Carbon taxes give Watercare opportunities

4 March 2005

Carbon taxes give Watercare opportunities to improve

New Zealand’s largest water and wastewater company, Watercare, has reshaped its operations to prepare for a carbon tax and has reduced its exposure – and its carbon emissions.

Watercare chief executive Mark Ford says New Zealand’s commitment to implementing the carbon accounting provisions of the Kyoto Protocol helped the company’s efficiency drive by sharpening the focus on reducing emissions, investigating alternative energy sources and improving environmental outcomes.

“We have prepared for this. We factored it into our business planning and as a result we’ve been able to change our business to suit and we’re also delivering better environmental outcomes,” he says.

Watercare generates 25 per cent of its own energy requirements from alternative energy sources.

The company’s Mangere Wastewater Treatment Plant generates 33 per cent of its energy needs from methane gas extracted from the waste treatment process. In July the company will commission leading edge technology that is expected to make 25 per cent more methane gas available, lifting the plant’s self-sufficiency over 50 per cent.

Burning methane in the plant’s generation units produces carbon dioxide as a waste gas but as methane is 21 times more potent than carbon dioxide, it represents a significant net reduction.

The new cell lysis technology uses ultrasonic waves to break down cell walls in sludge extracted from wastewater enhancing production of methane gas in the treatment plant’s digesters. It reduces methane emissions from the landfill and also reduces the overall volume of biosolid waste in the process. Watercare is also investigating sustainable use of biosolids produced at the plant including its potential for use as a fuel.

Watercare also operates hydro generation units in two of its water supply dams, one in the Hunua Ranges and one in the Waitakere Ranges. Mr Ford says Watercare also took up the opportunity to earn carbon credits (offsetting the carbon tax) with more alternative generation.

“We had previously implemented alternative energy projects with a strong economic and environmental payback but we also take a longer term view. The carbon credit regime put other more marginal alternative energy projects into the frame – as it was intended to do.”

The company was awarded 10,829 carbon credits in the first round of the programme for installing a turbine generator at the Mangatawhiri Dam. Each carbon credit equals one tonne of carbon dioxide or its equivalent in other greenhouse gases that would otherwise be released to the atmosphere. Watercare generates four gigawatt hours a year from turbines in raw water mains. Investigations into a fourth turbine at another dam are also underway.

Watercare is also investigating wind generation, assessing the potential of several Watercare sites. The overall objective is to increase energy self-sufficiency and provide insulation from expected increases in energy costs.

Watercare is also reviewing its vehicle fleet. The company has purchased two hybrid fuel vehicles for specific high mileage roles for the company’s Laboratory Services business and fleet replacement will be steered towards newer diesel and hybrid technology vehicles.

The company has appointed an energy manager and set up a company-wide energy management system. A range of energy conservation initiatives is underway including a review of lighting efficiency with a view to reducing electricity consumption. Watercare operates hundreds of electric pumps in its water and wastewater networks and the company is carrying out a complete assessment to optimise their deployment.

ENDS

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