He continues with the claim that so-called renewable systems, such as wind and photovoltaic, are competitive with coal-fired stations. If that is so, I wonder why the major utilities don't adopt them.

And he makes the assumption that as the current generating stations age, they will be replaced by his favoured schemes.

As for his claim that the government's target is affordable, perhaps he should explain to pensioners why they should pay an extra $4 a week to pay for systems that are mostly based on ideological considerations.

Unfortunately, I won't be around in 2050 to see the miracle of 90 per cent of our electricity provided by schemes he claims are ''without pollution'', as though there is no such thing as visual pollution, or that the plants can be built without first producing the raw materials.

I do, however, agree with him on the idea of pumped storage, and I remember the Trawsfynydd power station in Wales, which is now being dismantled after more than 30 years combining nuclear and hydro, as just one example.

But the professor gives the game away when he signs his letter with some of his credentials, including his directorship of the Centre for Sustainable Energy Systems, so he has a large barrow to push. In contrast, I have no barrow - I resigned as a fellow of the Australian Institute of Energy when I retired many years ago.

Alan Parkinson, Weetangera

Once again Andrew Blakers (Letters, March 20) is claiming that wind is cheaper than fossil fuel-powered generation.

He is not taking the capacity factor and its ramifications into consideration.

With wind you would need at least three times as much generating hardware to produce the required electricity and fossil-fuelled back-up generators operating in an inefficient manner for when the wind doesn't blow or is not strong enough.

The main component of the wholesale cost of electricity is the capital cost of the generators and the interest on that capital.

If you have three or more times as much hardware, the wholesale cost will be greater than three times that of one fossil-fuelled generator.

The Gunning Wind Farm cost $3.2 million per megawatt, including transmission infrastructure, and you would require at least three times the capacity, with back-up, to produce as much power as a fossil fuel-fired generator costing about $1.5 million per megawatt.

Advocates for renewables cannot seem to address the costs of their ideas. That the proposal is possible is all that matters to them. That is odd considering how they always claim the renewables are so cheap.

If wind is cheaper than coal-fired power, why are they still receiving subsidies?

J. McKerral, Batemans Bay, NSW

Wendy McCarthy (''Feminism's breakthroughs have hit a barrier'', Times2, March 21, p5) seems nonplussed over feminism's lost momentum.

Might it be that feminism fell foul of globalisation? That is, were they forced to lift their gaze from the micro (their Western lives) to the macro (the much bigger challenges facing women in the rest of the world)?

And then the rest of the world came home. So now they wonder how to maintain the rage over women not being promoted as fast as men (despite them alone taking long breeding sabbaticals in key years for management experience) and notice that there are now Muslim women immigrants living in their midst whose mediaeval culture and religion require them to live as property under black tents with slits etc. They've been silenced by cultural relativism. Time yet for them to call it as they see it?

Michael Jordan, Gowrie

''A bum deal for the earth,'' writes Elizabeth Farrelly (Times2, March 20, p1), and it seems a bum deal for Black Mountain Peninsula too, if the National Capital Authority has its way.

It appears the NCA has finalised the site selection process for a new slipway on Lake Burley Griffin and, alarmingly, a public recreational park has been declared the winner.

How can it be that the NCA supports locating an industrial business in a public park? Who is the guardian of our city's public spaces if it is not the NCA? Well, perhaps the NCA feels able to take its stand for two reasons.

Firstly, even the most tin-pot local council, fearing voter backlash, wouldn't dare pilfer land from a public park, especially for industrial use. Secondly, today's consultative ''planning process'' allows the site selection report to portray the most repugnant result as an outcome of good planning process. It is the process, not the outcome, which now seems all important.

Who had the temerity to suggest Black Mountain Peninsula as an option in the first place?

Why was a public park not immediately dismissed as an option by the city guardians? With this precedent, what safeguards do Canberra's other parks now have?

Reading the NCA's site selection report reveals no one wanted the slipway anywhere near their bit of bright water. Since all the other site options had more vested and powerful friends, Black Mountain Peninsula won the booby prize.

If all the planning expertise the nation's capital can muster puts an industrial slipway into a public park, then God help the ACT. It will need it.

Penleigh Boyd, Reid

The ACT government is to be commended for its far-sighted light rail project.

Canberra's car-lovers protest at each announcement (Letters March 14, et al), with the spurious objection that crowding on Northbourne Avenue is limited to brief periods. Meanwhile, the threat to car commuting rises inexorably, the latest problem being parking rates in the parliamentary triangle.

