Tag: hydro

Grand final: Sustainable Energy NZ #16 – counting up the dollars and sense

Welcome to the sixteenth and final post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series.

To recap, we started with a bit of energy accounting and worked out that Kiwi’s use around 88 kWh/d/p (methodology for what the kWh/d/p means is here), and that of this, about 33kWh/d/p came from sustainable sources or we couldn’t substitute. As a result, we’ve been looking for how to shift the remaining 55kWh/d/p of our current energy use to renewable energy sources. We approached this in two ways:

How much could we increase our energy generation capacity in renewable sources?

Here, we looked at hydro power, geothermal and wind (and a summary on the big three), solar, biofuels, marine and waste energy and did some basic calculations on the overall potential of these sources. Then:

How much could we achieve a BIG reduction in our personal and national energy consumption, and where those savings would come from.

We went through the areas of energy use for Kiwis, including road, air transport, home energy use and general consumption before doing some calculations on the overall reductions we think we could make.

What might it cost to achieve an all-renewable energy economy?

Today, we’re looking at how this might translate into action at a national level. This post contains both some costing, and suggestions for action that might effectively be channeled into effective change.

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

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.

Sustainable Energy NZ #2 – How much dam energy is there anyway?!

Welcome to the second post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. Today we’ll be crunching the numbers on hydroelectricity potential in New Zealand. For the background to the work and an explanation of the methodology, please visit our last post here. Remember that we are looking for around 55 kWh/d/p from renewable sources to replace what we currently use today. So, with that, today’s post!:

At the moment, ~15kWh/d/p of New Zealand’s energy comes from hydroelectric generation. How much more is feasible? For the United Kingdom, MacKay simply does back-of-the-envelope calculations, but because of widespread hydro-electrical use in New Zealand, there are reports that allow us to make a more complete assessment of hydroelectric potential. [8k8vf25] and [9nvw27h]. Firstly, I discount any scheme that would be in a National park, or protected by a strong Water Conservation Order (e.g. Motu), or extremely remote. Some 34 schemes of >20MW capacity have already been identified as economically and technically feasible (e.g. Mokihinui River). These deliver a potential of 10kWh/d/p. on top of the 15.4kWh/d/p already commissioned. 26% of that is from North Bank Tunnel project in the Lower Waitaki and a further 22% comes from four possible schemes on the Clutha River.

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Going renewable doable by 2050, new analysis suggests

A new study published in Energy Strategy Reviews this month affirms that sourcing 95 percent of our energy from sustainable sources by 2050 is possible, using already available technologies. The authors are from the Dutch renewable energy consultancy Ecofys. Their paper includes technical detail, but the general salient points are well identified and clear to the non-expert reader. Familiar themes are sounded and buttressed with careful and sensible analysis.

Efficiency and electrification are two key requisites on the way to the 2050 goal.  The scenario proposed by the study envisages a slightly lower power demand in 2050 than in 2000, even allowing for established forecasts of population growth and GDP growth. It surveys demand under three sectors – industry, buildings and transport – indicating in each case the prospects of much lower demand from the application of efficiency measures as compared with current business as usual (BAU) practices. The electrification which plays an important part in lowered demand occurs primarily in the buildings and transport sectors.

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Brownlee’s energy strategy: dig and burn

The newly released Draft NZ Energy Strategy (PDF, web) is a winding back of the clock from the substantial statement released under the previous government only three years ago. When announcing early in his term as Minister that a new strategy was required Gerry Brownlee complained of the old one:

“You need only read the foreword of the NZES. “Sustainability” and “sustainable” are mentioned thirteen times, “greenhouse gas” is mentioned four times, and “climate change” is mentioned three times. That is all very good, but security of supply rates only one mention. Affordability is not touched on at all. Nor is economic growth.”

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