Attn home builders /renovators. Climate change commission to ban natural gas

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Fred99

13684 posts

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#2716727 1-Jun-2021 14:38

Rikkitic:

I actually remember articles and even discussions on the radio in which it was 'proven' that no rocket could develop enough thrust to overcome the weight of the fuel. The mathematics were all perfectly correct but the experts cited didn't consider the possibility of multiple stages. Sometimes a little knowledge can be dangerous. A lot can be downright deceptive.

This is a easily read article describing "The Tyranny of the Rocket Equation"

IIRC with current fuel and rocket technology, we'd never be able to reach orbit escape velocity from a planet 50% larger than earth. Off topic and maybe better in the thread about UFOs, but maybe we should assume that occupants of all "goldilocks zone" exoplanets with mass larger than Earth would have never advanced though the steps to the space age, so the LGM in UFOs can only be from planets similar in size to Earth - or smaller.

SomeoneSomewhere

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#2716732 1-Jun-2021 14:42

I think we're drifting a little off topic here. Debating whether people are right in writing off technology as impossible even theoretically is generally ineffective, and continues the 'give us another 15 years and we'll find something that works' saga.

Fred99

13684 posts

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#2716736 1-Jun-2021 14:45

SomeoneSomewhere:

They're still a decade away from being viable, though. AKA never. The heavy metals needed for the fuel cells push the cost past a battery, and it's still less efficient.

But here we are:

https://www.hyundai.co.nz/hyundai-motor-and-h2-energy-to-bring-the-world-s-first-fleet-of-fuel-cell-electric-trucks-into-commercial-operation-

Sidestep

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#2716748 1-Jun-2021 15:24

SomeoneSomewhere:

They're still a decade away from being viable, though. AKA never. The heavy metals needed for the fuel cells push the cost past a battery, and it's still less efficient.

The FCmove fuel cell in Auckland Transport's new FCEB – to be used on the Botany -Britomart route (and built in Rolleston by Global Bus Ventures) isn't full of heavy metals? They're used in hydrogen truck and bus fleets all over the world.

frankv

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#2716755 1-Jun-2021 15:41

Fred99:

https://www.hyundai.co.nz/hyundai-motor-and-h2-energy-to-bring-the-world-s-first-fleet-of-fuel-cell-electric-trucks-into-commercial-operation-

Looks like they may have delivered 10 trucks so far, so maybe slower than KiwiBuild. ;)

From https://www.autocar.co.nz/autocar-news-app/hyundai-updates-xcient-hydrogen-fuel-cell-truck

The system comes paired to an e-motor producing 350kW of power and 2237Nm of torque. Three 72kWh batteries represent an additional source of power.

I guess the batteries are because the fuel cells aren't very responsive to change in demand. So the fuel cells run at 180kW, and when there's excess supply they charge the batteries. When there's more demand than the fuel cells can supply, the batteries provide some power. And maybe also to recover some energy via regen braking.

Fred99

13684 posts

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#2720170 7-Jun-2021 14:30

Here's an interesting article:

https://www.mining.com/scientists-develop-cheap-and-easy-method-to-extract-lithium-from-seawater/

A viable method to concentrate and extract lithium (for batteries) using electrolysis, producing hydrogen and chlorine as a "by product" offsetting energy input cost, the lithium produced by this method could be far less expensive, and the resource in seawater is practically unlimited.

Unlike previous claims that lithium could be extracted from seawater, this may be economically viable.

frankv

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#2720622 8-Jun-2021 11:03

$5 electricity to get 1kg of lithium, which sells for about $13. Plus you get chlorine and hydrogen as a by-product.

aucklander

477 posts

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#2730562 18-Jun-2021 11:10

if an older house is fitted with gas HWC or gas cooking appliance, etc - the electrical power supply to that house was sized to EXCLUDE these loads. Switching them to electric means the feed from the street becomes undersized and needs to be replaced? Generally that involves digging up driveways or excavating behind retaining wall, possibly damaging other services in the process - water, phone, fiber? Just banning things appears to be the go-to option for the Govt, without thinking of (any?) implications.

just been through a house extension project and there was a very strong possibility that I have to switch the electric cook-top to gas, in order to be able to install a second HWC for the two new bathrooms added in the extension. Plus a multi-split AC with 3x indoors... But in the end the electrician agreed it is not needed, as it is very unlikely all loads would be on at the same time. But if it happens, the fuse in the box at the boundary would blow (and that you cannot replace yourself...);

The point I am trying to make is the electricity network still proves not to be able to meet the demands of the users, and the approach is to revert to LPG for any shortfall.

