The Australian Government’s domestic solar PV subsidy…

The federal government has recently announced it will scrap the unpopular means test for the federal subsidy for domestic solar PV arrays, which restricted the rebate to households earning less than $100,000.

The size of the rebate was, formerly, $8 per watt of installed nameplate capacity, up to a maximum of $8000. The rebate will now be smaller; $5/W, up to a maximum of $7500.

Sounds good, right? But it’s horrendously expensive – the government is in effect paying $5/W for the cheapest, nastiest polycrystalline silicon PVs on the market.

There are scores of companies jumping on the bandwagon to sell these little 1-1.5 kW rooftop PV systems, advertising and promoting and installing them – because they’re making a fortune from the increase in business resulting from the subsidy.

The government rebate does not cover the full cost of such a system – therefore, in order to get as much interest as possible, the vendors are trying to keep the costs of such systems as low as absolutely possible, so that the cost that the customer pays is as small as possible. Therefore, all such systems are exclusively cheap, inefficient, basic polysilicon devices. After all, an advanced solar-concentrating collector with a high-efficiency CdTe cell or stacked heterojunction cell or sliver cell or whatever does not attract any higher subsidy than the basic polycrystalline Si device.

Advocates such as the Australian Greens say that such a scheme “supports the solar industry” – but all it does is supports the environmentally-damaging low-cost manufacturing of polycrystalline silicon in China, and doesn’t support innovation in advanced PV technology or anything like that.

What if the same amount of subsidy might be better spent elsewhere? Here’s a hypothetical idea to think about.

1. Go and find a suburb or a city or a community which has about 31,000 households. I’m certain there are 31,000 households in this country who support what I’m about to elucidate.

2. Get each household to put up AUD $1200 or so, temporarily.

3. Take that 25 million US dollars and purchase a 25 MWe Hyperion Power Module, or something similar.

4. At 25 MWe divided between 31,000 households, that’s a little over 25 GJ per year, which is a little more than Australia’s present average household electricity consumption. This doesn’t just generate a fraction of your household electricity needs – it generates 100% of it, and there will be no more electricity bills.

5. That corresponds to a nameplate capacity of 807 watts per household. Since the government hands out a subsidy of $5/W for solar photovoltaics with a 20% capacity factor, they should hand out $22.50/W for nuclear energy with a 90% capacity factor, right?

6. Collect your $18,157.50 rebate from the government. Less the $1200 investment, that’s $16,957.50 immediate profit in your pocket. This is exactly the same rate of payment per energy produced that presently exists in the form of the PV subsidy.

7. Go to the pub. Got to stimulate that economy, you know.

I wonder how many ordinary Australian households would support nuclear energy if you paid them $17,000 for doing so?

To replace one Loy Yang type coal-fired power station* with solar cells, we would need 6,082,342 homes equipped with 1.5 kW solar photovoltaic arrays.
With an $7500 rebate for each one, that would cost the government 45.6 billion dollars per each large coal-fired power station.

* (Loy Yang generated 15,995 GWh in 2006.)

Solar photovoltaics typically have a capacity factor of about 20%, and we’ll suppose the panels have a lifetime of, say, 30 years.
Therefore, this scheme costs the government 9.5 cents per kWh generated.

If the government purchases nuclear power plants, they will cost, say, 10 billion dollars (let’s be conservative) for a nuclear power plant with two 1100 MW nuclear power reactors which will operate with a 90% capacity factor and a lifetime of 50 years. The capital cost of plant dominates the overall cost of nuclear energy.

Therefore, the nuclear power plants would cost the government 1.15 cents per kWh – 12% percent of the cost of the solar rebate scheme. That’s the government’s rebate alone – without the rest of the price of these systems.

All this solar rebate is is another mendacious political enterprise involving renewable energy which can’t be scaled up, which hands out free money to the public, makes a bunch of money for the solar panel vendors (including many dangerous fossil fuel vendors such as British Petroleum), and mendaciously makes the government look like they’re actively getting the country running on clean energy.

ASIDE: I’m going to start cross-posting some blog content on the Daily Kos. I think it’s a nice site to engage with many, many readers – many of whom perhaps aren’t already so convinced of the virtue of nuclear energy – so, there’s plenty of engaging, active discussion, and the opportunity to maybe convince some people – even if that’s just a few people it’s still a very positive thing.

A Question, dear readers…

I’m currently interested in trying to find an example of any kind of scholarly paper or article published by Helen Caldicott, which has been published in a peer-reviewed journal, which is not just the usual “nuclear power bad” stuff we’ve all heard before. For example, any example of an article dealing with research into or treatment of cystic fibrosis, which was her area of professional expertise. Given that Caldicott was “Researcher in Cystic Fibrosis, Boston Clinic; formerly Director of Cystic Fibrosis Research, Adelaide Children’s Hospital, Adelaide. Australia.”, or at least so I’m reading, I’m surprised to find that despite running a few search queries through Elsevier, Medline, Web of Science and so forth, I’ve not been able to find any such example of any published works. I’d like to see a kind of baseline example of what her grasp of critical thinking, science and scholarly research was like, before it was swamped by this fervent dogma and drowned out.

