Solar power realities – supply-demand, storage and costs

The two recent posts focusing on Peter Lang’s wind study have generated considerable debate, and some very stimulating discussion, among BNC readers. This post is a follow-up, which this time highlights Lang’s analysis of solar power and related problems associated with energy storage.

This is about solar photovoltaics (PV), which generate electricity directly via the photoelectric effect. The other rising player in the solar field is concentrating thermal power from deserts, which use a steam turbine to generate electricity via a temperature differential, in the same fundamental manner as a coal-fired or nuclear power station. I asked Peter whether he was planning to do an analysis of CSP. He told me:

I’ve had a bit of a look at doing a similar paper for CST, but I wasn’t able to obtain the detailed output and cost figures I need. It seems the researchers are holding the figures close to their chest.”

I’ve had similar advice on this matter from Ted Trainer. He has attempted an analysis of CSP, and I might post up a highlight of this shortly, and describe some of the gaps in knowledge that Ted and others are seeking.  Lang says the following on this matter:

There are two technologies for generating electricity from solar energy: solar thermal and solar photovoltaic. This paper uses solar photo-voltaic as the example because energy output and cost data are more readily available than for solar thermal. It is not clear at this stage which is the lower cost option for large generation on the scale required (see here): so any cost difference is insignificant in the context of the simple analysis presented here.

Lang’s ‘Solar Realities’ paper (download the 17 page PDF here) is summarised as follows:

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 analysis, which focuses on the Australian national energy market (NEM) but is obviously relevant for other countries, considers electricity demand, the characteristics of solar PV and one possible means of storing its energy (pumped hydropower), capital costs of a system that could reliably meet demand for 1-day through to 90 days, and then an attempt to frame these numbers in perspective with an alternative low-carbon energy source — nuclear power.

The ‘Introduction’ of Lang’s paper sets the context quite clearly, with the following statement:

The paper takes the approach of looking at the limit position. That is, it looks at the cost of providing all the NEM’s electricity demand using only solar power for electricity generation. Looking at the limit position helps us to understand just how close to or far from being economic is solar power.

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