Methods of electricity generation

Many who have a strong opinion on electricity generation have little comprehensive knowledge of the subject and often little knowledge at all. Being able to turn a switch on and off and paying an electricity bill is not a strong basis for a strong opinion. Also, many believe that ideology and laws are stronger than the laws of Nature (the technology involved) if forced. The reality is the reverse.

Fossil Fuels

Fossil fuels remain the mainstay of the world's electricity generation. There is a need to replace them because their CO2 emissions are adding to the concentration of a potent greenhouse gas in the atmosphere. The amounts look small, in terms of parts per million (around 420 ppm). Observations from satellites and space craft confirm a strong deviation in the world's outgoing longwave radiation (OLR) at about 15 microns wavelength, corresponding to an absorption band of CO2. This is clear direct evidence of a warming effect in the atmosphere but not clear information in itself as to the timing and manifestation of this warming effect.

Coal can provide reliable, available 24/7 electricity at lowest cost, while gas emits less CO2 than coal for the same amount of electricity but is unsustainable into the future.

Nuclear

Nuclear fission is a mature technology for electricity generation and shares dispatchability with fossil fuels. That is, it can provide electricity 24/7 irrespective of the weather. It is also carbon-free. There are some 400 nuclear reactors in use with some 60 under construction around the world.

However, it has a long term limitation. Tens of thousands of metric tonnes of radioactive waste that have accumulated from commercial power plants and years of national defence operations continue to age at sites around the globe. As the hazardous material and the containers it sits in await permanent disposal, the stockpile keeps growing. It is said that in some cases the aging containers have already begun leaking their toxic contents.

Vitrification involves the processing and transformation of the spent fuel into a glass. It has been used for high level waste immobilization for over 40 years in most countries that have a nuclear power program, including France, Belgium, Russia, UK, Japan, and the USA.

However, it does not apply to all types of nuclear waste and it cannot be assumed it is a permanent solution (Critical Limitations of Main Sources of Electricity Generation; onlineopinion.com.au/view.asp?article=23108).

Nuclear fission can only be considered as an interim measure.

Nuclear fusion would be carbon-free and without radioactive waste, but at this time we cannot control the reaction.

Weather-dependent Intermittents

Solar and wind generation of electricity are mostly called 'renewables' but they are more accurately described as 'weather-dependent intermittents' because that is what they are.

A belief has sprung up and taken hold that these intermittents are the immaculate solution to our energy needs. We are told that they are free, the lowest cost of all generating types. This is true only to the extent that sunbeams and breezes are free for the taking. The electricity derived from these free energy sources is not free and that is what counts. The facilities required to capture the diffuse energy, convert it to electricity suitable for our appliances and transmit it to the points of consumption are clearly not free and not renewable, but this irrefutable fact is ignored or not understood by the all-renewable believers.

The principal limitation of these weather-dependent intermittents is their intermittency (onlineopinion.com.au/view.asp?article=22797). The consequences of the intermittency is to change them into the most expensive form of electricity. You need four 10 MW solar generators or three wind turbine generators to equal a 10MW coal one. Modellers who want to get the 'right' result conveniently forget the factor of 3 or 4 to include in the costs. This alone should be enough to stop saying 'renewables are the cheapest form of energy' but when you consider the cost of battery backup it is clear that the intermittents are not the cheapest form of electricity but the most expensive. Indicative cost comparisons show that storage costs for Li-ion batteries is some 30,000 times that of coal (Large-scale electricity generation; onlineopinion.com.au/view.asp?article=23405). Although battery storage is a valid concept, it does not translate to an industrial scale grid, being economically prohibitive. Clearly, to say that the weather-dependent intermittents are 'the cheapest form of energy' is an absurdity.