ArthurDent Posted April 24, 2020 Share Posted April 24, 2020 2 hours ago, Addicted to music said: Biggest benefits of Enphase micro inverters for places that have shade issue. There is also a safety benefit to convert DC to AC at the panel. Safer to have AC routes than HVDC running everywhere. Yeah, not a fan of having high voltage DC running everywhere. AC is way safer and with less losses. Link to comment Share on other sites More sharing options...
Addicted to music Posted April 24, 2020 Author Share Posted April 24, 2020 On 21/04/2020 at 11:18 AM, rmpfyf said: Solahart Powerstore - no pumps, thermostats, water on roof, nothing. No flames, no gas piping. Higher efficiency, more energy. You'd love it. Had that quoted today, it isn’t exactly cheap, $5k is a lot of money! Fully installed with all the power management and monitoring set! However if anyone wanna go down this route definitely see if you can have this priced in with panels installed.... I’d like the idea of excess FIT being used on site and be able to managed what the system is capable of. Link to comment Share on other sites More sharing options...
Addicted to music Posted April 24, 2020 Author Share Posted April 24, 2020 7 minutes ago, ArthurDent said: Yeah, not a fan of having high voltage DC running everywhere. AC is way safer and with less losses. Me neither, High voltage DC is scary stuff, it puts demand on the quality of connections and installation, then there’s inspections.... if you ever seen 7KV -10kV on a high voltage wire in the dark? There’s a purple halo around the wire, and the distances required to stop arcing is critical, I’ve seen leaks through solid insulation at that voltage, not that you’ll see that up to 1000VDC.... for a PV.. i did have an Enphase quote but ended up ditching it, as you can see it wouldn’t have benefited cost wise as I have no shade issues....apart from that evaporative unit.... 1 Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted April 24, 2020 Share Posted April 24, 2020 3 hours ago, Addicted to music said: Biggest benefits of Enphase micro inverters for places that have shade issue. There is also a safety benefit to convert DC to AC at the panel. Safer to have AC routes than HVDC running everywhere. That's a fallacy - why is it safer? Link to comment Share on other sites More sharing options...
ArthurDent Posted April 24, 2020 Share Posted April 24, 2020 29 minutes ago, rmpfyf said: That's a fallacy - why is it safer? When was the last time you saw a AC isolator switch catch fire or an arc fault on an AC system. https://memberarea.necawa.asn.au/Admin/ViewContentPage?uniqueName=fires-from-rooftop-mounted-dc-isolators-on-solar-systems http://www.acsolarwarehouse.com/news/solar-fires-dc-arc-faults-on-solar-systems/ https://www.solarquotes.com.au/blog/rooftop-dc-isolator-mb1097/ https://www.communityrun.org/petitions/remove-the-solar-dc-isolator-from-the-roof 1 Link to comment Share on other sites More sharing options...
Addicted to music Posted April 24, 2020 Author Share Posted April 24, 2020 (edited) 26 minutes ago, ArthurDent said: When was the last time you saw a AC isolator switch catch fire or an arc fault on an AC system. https://memberarea.necawa.asn.au/Admin/ViewContentPage?uniqueName=fires-from-rooftop-mounted-dc-isolators-on-solar-systems http://www.acsolarwarehouse.com/news/solar-fires-dc-arc-faults-on-solar-systems/ https://www.solarquotes.com.au/blog/rooftop-dc-isolator-mb1097/ https://www.communityrun.org/petitions/remove-the-solar-dc-isolator-from-the-roof DC isolators were the issue. There were severe manufacturing defaults that required recalls... Also we are the only place in the world to put an isolator close to the panels and we are the only country in the world to suffer from fires with PV caused by faulty DC isolators. There is a lobby trying to have these removed to minimised the possibility of a fault..... I actually put a lot of these links in another thread on solar for the host, Edited April 24, 2020 by Addicted to music 1 Link to comment Share on other sites More sharing options...
Addicted to music Posted April 24, 2020 Author Share Posted April 24, 2020 (edited) edited Edited April 24, 2020 by Addicted to music Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted April 24, 2020 Share Posted April 24, 2020 23 minutes ago, ArthurDent said: When was the last time you saw a AC isolator switch catch fire or an arc fault on an AC system. https://memberarea.necawa.asn.au/Admin/ViewContentPage?uniqueName=fires-from-rooftop-mounted-dc-isolators-on-solar-systems http://www.acsolarwarehouse.com/news/solar-fires-dc-arc-faults-on-solar-systems/ https://www.solarquotes.com.au/blog/rooftop-dc-isolator-mb1097/ https://www.communityrun.org/petitions/remove-the-solar-dc-isolator-from-the-roof Great, so you've pointed out a problem with DC isolators, not with DC. Arc fault protection is a known thing. Australia might not have standards to suit but many countries do, and firmware is duly implemented. Again - why is AC safer in rooftop PV? Not having a specific go at you though this one gets used a lot by microinverter types and it's not quite correct. System safety is a function of risks and controls. If risks are known and controls are properly implemented, appropriate and/or equivalent levels of safety can be reached. Link to comment Share on other sites More sharing options...
