An
outline of the negative case.
Ted
Trainer.
3.6.2022
The
potential and limits to renewable energy are hotly debated, and far from
settled. Many people take it for granted that it can meet all our energy
needs, and numerous impressive agencies and technical reports say this. However
until the last few years when a few simulations based on detailed
weather data have become available nearly all pronouncements have been
little more than speculation and most have simply selected bits of
evidence to confirm preferred beliefs. I have examined about ten of the
simulation studies for the Australian situation and have published
various analyses showing how inconclusive they are. There are now
several analysts and studies casting doubt on the 100% renewable claim.
(E.g., Moriarty and Honnery 2010, Clack et al., 2017, Heinberg and
Fridley 2016, Heard et al. 2017, Friedmann, 2016, de Decker, 2017, Floyd
and Palmer, De Castro and Capellan-perez.) Heard et al., (2017),
recently published a scathing review of claims.) For a list of 84 papers
see RE100%Doubters.html
Just
as you can run your house on torch batteries, it is technically possible
to run everything on renewables … but that doesn’t mean you could afford
to do it. The crucial question is what would it cost to have enough
generating capacity to meet demand at any time despite the intermittency
of renewable energy? The simulations we now have generally find that to
meet an average electricity demand of one GW you would need renewable
generating plant capable of generating four to
seven GW, and with plausible assumptions it
would be much higher; de Decker says in some situations it is 10.
Whether we could afford that is not settled, but below I indicate why it
is very unlikely that we could.
What
about the claim that wind and PV can produce a kWh more cheaply than
coal now? That could be true now,
but it is quite misleading. It
doesn’t tell us much about what a kWh would cost if it came from a
system with enough redundant renewable capacity
to be able to supply that kWh at any time. Again
that system might have to contain 4 to 7 times as much wind and/or PV
capacity as we would need in the form of coal-fired generators, and it
would have to contain a great deal of storage capacity.
Won’t
batteries solve the storage problem? Not unless costs fall enormously.
Grid level systems that have been built have cost around $1000 of more
for the capacity to store 1 kWh. The “Big Battery” Elon Musk built in
South Australia cost $1550/kWh.) (…see
my examination of the storage problem for renewables, Trainer 2017a.) If
you want to store the output from one power station for one day you
would need capacity to store 1 million x 24 kWh = 24 million kWh, and if
the storage cost fell to $100 per kWh that’s going to cost you $2.4
billion…which as much as it would cost to build another coal-fired power
station. A national system would need the capacity to store enough to
meet total demand for many days in a row, in European winters probably
for weeks.
Pumped
hydro storage? Enthusiasts do not
deal with the difficulties satisfactorily, especially the lack of
affordable sites stated by two major studies. (Again see Trainer 2017a.)
Claims
about renewable potential are of little or no value unless they are
derived via complex simulations based
on detailed weather data for a region over a long period. Only these can
tell how much redundant plant would be needed to meet demand in the
worst weather conditions. Very few such studies have been carried out
anywhere in the world. In 2012 Elliston, Diesendorf and Macgill (2012)
published what I think was the first analysis of this kind for
Australia, based on recently available detailed weather data for about
40 regions across the country. This valuable study concluded that a 100%
renewable supply system could meet all electricity demand reliably, at a
production cost of about 10-15c/kWh. At
that time it was costing about 3-5 cents to produce one kWh by a
coal-fired generator. In 2015 Lenzen et al. (2016) published the second
Australian simulation concluding that the production cost could be 20c,
and possibly 30+c.
These
simulation studies inevitably involve many assumptions and in my view
those made by Lenzen et al. are more acceptable, (… although I have
published a detailed case that its assumptions re solar thermal
efficiency in winter are much too favourable, probably two times too
high. The findings on getting through difficult periods in winter relied
very heavily on solar thermal, so the assumptions I think would be more
defensible would significantly raise the
cost conclusions; see Trainer 2017a.)
Wind
is the cheapest renewable and Elliston, Diesendorf and MacGill assume it
will be a major contributor, providing up to 58% of electricity, but
Lenzen et al. assume that it would/should be limited it to 30% in view
of the studies indicating that above this level problems in integrating
wind into the supply system become difficult and costly. So differences
in conclusions in the renewable field are typically due to differing
assumptions, and thus conclusions can differ greatly.
