Stuart Smith needs to back up his claim of "The reality is a diesel vehicle would have less emissions than charging the electricity from a diesel generator" because I suspect that a large utility scale diesel generator would be more efficient than a diesel vehicle. Just more scattergun politicking from the Nats.
Smith also "doesn’t think Rakiura’s climate is amenable to solar infrastructure" so he obviously isn't familiar with Scotland's uptake of solar generation despite being at an 8 degree higher latitude than Stewart Island: https://en.wikipedia.org/wiki/Renewable_energy_in_Scotland
nice_lady,
May 13, 10:33am
Converting one form of energy to another always involves losses and inefficiencies.
intrade,
May 13, 10:46am
Yea, try and explain that to all the morons on this planet.
tygertung,
May 13, 12:49pm
Convert beers into pedal power?
apollo11,
May 13, 12:51pm
Which planet are you from? You must have done some really bad stuff to be sent here.
cjohnw,
May 13, 1:15pm
Or did we do the bad stuff and got punished?
martin11,
May 13, 1:43pm
Finally admitting thats what you are ?
s_nz,
May 13, 2:53pm
Would actually need to run the numbers to see if the Stewart Island network + an ev came out better or worse than a diesel car. The Network is solely powered by big (208kW to 360kW each) reciprocating diesel generators. While they would beat car engines for efficiency they aren't great compared to combined cycle turbines and the likes that you would see on the main NZ grid.
Point is kinda moot anyway. Doc doesn't yet have full saturation of EV / PHEV cars where appropriate models exist, so the outlander PHEV could have been deployed somewhere on where it could be charged from the national grid, and a cheaper, more efficient on petrol Rav4 hybrid (Or some existing car from the doc fleet) could have been deployed in it's place.
This is true, however it is wrong to assume that the presence of more transformations leads to a less efficient system.
For example a 50% efficient combined cycle gas plant feeding a 80% efficient EV via a 97% efficient power grid would give a 38% efficient system. Easily beating the typical 20% efficiency of a petrol car, and 30% efficiency of a diesel car.
apollo11,
May 13, 3:33pm
Surely the universe couldn't be this cruel.
intrade,
May 13, 3:37pm
10 a petrol car is 27% plus efficient and diesel 34% with marine wazilla sulzer over 50% and The wasted heat is used to warm the passenger compartment of a petrol and diesel car, As a electric needs more extra energy to make that heat. All conveniently overlooked. Not to mention the cooling The ev also needs when not driven
harm_less,
May 13, 4:43pm
The cabin heating in some EVs is actually integral to the battery thermal management (cooling) so essentially waste heat akin to that from a fossil fueler.
Land access issues were delaying the installation of 2 wind turbines on Rakiura/ Stewart Island at a cost of $3.2 million.
https://www.stuff.co.nz/southland-times/news/123072264/land-access-delaying-stewart-island-wind-turbines The turbines are alleged to be able to reduce the current diesel for the generators bill of $160K per year by 40 percent ($64K) so a post wind turbine installation diesel bill ($96K per year). Doesn't say what the maintenance cost of the generator system is. The turbines might have an ( O and M - operating and maintenance cost of (guess) $50K a year each). So the residents could end up with higher electricity costs after turbines are installed? Solar PV is a function of cloud cover. Certainly in summer one would expect high quality solar pv could work on Stewart Island. Sunshine hours nz https://figure.nz/chart/KCFvVXndcpjM8Rfx (Invercargill 1670 sunshine hours/ year) Though I doubt it would ever be like Melbourne where they water spray (with rain water) their solar panels to cool them in summer. 65C reduces solar pv output 20 percent and cooks the panels. Water gets back 10 percent and a cooler panel. https://youtu.be/XW5cUVfLlIk Current map of European refuelling hydrogen stations. Guess the Euros don't have the patience to wait for a electric recharge. https://h2.live/en The US H2 stations are mainly in California.
serf407,
May 13, 7:08pm
Hyundai NEXO hydrogen australia record on single tank 887.5km april 2021 Brendan Reeves - drives. https://youtu.be/RyupLuOVny0
marte,
May 13, 8:24pm
How many Kgs of Hydrogen & how much does the tank/fuel cell weigh?
Im wondering about how it compares to the electric battery packs weight
gblack,
May 13, 9:09pm
I knew that the DOC thing with the Outlander would pop up here.
Only had to think about it for a few seconds to realise that it is far from ridiculous as made out by the Nats.