The central working area is best accommodated by distributed parking (at no cost) in its suburbs, with an efficient light rail concentrating the workforce at its centre, a model in use in major capitals overseas.

We do not need to make the centre of Canberra into car parks. The rail corridors need to be preserved: the light rail project is a beginning.

We still have the opportunity for civilised city growth. Let's keep it.

Jack Palmer, Watson

Douglas Mackenzie (Letters, March 19) wrote, ''The real Abbott agenda is becoming more obvious … and, in the process, cause as much collateral damage to unions as [he] can''. Oh, I don't think so. I think the unions are on a self-destruct mission of their own. Craig Thomson and Michael Williamson did great for the HSU and Labor movement, didn't they? The Labor government stuck by Thomson; does Mr Mackenzie? There is an inquiry into the CFMEU, which is just a sanitised version of the BLF. Does Mr Mackenzie support graft and corruption in the unions? And now there is Gary Kennedy, abusing Gina Rinehart in the most abusive terms and suggesting that Alan Joyce should get a bullet in the back of his head. Does he support Gary Kennedy's statement? If he answers ''yes'' to any of these issues, then no wonder the union movement is dead. The Coalition doesn't have to do a thing.

In 1997 I was a member of the CPSU working in DAS. When DAS was folded I, as a union member and delegate, went to the CPSU to ask what was being done. There was a big fat nothing. The union was only interested in those jobs it could save not those it had to fight for and possibly lose. So the acronym CPSU to me now means Couldn't Push Something Uphill.

I am now retired and I would tell any young person joining the workforce, ''Don't join a union.'' May I suggest Mr Mackenzie, other union members and rusted-on ALP voters read the book Looking for the Light on the Hill by Troy Bramston.

John Perkins, Cooma, NSW

As Nicholas Stuart admitted in a previous article on the F35 he ''was not competent to judge what he has seen and heard'' during his earlier visit to the US funded by Lockheed Martin. This latest article, ''Fighter aircraft plan marred by strategic mistake'' (Times2, March 18, p5) only confirms this.

Contrary to his argument that three squadrons of 12 aircraft at $130million equate to three squadrons of 24 aircraft at the bargain price of $85 million each for an increased order, I calculate you would only get half as many extra aircraft for the reduced price. Admittedly not an insignificant increase; however, that final cost is yet to be determined.

Then he suggests Defence made a strategic mistake in not considering the carrier-launched C model or the vertical takeoff B model. His suggestion that we should be considering fitting catapults and arresting barriers on helicopter landing ships would have been quickly rejected by Defence for good reasons and cost would have been only one of them.

Lockheed Martin may have done feasibility studies but that is not a persuasive argument. Similarly, there would have been very good reasons to reject the vertical takeoff model. Apart from the cost and additional complexity of the B model the logistics of supporting such a sophisticated aircraft ''on small islands or in undeveloped countries'' are extreme.

I can only suggest Mr Stuart do a little more basic research in future.

A. Wilkinson, Gowrie

I think that what worried us most about the communist era was that it provoked well-meaning activists to attempt to change the way that the rest of us lived our lives, based on the flawed arguments contained in the Communist Manifesto. Eventually, their attempts failed, due to the contradictions in that document.

Now, increasingly, our lives are being disturbed by a new group of well-meaning activists who also want to ''reform'' the world, based on another logically flawed document - the so-called Universal Declaration of Human Rights. If you don't think it is flawed, please read Article number one and think about it - seriously. For some time now, these new human rights evangelists have been increasingly opposed by Islamic and Confucian cultures.

With the Crimea as the catalyst, they seem about to be joined by the Orthodox Christian culture. Events in France and in the wider European Union indicate that the Roman Catholic Christian culture is becoming restive, too. Yet, no culture is without some flaws. That includes the West.

The crisis in the Crimea is not about Russian expansionism, nor totalitarianism revisited. It is about resisting the imposition of another flawed ideology that will ultimately fail, caused by its own contradictions.

Heaven preserve us all from human rights fundamentalists.

Peter Rusbridge, Kambah

Tony Abbott's lack of meaningful contribution to the climate change debate demonstrates his complete lack of leadership on this issue. Direct Action, with its emphasis on soil sequestration alone will be insufficient. Soil sequestration has no effect when using marginal or degraded land with low rainfall. His lack of action and the government's current low greenhouse gas reduction target (which will clearly not be met) will cause runaway climate change, locking in a lethal climate and enormous sea level rise, sooner than thought.

