Wednesday, September 3, 2008

Destructive Lust For Power

Destructive lust for power
Wednesday, 3 Sept. 2008
Opinion, Richard Reeve
Otago Daily Times

Does the answer to our future energy needs lie in industrial-scale wind farms or giant hydro projects? Neither, argues Richard Reeve.

A recent question asked of many Otago wind farm opponents is, would they prefer giant hydro on the Clutha to wind farms?

The question is sometimes intended rhetorically as a taunt: what alternatives do we have? Dams on the Clutha have historical notoriety, and the industrial wind farm option is insinuated, rightly or wrongly, as a palliative to more giant hydro such as created Lake Dunstan.

The answer is no; none of the present giant and irreversible Renewable Energy initiatives proposed for the South Island are preferable or indeed necessary.

Irrespective of what schemes for new generation are proposed, New Zealand's energy crisis will be perpetual so long as no serious efforts are being made to recognise and understand the stem of the whole problem, which is our inability to control our own consumption.

Unless we address escalating consumption, the present allocation of energy to different sectors of society, and our gridlock dependency on large-scale generation solutions, in the year 2108, while teenagers are zipping across Dunedin's once-nested beaches on the latest electric trail bikes, we will still be debating where to put new solar farms, which bays to put tidal turbines in, what ridges to flatten for wind farms and whether to dam again.

There is no solution to New Zealand's energy needs that relies on the irreversible devastation of natural landscapes, sea and rivers.

This is because the problem is inherent in our culture, rather than in mere constraints on development related to putting these resources to use.

Successive New Zealand Governments suggest development schedules with a projected future of the next two to three decades, ignoring the consequences of these schedules a century later; yet the legacy of 19th-century colonial imperialism is a cornerstone of our environmental history now.

As a nation, we pretend that we understand ourselves, disregarding the blind spots in historical self-awareness examined by 20th-century philosophers of history as diverse as Hans-Georg Gadamer and Karl Popper.

What Meridian, TrustPower, Contact and others are proposing as essential development will in numerous instances look like rushed, irreversible destruction to future generations, who will regret our recklessness just as we regret the clear-felling of the giant kauri forests or the slaughter of whale populations for oil.

Protecting future generations from these blind spots means carefully thought-out integration of renewable energy, with the intention of minimising irreversible impact.

Where this is not presently possible, with companies insisting on economies of scale as the only way to justify new generation economically, New Zealand must make it happen.

We need small wind farms, more distributed and municipal generation, and no Mokihinui or Clutha dam.

If giant wind farms are built at all, they should be constructed out to sea.

In this respect, the Government's recent national policy statement on renewable electricity generation is commendable in appearance at least, though there can be little doubt that "reversibility" will become the new "sustainability", a word gutted of its original meaning for business councils to flop about like a toy in front of politicians.

Both Mahinerangi wind farm and the Wairau hydro tunnel are regarded by TrustPower and Infratil as "reversible", "sustainable" developments.

In the energy mix, the climate change issue cannot be ignored.

It is a worthy ambition to replace carbon-emitting thermal with renewables, but not where the renewables option is extrapolated as essentially good to the point where irreversible local detractions are regarded as a viable trade-off.

Hydro and giant wind have both been touted as climate-friendly, notwithstanding the fact that 2008 demonstrated clearly that there are extended periods when the lakes are low and there is very little wind, necessitating some form of reserve baseload generation.

Currently, other than hydro, this baseload is thermal and geothermal.

With any transition to electric transport, this baseload will need to increase significantly, and no combination of hydro and intermittent wind will sustainably meet the rise in demand occasioned by such a change.

In fact, reliance on too much wind generation will merely result in more reserve generation being built to accommodate periods like the 2008 drought.

In the present decade, we would be wiser to invest seriously in structural conservation, the practice of "negawatts", rather than building industrial wind farms, though smaller, sensitively placed wind will reduce pressure on hydro.

