When I first got interested in energy related issues I encountered what amounted to the "Green" party line. That was that Renewables would soon be so cheap, and our energy use would be so efficient that electricity would be virtually given away. I began however, to find reliable sources of information. Sometimes that reliable source was a press release for a "renewables" project, a wind farm or solar array. Reliable information could include the cost of the project, although this almost never included transmission lines. The press release often included the rated output of the project. If it was a solar project, the press release might refer to the area the project covered. The press release got really interesting when it talked about the projects cost. I should say estimated cost, because I suspect that some of those projects I read about ended up costing more than the reported cost in the press release.
I began to analyze this information. I was interested in the answer to the question, how much would it cost to replace CO2 emitting fossil fuel in electrical generation with a post-carbon energy source. That is where I ran into the reliability problem. You cannot replace coal powered electrical plants with wind generated electricity if the coal mainly produces electricity in the day time, and the wind blows at night. It was explained to me by some renewable advocates that the day time coal could be replaced by solar generated electricity, while night time power would be supplied by wind. This sounded good, but that meant that you had to pay for at least two generation facilities in order to be assured round the clock energy production. That got to be a little expensive, but then I discovered that even with solar and wind generation facilities you might not always have electricity when you wanted or need it. So you needed electricity from other sources.
Surprisingly renewables advocates told me that those other sources would burn fossil fuels. But that did not satisfy me, because the point of my exercise was to discover how much it would cost to replace fossil fuels., not how much burning fossil fuels would cost as a crutch for the limitations of renewables.
Some renewabes advocates told me that energy from renewables could be put into storage, and drawn out when there was demand for electricity. How much would that cost, I wondered. So I checked on the cost of various storage plans, pumped storage, Large batteries and compressed air. it turned out that there were inefficiencies and sources of energy lost coupled with all of these, ad none of them came cheep. When I started calculating the cost, an interesting pattern emerged. In every case, renewables plus storage was more expensive than the highest estimated nuclear cost. Even when I made assumptions that were favorable to renewables, for example assuming that the cost of nuclear power would be subject to inflation, while the cost of renewables would not be, the cost always turned out to be higher for renewabes. When I assumed a level playing field, the cost of reliable renewables would strikingly higher than nuclear, so much so that no one in his or her right mind would support renewables.
Someone suggested to me that I look at Mark Z, Jacobson's base wind scheme. I read Jacobson's papers and realized that his promised base load output, was about 20% of the name tage output of his wind facilities. Thus in order to produce a promised base load capacity of 1 GW 80% of the time, wind producers would have to put up 5 GWs of wind generation capacity. But 5 GWs of wind capacity was more expensive than a 1 GW nuclear power plant. Once more a favored renewables scheme proved more expensive than nuclear. The problem was much worse than this, however. None of the renewables schemes was as reliable as nuclear was. Jacobson's base load wind delivered 79% of the time, while the average nuke delivered 92% of the time. What is more, at least part of the nukes down time would be for maintenance, and could be scheduled in advance. The Nuke clearly offered superior flexibility over renewables, the nuk would almost always deliver electricity on demand.
I recently discovered that Australian Climate Scientist Barry Brook was posting information on his blog Brave New Climate that resembled my studies and which came to similar conclusions. These studies, many of which were preformed in part or completely by people who had far more expertise than i have came to the same conclusions that I came too.
i regard Barry as a major figure in the carbon mitigation debate. Perhaps there is a little vanity in this assessment, In many respects Barry's thinking is similar to mine, however, we party company in one significant respect. Our views on preferred nuclear technology differ, and the clash has at times been rancorous. I will deal with the issues on another occasion. At present I want to focus on Barry's month long attack on renewables. On August 8, Barry posted on brave New Climate a discussion of a paper by Peter Lang. Barry describes Peter:
(Peter is a retired geologist and engineer with 40 years experience on a wide range of energy projects throughout the world, including managing energy R&D and providing policy advice for government and opposition. His experience includes: coal, oil, gas, hydro, geothermal, nuclear power plants, nuclear waste disposal, and a wide range of energy end use management projects)The post was titled "Does wind power reduce carbon emissions?" The Lang paper offered the following statement:
A single 1000 MW nuclear plant (normally we would have four to eight reactors together in a single power station) would avoid 6.9 million tonnes of CO2 equivalent per year. Five hundred 2 MW wind turbines (total 1000 MW) would avoid 0.15 to 1.3 million tonnes per year – just 2 to 20% as much as the same amount of nuclear capacity. When we take into account that we could have up to 80% of our electricity supplied by nuclear (as France has), but only a few percent can be supplied by wind, we can see that nuclear can make a major contribution to cutting greenhouse emissions, but wind a negligible contribution and at much higher cost.“The discussion which followed contained over 150 comments. This post was followed by an august 13 post titled, Wind and carbon emissions – Peter Lang responds. Lang's second essay offered the following statement: I would argue that average capacity factor is not valid for determining the amount of back-
up generation capacity required. The total generation system must be able to provide peak power when there is no output from the wind turbines. When wind power is zero, or near zero, at the time of peak demand, we need sufficient conventional generator capacity to provide the peak demand. This is because electricity demand must be matched by supply at all times. In other words, wind power cannot displace much, if any, conventional generator capacity.If wind doesn't reduce CO2 as much as nuclear does and cannot be counted on in periods of peak electrical demand, what good is it? One hundred eighty four comments followed.