Unbelievably, he advocates new logging in pristine forests of Tasmania, undoing any gains that could be made through sequestration. Ultimately dryer weather patterns will cause forest fires that will incinerate the forests, allowing for no regeneration. Sequestered carbon will instantly return to the atmosphere and be lost, with our paid taxes and our children's and grandchildren's lives.

Chris Hansen, Rivett

Douglas Mackenzie (Letters, March 21) heard Eric Abetz use the word ''hypothecate'' on ABC TV instead of ''hypothesise'' and suggested he increased the English lexicon. Anyone who has been in India would have noticed that many of the dilapidated yellow Ambassador taxis often have the words ''hypothecated to XYZ bank'' on the back, meaning it is on hire purchase or lease; hypothecation is not a term used much in Australia. I didn't hear Eric Abetz on that program, but while he didn't increase the English language, he may have murdered it; I'll leave Douglas Mackenzie to be the judge of that.

David Williams, Watson

Michael McCarthy (Letters, March 19) has said that possums in the roof cavity are not noisy. Perhaps he could stay here for a week and tell me that! Also, he isn't aware of them doing damage! I had two plasterers here for eight hours three weeks ago patching and painting the walls where they have been in the wall cavities, and I even have a video of the possum fur coming through the wall and the possum growling at me when poked.

I have tried lights in the roof space, and even an owl that makes noise with movement, all to no avail. We have tried cutting back all trees, which really makes no difference as the possum goes along the wires; we have also mixed Vicks/ Vaseline as they don't like the smell or the feel of it. We have had wire placed in all possible entry points, a possum house put in the tree outside … What it boils down to is that no one can find the point of entry, and I am frustrated to the point where even two emails to Minister Rattenbury have not been able to assist me. I give up.

Corinne Carey, Dickson

Talk about stereotyping, Phil Johnston (Letters, March 21)! I am a 66-year-old woman, and semi-retired. Until recently I drove a Subaru Impreza WRX. Unfortunately the engine blew up and I'm now driving a regular Impreza. The WRX was much more fun to drive and I want another one. My dad is long gone, I don't sell or take any drugs, apart from the occasional aspirin, and I am currently saving my money so that I can pay cash for the WRX one day. I will probably be 70 by then! PS: Parking tickets never seemed to be a problem; speeding tickets can be!

Anne Willenborg, Royalla, NSW

TREAD CAREFULLY

Senator Arthur Sinodinos' impending appearance before the Independent Commission Against Corruption should remind board members of the requirement to look carefully at all details of the businesses they oversee.

Sankar Kumar Chatterjee, Evatt

MARCHING ON

It was edifying and heartening to read H. Ronald's invective (Letters, March 20) regarding the March for March marchers. To be set upon by Mr Ronald and so studiously ignored by Mr Abbott are both clear indications that the march achieved its aim.

Fred Pilcher, Kaleen

VILE PLACARDS

I thank Jan Gulliver and Chris Williams (Letters, March 21) for confirming the incoherence of the March for March participants. The best defence Ms Gulliver could muster for the utterly vile placards that peppered the activity throughout the country was the fanciful and predictable assertion that they were the work of conservative infiltrators, with me a likely local culprit. Mr Williams offered little more than unsubstantiated name-calling.

H. Ronald, Jerrabomberra, NSW

GRAND DESIGNS

About $2.7 million just to design - not to build - an expansion of the Alexander Maconochie Centre (''Packed jail to receive $3m redesign'', March 20, p1)? Nice work if you can get it.

Karina Morris, Weetangera

FEDERAL RULES

Paul McElligott (Letters, March 19) should know that section 109 of our constitution allows the Commonwealth to override state law, thus avoiding in this case a messy death penalty intra-state argument if most voters want the abolition repealed. As for witch burning and adulterer stoning, I don't remember them being part of Australian law.

Greg Cornwell, Yarralumla

ALL AT SEA ON SPENDING

Surely at a time when the federal government is advocating cuts to all and sundry, its lifeboat strategy is an appalling example of misspent money. The boats cost $200,00 each and are used just once.

Robyn Lewis, Raglan, NSW

SIGN OF THE TIMES

The east-bound Butters Drive sign on Hindmarsh Drive between Ainsworth Street and Yamba Drive was hit about 12 months ago. The still-attached poles remain lying mangled on the median strip, bent 90 degrees from their anchorage point, a danger to pedestrians. Typical of Territory and Municipal Services to leave it in excess of 12 months and counting.

J. Curlewis, Farrer

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