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Si_Oakwood

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Hi all,

I'm not an electrician, software engineer actually. Mostly here to learn about Solar PV and hopefully exchange info, especially anyone with Growatt experience. Currently a novice at Solar PV but hoping to pick it up as I get more into it.

Have just had x14 450w Longhi Solar panels (7 East/7 West), a Growatt Hybrid SPH 3600 Invertor and x2 3.3kWh batteries installed about a month ago. Waiting for them to fix the west facing panels (suspected faulty panel, so Solar stops around 6pm) but rest is working well. Added timers to dual fuel Towel Rail and Cylinder immersion heater to maximise solar/battery usage, and we are already barely drawing from the grid (it is July).

Next step will be to decide what to do about central heating, ASHP or electric boiler seem decent options (currently standard gas boiler).

Cheers
Si
 

binky

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Hi all,

I'm not an electrician, software engineer actually. Mostly here to learn about Solar PV and hopefully exchange info, especially anyone with Growatt experience. Currently a novice at Solar PV but hoping to pick it up as I get more into it.

Have just had x14 450w Longhi Solar panels (7 East/7 West), a Growatt Hybrid SPH 3600 Invertor and x2 3.3kWh batteries installed about a month ago. Waiting for them to fix the west facing panels (suspected faulty panel, so Solar stops around 6pm) but rest is working well. Added timers to dual fuel Towel Rail and Cylinder immersion heater to maximise solar/battery usage, and we are already barely drawing from the grid (it is July).

Next step will be to decide what to do about central heating, ASHP or electric boiler seem decent options (currently standard gas boiler).

Cheers
Si
I wouldnt change your heating until forced to. The unfortunate truth about solar is winter outputs are not sufficient to meet heating demands
 

Geoff1946

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Unless your boiler is really ancient or becoming unreliable I would leave it alone. You are going to want to buy in energy in winter and whilst no-one knows how the pricing is going to be in the coming months/years I think gas will still be way cheaper than electricity.
It could also be more reliable because it can't be easily turned off like electricity can in event of energy rationing. I'm presently considering buying an invertor and a leisure battery so that I can run my gas boiler through any power cuts.
 
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As above, don't go electric heating.
If anything, and this is only a suggestion as you are a software exgineer, install some suplementary electric heaters. Then setup home assistant (on a rasperry pi). Then figure out a way to get talk to your stuff and also read amount of energy currently being imported/exported. Then create some sort of priority setup in home assistant to switch the load (heaters) on dependant on surplus juice. Oh, and you would need some sort of smart plugs or relays (running tasmota seems to be the popular way to integrate them into home assistant. These would be the remote switches for the heaters.

I'm just playing with this myself, but my setup is a little simpler as I only have Solar as it stands, no battery. So far got an ESP8266 reading data from my inverter (Samil Power) and sending to MQTT server (also running on my raspberry pi). And I have an OB115 CT meter reading the import / export data. Another ESP8266 module connects to this meter via MOD BUS and also sends that data to the MQTT server. Still early days but it gives me something to play with. I think Home Assistant have a direct integration for Growatt stuff. Not 100% what is supprts though. I had to figure out reading my inverter the hard way. A serial port sniffer and running the desktop app / monitor. Was a right pain to figure out.

Waffling now, sorry.
 

Si_Oakwood

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hey all, thanks for the excellent replies, info and advice, very helpful, and all gratefully received.

I'll wait a bit and see what the winter readings are like. We are on economy 7 and so another option could be ceramic/storage heaters. The theory/long-term goal is we become gas-free, actually have it disconnected and then avoid the gas standing charge too.

Also yes gas is cheaper for heating atm, so not rushing into this. Although it's possible with the better elec boiler efficiency and if gas continues to go up faster than elec then it may be financially viable at some point (especially with econ 7). But that's a lot of if's lol.

and thanks @Barx for the raspberry pi / home assistant idea, will look into that too. (y)
 

Gian

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Hi all,

I'm not an electrician, software engineer actually. Mostly here to learn about Solar PV and hopefully exchange info, especially anyone with Growatt experience. Currently a novice at Solar PV but hoping to pick it up as I get more into it.