It's pretty obvious that big diesel generators running in a fixed optimal rpm range will be more efficient than a small engine revving up and down in a car. This is exactly how hyper milers get better fuel economy.
Hybrids also get better fuel efficiency - again using batteries and electric motors to allow the ICE motor to operate in the optimal range.
In don't know what diesel vehicles National would have had DOC used if not an Outlander PHEV - maybe a RAM or F350 or something, but seems like not that clear cut that charging off the local grid is that that bad.
But clearly getting wind and PV solar into the Stewart Island grid would save some money over the long run. Hopefully all the islands not tied into the main transpower grid move to some geothermal/wind/solar to save burning diesel unless really needed
s_nz,
May 13, 11:53pm
Not sure why hydrogen cars came up in this tread. I don't think that technology is suited for Stewart island.
But for comparison the Kona Electric which doc has purchased a bunch of has beaten 1000km in an economy run. Should note that was an extreme test. 30km/h doing loops on a track.
6.33kg's of hydrogen stored in thee 52L tanks (total 156L). 700bar (10,153PSI).
Not sure what the weight of the hydrogen tanks of the nexo are, but the smaller (5kg hydrogen capacity, 122 liter) tanks in the Toyota Mirai weight 87.5kg combined.
Not sure of the Kona EV's battery pack weight, but the 66kWh pack in the chevy bolt is 440kg (stressed member in that application). So the hydrogen tanks are a lot lighter.
Complicating the matter is that all fuel cell hydrogen vehicles are essentially series hybrids (like the nissan note e-power). The fuel cell dosn't have enough peak output to handle harsh acceleration, so the fuel cell charges a relatively small traction battery pack, which in turn runs an electric drive train. So the entire fuel cell system is weight that a pure EV doesn't need to carry.
Likely the best comparison is to just look at kerb weights: Kona EV: 1,535–1,743 kg (formour is the smaller battery size not available in NZ) Nexo Hydroen car: 1,814–1,873 kg Ioniq 5: 1,920–2,060 kg
Note the nexo is quite lot bigger SUV than the Kona (670mm longer). The Ioniq 5 is a better match size wise, but it's AWD, and vastly more powerfull in higher trims than the Nexo.
I think it is hard to design compact hydrogen cars, those three 52L cylinders are bulky and need to be places away from crash impact area's. (for comparison a AL80 scuba tank is 12L)
framtech,
May 14, 12:01am
Its looks like not many have even been to stewart Island, why doc need a car on the island is crazy, all they need is their legs or at worst a electric bike, the place is so small you only need a vehicle to cart materials and freight from the air strip. most common would be an old flat deck as rust will eat up most vehicles. most of the transport on the island is by boat. we are moving into a world of crazy where common sense is a dirty word and while the racists try and knock down the middle aged white man and ridicule his intelligence and his massive achievements of the last 100 years in New Zealand , injecting Maori names in every place, will not change the fact that the same intelligence will not be brainwashed by things like this EV gobbledygook and dictatorship by lefties and greenies. DOC are a prime example of amateurs dictating nature to nature with a destructive outcome while they hoodwink idiots, the same fools that promote destructive tourism to line their pocket agendas.
marte,
May 14, 9:22pm
#18 Thanks for that. I read the small kgs of hydrogen, like 7Kgs for a full tank & wondered if that ment a significant savings in weight ( after taking into account the tank itself + the fuel cell + extra hydrogen only stuff ) vs equivalent weights in ICE & hybrid & EV cars.
So, No. No significant weight savings in Hydrogen cars, so no special reason to go Hydrogen power. The gain in rapid fueling like a ICE car vs long charging times of a EV does not give you much advantage because thats now lost in a 3rd stage between electric generation-hydrogen manufacture to electricity again, into battery to turn the basically a EV motor to drive car forwards. Add in the safety factor too.
To build EVs in the US, make flying taxis and install hydrogen refuelling station.
bill-robinson,
May 15, 9:32am
have a pressurised container in the back of my car, no thanks. i have seen photos of the damgedone to a car when one of the CNG canisters blew up, the 2 people in the car spent time in hospital as well. no fire, just sudden compression.
Methanex methanol plant, Waitara, New Zealand. The company will idle a plant over winter to free up gas for electricity supply.
wembley1,
May 29, 4:45pm
In NZ in the eighties? The steel in the cylinder was wrong and was too brittle and quite literally exploded. Usually when compressed gas cylinders “explode” they rupture and peel open like a banana
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