100% Renewable Energy Not the Only Way to a Low Carbon Future

06.19.17 | Blog | By:

Before you keep scrolling or clicking on something else because renewable energy issues are just not in your wheelhouse and/or much of a priority and you think it has nothing to do with fuels or vehicles, stop. This one’s important. This blog post, by Varun Sivaram, highlights a paper that he and a number of experts recently published in the Proceedings of the National Academy of Sciences (PNAS) this week that challenges the notion that a 100% renewable energy future is possible (at least by around 2050). And this is important for a couple of reasons. First, that notion is heavily influencing policymakers around the world, not just in the U.S. Second, and as a byproduct, I believe that this is influencing the selection of electrification as pretty much the only transport decarbonization solution out there. And though it will be part of the equation, it’s not the only game in town.

It was Stanford Professor Mark Jacobson and colleagues who argued in another PNAS paper that such a future — one where wind, water, and solar energy could supply virtually all of America’s energy needs — was possible and even a low-cost decarbonization solution. Wind and solar would dominate, backed by hydroelectric plans to compensate for lulls in power. There would be enough electricity to power the production of hydrogen for the passenger car fleet, heavy-duty trucking, ships and aviation. Fossil fuels would be eliminated and nuclear reactors shut down.  This would all need to happen between 2050-2055. What would it really mean? Sivaram notes:

“[T]heir proposal would be astronomically expensive and complicated. It would require adding hydroelectric generation capacity equivalent to six hundred Hoover Dams. It would entail deploying over a hundred times as much energy storage capacity as currently exists in the United States by using barely-tested technologies like ‘phase-change materials.’ It would take trillions of dollars of investment in new electricity transmission lines and infrastructure to produce, transport, and store hydrogen. And it would demand an expansion of solar and wind power capacity well in excess of any buildout of power plants that the world has ever seen.”

And this appears to just concern the power sector. A lot would also need to happen in transport , fuels and vehicles as well, which would neither be cheap nor easy. Sivaram says, “[B]y calling this a ‘low-cost solution,’ Jacobson et al. overstate their conclusions. As a result, they dress up what is in essence a provocative piece of science fiction as a serious resource for policymakers to make decisions.” That includes for fuels and vehicles. That, Sivaram and the other authors point out, could ultimately make the clean energy transition harder:

“[B]y targeting a future powered only by renewable energy, US policymakers would tie one hand behind their backs as they confront an already daunting challenge. They may see little reason to prop up nuclear reactors that are closing down at an alarming rate, even though nuclear power is America’s largest source of clean energy. And, expecting the demise of fossil fuels, they might fail to invest in technology to capture and store the carbon emissions from fossil-fueled plants.


Indeed, the biggest mistake policymakers could make would be failing to invest in a range of new energy technologies, lulled into complacence by studies, such as the one by Jacobsen et al., that argue that existing technologies are all we need. To be sure, the costs of solar and wind power have fallen dramatically and look set to continue doing so. But much more will be needed for a clean energy revolution.”

Sivaram notes that the key is in investing in research, development, and demonstration (RD&D) of new technologies and increasing, not decreasing, the number of options at hand. The question is whether this is going to resonate in the Trump Administration and/or Congress in a time where serious, significant budget cuts are being considered for key R&D programs within federal agencies such as the Department of Energy.


Tammy Klein is a consultant and strategic advisor providing market and policy intelligence and analysis on transportation fuels to the auto and oil industries, governments, and NGOs. She writes and advises on petroleum fuels, biofuels, alternative fuels, automotive fuels, and fuels policy.