Have just had x14 450w Longhi Solar panels (7 East/7 West), a Growatt Hybrid SPH 3600 Invertor and x2 3.3kWh batteries installed about a month ago. Waiting for them to fix the west facing panels (suspected faulty panel, so Solar stops around 6pm) but rest is working well. Added timers to dual fuel Towel Rail and Cylinder immersion heater to maximise solar/battery usage, and we are already barely drawing from the grid (it is July).

Next step will be to decide what to do about central heating, ASHP or electric boiler seem decent options (currently standard gas boiler).

Cheers
Si
I would keep hold of your old boiler , your system will drain those battery's running a heat pump. I have battery's and when you have loads the battery does not last well. I would possibly look at working both electric and gas together. I have decided for myself not to dump my gas boiler but to replace it and keep a newer one working in conjunction with a heat pump. I personally do not want all my eggs in one basket. My decision is based on where I live and the power cuts we have. If I had an heat pump I would have not been able to heat my home in winter with my 4.5 KW gererator. But I can with gas so we can still cook heat home and have hot water. I am upgrading my Genny to a 10kw so I can charge my electric vehicles. Even with a 10kw Genny I would not be able to run my electric shower whilst charging car. It's all good now but another 5 years time problems will arrise as more people will be on all electric and our network cannot deal with all those new loads. You all may be reading this and thinking what a load of crap, but I live rural and my last power outage was a 3 day outage. I had heating ,hot water and cooked. All on a 4.5 KW Genny. If I had all electric and heat pump I would not have been able to do this. The only reason I am using to a 10kw Genny is for the electric vehicles. With every home adding a heat pump and ev charger loads will be higher and this will affect even built up areas .
 

Si_Oakwood

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I would keep hold of your old boiler , your system will drain those battery's running a heat pump. I have battery's and when you have loads the battery does not last well. I would possibly look at working both electric and gas together. I have decided for myself not to dump my gas boiler but to replace it and keep a newer one working in conjunction with a heat pump. I personally do not want all my eggs in one basket. My decision is based on where I live and the power cuts we have. If I had an heat pump I would have not been able to heat my home in winter with my 4.5 KW gererator. But I can with gas so we can still cook heat home and have hot water. I am upgrading my Genny to a 10kw so I can charge my electric vehicles. Even with a 10kw Genny I would not be able to run my electric shower whilst charging car. It's all good now but another 5 years time problems will arrise as more people will be on all electric and our network cannot deal with all those new loads. You all may be reading this and thinking what a load of crap, but I live rural and my last power outage was a 3 day outage. I had heating ,hot water and cooked. All on a 4.5 KW Genny. If I had all electric and heat pump I would not have been able to do this. The only reason I am using to a 10kw Genny is for the electric vehicles. With every home adding a heat pump and ev charger loads will be higher and this will affect even built up areas .
totally agree thanks @Gian
I think I'll keep as many options open as possible for now, especially as it's so new to me at the moment.
 

BorisJ

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Although it's possible with the better elec boiler efficiency and if gas continues to go up faster than elec then it may be financially viable at some point (especially with econ 7).
All electric heaters or boilers are 100% efficient. All the electrical energy is turned into heat and there is no chimney to lose any. So you can’t get better electric boiler efficiency.

Heat pumps of course are another thing.
 

binky

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hey all, thanks for the excellent replies, info and advice, very helpful, and all gratefully received.

I'll wait a bit and see what the winter readings are like. We are on economy 7 and so another option could be ceramic/storage heaters. The theory/long-term goal is we become gas-free, actually have it disconnected and then avoid the gas standing charge too.

Also yes gas is cheaper for heating atm, so not rushing into this. Although it's possible with the better elec boiler efficiency and if gas continues to go up faster than elec then it may be financially viable at some point (especially with econ 7). But that's a lot of if's lol.

and thanks @Barx for the raspberry pi / home assistant idea, will look into that too. (y)
I believe Elnur are now selling a solar night storage heater, which might be of interest. I use a Solic 200 to direct spare leccy to my underfloor heating in my kitchen. Anything that puts heat into your house will reduce the amount of gas you need to burn.
 

Si_Oakwood

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Back panels all working now, lovely sunny day yesterday and virtually no elec or gas drawn from grid all day. Battery was fully charged by 9am. Sadly don't have a smart meter yet (or MCS certificate) so the light blue is everything we gave to the grid for free.

chart.png
 
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