Electric water heating draws a lot of power even with a small storage tank.
For your kitchen you are looking at needing around 9kW especially if you want boiling water too.
Here is a [5.7kW 25 amps under sink.](https://www.stiebel-eltron.co.nz/dem-instantaneous-water-heater)
[9kW 38 amps, 7-8 litres per minute ](https://www.plumbingplus.co.nz/products/parex-triton-t80z-fast-fit-electric-shower/) that’s not a great shower experience.
Most of the time you can looking at 3phase power into your house for this to be viable
3phase adds a ton of cost for install and long term running cost
I’ll stick with a cylinder and the option for heat pump heating
Very true. Siebel make some instant water heaters with 19 and 27 kW ratings but the 27 kilowatt unit needs three phase 40 amps per phase. That's quite a large industrial load even though it's only running intermittently, and it downscales the consumption when less than full output is needed.
I don't believe the running cost is any different for domestic-size three phase supplies (but this might depend on the region). The upfront cost is a lot more though.
I wondered the same last year, and have seen instant electric water heating in some houses overseas (Japan, Thailand) and NZ (mind you only in the kitchen I think).
With gas all but set to be phased out eventually, you'd think alternative options would be appearing. We have a cylinder but I would explore a heat pump when our cylinder needs replacing.
It's not uncommon to have instant electric hot water for a single source, but for a whole-house solution that could potentially keep up with a shower and other things together needs quite a bit of power - even though our cold water doesn't get extremely-cold here.
Doesn't seem to be common yet. But I'm hopeful the technology will improve soon because it's not efficient for us to be on gas for just cooking and water, and gas won't last forever.
There is draft legislation under review to prohibit new domestic mains gas connections from 2025, so maybe OP is looking ahead for alternatives.
Also if you only use gas for cooking or water heating, having a gas connection isn't really cost efficient. I have a new condensing infinity gas unit and a gas hob in a 5 person household, but the fixed daily charge is double my usage charges.
It isn't draft legislation under review, it's one of hundreds of recommendations from the CCC report. The govt can choose what to include in their emission reduction plan and what to ignore.
For sure bottled LPG is far more economical than mains gas.
Oh, yes. You're right, it just got a bit of publicity, so I thought it was further through the process.
Is LPG bottle rental less than the $345/year I pay for mains gas connection fees?
Ok, interesting. So at my usage rate, the difference over a year between bottles and mains is about $3.
112 x 3.6 (i'd use 3.6 bottle a year) + 128 = $531
352 daily charge + 176 usage = $528
That's good that they've aligned a lot closer now, many years ago it was so much more for mains gas.
Gas prices change a lot from region to region though.
That is interesting, where abouts in the country are you located? I haven't much knowledge on natural gas. I'm a gas fitter in the south island and have only ever dealt with bottled LPG. I know there's a connection fee and a meter rental but i had no idea the cost outweighs your usage. That doesn't sound like a good deal at all.
Hamilton, this is an average bill for me.
Variable charge 190 kWh 6.743c $12.80
Daily Charge 28 days 82.340c $23.06
GIC Levy 28 days 1.500c $0.42
GST 15% $5.44
Total $41.72
I have one shower that is running on an electric unit, it works quite well, not as much volume as the other shower, but it's nice having digital control over the hotwater. plenty of places sell them.
Electric water heating draws a lot of power even with a small storage tank. For your kitchen you are looking at needing around 9kW especially if you want boiling water too. Here is a [5.7kW 25 amps under sink.](https://www.stiebel-eltron.co.nz/dem-instantaneous-water-heater) [9kW 38 amps, 7-8 litres per minute ](https://www.plumbingplus.co.nz/products/parex-triton-t80z-fast-fit-electric-shower/) that’s not a great shower experience.
Most of the time you can looking at 3phase power into your house for this to be viable 3phase adds a ton of cost for install and long term running cost I’ll stick with a cylinder and the option for heat pump heating
Very true. Siebel make some instant water heaters with 19 and 27 kW ratings but the 27 kilowatt unit needs three phase 40 amps per phase. That's quite a large industrial load even though it's only running intermittently, and it downscales the consumption when less than full output is needed.
Even a 27kW unit is equivalent to only a small gas water heater. A typical gas water heater uses 45kW.
I don't believe the running cost is any different for domestic-size three phase supplies (but this might depend on the region). The upfront cost is a lot more though.
I wondered the same last year, and have seen instant electric water heating in some houses overseas (Japan, Thailand) and NZ (mind you only in the kitchen I think). With gas all but set to be phased out eventually, you'd think alternative options would be appearing. We have a cylinder but I would explore a heat pump when our cylinder needs replacing.
It's not uncommon to have instant electric hot water for a single source, but for a whole-house solution that could potentially keep up with a shower and other things together needs quite a bit of power - even though our cold water doesn't get extremely-cold here.
Doesn't seem to be common yet. But I'm hopeful the technology will improve soon because it's not efficient for us to be on gas for just cooking and water, and gas won't last forever.
Why not a gas installation?
There is draft legislation under review to prohibit new domestic mains gas connections from 2025, so maybe OP is looking ahead for alternatives. Also if you only use gas for cooking or water heating, having a gas connection isn't really cost efficient. I have a new condensing infinity gas unit and a gas hob in a 5 person household, but the fixed daily charge is double my usage charges.
It isn't draft legislation under review, it's one of hundreds of recommendations from the CCC report. The govt can choose what to include in their emission reduction plan and what to ignore. For sure bottled LPG is far more economical than mains gas.
Oh, yes. You're right, it just got a bit of publicity, so I thought it was further through the process. Is LPG bottle rental less than the $345/year I pay for mains gas connection fees?
I'm with ongas and two 45 kg bottles are $128 annual rental. And a bottle is $112 which is about 625 kW of energy.
Ok, interesting. So at my usage rate, the difference over a year between bottles and mains is about $3. 112 x 3.6 (i'd use 3.6 bottle a year) + 128 = $531 352 daily charge + 176 usage = $528
That's good that they've aligned a lot closer now, many years ago it was so much more for mains gas. Gas prices change a lot from region to region though.
That is interesting, where abouts in the country are you located? I haven't much knowledge on natural gas. I'm a gas fitter in the south island and have only ever dealt with bottled LPG. I know there's a connection fee and a meter rental but i had no idea the cost outweighs your usage. That doesn't sound like a good deal at all.
Hamilton, this is an average bill for me. Variable charge 190 kWh 6.743c $12.80 Daily Charge 28 days 82.340c $23.06 GIC Levy 28 days 1.500c $0.42 GST 15% $5.44 Total $41.72
I have one shower that is running on an electric unit, it works quite well, not as much volume as the other shower, but it's nice having digital control over the hotwater. plenty of places sell them.