This was followed by an August 16 Lang based post, Solar power realities – supply-demand, storage and costs. This time a Lang paper goes after solar power.
Four hundred thirty six comments followed this post. The Lang paper on solar power was followed by an August 31 post,Solar thermal questions, this time based on a paper by University of NSW academic, Ted Trainer. The Trainer essay is an all out, no holds barred, take no prisoners assault on solar, and what sort of intellectual respectability is left to solar advocates after their thrashing at Trainer's hands is open to question. Trainer writes:
This paper provides a simple analysis of the capital cost of solar power and energy storage sufficient to meet the demand of Australia’s National Electricity Market. It also considers some of the environmental effects. It puts the figures in perspective. By looking at the limit position, the paper highlights the very high costs imposed by mandating and subsidising solar power. The minimum power output, not the peak or average, is the main factor governing solar power’s economic viability. The capital cost would be 25 times more than nuclear power. The least-cost solar option would require 400 times more land area and emit 20 times more CO2 than nuclear power.
Conclusions: solar power is uneconomic. Government mandates and subsidies hide the true cost of renewable energy but these additional costs must be carried by others.
The Trainer essay and Barry's discussion drew 98 more comments. Finally on the 10th Barry followed up Lang's first solar essay, with Solar realities and transmission costs – addendum.
The heat storage capacity of solar thermal systems overcomes some of the intermittency problems that trouble wind and PV systems, such as the occurrence of night time. The standard provision will be 12 hour storage enabling continuous 24 hour electricity delivery. However examination of climate data reveals that even at the best sites sequences of 4 or more days without sunshine are not unusual. The best US sites often have 2 runs of 4 consecutive days of cloud in a winter month. (Davenport, 2008)
If 1000 MW(e) output was to be provided for four cloudy day from stored heat, some 290,000MWh of heat would have to be stored. Storage cost has been estimated at $(A)10/kWh(th) meaning that the required storage plant would cost more than $8 billion, or around twice the cost of a coal-fired plant plus fuel. However this refers to trough technology and it is likely that for the ammonia process costs would be higher.
Again we would be faced with the prospect of very high capital costs for a large amount of plant that would not be used most of the time, and would still be insufficient occasionally. There would also be the question of whether there would be enough solar radiation in winter to meet daily demand and also recharge a large storage sufficiently to cope with the next run off 4 cloudy days.
Basically Lang compares the cost of providing reliable power for Australia with Nuclear and solar power. Trainer had observed,
examination of climate data reveals that even at the best sites sequences of 4 or more days without sunshine are not unusual. The best US sites often have 2 runs of 4 consecutive days of cloud in a winter month. (Davenport, 2008).Lang noted,
A loop through the midday images for each day of June, July and August 2009, shows that much of south east South Australia, Victoria, NSW and southern Queensland were cloud covered on June 1, 2, 21 and 25 to 28. July 3 to 6, 10, 11, 14. 16, 22 to 31 also had widespread cloud cover (26th was the worst), as did August 4, 9, 10, 21, 22.. This was not a a rigorous study.Thus Lang was thus responding to this data by asking how much would it cost to provide electricity during cloudy winter days in Australia..
It is assumed that South East Australia would need a power reserve capable of providing electricity during the cloudy winter days. That reserve can be either provided by nuclear power plants or by solar systems with three days energy storage, that is capable of being transformed into electricity. Lang's conclusions can be summarized with the following table:
Discussion of the latest Lang post continues, but it is clear that Lang, Trainer and Brook have destroyed the case for renewables beyond redemption.