Guest essay by Eric Worrall

According to climate researcher Jen Purdie, even New Zealand with its abundance of windy mountains, geothermal sources and vast hydropower lakes cannot provide enough renewable energy for people to live in comfort and ease.

The author calls it “managing the demand”, but the message is clear.

As NZ gets serious about climate change, can electricity replace fossil fuels in time?

February 16, 2021 2.15pm AEDT
Jen Purdie
Senior Research Fellow, University of Otago

As fossil fuels are phased out over the coming decades, the Climate Change Commission (CCC) suggests electricity will take up much of the slack, powering our vehicle fleet and replacing coal and gas in industrial processes. 

But can the electricity system really provide for this increased load where and when it is needed? The answer is “yes”, with some caveats.

It’s hard to get a sense of the scale of the new generation required, but if wind was the sole technology employed to meet demand by 2050, between 10 and 60 new wind farms would be needed nationwide.

Managing the demand

As well as providing more electricity supply, demand management and batteries will also be important. Our modelling shows peak demand (which usually occurs when everyone turns on their heaters and ovens at 6pm in winter) could be up to 40% higher by 2050 than it is now. 

But meeting this daily period of high demand could see expensive plant sitting idle for much of the time (with the last 25% of generation capacity only used about 10% of the time).

This is particularly a problem in a renewable electricity system when the hydro lakes are dry, as hydro is one of the few renewable electricity sources that can be stored during the day (as water behind the dam) and used over the evening peak (by generating with that stored water). 

Demand response will therefore be needed. For example, this might involve an industrial plant turning off when there is too much load on the electricity grid.

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What a miserable vision of the future. A future where energy is rationed. A future where if you try to turn on an appliance at the wrong time a government approved smart meter will nag you about the bill you will have to pay, or inform you that no clothes washing or dish washing machines are permitted be switched on until 2pm tomorrow, when the solar panels are online.

All of this is only a problem because the New Zealand government is fixating on unreliable zero carbon energy sources.

Even if you think CO2 emissions are important, there is an alternative which would not mess up everyone’s lives. New Zealand energy demand currently peaks at around 900MW, less than the output of a single large nuclear reactor.

One or two decent size zero carbon nuclear plants, and there would be no need for any of this. Modern nuclear plants are safe – even in Earthquake prone New Zealand, passive safe reactor designs like pebble bed, which are physically incapable of meltdown even with total coolant loss, would not cause a major radiological incident if the reactor was damaged by an Earthquake.

Affordable, reliable zero carbon electricity would be available 24×7, any time you flick a switch.

via Watts Up With That?

February 19, 2021 at 12:38AM