In
my attempt to derive a possible retail price from the production cost
conclusions Lenzen et al. come to I list 13 factors they didn’t and/or
couldn’t consider but which would be likely to increase the production
cost. (Trainer, 2017b.) Examples are, the fact that the capital cost
assumptions used were for a time when the $A dollar was about 35% higher
than it is now 2017), meaning the turbines and panels etc. that would
have to be imported would now cost far more, the high probability that
the year studied, 2010, was not the most difficult one ever likely to
occur, and the fact that construction in remote areas has been estimated
to increase construction costs 10%. The four factors I could quantify
multiplied the Lenzen et al. production cost from 20 c/kWh to about 46
c/kWh. One important factor I could not include is the energy embodied
in the construction of the huge amount of turbines, PV farms,
transmission lines etc. that would be required. (I have since derived
the uncertain estimate that this would add 17% to the electricity that
has to be generated, and therefore to the plant needed to do it; see
Trainer 2017c.)
The
next important question is, given this production
cost of electricity, what might the retail
price be? For coal-fired power at the time of
the study the retail price was about 5 times the production cost; i.e.,
it added about 22 cents to the maybe 3-5 cent production cost, mostly
for distribution of electricity to consumers. So it seemed to me that
the retail price from the pattern of renewable supply which Lenzen et
al. found to minimise cost would probably be at
least 46 + 22 = 68 c/kWh, and more likely around
90 c., i.e., 3 to 4 times the retail price at the time of the study. In
my view this might be “affordable” but it would be extremely
economically disruptive. Protest over electricity prices in Australia is
a major political issue already.
I
should note that I am not confident about these conclusions; they are
possibilities I have come to given the information I have.
Keep
in mind that this has been about Australia which has probably the best
renewable energy sources of any rich country. My
attempt to assess the prospects for Europeans (Trainer, 2013) concluded
that they would be most unlikely to meet all electricity demand from
renewable sources. In winter Europeans frequently endure weeks of
continually very cold, stable and cloudy conditions, and have little
biomass for back up.
But
all that is only about providing electricity. Over 80% of our energy use
is not electrical; much of it is in the form of liquid fuels. Meeting
this demand is far more problematic. Following is an indication of my
recent attempt to clarify the task of meeting total Australia’s energy
demand via renewables. (The easily followed derivation is detailed in
Trainer, 2017d.)
I
assumed, among other things, all light vehicles converted to
electricity, use of the 96 million tonnes/y of biomass Crawford et al.
(2012) think could be taken for energy, most of it producing ethanol,
use of hydrogen thereby providing for all storage required, and
conversion of as many functions as possible to electricity. (All the
assumptions, derivations and arithmetic are in the paper.)
I
found that the total amount of electricity that would needed to meet
estimated 2050 total energy demand came to 5,867 PJ, in addition to use
of all available biomass. This is over 8 times present electrical
output. If the retail price of electricity was 50c kWh (and the argument
above was that it could well be twice this) the cost of energy would be
$814 billion p.a., which is around 54% of 2015 GDP, or 27% of 2050 GDP
assuming 2% economic growth. Note that this does not include the cost of
the biomass, converting it to ethanol, the transmission lines, the
hydrogen production equipment, piping and storage system, or any of the
embodied energy costs built into the wind, turbines, PV farms
transmission lines, storage tanks etc.
If
this (not confident) analysis is at all valid then100% renewable supply
to meet all energy demand would be utterly impossible to afford. At
present Australia spends about 8% of GDP on energy. For
the US it has been found that if the percentage goes above about 6% for
any period of time there is recession. (Hall and KIitgaard, 2014.)
As
noted, I have more recently attempted to estimate the Energy Return on
Energy Invested (EROI) for a 100% renewable electricity (not
total energy) generating system (Trainer, 2017d), bearing in mind that
such a system must have a lot of generating capacity sitting idle much
of the time, maybe five times as much equipment as would do the job in
the form of coal-fired plant. The present energy system’s EROI is
probably around 18, but I estimated that for the 100% renewable
electricity supply system Lenzen et al. analyse, it would be 5.9, and
there are reasons for thinking it would be considerably lower. For a
100% renewable system to meet all energy demand (electricity is only 20%
of that), the figure would be much lower.
This
has been an indication of the kind of detailed analysis that must be
carried out before we are in a position to make confident assertions
about whether renewables can save us. The fact is that we are a long way
from clear and confident conclusions in this area, but there is a strong
case that we could not afford the amount of capacity needed to be 100%
dependent on renewables.