For the present, we need our thermal reserve generation.

In 25 years, that baseload is likely to come from tidal, geothermal and solar, supplementing our existing hydro and with a variety of wind farms to boot - to wit, those built before the wind-investment bubble burst.

One can well imagine, if the Otago wind farms are thwarted, new environmental conflicts arising with the advent of utility-scale solar in Central Otago, the Mackenzie Country, Nelson and Blenheim, and dolphins being killed by ostensibly benign tidal turbines and pelamis technology.

We should think small, and work generally to diminish the need for new plant being constructed.

Yet, where is the basic demand-side management technology that would allow domestic consumers to monitor the cost of their energy consumption on a real-time basis?

Why do we continue to run worthless lighting in every city in New Zealand, when social security is not an issue inasmuch as adequate illumination is provided by a small portion of the present amount of lighting being run?

Why was Rio Tinto allowed to increase its base consumption of electricity from 554MW to 572MW per annum from 2013? Energy conservation is, like, so 2004.

The greatest service paid to the New Zealand public in terms of domestic energy conservation may, in fact, be by TradeMe, where ordinary Kiwis go to buy secondhand carpet or insulation.

Equally, where are there any serious directives in place to encourage distributed generation or community initiatives for local generation (perhaps three wind turbines for a small town)?

Wind farms do not have to entail intensive development amounting to hundreds of megawatts; nor should ideal wind conditions be the sole determinant of where wind farms will be built.

An intellectual environment has developed in which dubious binaristic distinctions cause dispute among environmentalists whose views and aims are in fact often similar.

There is no choice between giant wind and giant hydro; we may have neither, we may have both.

Either will have irreversible adverse local effects.

Environmentalist opposition to mad energy schemes must face the obstacle of vast legal resources being brought to bear in the Environment Court by businesses with huge budgets.

It doesn't matter that the Mokihinui gorge and Clutha unequivocally trigger RMA issues of national importance, opponents face a highly uneven, uphill battle so long as third-way-style political parties like Labour and National wilfully navigate NGOs and the public as mere obstacles for fundamentally corporate interests.

Richard Reeve is an Otago poet, editor and environmentalist.

Posted by Molyneux Rush at 4:58 PM
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Clyde Dam Highly Problematic

Since the filling of the Dunstan reservoir behind the Clyde dam was completed in 1993, the Clyde dam controversy has faded in the minds of most New Zealanders. But the woes of the last 'think big' project have not gone away. Despite extensive and costly mitigation measures, issues remain regarding gorge instability, faultlines, and reservoir sediment build-up.

The Cairmuir-Dunstan Fault cuts across the gorge just above the dam, and the River Channel Fault disects the dam and the powerhouse. The discovery of the River Channel Fault came as a surprise to dam workers, who uncovered the micro-fractured rock running in a wide band along the riverbed. Obviously, fissured rock is not suitable for dam foundations. The first solution was to pump vast amounts of slurry concrete into the fault, but concerns mounted over the extent and depth of the faultline, and the likely futility of 'dental' concrete.

Finally, experts were called in to determine the extent of the fault issue. It was calculated that the River Channel Fault was 12-15km deep. This lead to a dam re-design in 1982 (during which a sluice channel was omitted leading to later modifications that reduced the dam's MW output by one-third). Subsequent investigations carried out by a team of some 40 geologists revealed serious instability issues throughout the gorge. The result was an incredibly expensive gorge stabilization programme, costing $936 million dollars (2005 value), resulting in the total cost of the project blowing-out to $1.4-1.8 billion dollars. The exact cost is unavailable or unknown, suggesting the true cost could be even higher.

There was considerable doubt over whether or not the dam would be safe, but in the end the government of the day, under Prime Minister Robert Muldoon, refused to admit that the project had been botched, and it was finished, complete with a controversial 'slip-joint' to accommodate earthquakes up to, supposedly, 7 on the Richter Scale.