Addicted to music Posted April 24, 2020 Author Share Posted April 24, 2020 4 minutes ago, rmpfyf said: Great, so you've pointed out a problem with DC isolators, not with DC. DC is harder to switch, it’s self explanatory on the links... whether it’s DC isolators or DC itself it doesn’t matter, the reality is that we are in DC domain... 11 minutes ago, rmpfyf said: Not having a specific go at you though this one gets used a lot by microinverter types and it's not quite correct. System safety is a function of risks and controls. If risks are known and controls are properly implemented, appropriate and/or equivalent levels of safety can be reached. Eliminate the risk by not implementing the system and you have no need for controls..... simple... 1 Link to comment Share on other sites More sharing options...
ArthurDent Posted April 24, 2020 Share Posted April 24, 2020 (edited) The other advantage of AC systems which could also be considered a safety issue is line losses. Our power grid to our homes is AC for a reason even though that opportunist Edison wrongly went for a DC system with a power plant on every second block. And who knows what these are? Edited April 24, 2020 by ArthurDent 1 Link to comment Share on other sites More sharing options...
Addicted to music Posted April 24, 2020 Author Share Posted April 24, 2020 18 minutes ago, ArthurDent said: The other advantage of AC systems which could also be considered a safety issue is line losses. Our power grid to our homes is AC for a reason even though that opportunist Edison wrongly went for a DC system with a power plant on every second block. And who knows what these are? It’s basically ohms law that applies. Resistance (ohms) increases with distance...hence the losses. . Because of the characteristics of AC, it can be applied to longer distance safer than DC. Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted April 24, 2020 Share Posted April 24, 2020 2 hours ago, Addicted to music said: DC is harder to switch, it’s self explanatory on the links... whether it’s DC isolators or DC itself it doesn’t matter, the reality is that we are in DC domain... Not a safety issue per se. 2 hours ago, Addicted to music said: Eliminate the risk by not implementing the system and you have no need for controls..... simple... You have different risks with AC reticulation, not eliminated risks. If you want to get rid of DC, don't have solar. 1 hour ago, ArthurDent said: The other advantage of AC systems which could also be considered a safety issue is line losses. Not a safety issue and AC is neither immune. No reasonably strung system is likely to suffer line losses of any significance. Link to comment Share on other sites More sharing options...
Addicted to music Posted April 25, 2020 Author Share Posted April 25, 2020 19 hours ago, rmpfyf said: Not a safety issue per se. . If the components are well over rated and care in installation is taken, no, but the possibility is there even all this ticks all the boxes. 19 hours ago, rmpfyf said: You have different risks with AC reticulation, not eliminated risks. If you want to get rid of DC, don't have solar. You eliminate the possibility of DC arcing, not exactly present in AC. HVDC will find its way through well rated insulation in time, I’ve seen it in multiple times in the application I work in. Dont have Solar? Not a possibility for clean energy is it? Single Panels producing 40-60VDC max isn’t an issue.... that’s why microinverters is such a great option. Connecting panels in series where there’s hundreds of DCV become an issue, have those connection run down behind a brick wall with both wires super close together, then you have 2 isolator switches is a real issue, if they end up being discovered “unfit for purpose “ where they are known to to start fires and a recall finally announced, now that’s a real issue. Like I said we are the only country in the world that makes it a requirement to have a isolator next to the panels, we are the only country in the world to suffer multiple PV Solar fires.... No where in the world, even with extreme climates suffer the same rate in PV fires. Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted April 25, 2020 Share Posted April 25, 2020 1 hour ago, Addicted to music said: You eliminate the possibility of DC arcing, not exactly present in AC. HVDC will find its way through well rated insulation in time, I’ve seen it in multiple times in the application I work in. Not a possibility for clean energy is it? Single Panels producing 40-60VDC max isn’t an issue.... that’s why microinverters is such a great option. No offence though this shows a gross misunderstanding of electrical risk. It is not a function of voltage as in 'lower voltage equals lower risk' is incorrect. Many, many industrial accidents arise from this very incorrect assumption. 1 hour ago, Addicted to music said: Connecting panels in series where there’s hundreds of DCV become an issue, have those connection run down behind a brick wall with both wires super close together, then you have 2 isolator switches is a real issue, if they end up being discovered “unfit for purpose “ where they are known to to start fires and a recall finally announced, now that’s a real issue. Like I said we are the only country in the world that makes it a requirement to have a isolator next to the panels, we are the only country in the world to suffer multiple PV Solar fires.... No where in the world, even with extreme climates suffer the same rate in PV fires. Again, that's an isolator problem. And isolators that work do also save lives in making roof work safer. There's no doubt that making a DC isolator fit for purpose is a more robust exercise than same rated current AC. There is no doubt that designing a switch to sit on the roof is not a trivial task. There is no doubt that emergency services hardly ever climb onto the roof and flick the switch. This points to a review of the necessity and specification of DC isolators. It does not mean that microinverters are a 'better' or 'safer' option. Link to comment Share on other sites More sharing options...
