Solar options for home in 2022.

Forums › Home Workshop DIY › Solar options for home in 2022.

1 | ... | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | ... | 98

212 posts

Master Geek

#3349070 1-Mar-2025 19:19

timmmay:

Do these parts look reasonable to control hot water cylinder from home assistant, so I can have the hot water cylinder heating when there's sufficient solar power available? Any better ideas?

Shelly Pro 1 Relay. I'd have liked the Pro1 PM for power monitoring but I think it will burn out after a year or two with 3kw going through it even though it's within spec, hence the contactor.
Siemens contactor - SENTRON 5TT INSTA Contactor, 230 V ac Coil, 2-Pole, 20 A, 2NO
ABB 1P Pole 40A Isolator Switch - so that if the Shelly / contactor fails closed we can manually turn the hot water cylinder on
My solar installer says this is simple for them to install.

I'd still like to be able to measure the energy used by the hot water cylinder, ideally in a way that isn't able to burn out. I don't really need to do this, I'd just like to, to get it into the Home Assistant energy dashboard.

Oddly enough, the https://www.smarthome.com.au/ website works fine when you're not logged in, but if you register and log in I get http 500 errors on every page. If you then log in again on a new browser it works ok. That's a weird bug.

There's nothing wrong with the parts. But is a fancy relay so you will probably end up importing some peak rate power.

As far as measuring consumption the element had a fixed rate, just monitor the time.

Otautahi Christchurch

timmmay

20575 posts

Uber Geek

Trusted

Lifetime subscriber

#3349081 1-Mar-2025 21:54

Yes we will end up importing some peak rate power, and exporting sun power, we're not trying for perfect we're just trying for pretty good. However I may just get a diverter because it sounds a hell of a lot easier, but they cost $1,500 instead of $250.

With the simple relay system we can easily measure the amount of time the whole water cylinder is on top estimate usage, but we won't know when it gets up to heat and the thermostat turns it off because it doesn't have power measurement. I probably don't need power monitoring, it's just something that would be nice to have. It's a shame the Shelly can't actually handle its rated power consumption long term, otherwise they would be good.

HarmLessSolutions

969 posts

Ultimate Geek

Subscriber

#3349087 1-Mar-2025 22:03

timmmay:

Yes we will end up importing some peak rate power, and exporting sun power, we're not trying for perfect we're just trying for pretty good. However I may just get a diverter because it sounds a hell of a lot easier, but they cost $1,500 instead of $250.

With the simple relay system we can easily measure the amount of time the whole water cylinder is on top estimate usage, but we won't know when it gets up to heat and the thermostat turns it off because it doesn't have power measurement. I probably don't need power monitoring, it's just something that would be nice to have. It's a shame the Shelly can't actually handle its rated power consumption long term, otherwise they would be good.

The real advantage of a diverter is seen on partly cloudy days. The diverter 'chases' the generation level and uses only that amount, until the HWC reaches temperature. With a timer or manual control there's a real possibility of the HWC drawing at full power (from the grid) for any shading related generation troughs. We see this activity with the EVSE we use for our Leaf but at least we have the option of choosing only clear days, or night rate charging scheduling, in this case.

https://www.harmlesssolutions.co.nz/

timmmay

20575 posts

Uber Geek

Trusted

Lifetime subscriber

#3349089 1-Mar-2025 22:26

I understand, and I understand the benefit. My only concern is around the payback period, $1500 or more buys a lot of power.

Our power cost will be 21c anytime, buyback 17c, they're so close I'm not really too concerned about using grid power or exporting more.

HarmLessSolutions

969 posts

Ultimate Geek

Subscriber

#3349090 1-Mar-2025 22:34

timmmay:

I understand, and I understand the benefit. My only concern is around the payback period, $1500 or more buys a lot of power.

Our power cost will be 21c anytime, buyback 17c, they're so close I'm not really too concerned about using grid power or exporting more.

Fair reasoning and on those numbers it's also hard to justify the cost of batteries except for the blackout resilience aspect. Our peak rate is 37c and shoulder 30c vs 18.5c night and 17c FIT so avoiding HWC draw in the mornings is far more of a concern.

