Sustainable Energy NZ #5 – Summing up the Big Three – hydro, geothermal and wind

by Oliver Bruce on October 24, 2012

Welcome to the fifth post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. Today we’re summarising the numbers on wind, hydro and geothermal potential in New Zealand (and finding they’re pretty big!). For the background to the work please our introductory post here. Also check out our earlier posts on the potential of hydro power,  geothermal and wind. Note: the units are in kWh/day/person – ie. if you ran a 40W lightbulb for 24 hours, it’d take ~1 kWh over the space of a day. We then divide it by person to give you a sense of the scale of the resource proportionate to the size of the population. Be sure to check out the methodology.

So, after going through the numbers for hydro, geothermal and wind, we find that we have a total realistic extra potential generation of 59.4kWh/d/p (hydro 23, geothermal 4.4, and wind 32kWh/d/p), without considering offshore wind. So, if we don’t mind parts of the country covered with windmills, multiple new hydro schemes, including all those proposed for the Clutha and Waitaki Rivers, and new geothermal schemes, we can readily get more than our required 55kWh/d/p from hydro, geothermal and wind alone.

We don’t have to say yes to every wind and hydro proposal but we have to say yes to a great many of them. And if we want power to be affordable for everyone, we have to say yes to proposals in places where it is cost-effective to generate power.

In other words, it’s a feasible possibility.

The important point to make here is that much of the energy we’ll be generating will be in different forms to those we will be replacing – i.e. we’ll be generating a lot more electricity, but moving away from energy in liquid fuels. It’s worth noting that even if we manage to find a significant resource of oil in our offshore drilling efforts, this will be sold on the international market. Also, because they’re finite won’t change the long term requirement of having to transition towards renewable energy sources.

Aside from these options, there are other possible sources of power that will become more important over time. We’ll be having a look at them in our next post.

Summary: We could meet of our energy requirements (note: not including our air travel, diesel fuel used for shipping or the embodied energy in imported products) almost exclusively on a hydropower, wind and geothermal. It would mean saying yes to schemes that are in places where it’s cost effective to generate power.

Up next: We crunch the numbers on solar for New Zealand and find it’s a pretty massive resource.

{ 6 comments… read them below or add one }

Bob Bingham October 24, 2012 at 5:37 pm

I think you are underestimating the availability of natural energy and geothermal in particular. Because we have always had so much cheap oil and have been content to let the pollution from coal go into the atmosphere we have not tried hard enough to develop alternative sources of energy.
The industrial revolution was started with wind and water we just went down the wrong track when Stevenson developed a better steam engine powered by coal.
New Zealand in particular has an abundance of geothermal energy and we need to join with other nations to share technology and get producing as quickly as possible. As the developing nations start to share our lifestyle the price of oil will rocket and we should be keeping it for export while we run the country on home produced natural energy.

3.

Phil Scadden October 24, 2012 at 10:15 pm

Well Bob, the reports we used to come up with the numbers were based on detailed studies of the available resource. If you think they underestimate the potential, then you need to show us what those studies missed. Hot dry rock has the problem that conditions that create the resource are poor thermal diffusitivity which gives you “fossil heat”. This same characteristic makes it hard to extract heat from.

Bob Bingham October 25, 2012 at 8:09 am

The point that I was making is that with oil so cheap and plentiful (And it is a beautiful fuel ) we have not developed technology for other energy systems. There are almost no electric cars, buses or trains because it is not economic, but it will not be like that forever and we should prepare in advance. By investing in research and technology now we can avoid the worst of the economic crash when the next oil price hike arrives.
We need energy and a lot of it so its better to make our own rather than import it. Or sell our own oil abroad and use the cash to invest in electricity.

Phil Scadden October 25, 2012 at 11:32 am

I substantially agree with you but a very important point from MacKay’s book, is that physical limits exist on energy and no amount of technology will change that. As well shall see, technology has the possibility of providing more energy from solar, tide and biofuel.

John ONeill October 24, 2012 at 8:12 pm

I asked someone at an open day at Otago Uni how the increase in heat with depth in the Southern Alps compares with that around the volcanic plateau. She said it’s anomalously steep down here because of erosion shaving the tops off the mountains – the lower rock strata haven’t figured out they’re closer to the surface than they were back in the ice ages ! With heat flows that slow, it will take a lot of drilling if you want to rely on geothermal long term.

jh October 24, 2012 at 8:40 pm

Order more of those please:

10 million New Zealanders by 2062?

Professor Paul Spoonley
Increasing New Zealand’s population to 10 million people, under a comprehensive 50 year Population Policy to build the economy, is just one of the ideas being discussed in an immigration conference at Massey University’s Albany campus from October 24–26.

The conference, entitled Pathways to Metropolis in the 21st Century: Immigration Issues and Futures aims to communicate research results from publicly funded programmes. More than 300 delegates are expected to attend from New Zealand and around the world to discuss topics ranging from megatrends and scenarios in the Asia/Pacific region, future workforces and the skills required for the 21st century, and pathways for development in Auckland.
http://www.massey.ac.nz/massey/about-massey/news/article.cfm?mnarticle_uuid=A52BA19A-E770-3312-3B87-AFC9F993790A
Whatever the expert research says the government will run with (given the ideological and financial greese).

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