Feature

Powering The Future

Energy efficiency and the use of renewable resources will benefit both New Zealand and the world.

By Kirsty Hamilton

Energy from clean, environmentally-constrained, renewable sources is the pathway to a survivable future for the planet. Only this avenue heeds the need to reduce CO₂ emissions responsible for global warming. Energy efficiency is the first crucial step on the way.

New Zealand needs to consider its energy future, particularly given the "power crunch" likely when the Maui gas field dries up. The strongest push from certain sectors is for greater exploration of new supplies of fossil fuels, and greater development of traditional sources of power such as hydro, coal and, most recently, nuclear to meet future demand.

This supply-side approach ignores some of the most obvious immediate gains of energy supply through energy efficiency. It equally ignores the potentially plentiful supply of indigenous renewable energy resources in New Zealand.

Energy Efficiency

Planned and implemented now, energy efficiency can prevent the sudden need for major new energy sources. The potential is currently vast and largely unexploited. Studies done by Electricorp show that it is technically feasible to save 57% of New Zealand's current electricity use, at a cost of 1.6c/kWh.

Arguments about the details of costs ignore the fact that it is a low-cost option, particularly in comparison with the $20-25 billion expenditure forecast for new power stations.

The 57% figure is based upon a "demand-side management" approach where supply of the actual demands or services is provided with maximum efficiency.

This involves the utilisation of energy efficient technology, principally in the areas of lighting, motors, air conditioning and low- nd high-temperature heating. The effectiveness of these technologies is enhanced by increased building insulation and efficient design, such as the passive solar design of buildings.

In the short term, there are a number of important ways of maximising energy efficiency at the energy end of the equation. These include minimising losses that occur when converting one energy source to another, and using combined heat and power generation, where waste heat is used to produce steam, or generate electricity.

New Technologies

The goal for the future should be the rapid expansion and use of renewable energy technologies so that they supply all of our energy needs. Options such as wind, solar-thermal, photovoltaics, biomass, biogas and wave power are all applicable for New Zealand. With current electricity generation approximately 75% hydro-based, New Zealand is in one of the best positions of any industrialised country to make full use of clean, renewable resources to stop current thermal generation completely.

A US report concluded that over 92% of proven energy reserves there consist of renewable resources. Coal, nuclear and photovoltaic power generation use approximately the same land area per megawatt produced if the entire fuel cycle is taken into account, yet the solar option requires two-thirds less water and has negligible air and water emissions.

When development of renewable resources has occurred, the financial rewards have been vast. The solar industry in the US commands US$200 million in photovoltaic sales alone. More than 350 MW of utility grade solar-steam-to-electric plants are now operational, more than 1.2 million buildings have solar water heaters and a further 300,000 buildings use passive solar design.

Potential For Development

In New Zealand, the opportunities are manifold. Fermentation of agricultural and other organic wastes to make biogas is considered by some manufacturers to be the most cost-effective solution to both waste minimisation and energy needs.

Biogas also has the potential to replace CNG as a transport fuel, and is already being generated and used for this on some farms. A MAFTech research unit near Dunedin is doing important work on waste-to-biogas applications.

On the transport front, innovations in electric and solar-electric cars point the way to the car of the future. In the meantime, super-efficient, emission-reduced models are already on the market.

Tide and wave power are being investigated by Electricorp. Potential has also been identified for the provision of considerable electricity supplies from wind generation, with the promise of more as the technology is further developed.

Agenda For The Future

Power suppliers and governments with foresight recognise that short and long term benefits accrue from energy efficiency and the use of renewable energy resources.

These benefits are by no means solely environmental. They include energy security, diversification into new areas of manufacturing, such as energy-efficient technology, new technology-based export opportunities and massive potential for employment.

What is clearly required is some initiative and direction from our energy decision-makers. It will be incumbent on the government to invest in research and development of New Zealand's indigenous renewable energy resources. Funds should be created for this exciting sunrise area, and diverted from the coal and petroleum resources surrounding New Zealand.

Current market barriers to the use of renewable energy resources, such as energy pricing structures, high discount rates and lack of information, should be identified and removed.

Above all, there needs to be commitment from New Zealand as a whole that we can and will investigate these opportunities before the next round of fossil fuel power stations are planned and built. We have a clean, green reputation -- let's put that into practise when it comes to our energy future.

Kirsty Hamilton is the atmosphere and energy spokesperson for Greenpeace