In our case we prioritise self consumption which boosts our ROI and limits the benefits of a battery.

https://www.harmlesssolutions.co.nz/

timmmay

20575 posts

Uber Geek

Trusted

Lifetime subscriber

#3349093 1-Mar-2025 22:45

Yeah we're not doing battery. They're easy to add later if we decide we want one. We get about one blackout a year, might be good for disaster prep but that may be a step too far even for me. A generator possibly cheaper, though less useful generally.

wired

187 posts

Master Geek

#3349144 2-Mar-2025 08:48

The economics of having batteries could change next year. The government is wanting to get the distribution companies to rebate customers who feed into the grid during high demand periods, so that will make batteries more desirable.

The Electricity Authority has a consultation paper active with feedback due at the end of the month, with possible implementation 1 April 2026.

Consultation Paper

It may not be enough of a rebate to make it economical but it could certainly help.

timmmay

20575 posts

Uber Geek

Trusted

Lifetime subscriber

#3349156 2-Mar-2025 09:58

If it's a good subsidy we might go for it. We wouldn't pay much though, we just won't get much benefit, and using it to prop up the grid it will probably charge / discharge often which can wear batteries out more quickly.

timmmay

20575 posts

Uber Geek

Trusted

Lifetime subscriber

#3349157 2-Mar-2025 10:03

Has anyone heard of "Sun Stash" solar diverter? Found it on Perplexity. It apparently supports home assistant which is a bonus. The case is somewhat ugly, I wonder if it can go into the ceiling cavity or if it would overheat.

Nothelen

2 posts

Wannabe Geek

#3349680 3-Mar-2025 16:56

Hi all.

I am a Nissan Leaf driver and have a spare battery I was looking to use in a home solar situation.

I found Dala's site informative but have trouble equating that to the NZ environment.

So, is it at all possible to have a roof load of Solar Panels and go off-grid in NZ ?

What about repurposing a Leaf battery and what Inverter options could come into play ?

Dala seems to be recommending a Fronius Gen24 Plus but I have doubts that works with an off-grid setup.

Grid-tie could be an option but only as a last resort.

Lastly, how much of a nightmare would NZ certification be ?

fastbike

212 posts

Master Geek

#3349685 3-Mar-2025 16:59

Nothelen:

I found Dala's site informative but have trouble equating that to the NZ environment.

Head over to his discord server where much of what you are asking is being discussed. Plenty of kiwis there too.

Otautahi Christchurch

eonsim

398 posts

Ultimate Geek

Trusted

#3349766 3-Mar-2025 22:42

timmmay:

Do these parts look reasonable to control hot water cylinder from home assistant, so I can have the hot water cylinder heating when there's sufficient solar power available? Any better ideas?

Shelly Pro 1 Relay. I'd have liked the Pro1 PM for power monitoring but I think it will burn out after a year or two with 3kw going through it even though it's within spec, hence the contactor.
Siemens contactor - SENTRON 5TT INSTA Contactor, 230 V ac Coil, 2-Pole, 20 A, 2NO
ABB 1P Pole 40A Isolator Switch - so that if the Shelly / contactor fails closed we can manually turn the hot water cylinder on
My solar installer says this is simple for them to install.

I'd still like to be able to measure the energy used by the hot water cylinder, ideally in a way that isn't able to burn out. I don't really need to do this, I'd just like to, to get it into the Home Assistant energy dashboard.

Oddly enough, the https://www.smarthome.com.au/ website works fine when you're not logged in, but if you register and log in I get http 500 errors on every page. If you then log in again on a new browser it works ok. That's a weird bug.

Shelly EM will give you the contractor control plus allow monitoring of one or more circuits depending on which model.

timmmay

20575 posts

Uber Geek

Trusted

Lifetime subscriber

#3349805 4-Mar-2025 06:57

eonsim:

timmmay:

Do these parts look reasonable to control hot water cylinder from home assistant, so I can have the hot water cylinder heating when there's sufficient solar power available? Any better ideas?

