As the American humorist Will Rogers said: “It’s not what we don’t know that gives us trouble, it’s what we know that ain’t so.”
“We can have a reliable and economic supply of electricity without burning fossil fuels”
Blackouts are inevitable if we do not have sufficient energy in reserve to make up for the loss of hydro generation in a dry year. In a 1:20 dry year the shortfall amounts to 10% of annual consumption.
To make up for the shortfall we need to have an energy store that can be converted into electricity over the four month dry period. Ever since Meremere power station was commissioned in the 1950s, we have relied on coal-fired stations supplemented by gas and oil to provide the dry year reserve.
We now have a government that subscribes to the unfounded belief that man-made CO2 causes dangerous global warming. It also believes that if New Zealand makes massively expensive efforts to reduce emissions of greenhouse gases the rest of the world will follow our lead and climatic disaster will be averted. Dream on!
Never mind that the IPCC climate models show that if everyone abided by their Paris agreement promises – so far, nobody has – and keeps it up until the end of the century, the world will be cooler by 0.17° – which you can’t even measure! The whole thing is an exercise in futility.
Without Huntly power station there no short-term options for keeping the lights on in a dry year. As this winter demonstrated, the system is now close to its limits in a normal year. Transpower has already warned that the dry year risk is steadily increasing.
Many people believe that geothermal, hydro, wind and solar power can solve the dry year problem. Not so. Geothermal (which emits CO2) runs flat out day and night so it cannot provide extra energy when needed. Any new conventional hydropower stations would need massive storage which, inevitably, the Green Party would oppose. Wind power is of little use because it produces power only when the wind blows and not when it is needed. Solar power is even more useless because shortages occur in the autumn and early winter when the days are shorter.
Some people believe that batteries are the answer but they cannot store energy in a wet year and release it in a dry year because they self discharge by about 3% per month. Anyway, they are prohibitively expensive and have a life of less than 20 years.
Nuclear power could do the job but it is prohibitively expensive to have a nuclear power station sitting idle and only used every few years when there is a shortage risk.
In the short term, there is no alternative to keeping Huntly for dry year reserve with 1 million tons of coal available. In the longer term, gas storage would be an option but, as the government has injected huge uncertainties into the future of gas in New Zealand, no one would contemplate investing in it.
There is, however, one option left. It is to build a large dam in the hills above Roxburgh Hydro station to store the huge amount of water needed by a pumped storage scheme that could get us through a dry year.
Preliminary investigations indicate that it will be much thismore expensive than storing coal or gas. Engineering studies RMA approval and construction would probably take 15 - 20 years. By that time, the world is likely to have cooled and it will suddenly be fashionable to burn fossil fuels to raise carbon dioxide levels to warm the climate and make up for the shortfall in plant growth!
At the moment, the only options are to continue to burn coal or suffer rotating blackouts.
"Things you know that ain’t so" is a regular column by Bryan Leyland exposing the truth behind popular misconceptions.