That seems strange. Can anybody else find any such articles, or published works?

The footprints of coal and nuclear fuels.

In 2007, coal consumption in the United States – just for electric power generation – was 1.046 billion tons (1,046 million tons).

That’s a lot of coal.

Crushed bituminous coal has a bulk density of about 833 kg/m³, so therefore, that coal occupies a total volume of one cubic kilometer.
(1.046 billion tons / 833 kg/m³)^1/3 = 1.04 km.)

Combustion of coal produces carbon dioxide at a rate of about 1.83 kg CO₂ per kg coal.
Of course, CO₂ is just one particular component of the stream of dangerous waste output from coal combustion – there’s the particulate matter, the SO₂, the NO₂, the fly ash, the polycyclic aromatic hydrocarbons, and so forth.

So, each year, the use of coal for electricity generation in the United States generates 1.91 billion tons of CO₂ output to the atmosphere.

Applying the ideal gas equation, we can find the volume that this CO₂ occupies, assuming that it’s at a temperature of 300 K and a pressure of one atmosphere.

(T = 300 K is very frequently used as the value of “room temperature” or “ambient temperature” when performing scientific or engineering calculations in the Kelvin scale, since it’s a nice round number.)

(1.91 x 10⁹ tons * R * 300 K / (44 g/mol * 1 atm))^(1/3) = 9.90 km.)

The volume of CO₂ produced each year from coal-fired generators in the United States corresponds to a cube of CO₂ with a dimension of just under 10 kilometers on a side. Over the course of a decade, that adds up to a column of CO₂ which is 9.90 km on a side and occupies the entire thickness of Earth’s atmosphere.

But what about nuclear fuels?

Coal yields an output of thermal energy when it is combusted of about 24 MJ/kg – therefore, 1.046 gigatons of coal corresponds to about 2.28 x 10¹⁹ J of energy.

One atom of fissile nuclear fuel like uranium-235 generates about 200 MeV of energy in a nuclear fission – and of course, that atom of ²³⁵U has a mass of 235 u (atomic mass units).

So, to generate 2.28 x 10¹⁹ J of thermal energy, we need to fission about 277.7 tonnes of ²³⁵U.

((2.28 x 10¹⁹ J / 200 MeV) x 235 u = 277.7 tonnes.)

(By the way, did I ever mention that I really like Google calculator?)

Uranium is quite a dense material – metallic U has a density of 19.1 g/cm³.

Therefore, the amount of uranium required to replace that billion tonnes of coal is only a volume of uranium metal corresponding to a cube measuring about 2.44 meters, eight feet, on a side.

(((2.28 x 10¹⁹ J / 200 MeV) x 235 u / 19.1 g/cm³)^1/3 = 2.44 m.)

Now, I know what you’re probably thinking. That assumes that we’re using pure ²³⁵U as a nuclear fuel, and that it’s consumed in fission with 100% efficiency, and that is not the case with real, practical nuclear fuels in existing nuclear power reactors.

OK, so let’s revise the calculation a little to reflect the characteristics of a typical, existing light-water reactor more realistically.

A light-water reactor typically uses low-enriched uranium dioxide (UO₂) fuel, and a modern power reactor typically achieves a burnup of something like 50 GWd (thermal energy) per tonne U.

Therefore, the generation of 2.28 x 10¹⁹ J of thermal energy from a conventional, once-through, inefficient LEU fuel cycle in a light-water reactor requires the use of 5987.4 tonnes of low-enriched UO₂ fuel.

((2.28 x 10¹⁹ J / (50 GW days/tonne)) x (270/238) = 5987.4 tonnes.)

UO₂ has a density of 10.97 g/cm³.

Therefore, the amount of LEU uranium oxide fuel required to replace that billion tonnes of coal is a volume corresponding to a cube measuring about 8.17 meters, 27 feet, on a side. The used, irradiated fuel – even before any recycling or recovery of unused uranium and actinides is performed – occupies about the same volume. Yes, you can put it in a garage, or put it in a basement, or something.

(((2.28 x 10¹⁹ J / (50 GW days/tonne)) x (270/238) / 10.97 g/cm³)^1/3 = 8.17 m.)

Perhaps soon I certainly shall download SketchUp and have a play around with it in order to make some visualisations of these quantities.

Finally, a hat tip to Jason at Pro Nuclear Democrats for an interesting and very educational post which was my inspiration in creating this post.