How about an energy debate, green warts and all?

This is one for the “did you really mean to say that” drawer.

Federal ministers Mark Butler (environment) and Gary Gray (resources and energy), announcing “the largest solar power station in the southern hemisphere”, shared with us the fact that it will need to cover an area four times the size of Sydney’s CBD to provide enough electricity for a town the size of Tamworth.

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.

Another example of this appeared in the weekend edition of the The Australian Financial Review, which informed us that “the equivalent of two large coal-fired power stations now sit on Australian rooftops”.

Really?

Last time I looked, all the rooftop solar photovoltaic arrays on a million Australian homes had a capacity of about 2400 megawatts and were contributing 2368 gigawatt hours a year to electricity supply.*

This capacity is a little less than that of the four-unit Bayswater A power station in the Hunter Valley – part of the Macquarie Generation portfolio the O’Farrell government is seeking to flog off at the moment – and that generator churns out about 16,000 GWh a year.

Or to put it another way, to provide the equivalent of the generation output of this power station from household PVs, we’d need five million rooftops – and there are a little less than 10 million homes in the country just now.

While this may seem something of a sideshow in an environment where we are galloping off to the federal polls in September, it actually isn’t.

The Greens, who are bent on sustaining their balance of power in the Senate, are riding strongly on renewable energy and seeking to sell the sizzle of the issue to a community that largely has little idea about the details but knows what it thinks it likes.

The Labor government is not much better in this respect.

Grabbing for media attention over the western New South Wales solar project, Butler was keen to talk about “transitioning to a green future” without discussing the costs there-of – which is quaint for a government busy trying to bury the $25 per tonne carbon price.

The green side of things are ever so keen, in their turn, to talk about the “landmark” study of 100 per cent renewable energy that they foisted on the Gillard government and how the Australian Energy Market Operator (who copped the task) sees the goal as “feasible and affordable” without either drawing attention to the AEMO caveats or the fact that the true cost is anyone’s guess, as is the level of carbon price needed to effect the shift.

AEMO itself has been careful to say that its findings are “hypothetical and considered only a limited range of factors”.

Like, for example, that it was precluded via its riding instructions from taking into account the costs of government policies that may be needed to drive the transition.

(This is why jobs like this get given to an AEMO, which will do what its told, and not a Productivity Commission.)

AEMO says the $332 billion price tag it placed on the move depends on “technology costs projected well into the future and does not consider transitional factors to arrive at anticipated costs reductions”. 

In practice, it adds, “the final figure would be higher as transition to a renewable power system would occur gradually”.

That’s not the Greens view, of course.

They want to see us 80 per cent there by 2030, which is not so much a mad dash as a leap over a cliff.

One of the things not factored in to the AEMO costings is the acquisition of up to 5000 sq km of land – which, it says somewhat wryly, “could prove challenging and expensive”.

To help get your head round things, this area is not far short of double the size of the Australian Capital Territory.

By the way, this study is not for Australia as a whole.

AEMO looked only at the “NEM” – the east coast electricity grid.

And the operator was prevented by the Gillard government from giving any consideration to the comparative costs of nuclear power, gas generation or coal plants using carbon capture and storage.

It also modelled on the basis of a massive transport shift to electric vehicles.

And, not least, given the rural community’s frequent NIMBY views (as witness the fuss in New South Wales over coal seam gas developments), it is worth mentioning that the AEMO perspective is big on onshore wind farms, with a requirement for around 2030 of about 1.5 ACTs of land.

The real issue here is not the exactitude of modelling – hypotheticals do not generate and deliver electrons – but the fact that, for a nation obsessed with the impact of energy bills on its cost of living, an alternative lifestyle heavily oriented to green power is not utopia and still less will it be utopia for manufacturing.

In this context only days ago Sue Morphett of Manufacturing Australia, dealing with higher gas prices coming down the east coast pike, was emoting over a scenario in which 200,000 jobs go west along with $28 billion in national economic value.

Context is not an optional extra in thinking about the future of east coast energy supply.

It is ground zero – and it keeps getting ignored by ideologues, wishful thinkers, politicians on the make and media types with goldfish bowl mindsets.

Keith Orchison, director of consultancy Coolibah Pty Ltd and editor of OnPower, was chief executive of two national energy associations from 1980 to 2003. He was made a Member of the Order of Australia for services to the energy industry in 2004.

*This article previously stated that rooftop solar contributes 800 GWh to Australia's power production annually. The correct figure is 2368 GWh (as of the 12 months of September 2012) and the article has been amended accordingly.