The 'slip-joint' was hailed as an engineering achievement, but one of New Zealand's most respected geo-technical scientists at the time, Gerald Lensen, insisted that it was designed incorrectly, because the River Channel Fault is 'tensional' (pulling apart) and not 'lateral' (slipping sideways). Needless to say, this fact has been kept quiet ever since.

Now, according to GNS scientists, the 'big one' is overdue along the Alpine Fault (bigger than the 7.8 Fiordland quake in July 2009). Meantime, the 6,500 measuring and monitoring stations quietly observe the landslide movements, reduced but not stopped, and visible silting up continues in the Kawarau Arm at an alarming rate estimated to be 1.46 million cubic metres per year, building up the reservoir bed profile by an estimated 1.85m annually.

The Decline of Large Hydro

In the 21st century, energy that is "renewable" is defined as energy from a source that is both naturally replenishing and environmentally safe and sustainable. The term “new” renewable energy has also been used to define the latest wave of renewable technologies that are truly environmentally sustainable.

By such standards, hydropower over 10 MW is no longer considered renewable because the negative impacts of large hydropower outweigh the so-called renewable benefits, which have inherent limitations.

In New Zealand, we are told that to maintain our present society and standard of living we need a minimum increase in power availability of 2.5% per annum (peak power), with 170 MW of new generation added each year. Based on this figure, we would need the equivalent of one Luggate dam (86 MW) every 6 months, or one Tuapeka dam (350 MW) every 25 months, or another Clyde dam (432 MW) every 29 months. Clearly, this is not a credible long-term solution.

World-wide, large hydropower declined in the 1990s because of mounting opposition that culminated in the World Commission on Dams report (2000), which acknowledged that large dams do not meet best practice guidelines in the water and energy sector. The global recession spurred more large dam projects, especially in developing countries, but the tide has turned and large hydro is again in decline as new renewable technologies sweep the world.

The intrinsic problems associated with large dams have long been glossed over. Hydroelectricity is often falsely promoted as cheap and reliable. While the operating costs of hydroelectric dams can be relatively low, their construction costs are extremely high, running into the billions of dollars for major projects. They are also prone to cost overruns. The WCD (World Commission on Dams, 2000) found that on average dams cost 56% more than forecast. And 55% of the hydroelectric projects studied by the WCD generated less power than planners promised.

New Zealand's Clyde dam is an obvious example of disastrous cost overruns. According to the public record, the 1982 winning bid from the joint venture of W. Williamson & Co. of Christchurch and Ed. Zublin AG of Stuttgart, was $102.6 million. Ten years later when the dam began producing power, the cost had climbed to $1.4 – 1.8 billion. Conversely, the planned generation of 612 MW had fallen to an actual capacity of 432 MW.

Typically, construction and mitigation costs are under-estimated, long-term costs are ignored, the value of the proposed dam and mitigation measures are inflated, while the value of the current and potential benefits from the existing environment are under-reported.

The proponents of large dams also invariably claim that large hydropower is "green" energy. However, the carbon footprint of a large-scale hydro project is anything but "green". A comparative study at the University of Auckland found that large hydro has a full-life carbon footprint that is 2.5 times larger than that of tidal energy.

A similar comparative study in the U.K. found that in terms of grams of CO2 equivalent per kWh of electricity generated, large hydro in the U.K. comes in with a carbon footprint 2 to 6 times larger than that of wind power. Specifically, large hydro has been measured at 10-30gCO2eq/kWh while wind has been measured at only 4.64gCO2eq/kWh, the lowest except for nuclear (Carbon Footprint of Electricity Generation, 2006).

It is easy to understand why large dams rate so poorly. For example, the Clyde dam contains 1 million cubic metres of concrete, equivalent to about 3 million tonnes. Manufacturing one tonne of cement requires 4.7 million BTU’s of energy, which is the amount contained in about 170 litres of oil or 190 kilograms of coal. Obviously, this combined with emissions from machinery involved in earthworks for foundations, roading, terrain forming, landslide mitigation, and through the loss of river corridor carbon sink forests or vegetation, adds up to an enormous carbon footprint.

