Any incremental load (beyond what is supplied from Hydro, geothermal and wind) on the grid in NZ comes mainly from Coal burnt at Huntly power station.
After allowing for electricity transmission, conversion and battery storage losses in an EV, would it be more efficient to just burn the coal at the point of demand?
Sure, if you want to drive an antique steam wagon.
This is basically the green lie about electric vehicles in other parts of the world. The power stations do the polluting instead of the cars.
paul861,
Jul 21, 12:56am
i'm not convinced hydro is good enviromentally
the-lada-dude,
Jul 21, 2:07am
And i'm not so sure we should be extracting so much energy from the sun, we must be weakening it, and it will go dimmer quicker !
the-lada-dude,
Jul 21, 2:08am
how are you going T9 ?
tamarillo,
Jul 21, 4:42am
Surely an EV can charge overnight when load is low so coal is off.
mojo49,
Jul 21, 5:01am
Now you have got to the nub of the issue. However if we use more of the sun's energy, it will cool down a bit and that combined with reducing the CO2 in the atmosphere will reverse global warming. Once the sun cools enough we could go back to using oil and warm the planet up again. So long as we get the balance right we could go one for years and years. Problem solved!
,
Jul 21, 5:13am
This is only a right this very second problem, so it would be an issue if all the cars suddenly became electric right now. However its not a problem over the expected timeframe for the uptake of EVs. We have plenty of potential renewable energy available for development, so no, this is silly.
tony9,
Jul 21, 5:15am
You are thinking capacity, not energy use.
Our renewable sources provide about 80% of our power needs.
Imagine a large tank full of energy, it is big enough to hold enough energy (MegaWatt Hours) to supply all our electricity needs for a year. The bottom 80% is from our renewable sources, the top 20% comes from coal and gas. The bottom 80% is filled from a fixed supply, the top 20% is filled as needed from oil and gas.
If we use less energy in a year, we will need to put in less coal and oil. If the usage drops too low for the year we may have spilt some water.
Anything extra we take from the grid at any time means more coal, gas and oil is burnt.
It does not matter what the load is at any time (from a generation perspective), what matters is how much energy (power over time) is taken out.
tony9,
Jul 21, 5:20am
No, it is not silly, it is the situation that exists for the next 5 years, at least. Why do you think the Huntly 250MW coal fired units have been extended to at least 2025?
To make it worse, if NZ is committed to reducing or cutting out coal use, and not finding more gas, how do Fonterra, DHB's and other large commercial users replace coal? It will be either electricity or oil.
sw20,
Jul 21, 5:23am
In the North Island this may well be true.
South Island is 100% renewable.
tony9,
Jul 21, 5:25am
No different, we are running with a common grid via the HVDC link.
If you charge an EV in Dunedin the extra energy will come from coal or gas burnt in Huntly as there is less power to head north.
,
Jul 21, 5:33am
It will be electricity in the longer term, I can't find the link right now but if you hunt around you'll find there's a document (I think from MBIE) outlining it, but we have over 2000 Mw of renewable generation for construction.
By 2025 I'd be surprised if EVs made up more than about 20% of the fleet, with ripple type control this wouldn't even use our existing overnight power surplus. You're looking for boogiemen where none exist, sure there will be technical challenges around the generation of electricity in the future, but the impending and serious threat to our prosperity that is anthropogenic climate change means it pales into comparison compared to the consequences of not changing. Hell worst case scenario you could just close Tiwai Point (which will probably happen anyway).
I think this is more about your own unexplained biases than an insurmountable technical problem.
sw20,
Jul 21, 5:35am
Sweet fanny adams power moves North to South. Usually only when the South lakes are low.
tony9,
Jul 21, 5:45am
That is my point.
If more power is used in the South, less is available to go North. So Huntly etc. have to push out a bit more.
kevymtnz,
Jul 21, 5:47am
NZ does not burn coal and has not done for quite sometime NZ power cost are a ripoff
apollo11,
Jul 21, 5:50am
Our system at the moment is designed to meet peak demand. This is usually what the coal/gas generation is used for. EV's plugged into the grid have the potential to be used as an enormous backup battery so that there is no need for peak generation. It would also enable more efficient use of renewable sources.
tony9,
Jul 21, 6:04am
You keep mentioning this, but you are confusing capacity (MW) with energy MWHrs). Most of the renewable generation is wind, which has about a 20% load factor, and high maintenance outages. If all that was actually built (history says maybe 30% will be found to be viable and economic) then that could replace just one unit at Huntly.
BTW, this thread was intended to be a bit tongue in cheek. But, until 2030 at best we will be burning coal for power, steam powered trucks like the one in the OP would be more fun and only a bit less efficient.
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