. According to the study, wholesale electricity costs – including the cost of generation plus incremental transmission investments – would wind up around 10 per cent cheaper in 2035 under the 90% Clean case than today, mainly owing to low renewable energy and battery costs.