There are over 54,000 large dams in the world, some 5,000 of which are over 50 years old. The typical design-life of such dams is 80 years, and an increasing number of old dams are being classified as high risk. It is a telling fact that more dams are being decommissioned than built in the U.S., but dam owners typically avoid decommissioning issues and try to evade the considerable costs associated with dam removal and river restoration. This scenario points to a looming dam safety crisis.

In the past, the benefits of large dams were viewed as outweighing their obvious short and long-term environmental impacts. That has changed.

Large hydropower once represented the epitome of 20th Century technology and a passport to prosperity, projecting a misguided belief that Nature could be controlled without consequences. In the 21st Century, we face a new reality, for which 20th Century energy solutions are unacceptable.

Roxburgh Dam Decommissioning?

The Roxburgh dam was commissioned in 1956, and it is New Zealand's oldest concrete gravity dam. Such dams have a design lifespan of 80-100 years, but the actual lifespan of a dam depends on the rate at which its reservoir fills with sediment. Assessing the remaining life of a dam and reservoir is complex, but reservoir flooding events indicate that time is running out.

When other issues are added to the picture, questions must be asked.

The Roxburgh dam - like the Clyde dam, has faultine and landslide issues that are potentially catastrophic (something which has been kept quiet). However, when the Roxburgh dam was built, there was minimal geotechnical investigation and mitigation undertaken, despite obvious evidence of major landslides in the Roxburgh Gorge, notably at Island Basin.

But reservoir sedimentation is the most problematic issue. In fact, within 15 years of the dam's commissioning, the dam's two low level sluice gates were inoperable, and since then the silt burden has filled much of the Roxburgh reservoir reaching back to Alexandra. In 1995, ECNZ estimated that 1.5 million cubic metres of silt had entered the Roxburgh reservoir every year before the Clyde dam was built, and that a total 50 million cubic metres of silt had accumulated in the reservoir, raising the bed profile 'considerably'. Attempts to 'flush' the silt have had little effect, and have not reversed this process. This is probably because of the 'Gates of the Gorge,' a narrow bottleneck just below Alexandra.

As a result, Alexandra has become flood-prone, and has installed flood defence walls along the river. But even these will not be high enough to prevent future flooding, because the riverbed will gradually keep rising. It was thought that by building the Clyde dam that this sedimentation problem would be largely solved, but some silt still gets through to continue choking the reservoir and river, and the Manuherikia River still contributes silt when it is high.

Efforts continue to "buy time" for the Roxburgh dam. More "flushing" will only move some of the sediment load further toward the dam. (Flushing has failed to remove sediment wherever it has been tried, including on the Colorado.) Physically removing millions of cubic metres of sediment is not practicable because of the costs involved. An interim measure is to remove some sediment from the Manuherikia confluence, and also from the Galloway area, but this does not address the major constriction at the 'Gates of the Gorge.'

The most desperate strategy is to raise the operating level of the Roxburgh reservoir, and this was done in 2009 when a rise of .6m was consented. While this allows water to reach the dam more easily, it also increases the risks associated with flooding events, both at Alexandra and the dam. In the life cycle of a dam, this is the "Russian roulette phase."

The dam owners and the Crown must face up to the fact that the Roxburgh dam and reservoir will not last forever, and that enormous risks are imposed on communities in the meantime. A feasibility study is needed to determine the most effective decommissioning and de-silting methodology. Where such dam removal projects have been undertaken overseas, the costs as a proportion of construction, range from 35% to 150%.

However, since there has been no provision for the ultimate decommissioning of the Roxburgh dam (typical of the hydropower industry), there is something of a head-in-the-sediment policy on this issue.

Questions should be asked, including the most difficult question of all ... when the time comes to decommission the dam, who will pay?
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