S&P reviews research on feasibility of 100% renewable electricity grid — results inconclusive
Only a few years ago, the prospect of relying exclusively on renewable energy to power cities, states and even the global economy was widely considered science fiction at best and a distracting pipe dream at worst. More recently, though, the concept has emerged as a subject of serious debate in venues ranging from U.S. state capitols and corporate board rooms to university and government laboratories. But a trio of recent studies on 100% renewable energy systems indicates that debate has only begun.
According to a report published April 3 by REN21, a nonprofit group affiliated with the United Nations’ environmental program, more than two-thirds of global energy experts polled on the feasibility of reaching 100% renewable energy across all sectors of the worldwide economy, compared to about 19% in 2014, found the transition “both feasible and realistic.” Despite the overwhelming affirmation, “some remain unconvinced that a fully renewable energy supply is feasible or even necessary,” added the report, which highlights “great debates” on 100% renewables based on a survey of 114 research scientists, energy regulators, renewable energy advocates, utility representatives and financiers.
Opinions differed widely depending on region, with most energy experts in Europe, Australia and New Zealand viewing 100% renewable energy as “technically and economically feasible,” while most experts in the U.S., Japan and developing nations were generally skeptical. Only two of eight U.S. survey respondents — who included representatives of the U.S. Department of Energy’s National Renewable Energy Laboratory, the University of California, the University of Pennsylvania, PG&E Corp. subsidiary Pacific Gas and Electric Co., a consulting firm and an advocacy group — believed 100% renewable energy was obtainable as early as 2050.
U.S. participants singled out the transportation sector as the most challenging part of the economy to go completely green, but they also cited technical difficulties in the power sector associated with the large-scale integration of intermittent solar and wind resources, “inadequate storage technologies,” and “insufficient political will” as major hurdles. “Socio-economic and political barriers are the biggest; technical difficulties are not as challenging,” said one U.S. survey respondent.
Such doubts, however, have not stopped Hawaii from starting to implement its 100% renewable portfolio standard, or lawmakers in Massachusetts, North Carolina and California from seeking to boost their own renewable energy targets to 100%, or New York from conducting a study on going all green as well. But if legislators weigh recent academic assessments of the feasibility of fueling entire economies with renewable energy, they will find some mixed reviews.
‘Unsupportable, and arguably reckless’
A paper published April 2 in the scientific journal Renewable and Sustainable Energy Reviews, for instance, found that two dozen studies considering 100% renewable energy scenarios failed to make the case that such futures are feasible. “Our assessment of studies proposing 100% renewable-electricity systems reveals that in all individual cases and across the aggregated evidence, the case for feasibility is inadequate for the formation of responsible policy directed at responding to climate change,” concluded a team of researchers from three Australian universities in the paper.
“The purpose was to put an effective, empirical framework around assessing the feasibility of proposed energy pathways, preferably one that could be readily applied by policy makers who actually need to plan and make decisions,” said co-author Benjamin Heard, a doctoral candidate at the University of Adelaide, in an email. Titled “Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems,” the study found all previous efforts to assess the viability of 100% renewable systems “have substantially underestimated the challenge of excising fossil fuels from our energy supplies.” It also called analyses that exclude consideration of other carbon-free technologies, specifically nuclear energy and fossil fuel plants with carbon capture and storage capabilities, “unsupportable, and arguably reckless.”
The study scores the 24 100% renewable energy reports based on consistency with mainstream energy demand forecasts, simulations of meeting demand at different timescales, identification of transmission and distribution needs, and maintaining essential ancillary services. But even high scoring studies are lacking, said Heard, adding that “the burden of proof lies on the proponents to demonstrate that their proposed set of solutions may be effective at real-world timescales.”
One high-scoring study on powering the U.S. with wind, solar and water power, co-authored by Stanford University professor Mark Jacobson, a high-profile proponent of 100% renewable energy, “scored well for a fine-grained supply-demand simulation” but was “unfortunately based on a totally implausible scenario,” Heard asserted.
‘Doesn’t debunk anything’
Jacobson is the co-founder of The Solutions Project, an initiative promoting the transition to 100% renewable energy systems. He and a team of Stanford scientists created 50 high-level plans for U.S. states to rely on combinations of each state’s specific solar, wind, water and geothermal resources. The outspoken Jacobson defended his research, and blasted Heard and his study in an email. “This paper doesn’t debunk anything,” he said, adding, “This is probably the least rigorous ‘review’ paper I have ever encountered.” The authors’ agenda, Jacobson charged, is to promote nuclear power, saying the review “is written by nuclear shills who have financial conflicts of interest in what they are saying, and none is an energy expert, particularly on wind, water, or solar power.”
Heard confirmed that South Australia uranium mine operator Heathgate Resources Pty. Ltd. was a client at a recently shuttered consulting firm where he was a director for more than seven years. Heathgate is a subsidiary of San Diego-based nuclear power and defense company General Atomics. Heard also sits on the advisory board of nuclear reactor developer Terrestrial Energy, which identifies him as “a leading voice for nuclear power as an essential part of the climate solution.” Denying that financial interests played any role in the study’s findings, Heard called the Terrestrial Energy position “an unremunerated, non-executive advisory role.”
The “Burden of Proof” paper “does not draw a useful conclusion — it simply points at shortcomings,” said Australian National University professor Andrew Blakers, who criticized the report for not giving enough attention to the role of high-voltage transmission and pumped hydroelectric storage in making 100% renewable energy systems possible. “It has missed the point of successful 100% modelling,” he said. Blakers co-authored a report published in February finding that Australia could be powered 100% by distributed solar and wind power, supported by high-voltage transmission and pumped storage. The study is based on what he calls a “non-heroic assumptions policy” that only considers technologies in mass production today. “We can get reliable prices for these technologies,” he said.
In response to criticism of his work, Heard replied, “The critics are inverting the premise of the paper, and shifting the burden of proof away from those proposing novel pathways and on to those who seek certainty and firm evidence.”
Firm evidence, so far, is limited to a few regions, such as geothermal-powered Iceland and parts of Washington state, where numerous public utilities run at or near 100% renewable energy thanks to abundant hydropower. That means the 100% debate is unlikely to be settled anytime soon. What is certain is that renewables’ share of the overall mix continues to grow: Texas set a new record for wind power penetration on March 23, when wind turbines briefly supplied 50% of the electricity in grid operator ERCOT’s service territory. That same day, the California ISO set a new record for renewables of its own, at nearly 57%.
By GARRETT HERING - See more at: http://marketintelligence.spglobal.com/our-thinking/news/great-debate-rages-over-100-renewables#sthash.5p6R5bBL.dpuf