Addicted to music Posted February 13, 2021 Author Share Posted February 13, 2021 (edited) Extremely happy with what we have, 20 330 Qcells and a 5kw SMA inverter. We haven’t had a hot summer but when the sun does shine it’s producing better than expected. I wish we were allowed a bigger capacity inverter as it looks like the power from the panels have been capped by the 5kw inverter. And all on 2 sides Nth and west facing. For such a limited system we are achieving 40kwh on a sunny day. Even with $0.10 Feed in we are now profiting. Edited February 13, 2021 by Addicted to music Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted February 13, 2021 Share Posted February 13, 2021 @Addicted to music doesn't look AC limited at all - looks pretty good - probably worth plotting string current over same period if you can Link to comment Share on other sites More sharing options...
sloper Posted February 13, 2021 Share Posted February 13, 2021 Goodaye all Ours system,s best day was 42kw here in Melbourne, with a average summer day being 32kw. 6.6kw of panels into a 5kw invertor. Last year they sent us a $1k cheque and last bill was already in credit of $350 We get a small bill in winter. Paid off in 2 years not the 3.5 l had predicted. Would like a battery but its just not worth it. regards Bruce 2 Link to comment Share on other sites More sharing options...
Addicted to music Posted February 14, 2021 Author Share Posted February 14, 2021 @sloper Right at this time, if you have a electric hot water service the state government is pushing to have old heater element types that taxes you’re electricity use with incentives to install a heat pump type water storage unit simular what @rmpfyf has. It’s limited to the smallest capacity around the 170lt. There are brands with tanks that goes up to 270-330lts max but that’s added costs but well worth if you have a large family. If you’re headed this route it’s better than a battery as it will manage the solar usage and not feed it back to the grid. Excellent idea, the only limitations is the quality of the tanks used. Theres a push from a particular brand that I won’t name here are pushing cheap heat pumps with 130-170lts no out of pocket expense, where a lot of high volume builders are taking up this scheme, just beware that all is not what it seems, the warranty is limited which is the 1st warning signs, the next signs is check and do your research as some are totally unreliable. No good if you spend $4-8k on a system where the tank leaks in a few years. The other issue is not many of these units are out there long enough to prove reliability. If I were to go for one it must have a stainless steel tank that’s maintenance free that can cope with all hardness of water, but that’s just me! My max per day was in e December as you would expect but as you notice we have had sunny days Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted February 14, 2021 Share Posted February 14, 2021 52 minutes ago, Addicted to music said: Right at this time, if you have a electric hot water service the state government is pushing to have old heater element types that taxes you’re electricity use with incentives to install a heat pump type water storage unit simular what @rmpfyf has. I don't have a heat pump, I have an electric hot water tank with built-in high-response diverter, two elements connected to a dedicated HEMS. One of these https://www.solahart.com.au/products/battery-storage/solahart-powerstore/ We now have 17.6kW of PV on 16.4kW of inverter. Maximum generation ever 125kWh/day. Self-consumption favours hot water first, there is very little boosting offpeak and we don't pay for hot water in a net sense. I didn't want a heat pump. Sorry. I've played with a lot before - the Chromagen/Midea units are complete crap - I've had Stiebel Eltron units pack up and replaced them with nicer Glen Dimplex units, there's Sanden and Reclaim (Chofu) out there as well however we're talking about stuff with a lot of moving parts, very little aftersales, noise and poor thermal resistance in the cold. I have zero moving parts in my electric tank and though it's around 3x less efficient, I have a silly amount of PV, low-flow heads and when the tank is full it gets used for other stuff anyway. The only heat pump system I've ever done which I'd recommend are whole-of-house units, literally one big unit that does space heating/cooling and water (Glen Dimplex out of the Euro parts catalogue - very impressive) or LG Electronics (now these are properly in market). You'd be very committed to do one as an add-on though, these are best reserved for new builds. Doing some occasional work for a company developing a nice battery storage system in Australia; I might add a battery next year, might go a third phase of PV Link to comment Share on other sites More sharing options...
