Our rivers are not renewable

So-called renewable energy can have a serious impact on the environment. Forest & Bird South Island Conservation Manager Chris Todd says we need to make sure power generation is truly renewable and responsible. This article originally appeared in Forest & Bird Magazine #329, August 2008.

Our wild rivers are threatened by climate change and runaway power consumption.

Electricity demand is predicted to keep growing at 1.3% - 2% or an extra 150-200 megawatts of generating capacity every year. That extra demand is equivalent to the generation produced by damming two rivers the size of the Hurunui and the Mohaka every year.

To curb greenhouse gas emissions from coal and oil-fired power stations, the government has boldly committed New Zealand to producing 90% of its electricity from renewable sources by 2025, up from about 70% now. That means mainly hydro, geothermal and wind generation, with other technologies like tide-driven turbines under development.

"Renewable" energy is touted as environmentally preferable to energy generated by burning fossil fuels, but hydro development involves the destruction of our rivers' natural and scenic values, ecosystems and recreation. Development of wind farms in inappropriate settings can also have adverse effects on the surrounding environment, landscape and local communities.

If we used hydro-electricity to meet just 40% of predicted electricity demand, we would need to dam or divert the Waitaki, Clutha, Ngaruroro, Wairau, Whanganui, Hurunui, Mohaka, Mokihinui, Grey, both Waiau Rivers, the Taieri, Rangitaiki, Rangitikei, Waiaou, Raukokore, Waikato, Patea, Waimea, Ruamahanga, Awatere, Wairoa, Manawatu, Tukituki, Whakatane, Pelorus, Ashburton and Tarawera Rivers. What then?

We must not be panicked into destroying our heritage, only to find that we are in exactly the same position in terms of meeting demand for generation in 2025, minus our rivers.

There is no simple answer, but a range of ideas have worked well elsewhere and, used together, could create a much more sustainable future for energy.

It is more cost-effective to invest in reducing electricity demand than to increase electricity generation capacity. This "virtual generation," sometimes called "negawatt power," improves electricity supply by improving efficiency, rather than by building new power stations.

A market can be created to trade negawatts: an electricity company with additional demand that it could not meet through existing generation could pay its customers to reduce their power use, rather than pay more to develop new generation.

There are thousands of ways to reduce electricity demand, ranging from changing to energy-efficient light bulbs and insulating houses, to converting dairy sheds to use biogas generated from cow effluent. We need to decentralize and diversify electricity supply to encourage households and communities to set up their own small-scale generation close to where the supply is needed.

If power companies were obliged to buy power back from their consumers, we would see huge private investment in micro-hydro, wind and solar cells. For example, just one wind turbine could power a small community - and any excess power could be sold.

When we produce more electricity, it needs to be done responsibly, not as a knee-jerk response to perceived threats of black-outs.

Responsible renewable projects would not target the nation's pristine wild and scenic rivers (such as Meridian's current proposal to dam the West Coast's Mokihinui gorge and its large surrounding area of pristine rainforest.) Neither would they target the nation's most beloved landscapes.

Forest & Bird is working with the Wind Energy Association to develop industry codes of practice that will guide truly renewable and responsible generation. It is high time our power companies moved in the same direction.