Shelly Pro 1 Relay. I'd have liked the Pro1 PM for power monitoring but I think it will burn out after a year or two with 3kw going through it even though it's within spec, hence the contactor.
Siemens contactor - SENTRON 5TT INSTA Contactor, 230 V ac Coil, 2-Pole, 20 A, 2NO
ABB 1P Pole 40A Isolator Switch - so that if the Shelly / contactor fails closed we can manually turn the hot water cylinder on
My solar installer says this is simple for them to install.

I'd still like to be able to measure the energy used by the hot water cylinder, ideally in a way that isn't able to burn out. I don't really need to do this, I'd just like to, to get it into the Home Assistant energy dashboard.

Oddly enough, the https://www.smarthome.com.au/ website works fine when you're not logged in, but if you register and log in I get http 500 errors on every page. If you then log in again on a new browser it works ok. That's a weird bug.

Shelly EM will give you the contractor control plus allow monitoring of one or more circuits depending on which model.

@eonsim which model can do that without burning out? I've seen a few pictures of them failing after switching high loads for a year or two. I'd want the monitoring to not be inline, maybe using a clamp around the cable to monitor.

Any suggestions? I ordered the 1 Pro last night but I'm considering cancelling and getting one that can control two circuits just in case I want another in future.

fastbike

212 posts

Master Geek

#3349808 4-Mar-2025 07:14

timmmay:

@eonsim which model can do that without burning out? I've seen a few pictures of them failing after switching high loads for a year or two. I'd want the monitoring to not be inline, maybe using a clamp around the cable to monitor.

Any suggestions? I ordered the 1 Pro last night but I'm considering cancelling and getting one that can control two circuits just in case I want another in future.

I use iammeter for monitoring a heat pump. Grenz Electrical can supply/fit or there is a web store. They have single phase or you can use the three phase to monitor three different loads in a single phase home.
https://store.iammeter.com/wem3080-150a

Otautahi Christchurch

eonsim

398 posts

Ultimate Geek

Trusted

#3349809 4-Mar-2025 07:19

timmmay:

eonsim:

timmmay:

Do these parts look reasonable to control hot water cylinder from home assistant, so I can have the hot water cylinder heating when there's sufficient solar power available? Any better ideas?

Shelly Pro 1 Relay. I'd have liked the Pro1 PM for power monitoring but I think it will burn out after a year or two with 3kw going through it even though it's within spec, hence the contactor.
Siemens contactor - SENTRON 5TT INSTA Contactor, 230 V ac Coil, 2-Pole, 20 A, 2NO
ABB 1P Pole 40A Isolator Switch - so that if the Shelly / contactor fails closed we can manually turn the hot water cylinder on
My solar installer says this is simple for them to install.

I'd still like to be able to measure the energy used by the hot water cylinder, ideally in a way that isn't able to burn out. I don't really need to do this, I'd just like to, to get it into the Home Assistant energy dashboard.

Oddly enough, the https://www.smarthome.com.au/ website works fine when you're not logged in, but if you register and log in I get http 500 errors on every page. If you then log in again on a new browser it works ok. That's a weird bug.

Shelly EM will give you the contractor control plus allow monitoring of one or more circuits depending on which model.

@eonsim which model can do that without burning out? I've seen a few pictures of them failing after switching high loads for a year or two. I'd want the monitoring to not be inline, maybe using a clamp around the cable to monitor.

Any suggestions? I ordered the 1 Pro last night but I'm considering cancelling and getting one that can control two circuits just in case I want another in future.

Shelly pro em 50, it had two cable clamps and can monitor two circuits and has a 5a relay that can control a contractor. You connect the em relay to the contractors control circuit and then use a clamp to monitor the contractor load cable. then you have a second clamp you can monitor some other load.

https://www.shelly.com/products/shelly-pro-em-50

It's available in nz at a higher price so will have a standards approval for nz. https://www.lykalyte.co.nz/products/shelly-pro-em-50

1 | ... | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | ... | 98