Rikkitic

Awrrr
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#2730577 18-Jun-2021 11:42

aucklander:The point I am trying to make is the electricity network still proves not to be able to meet the demands of the users, and the approach is to revert to LPG for any shortfall.

Increase the voltage, reduce the current. It works for ovens, why not for other appliances?

Plesse igmore amd axxept applogies in adbance fir anu typos

Fred99

13684 posts

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#2730617 18-Jun-2021 12:55

If a standard 60A single phase home supply isn't enough, a good first step may be to have an honest and hard thinking session about personal energy use, efficient home design, and sustainability.

If you ~~need[~~ want a 500 square metre home to house your family of 10, to fast-charge 3 Teslas while heating your olympic size pool, you're already the elephant in the room.

SomeoneSomewhere

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#2730730 18-Jun-2021 16:03

Rikkitic:

aucklander:The point I am trying to make is the electricity network still proves not to be able to meet the demands of the users, and the approach is to revert to LPG for any shortfall.

Increase the voltage, reduce the current. It works for ovens, why not for other appliances?

The US does that because they use 120V for small loads, 240V for large ones like the oven.

We run everything on 230V anyway. It's not possible to do that here unless you go get three phase installed, which is larger capacity anyway.

They also tend to use 100-200A at 240V (24-48kVA) for a normal home (400A 96kVA for 'large' houses), whereas we usually use 63A 230V (15kVA) for a normal home and expand up to 40A or 63A 400V 3~ (30kvA or 45kVA)

SomeoneSomewhere

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#2730741 18-Jun-2021 16:17

Fred99:

If a standard 60A single phase home supply isn't enough, a good first step may be to have an honest and hard thinking session about personal energy use, efficient home design, and sustainability.

If you need[ want a 500 square metre home to house your family of 10, to fast-charge 3 Teslas while heating your olympic size pool, you're already the elephant in the room.

Energy and power are very different things. You can have an absolutely obscene annual energy usage by running your 63A (15kVA) feed near full 24/7 - say 10kW 24/7, that's 87,600kWh per year, or about a $1,100 monthly bill. The threshold for low vs standard user power plans is 8,000kWh per year, for example. You could get there by, for example, having a swimming pool and spa pool heated and filtered year round, with a bit of aircon thrown in, or coin mining.

Or you can have a perfectly normal annual energy draw but still need >15kVA. For example, an electric continuous flow water heater able to run two showers is around 24kW, depending on inlet temperature and other design decisions. It's going to use less energy because it's not wasting energy to insulation loss, and it's not taking up space in your house. Your typical storage water heater is just spreading that energy out over two hours not ten minutes. Likewise with charging an EV at 2kW for 10 hours or 5kW for two hours - except the former could mean that you're still not fully charged the next morning.

The UK typically has slightly larger feeds than ours (80A/18kVA or 100A/23kVA), and is starting to do cunning things like kill the aircon when the shower is in use, and have two bathrooms with the showers interlocked so they can't run simultaneously.

It's like the difference between 100Mb/s and 1Gb/s unlimited internet. The latter doesn't actually mean you use more data, just that you spend less time waiting for it.

gzt

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#2730819 18-Jun-2021 18:20

Fred99: If a standard 60A single phase home supply isn't enough, a good first step may be to have an honest and hard thinking session about personal energy use, efficient home design, and sustainability.

I think the point the poster is making is that the standard used to allow lower. Matching boundary fuses at 20A, 30A etc.

Fred99

13684 posts

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#2730826 18-Jun-2021 18:44

gzt:
Fred99: If a standard 60A single phase home supply isn't enough, a good first step may be to have an honest and hard thinking session about personal energy use, efficient home design, and sustainability.

I think the point the poster is making is that the standard used to allow lower. Matching boundary fuses at 20A, 30A etc.

True - but probably not so much with underground supply, and if it's overhead they may not have to rip up your driveway or garden to upgrade. If it's overhead and 20A in an old house, then I expect you've got all kinds of cans of worms to deal with if you want to install 40A cooktops and 50A instant water heaters.

SomeoneSomewhere

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#2730834 18-Jun-2021 19:46

There's still a moderate number of properties with 32A supplies, But in general you're looking at a major upgrade to replace all the 1930s rubber cable in rusted steel conduit first.

Underground supply, except for larger commercial properties, didn't start becoming popular until more recently.

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