In 2013, New Zealand had its warmest winter since records began, 1.3 degrees above the long term average. Australia just experienced its warmest 12 months on record, breaking the previous record set a few years ago. A recent study from the UK Met Office found half of 2012’s extreme weather events internationally were exacerbated by climate change.
Wind energy plays an important, global role in addressing climate change. Many developed nations have worked hard to reduce their carbon dioxide (CO2) emissions from electricity over the past couple of decades. Developed countries with a downward trend in CO2 per unit of electricity generated include the US, Denmark, Australia and the UK. Unfortunately for our image and for the future, New Zealand’s trend is in the other direction.
NZ’s carbon pollution has increased 30% since 1990. Our electricity sector emissions are up by 60%. According to the Ministry for the Environment, New Zealand’s emissions intensity by population is amongst the highest for developed countries.
Electricity is one of the sectors that could, quite quickly, reduce New Zealand’s carbon pollution. Currently electricity generation is around 15% of New Zealand’s CO2 emissions, contributing around 4 million tonnes per annum, or the equivalent of the emissions from a third of our cars.
CO2 emissions from the electricity sector, 1990-2012
According to the Ministry for Business, Innovation and Employment, 64% of the electricity sector’s CO2 emissions came from gas-fired generation, 29% from coal-powered plant, and the rest from geothermal, biomass and liquid fuels.
How does Wind Energy Address Climate Change?
One way we can reduce our greenhouse gas emissions – as well as our dependency on fossil fuels – is by increasing the proportion of electricity that is generated from wind and other renewable energy resources. Wind farms don’t emit greenhouse gases as they generate electricity, whereas coal and gas stations do.
Both coal and gas generation also create a lot of waste heat that cannot be easily used for generating electricity. Over 50% of the energy used to produce electricity from gas and coal is lost through the production process, which is not the case with wind energy.
The US National Renewable Energy Laboratory recently compiled the results of all peer-reviewed publications on lifecycle emissions for different energy sources. This study shows that it takes less than six months for a wind farm to produce more energy than it will consume in its entire lifetime. The lifecycle emissions (including manufacturing of components, transport to site, construction, operation and decommissioning) from wind farms are about 1% of the emissions from thermal generation.