Addicted to music Posted February 14, 2021 Author Share Posted February 14, 2021 @rmpfyf your post saids it all and sums it up about the renewable industry. Anything the heats reduces reliability, complicate it with moving parts and you compound the issues, it’s just the nature of beast.... Yep agreed with you on that brand, not very environmentally friendly when you are out laying $4k and it needs to be binned around the 5 yr mark and that’s if it gets to 5yrs... I’ve heard a whole development block with 35 units using the same brand and all the apartments had hot water leaks, change it to something well known and it’s all good..... I think it went to VCAT but still high volume builders will use it, great sales pitch for the bliss young couples/families who wants a new home! I also had your unit priced; $8k so I’m not going there . The figures at that price doesn’t work out! I believe you can get a module that manages the hot water tank if it’s electric for $1k but that’s not in the current State Government incentive.... Right now I’m sticking to something I know that has lasted 30yrs plus; 135lt Aquamax that has a stainless steel maintenance free tank! This is now 3 yrs old, but my parent and my brothers units are still going over 30yrs.. I’m sticking to what I know is reliable.... Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted February 14, 2021 Share Posted February 14, 2021 25 minutes ago, Addicted to music said: @rmpfyf your post saids it all and sums it up about the renewable industry. Anything the heats reduces reliability, complicate it with moving parts and you compound the issues, it’s just the nature of beast.... Yep agreed with you on that brand, not very environmentally friendly when you are out laying $4k and it needs to be binned around the 5 yr mark and that’s if it gets to 5yrs... I’ve heard a whole development block with 35 units using the same brand and all the apartments had hot water leaks, change it to something well known and it’s all good..... I think it went to VCAT but still high volume builders will use it, great sales pitch for the bliss young couples/families who wants a new home! I also had your unit priced; $8k so I’m not going there . The figures at that price doesn’t work out! I believe you can get a module that manages the hot water tank if it’s electric for $1k but that’s not in the current State Government incentive.... Right now I’m sticking to something I know that has lasted 30yrs plus; 135lt Aquamax that has a stainless steel maintenance free tank! This is now 3 yrs old, but my parent and my brothers units are still going over 30yrs.. I’m sticking to what I know is reliable.... $4k sounds exxy, I paid a lot less than that. Think your dealer might be taking you for a ride. Plenty of options out there - Glen Dimplex was selling the Free-E system for around $700 that you could retrofit with ease and works really well. There are others. Your tank has a natural gas appetite, I'm trying to get rid of it. The whole-of-house heat pump units are very, very robust. Have a mate doing 7 thermal zones with one including the pool and domestic hot water on a 10kW PV system, and I don't think he's paid for energy in a good while now. Nor run out of hot or cold anything. Only regret I have with the Powerstore is not getting a second tank and running some hydronic heating with it. Link to comment Share on other sites More sharing options...
Honreekea Posted February 24, 2021 Share Posted February 24, 2021 (edited) On 14/02/2021 at 4:32 PM, rmpfyf said: Only regret I have with the Powerstore is not getting a second tank and running some hydronic heating with it Can you expand upon this...? I haven't been able to google anyone company that combines to two thanks Edited February 24, 2021 by Honreekea Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted February 24, 2021 Share Posted February 24, 2021 10 hours ago, Honreekea said: Can you expand upon this...? I haven't been able to google anyone company that combines to two thanks What do you need to know? Link to comment Share on other sites More sharing options...
Mat-with-one-t Posted February 26, 2021 Share Posted February 26, 2021 A few have alluded to some issues, beyond the obvious ridiculous minefield of mess that is rebate systems (designed by the same people who design the system you navigate to claim on any insurance), which I reckon are really important here. - I think it is really important to consider the embodied energy cost of the gear you are considering. Time and time again, cheap PV solar panels have been shown to output less than advertised, dropping rapidly over a few years, or failing outright. If they have not exceeded their produced energy compared to the energy it took to make them, then they are a burden, not a benefit. Listen to expertise here, read proper reviews including data on testing, and save for the best you can manage. If you can only afford the cheap stuff, it is likely you’re best to save and wait! - I researched and had installed a combined gas hydronic heating system (22 panels) with a combined solar hot water 550lt stainless tank, where the heating can use a heat exchanger in the tank to circulate its hydronic heat. All sounds fine, and make sense to me, but my experience has always been the same. Most (I say most, not all) tradies go into headspins over anything that deviates from routine. I was recommended an installer, and from day 1 he had no clue, then began avoiding the job, then disappeared, then declared bankruptcy. Moral is that, if you’re a researcher like me, you may know more than a supplier!! Do your homework and use a proper expert..... 1 Link to comment Share on other sites More sharing options...
Honreekea Posted February 26, 2021 Share Posted February 26, 2021 On 25/02/2021 at 7:22 AM, rmpfyf said: What do you need to know? thanks for getting back to me. Already have the info I need. cheers Link to comment Share on other sites More sharing options...
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