POWER March 2017 - 56

RENEWABLE ENERGY
4. Solar economics. The cost of solar
power continues to drop rapidly. The Crescent
Dunes concentrating solar power plant in Nevada
cost about $1 billion and required a loan
guarantee from the Department of Energy,
but follow-up projects from developer Solar
Reserve are expected to see about 30% lower
construction costs and are being built with
100% commercial financing. Courtesy: Solar
Reserve
update estimates the total worldwide capital
cost at about $125 trillion in 2013 dollars.
(By way of comparison, the gross world
product in 2013 according to the World Bank
was a mere $75 trillion.) But much of that
money would be spent anyway on other energy
resources under a business-as-usual
approach. How would the 100% renewable
scenario compare? For one thing, the study
argues, the levelized cost of energy in 2050
would be less expensive, though not by much
(roughly $85/year per capita worldwide).
The main benefit would be avoided health
and climate impacts of around $5,800/year
per capita.
There are other costs as well, particularly
a major shift in energy sector employment.
While the study estimates that transitioning
to 100% renewables would generate 25.4
million construction jobs and 26.6 million
new jobs, it would also eliminate 27.7 million
current jobs. These shifts would not be
evenly distributed, with countries that rely on
fossil-fuel extraction for a significant portion
of their economies suffering disproportionate
losses.
of lithium in as little as 20 years. The authors
suggest this is likely to drive up lithium prices,
incentivizing recycling and development
of possible new resources. Meeting demand
for platinum used in fuel cells would also require
increased recycling.
Maintaining reliability on a grid with
greater than 80% intermittent resources requires
some additional changes, but the authors
argue that this challenge can be met
through a mix of approaches: greater interconnection
(including international " supergrids " ),
smart demand response, better
forecasting, energy storage (including distributed
thermal storage and vehicle-to-grid),
and oversizing generation capacity, with any
excess generation being directed toward hydrogen
production. Absent the hydrogen production,
these are measures that a number of
other groups such as the World Energy Council
(WEC) have also discussed as necessary
for greater renewable integration.
A 2015 follow-up study (see http://stanford.io/1IdZB0I)
ran a model over six years
that demonstrated that such an approach in
the U.S. could meet conventional
utility
standards for reliability. (For some recent
POWER articles on these subjects, see " Utilities
Grapple with Storage Integration " in the
December 2016 issue, " The Future of Load
Control for Solar PV " in the December 2015
issue, and " Reducing Weather-Related Risks
in Renewable Generation " in the January
2015 issue.)
The Price Tag
What would all this cost? A lot. The 2016
56
Uncertainties and Caveats
Though Jacobson and Delucchi have broken
ground in their degree of detail, other
researchers as well as entities such as the
National Renewable Energy Laboratory, the
International Renewable Energy Agency,
the WEC, and the World Wildlife Fund have
looked at what it would take to transition to
100% renewables worldwide. A 2013 study
by researchers at the University of Delaware
came to similar conclusions using perforwww.powermag.com
Another
2015 study looked at making
such a transition in the U.S. Under that scenario,
total U.S. generating capacity expands
from 1,167 GW in 2015 to 6,447 GW in
2050, with the relative percentages of each
type of generation slightly different from the
list above (more wind and less solar), while
total demand falls around 40%, as with the
global studies. The total cost of this capacity
would be about $13.4 trillion in 2013 dollars,
spread over several decades (the U.S. gross
domestic product in 2013 was a bit less than
$17 trillion).
By 2050, however, the levelized cost of
100% renewable generation, including additional
transmission and storage, is predicted
to have fallen below conventional generation
even without including external health
and climate costs. " WWS energy in 2050
will save the average U.S. consumer $260
(190-320) per year in energy costs ($2013
dollars), " the study says. " In addition, WWS
will save $1500 (210-6000) per year in
health costs, and $8300 (4700-17 600) per
year in global climate costs. "
mance data from PJM, finding that 99.9%
renewables by 2030 was feasible but would
require substantial overcapacity and had
to include externality costs to be economic
compared to fossil fuels.
When speaking of targets decades out,
many of the predictions underlying these
roadmaps are necessarily speculative. Estimates
of savings in climate change impact
costs also necessarily have a high degree of
uncertainty because of the difficulties in predicting
how changes in global temperatures
will affect human activity.
It's worth noting, though, that one reason
the Jacobson and Delucchi studies discussed
have been updated repeatedly is that
the costs of wind and solar generation have
fallen faster than expected. The projections
in the original 2011 studies proved to be too
conservative, with the market in some cases
reaching 2020 estimates as early as 2016
(Figure 4).
Other critics have focused on the exclusion
of nuclear, arguing that simply displacing
what is already a low-carbon resource that
provides about 10% of the world's electricity
in favor of another low-carbon resource isn't
the most efficient approach and unnecessarily
delays a transition to low-carbon generation
(depending on what study you look at,
nuclear has about the same to slightly higher
carbon emissions than wind and solar, but far
less than coal or gas). These critics also point
out that nuclear achieves far higher capacity
factors than wind and solar, while also beating
them by a large margin on power density.
While most of these studies recommend a
variety of policies to support the transition,
the question of whether such a program is politically
and socially feasible remains open.
Most of the policy recommendations are
broad, top-down approaches more suitable to
regions like China and the European Union.
As but one example, China has spent much
of the last year ordering halts to the development
and construction of hundreds of coalfired
power plants, something that would be
far more difficult in the U.S. (and would also
result in protracted litigation). Yet even China
has run into substantial problems with underutilization
of its vast wind capacity-by far
the largest in the world at 145 GW-because
of a variety of political and economic factors.
(And China is also highly unlikely to abandon
its rapidly growing nuclear fleet.)
The U.S., with its much more decentralized
political structure is likely to move more
slowly, even without considering a national
political climate that has shifted repeatedly
on support for renewables. Whatever the possibilities,
the reality is likely to take longer. ■
-Thomas W. Overton, JD is a POWER
associate editor.
POWER | March 2017
http://stan http://www.ford.io/1IdZB0I http://www.powermag.com
POWER March 2017

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