In Business Spectator on Monday ex-ESAA and APPEA boss Keith Orchison wrote of how Australians were largely blind to the challenges of going renewable. While the shift isn’t trouble-free, Orchison has pushed incorrect data and used spurious comparisons to make his point.
To start with Orchison notes Australians now have 2,400 megawatts of solar on their rooftops, “contributing some 800 gigawatt hours a year to electricity supply.”
The first figure of 2,400 MW (or 2.4 GW) is around the mark, but for it to produce just 800 gigawatt hours would work on assumptions that just don’t add up.
Calculating this number is an inexact science, but the figure is around four times that quoted in the article, at approximately 3,000 GW/h. This is using the formula used by the Australian Energy Market Operator in its 2012 solar PV report.
The complaint made by Orchison is solar isn’t an amazing contributor when compared to Australia’s largest power stations, such as the Bayswater A power plant in NSW.
Using the wrong figure of 800 GW/h, it is asserted that 20 million homes would need to have solar to produce the 16,000 GW/h that Bayswater A gets close to every year.
Insert 3,000 GW/h however, and this is immediately reduced to 5.3 million homes.
Next we should also consider that Australians are now opting for bigger systems, so the next million homes would likely produce more than 3,000 GW/h. Also, the efficiency of solar panels continues to improve, which would lift the GW/h per year figure higher still.
In fact it’s most likely that, even using conservative figures, just shy of five million homes would need to be installed with solar to get us to the level of generation of the Bayswater A coal-fired power station. We already have over one million, so less than four million more are required.
That sounds like a lot – and it is – but we mustn’t forget that this is installation on top of an already existing structure. It’s not taking up space needed for anything else. More to the point, homes aren’t the only rooftops in the country. There are plenty of commercial buildings that could go solar, so we aren’t restricted merely to 10 million homes.
Crucially, the data crunchers at AEMO find this level of solar rooftop penetration is below the saturation point. Under its rapid uptake forecasts – which we are currently on track toward reaching – this 16,000 GW/h figure from solar rooftops would likely be reached in just over a decade from now.
Orchison’s prose also questions the size of development needed to produce solar power at utility-scale.
Using Australia’s largest solar development as an example he comments:
“Which begs the question, how big a space filled with solar arrays would you need to energise a city the size of Sydney?
“There’s a core communications problem here in understanding the physical scale and cost of going down the renewable energy road.”
There are two points to make here:
1) How big a coal mine do you need to power a coal-fired plant?
It’s easy to query the size of the 155 MW AGL solar project, but once it’s installed and connection to the grid established you don’t need anything other than sun. A coal-fired plant however, is to put it mildly, useless with access to coal reserves. As such, any comparison is fraught as you need to factor in the mine/s providing the coal not just the plant itself.
For instance, the Loy Yang and Yallourn power stations in Victoria, combined with their associated coal mines, each cover an area about 10 times that of AGL’s solar project and have about 10 times the capacity. Generation output for a similar sized solar plant would still be lower, but there are other benefits of solar including its more flexible location options and the comparative impact on the environment. We can also expect significant technological advances given recent rapid development and PV’s relative infancy as an energy source.
2) What would the space be used for if you didn’t install a solar PV plant?
AGL’s solar project is in two sites that aren’t much good for agriculture. As such, the opportunity cost is minimal. Indeed, solar plants rely on being built in areas of strong sun resources – which is the majority of the country. The location of coal mines to service coal-fired plants however, is obviously much more restricted (ie. wherever there are appropriate resources in the ground) and the issue of opportunity cost is much more profound. Something many farmers protesting against coal mines in the rich fertile black soil country of NSW will attest.
None of this is saying a move to renewables is easy. It’s just not as challenging as the energy sector incumbents want Australians to realise. The complicated nature of the electricity market however, means getting this message out is incredibly difficult in a news cycle dominated by simple slogans built on errors.