Solar Energy - Power for the new Millennium

It seems that increasingly these days the public agenda is dominated by endless discussion of obscure intangible human inventions such as interest rates, share price indices and so on. In this environment it is easy to lose sight of some rather important fundamentals. Perhaps the most fundamental is energy. To the human animal as any other, energy means food to keep us alive, heat to keep us warm and even the energy needed to drive the water cycle and keep us supplied with drinkable water. Of course energy is also what makes all the trappings of our civilisation possible, transport of goods, information and ourselves and the manufacture of every single object we take for granted. In the global view 99.99% of the energy that makes life possible is coming from the sun. Turn off the sun and pretty soon we would be trying to live on a lump of rock at close to absolute zero (around –273oC). However the .01% which is the stuff that we actually 'pay' for in some way is the bit that is causing the world so much angst at the moment. At present on a world average this "costed" energy is made up of about 76% fossil fuels, 14% biomass (wood etc – a form of solar energy), 6% hydroelectricity (also a form of solar energy) 4% nuclear and tiny fraction from other solar energy sources

Much of the debate on the greenhouse issue is about uncertainty. It is worth reiterating a few facts, which are definitely not uncertain. There is a greenhouse effect – without it the average temperature of the planet would be around -19oC. Carbon dioxide methane and many other gases are contributors to the greenhouse effect. The concentration of carbon dioxide (and other gases) has beyond doubt increased in proportion to human emissions. The uncertainty arises in trying to determine what the effect of these changes is likely to be on the world's weather systems. The rational approach when faced with the possibility of an extremely bad outcome with an unknown probability is to take out some form of insurance. The obvious insurance policy is to look at ways of reducing greenhouse gas emissions without compromising standards of living and in the energy arena this leads to the search for renewable (solar) energy technologies.

Of course the greenhouse issue is not the only reason for pursuing solar energy technologies. Even without it we are faced with a considerable burden of pollution from fossil fuel use and the certainty that some day these resources will be exhausted. Recent events on the Indian subcontinent serve to remind those who might have forgotten about the Chernobyl accident that a nuclear based future also has major drawbacks.

So what can solar energy do?

What many people would not realise is that technologies exist for solar energy to replace other uses of fossil fuel. The key to many of these technologies is solar driven chemical processes. There are demonstrated solar technologies for chemically storing solar energy to allow 24hour electricity generation, to produce chemical commodities, to detoxify hazardous waste, to split water to make hydrogen and to make fuels for motor vehicles.

Won't solar energy systems require too much space?

What about the energy needed to manufacture solar equipment in the first place?

Isn't Solar energy simply too expensive?

The hard nut to crack is large-scale electricity production. While solar technologies are already competitive for electricity production for remote areas, current estimates for existing technology used on a reasonable scale, place them as being 2 or 3 times more expensive to the consumer than Australia's current cheap coal fired electricity. Considering the potential for cost effective efficiency improvements and future technology developments it is quite plausible to consider making the switch with very little discomfort. The extra 'cost' must also be seen in the context of the potential costs of global climate change. Estimating these is just as uncertain as predicting the changes themselves, but attempts to do so produce numbers that show that the solar technologies are actually cheaper. In the greenhouse debate much is made of the possible negative effect on the economy that such an increase in energy costs would have. In considering this issue it should be remembered that this is not money somehow lost from the economy, rather it is money that is directed into major high employment initiatives in manufacturing new products.

So what is happening in the ACT?

Politically speaking, the ACT government has lead other states and territories in making a minimum energy efficiency (modest though the requirement is) mandatory for new house designs and has adopted a decent target for greenhouse emission reductions of achieving emissions at 1990 levels by 2008 and 20% below 1990 by 2018. Exactly how this is to be implemented is currently being decided, hopefully by measures that have a real prospect of achieving the target.

The new millennium