By Deirdre Robert
Tomorrow marks Global Wind Day, described by organisers as "a day dedicated to discovering wind, its power and the possibilities to change our world". In New Zealand, the beginnings of wind energy go back to 1993 when a solo wind turbine was installed in the Wellington suburb of Brooklyn. Now New Zealand has seven major wind farms in operation and wind energy equates to 4 percent of electricity supplies in New Zealand—enough to power the equivalent of 1 in every 10 homes.
“Wind energy is an excellent complement to New Zealand’s existing hydroelectricity generation,” says the EECA’s Mike Underhill. “When the wind blows it means we can store water in our dams for days when it is needed.”
With the Government setting a target of 90 percent renewable energy by 2025, Underhill says increased wind energy generation will go some ways to meeting the target.
The increased popularity of wind generation is a sentiment echoed by NZ Wind Energy Association chief executive Fraser Clark, who says in the last four years wind energy production has doubled. By 2030, he says it will comprise of 20 percent of all electricity generation in New Zealand.
So what’s happening around the world to mark the occasion? The official Global Wind Day website offers an extensive list (see it here) that includes events in South America, Australia, Portugal, North America, and numerous countries in Europe. In New Zealand, the NZ Wind Energy Association says art competitions in schools, a photography competition and opportunities to climb wind turbines have all been organised.
But while there may not be any major events in New Zealand, the EECA has compiled this top 10 list of wind energy myths:
1. Wind is more expensive than fossil fuels: Not in New Zealand. New Zealand’s wind resource is one of the best in the world, and unlike many countries in Asia, North America and Europe, subsidies are not required to make investment in wind economical. Wind is now one of the cheapest forms of new electricity generation available in New Zealand, which is why most of the main generators are investing in wind. Wind is also a less risky investment for the future; most of the costs are upfront, and the resource is free, which means New Zealand is not leftexposed to increasing fuel costs as we would be for fossil fuels.
2. Wind is unpredictable and therefore unreliable: Wind is ‘variable’ which means that over the course of a day, generation can vary. It is however predictable; these variations can be usefully forecast. Over the long term – say, months to a year – it is possible to very reliably predict how windy a site will be on average. In fact, wind is much more reliable over the course of a year than inflows to our hydro catchments – and we use hydro for more than 50 percent of our total electricity generation.
3. Wind doesn’t necessarily blow when you need it most: at times of peak electricity demand: Wind farms in New Zealand are generating some useful power over 90 percent of the time. By having wind farms spread across the country in diverse locations we increase the likelihood that some wind farms are generating even if others aren’t. It’s exceedingly rare to have no generation from any NZ wind farm site at any one time – to give you a guide, this occurs for less than about an hour a year, and in some years not at all. So, statistically speaking, it is certain that some wind farms will be generating at peak times.
Wind also contributes to peak demand indirectly; this happens because hydro lakes can store water during windy spells. So, prior to winter peak demand, wind will be banking water in our lakes for use at peak times. Wind and hydro work very well together, even with New Zealand’s relatively limited hydro storage. In fact, wind reduces our susceptibility to ‘dry-period’ risk.
4. Wind needs to be backed up by thermal generation: All generation needs back up. This includes, for example, large thermal gas-fired generation such as Contact’s or Genesis’ combined cycle gas turbines. These require planned annual maintenance of up to several weeks, and also have unscheduled outages. That means having back up ready to replace a 400MW power station. Similarly, hydro needs backup during dry periods. A secure electricity system is made up of diverse technologies, fuel types and generation locations.
5. Wind turbines don’t help fight climate change: The embodied CO2 in the wind farm due to the steel, concrete and construction fuel use and so on is typically recouped within about 4-6 months of operation of the wind farm (assuming displacement of a gasfired generation). By building renewable generation that doesn’t emit CO2, we are precluding the need to burn fossil fuels to meet our electricity needs, so there is a direct climate change benefit. Renewable electricity will have an even greater CO2 benefit when electric vehicles start to be used in New Zealand: clean renewable electricity can replace petrol, particularly for urban commuting.
6. If we were all more energy efficient we wouldn’t need more wind farms: It’s not a matter of ‘either/or’; we need to do both. Energy efficiency makes sense in its own right, because it saves us money, it’s less wasteful of precious resources, and it often also increases comfort and health. However, even with an increased focus on energy efficiency in New Zealand, we will still have an increasing electricity demand and will need new generation. We also need to replace old generation facilities (for example, one unit of the Huntly thermal power station is scheduled for retirement next year).
7. Wind turbines kill lots of birds: Wind farms need to get Resource Management Act approval, and this is an excellent means to identify and avoid sensitive bird sites. Two of the biggest threats to NZ important species are habitat loss and in the longer term, climate change. Wind farms can help on both counts. Wind farm consents often include habitat restoration and pest control conditions that would not occur if the project doesn’t proceed; and wind farms are also a means to mitigate climate change.
8.Smaller wind turbines are better: Larger turbines have several advantages. Because they can access the windier conditions higher up, they produce more electricity, which means they are more cost effective. Larger turbines move more slowly, and fewer are needed for the same output, potentially reducing the visual impact. Having said that, there is no universal right and wrong about size and scale; it is about having the right sized project in the right landscape and environment (including social and cultural aspects).
9. People don’t like wind farms: The evidence says otherwise – surveys by EECA indicate a very high level of general support for wind farms (88 percent) as a source of electricity, which remains high even when wind farms are visible (71 percent). This is a theoretical question however, and the answer may be different if a wind farm was proposed on a landscape that the person valued highly.
10. We’ll need wind turbines everywhere to meet the 90 percent target: Depending on future demand, and the other forms of renewable energy utilised (for example geothermal, hydro, marine, solar), five to seven wind farms—in addition to those already consented—may be all that is required to meet the target in 2025. In other words, it won’t mean turbines on every hill!