In
my view renewable energy is not a very important issue in the quest for
sustainability. I think it’s too late to fix the climate problem and at
the very best renewable energy will be quite costly and this will add to
the mounting and terminal difficulties consumer-capitalist society is
running into. Many other factors will be more powerful determinants of
our fate, most obviously oil depletion, financial collapse, and the
discontent brewing among the perhaps 80% in rich countries for whom this
society is increasingly failing to provide.
What
then should we do? The answer is, emphatically, move
to 100% renewable energy supply as fast as possible! But
we cannot do that unless we undertake an astronomically big De-growth
transition to The Simpler Way. That means scrapping capitalism, and the
obsession with wealth and affluence, individualism and competition, and
instead being content to live frugally and cooperatively mostly in
highly self-sufficient local communities. The many people living in
Eco-villages today know that these ways can provide all with a high
quality of life on extremely low per capita resource use rates. (See
Lockyer’s evidence, 2017.) No other way can defuse the big global
problems, because they are basically due to the quest for affluence and
growth and the resulting unsustainable over-consumption. We
could make this transition easily and quickly…if enough of us wanted to
do it. (For the detailed case see thesimplerway.info/.) I
think the chances of this path being taken are very poor, but it is the
only sensible option, and lots of people are working for it, including
the Simplicity Institute (2017.)
Clack,
C. et al., (2017), “Evaluation of a
proposal for reliable low cost grid power with 100% wind, water and
solar”, PNAS, June 27, 114, 26, 6722 – 6727.
Crawford,
D., T. Janovic, M. O”Connor, A. Herr, J. Raison and T. Baynes, (2012), Potential
for electricity generation in Australia from Biomass in 2010, 2030,
and 2050, AEMO 100% Renewable
Energy Study, 4 Sept. CSIRO Report EP – 126969.
Elliston
B., Diesendorf, M.,and I. MacGill, (2012). “Simulations of scenarios
with 100% renewable electricity in the Australian National Electricity
Market”, Energy Policy, 45, 606 – 613.
Friedmann,
A., (2016), When Trucks Stop Running,
Dordrecht, Springer.
Hall,
C. A. S and K. A. Klitgaard, (2014), Energy and the
Wealth of Nations, Dordrecht, Springer.
Hart,
E. K., and M. Z. Jacobson, 2011. A
Monte Carlo approach to generator portfolio planning and carbon
emissions assessments of systems with large penetrations of variable
renewable, Renewable
Energy,
36, 2278 – 2286.
Heard,
B., et al, (2017), “Burdon of proof: A comprehensive review of the
feasibility of 100% renewable-electricity systems”, Renewable
and Sustainable Energy Reviews, 76,
1122-1133.
Heinberg,
R., and D. Fridley, (2016) Our Renewable Future,
Santa Rosa, California, Post Carbon Institute.
Lenzen,
M., B. McBain, T. Trainer, S. Jutte, O. Rey-Lescure, and J. Huang,
(2016), Simulating low-carbon electricity supply for Australia, Applied
Energy, 179, Oct., 553 – 564.
Lockyer,
J., (2017), “Community,
commons, and De-growth at Dancing Rabbit Eco-village”, Political
Ecology, 24, 519-542.
Moriarty,
P., and D. Honnery, (2010), The Rise and Fall of
Carbon Civilization, Springer, Dordrecht.
The
Simplicity Institute,
2017. simplicityinstitute.org/
Trainer,
T., (2013), "Can Europe run on renewable energy? A negative case", Energy
Policy, (63) 845 – 850.
Trainer,
T., (2017a), “Some problems in storing renewable energy”. Energy
Policy, (in press.) thesimplerway.info/REstorage.htm
Trainer,
T., (2017b), “Can renewables meet total Australian energy demand: A
“disaggregated” approach.” Energy
Policy, (in press.) thesimplerway.info/CanRE.htm
Trainer,
T., (2017c), “Estimating the retail price for 100% Australian renewable
electricity.” (In press, Energy Policy.) thesimplerway.info/REretailprice.htm
Trainer,T.,
(2017d), “The overlooked significance of the EROI for renewable energy
supply systems.” (In press, Energy Policy.)
thesimplerway.info/REsystemEROI.htm