Plugging away
New energy makes gains
If every power point in your house is plugged in and switched on this winter, don’t feel too guilty. New Zealand is a world leader when it comes to the use of renewable sources of electricity.
We have the third-highest proportion of renewable energy in the OECD, after Norway and Iceland.
Renewable energy now contributes 82 per cent of New Zealand electricity generation, up from about 65 per cent a decade ago. Most of that renewable power comes from hydroelectricity stations.
But geothermal and wind generation are starting to play a bigger part, as new generation is added to the market and gas-fired and diesel plants are retired.
Carl Hansen, chief executive of the Electricity Authority, said the new, renewable-energy plants were like new cars replacing old. ‘‘Even though old cars can still go from A to B, there’s the practicality of keeping them maintained. The cost of new parts means newer plants can be a better proposition for a company.’’
Consents have already been granted to add just under a third more generation to the New Zealand market, of which 96 per cent will be renewable.
Ministry of Business, Innovation and Employment (MBIE) principal policy adviser Andrew Millar said fossil fuels were now largely used to cater for periods of peak consumption when renewable energy was not available.
He said it could be possible to get to the point where no fossil fuels were required – but that would either mean creating much more capacity than was usually needed, to cover peak periods, or having more geothermal in the mix, which was not subject to weather or seasonal fluctuations.
The Government wants New Zealand to hit 90 per cent renewable electricity by 2025, a target Basil Sharp, chair in energy economics at the University of Auckland, said was feasible.
Weather patterns mean New Zealand can generate a lot of hydro and wind power. This country has been investing in hydro power since the 1950s.
Globally, places that have the
If our lakes are full and you ran the whole electricity system from them, they would run out in six weeks. Carl Hansen, Electricity Authority chief executive
heaviest reliance on renewable energy tend to be those with lots of natural resources available. Norway, the most renew-ablereliant, has large lakes. ‘‘In Norway, their lakes can hold two years’ worth of electricity. If our lakes are full and you ran the whole electricity system from them, they would run out in six weeks. We depend on there being regular rainfall,’’ Hansen said.
New Zealand had better wind resources than most other countries. Solar is becoming a more popular option, particularly for households. In 2014, solar panels produced about enough energy to supply every household in the Kaikoura District.
But one of the problems with solar energy is that it is most readily available at times when power is least needed.
Millar said: ‘‘At 6 o’clock on a winter’s night, that’s when you need the most power, but that’s not when solar power will be generating it. New Zealand’s energy demand is different to other countries’ because the biggest demand peaks are in the morning and evening, both times when the sun is not out so much.’’
Hansen said that meant any solar power households generated was likely to replace energy from other renewable sources, not fossil fuels.
Tidal power, tipped as a possibly more reliable form of hydropower, was still in the development stage, Hansen said. Nuclear power, popular in countries such as the United States, could be overkill for an electricity system of New Zealand’s size – political concerns about nuclear generation aside.
New Zealand’s Emissions Trading Scheme is a factor for companies deciding what kind of power to invest in. Because a coalfired power station emits carbon dioxide, they generally have to buy emission units, which adds to the cost of the operation of the plant.
Hansen said that meant the power they produced was then offered to market at a slightly higher rate and so did not get dispatched as often. ‘‘It’s dispatched only when it is needed, when cheaper, more renewable lower carbon generation is not available.’’
Greenhouse gas emissions in the electricity sector dropped by a quarter between March 2015 and March 2016, MBIE statistics show.
Millar said New Zealand was in a different position to a lot of other countries that had pledged to cut emissions, because most of them still had to switch from large-scale fossil fuel electricity generation to renewables. ‘‘In New Zealand we have done that already. For us the challenge is more in the transport space.’’
Millar said transport was responsible for 17 per cent of all emissions and was a key area that could be improved.
Moving to more renewal energy in the transport and industrial sectors could require incentives for electric cars, he said, to increase the uptake, or for businesses to come up with new solutions. Dairy firm Miraka uses renewable geothermal steam from the Mokai geothermal field to run its processing operations – most factories use coal.
Sharp said there were challenges ahead. ‘‘Fuels from biomass just cannot compete at prices we have experienced in recent years, even before the price of oil fell. Our current infrastructure is designed around oil products although Z Energy has shown initiative and plans to establish EV charging stations.’’