Using these terms is totally misleading. Coal, by its nature, is very dirty and very polluting.

Aside from releasing CO2, which contributes to climate change, mining and burning coal releases many highly toxic substances (mercury, heavy metals, radioactive particles and many others), causing multiple serious health problems.

OTHER RECENT ECO NEWS COLUMNS:

Even with the most modern technology, this pollution is unavoidable.

Australia's ageing existing power plants produce 1011 kilograms of CO2-e/MWh. Supercritical (HELE) plants produce 919kg CO2-e/MWh.

That is, the so-called "Clean Coal" stations produce 9.95 per cent less pollution than older stations burning the same fuel.

HELE plants operate at much higher temperatures and pressures, are very expensive to build and, while slightly less polluting, still have major environmental and health impacts.

Carbon capture and storage involves catching the CO2 from burning coal before it is released into the atmosphere. (Note one tonne of coal produces two tonnes of CO2, meaning huge volumes produced.)

The gas captured then goes through a complex process, is compressed, and sent for storage underground.

Sounds good in principle, but poses enormous logistical challenges of storage, pipelines and storage sites.

Costs are massive and construction times very long. There is also doubt about whether the gas would stay buried.

To date, the technology is not commercially viable.

There are no CCS power stations in Australia, and only three in the world.

Of HELE and CCS, Australian Industry Group says "... electricity prices would need to be sustained at very painful levels for the life of the project for that project to make its money back".

HELE and CCS are not the answer for Australia, they are a last-ditch attempt by fossil fuel industries to prolong their profit stream.

For environmental and financial reasons, Australia's energy future must lie with (now proven) reliable and cost-effective renewable sources of energy.