A recent report from the Department of Energy shows that the United States might be able to achieve 100% clean energy by 2035, but it won’t be easy. And is it really feasible? Here is what it will take to bring the U.S. into compliance with climate goals and get to total clean energy usage by 2035.
A DOE plan for clean energy
In August 2022, a study by the Department of Energy’s National Renewable Energy Laboratory (NREL) laid out four different paths the United States could follow to reach 100% clean energy in which “benefits exceed costs.” In other words, there are several ways forward that are sustainable and cost-efficient in production and usage. It will require a mix of technologies and approaches to achieve.
However, this study does not explain how to acquire enough land to produce 90% clean energy across the country. It also doesn’t state how to protect its reliability past 90% penetration. This was acknowledged by stakeholders when the report was published, and it remains a key issue.
Does that mean it’s not possible? Certainly not, but it is a roadblock on the path to sustainable energy.
The current state of clean energy in the U.S.
Today’s clean energy technologies, such as solar and wind energy production and nuclear, hydropower and geothermal, can bring the U.S. to a 90% emissions reduction due to their reduced costs as their technologies have matured.
Paul Denholm, DOE principal energy analyst and study co-lead author, says that this is because of our developing understanding of renewables and storage. But, “90% is a proxy for where we don’t know what resource or multiple resources will be needed for reliability,” he added.
The problem is that there is a lot of local opposition to building new infrastructure for clean energy production. So the issue becomes one of real estate, time and money, as well as local politics across a diverse nation. The full scale of infrastructure revision needed to achieve clean energy is enough to put some people off the idea entirely. Yet, it isn’t any different than building the original U.S. highway system or electric grid.
In fact, it’s much simpler than that. The key is getting many stakeholders on board. That means creating a plan with low costs and higher profits, efficiency and reliability for the consumer.
Four paths forward
In order to get to 100% clean power by 2035, there are four different possible paths envisioned by the DOE study:
1. Improve the cost and performance of current zero emissions technologies, including carbon capture.
2. Improve power transmission technologies. Create new permitting and siting approaches for land acquisition.
3. Push through higher costs and transmission constraints.
4. Use limited carbon capture technologies to balance emissions.
Each path assumes a 65% increase in demand on the grid due to continued growth in the electric vehicle sector and a growing population. This is one of the main challenges. Even as clean energy technologies mature, the demand keeps rising. Equally, we’re attempting the historic feat of shifting the entire transportation network to all-electric in just over a decade.
The DOE study focused on meeting these needs with large-scale energy production from factories. This discounts the contributions of improved energy efficiency as well as small-scale energy production, such as built-in solar on houses, office buildings and cars. Meaningful local policies can also encourage solar panel installation on individual homes.
Also under consideration is how peak demand hours affect the grid. Using more efficient technologies created in the near future and allowing for demand-side flexibility would lower projected annual load growth. The DOE estimates a lower load growth from 3.4% to 1.8%. Newer technology will lower demand and winter peaks along with more hydrogen use for clean transportation, energy generation and industry.
Can we really reach 100% clean energy by 2035?
The study also acknowledged that modeling was based on 2021 state and federal policies. It did not take into account the new 2022 Inflation Reduction Act and 2021 Bipartisan Infrastructure Law. The DOE estimates that those investments driven by these new laws along with other planned projects could lower emissions by 40% from 2005 levels and grow clean energy by 60-81% by 2030 but fall short at 78% power system emissions reductions by 2035.
Here’s how this breaks down to power generation needs:
1. New wind and solar power generation, creating about three times the 2020 level of energy, can provide 60-80% of new power generation by 2035. By 2030, projected annual growth rates for solar and wind, 43-90 gigawatts (GW) and 70-145 GW, respectively, will more than quadruple current levels of clean energy production.
2. In each of the four paths forward, overall capacity, which includes five to eight GW of new hydropower and three to five GW of new geothermal power generation by 2035, could be reduced 16-20% by using more efficient and distributed energy resources.
3. To create reliable power at all times of the year, 120-350 GW of 2-12 hours of diurnal storage will be needed by 2035. This could be via batteries, pumped storage hydropower or new technologies. An additional 100-680 GW will be needed at high variable renewable penetrations to account for power system uncertainties.
4. Nuclear power will be 9-12% of power generation by 2035 under three of these plans. Under one plan, it could more than double to 27% with sitting and permitting constraints on generation and transmission, according to study models. But this is not the likely scenario to play out, Denholm says, because the cost-effectiveness of investments in wind, solar, storage and transmission technologies is “clearly” better than new nuclear.
The result of these projections is that we likely need to build any and all possible solar and wind energy generation plants possible in the near future and continue to invest in the improvement of battery technologies.
How can we store and transmit clean energy more efficiently?
The NREL estimated that 1,400-10,100 miles of new high-voltage power lines will be needed to reach 1.3-2.9 times current capacity in order to transmit all of this new clean energy production. Wind power, combined with new transmission lines, has the lowest average system cost out of all options.
So why can’t we predict which energy production and storage option is best? First, the problem is that we are so late to solve this problem that it’s all hands on deck. All options are needed as efficiently and quickly as possible. Second, it’s unclear which technologies will produce the best results in which combination.
New energy technologies in the works
The DOE expects new technologies currently being developed to affect these projections. These technologies include synthetic natural gas or ammonia fuels, new types of batteries, thermal or pumped storage or compressed air storage and even gravity batteries.
What is not included in these projections is an understanding that some renewable energy technologies have built-in generation used by individual consumers — EVs that have regenerative braking, for instance. This may not make up much of a percentage of the overall technologies being planned for large-scale energy production, but as these technologies also become more efficient, we might see the extra energy demand from electric vehicles reduced.
Just as we take solar calculators for granted now, many products or devices in the future that currently draw from batteries or the grid may be self-charging in some way.
If energy production is reduced enough in cost that every consumer in America could install their own solar panels on a vehicle or home, we might be having a very different conversation. We may be talking about power companies going out of business and not wanting to compete with free solar or wind energy for all.
The tipping point is coming, but the need to start building clean energy infrastructure is already here.
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