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rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 796
Posted: 04:42am 16 Apr 2024
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I'm slowly exploring the limits. Living dangerously.
Yesterday we had two segments of underfloor heating running (6,000w total) along with the normal house load for 4 and a half hours ... then turned half off and ran the other for an extra hour.
Seemed to handle it okay. The electronics stayed cool ... just a few degrees above ambient, but the larger two toroids started to warm up to around 50C ... so turned on a pedestal fan which brought them back down to lower 40's. I need to fit the barrel fan I have planned.
Today I'm running both heaters again and I happened to spot the total load right up at 9,663 watts at one stage. Gulp!!
The load pulled the output voltage down to 225.9v at the inverter ... and lower again up in the house at the heater connections ... so it's time to fit the "feed forward current correction" that Klaus used.
I have the current transformer on the input bus, so just need to find/work-out the rest of the process.
Along with the nicely coloured power meter, I have a basic wifi one which enables me to keep an eye on loads without having to head out to the inverter. Here's a screenshot of the biggest load so far.
Cheers, Roger
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 796
Posted: 10:14am 25 Apr 2024
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The Warpverter is still going strong and behaving itself ... and has clocked up 1,616kWh so far.
I picked up another batch of panels, rails and a 5kW Growatt GTI from Marketplace last weekend. 15 x 440w Jinko panels for an extra 6.6kW. It cost me $1,000 but I had to remove them from the house which is slated for demolition.
I've leaned them up against the north facing wall of the shed and fed them in two strings into the GTI. They are all clamped together with a rail all the way through and all the bottoms clamped together ... then tied to the shed.
It was time to jump into ac-coupling so I hooked it up and turned it on ... and stood back. It all seemed to go smoothly and very slowly started to ramp up ... and as its output rose, the Warpverters dropped correspondingly. Was exciting to watch.
One thing I haven't mentioned is that at times the normally quiet hum of the Warpverter would turn into a 4 or 5 times louder rattle/growl ... and I spent ages trying to work out if it was heat or load related. It was always quiet again in the morning but many evenings it would sound really terrible compared to normal.
Anyway I eventually discovered it was my wife's electric blanket. No idea why and I must dismantle the controller and check how it's built. That leads me to explain that this new Growatt GTI has the same effect and any time it is connected and generating any output ... even just a couple watts ... it makes exactly the same noise.
And like with the blanket, when you turn it off, the noise slowly fades away to the normal gentle hum over perhaps 10 seconds.
We've got 19.2kW of panels now. I probably should stop.
24 x 250w = 6kW 24 x 275w = 6.6kW 15 x 440w = 6.6kW
Of course now that I want to see what she'll do, the weather has been very uncooperative ... though I did have a period where it was very impressive. I had both lots of underfloor heating turned on (6kW) plus the normal household load 1-2kW.
The GTI was maxed out and providing 5,012w, the Warpverter 2,236w ... but there was still 170 amps going into the battery!!!
There were times though when the sun disappeared that the battery was providing as much as 90 amps for periods of time ... but overall it all kept up.
Today was similar weather but I had the heating on again and an additional 1kW heater and it all ran from 9 this morning until 3.45pm till I switched the underfloor heating off.
The Growatt says it's produced 25kWh today and the Warpverter is up to 30.75 so far. The best part is the wife isn't complaining about the cold ... and I haven't had to do the wood fire thing yet.
Cheers, Roger
KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1358
Posted: 09:58pm 25 Apr 2024
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It's all too hard. Mike.
Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 583
Posted: 08:44am 26 Apr 2024
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Great idea with those solar panels, I assume they face North? Easy to clean too .
Your power demands are incredible compared to mine, glad that your wife is happy running on solar.
I had warpverter growling at times when I was AC back charging, never figured out why, thought it may be one of the chokes I had in it. But it had more serious problems, good to know that yours runs as expected .
That's a good size shed, no chance I could have one like that on my 645 sq m suburban block .
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 796
Posted: 12:12pm 26 Apr 2024
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Thanks Mike and Klaus
Yes it faces directly north ... very convenient layout. I was being lazy I suppose but the inverter is only a couple metres inside the shed from the right hand end of the panels, so it certainly saves in cable too.
We've always been very frugal with our power use because of the cost but with the potential for free power I'm getting a bit carried away. And after years of chasing firewood for heating, I'm a bit over it ... so if I can use what's there for heating as well I'll be very happy.
It is a shame the ac coupling makes it noisier but because it's in the shed and a long way from the living area it's no issue ... and the benefits far outweigh the nuisance value. The part of the shed to the right is my workshop where I work, but it's sectioned off and insulated so it doesn't bother me in there either fortunately.
I can hear it with the door open, but it's normally closed anyway.
The sheds are what sold me on the property when we bought it. The wife loved the house and I loved the sheds, so was an easy decision. It cost a bit to enclose the workshop area but is a great work space. And we have an upstairs section above it for storage. I guess it's one advantage of living in a regional area ... a bit more space. Cheers, Roger
KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1358
Posted: 06:31am 27 Apr 2024
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Hi Roger, I have 20 x 480W panels and they are amazing - added to the rest of the solar, it can get us through weeks of overcast rainy weather, providing we take steps to conserve power usage after early afternoon - by that I mean the big oven and larger hot plates. A medium size air-fry oven is handy then, or the occasional small gas bottle and portable stove, but everything else is pretty much normal use.
Even the Air-Con can be run all night and day, I realized years ago that the only to have efficient Air-Con is to have small split inverters (with eco mode) in each room that needed to be kept cool/warm, and only use one at a time, as there are only two of us that works, and cool does not mean stupid cold and warm is not stupid hot, seriously, the things I see people do and then complain about the power bill or usage - absolutely clueless about what it really means to run off OR on grid efficiently.
This is also a small suburban block like Klaus, but I have a heavy duty 6 x 9 shed, and a solid 6 x 6 carport, I still have one side of the 6 x 9 shed roof clear, it's facing south but that makes zero difference with over cast rainy condition, and extra panels for bad conditions don't care much about angle, actually they seem to like almost no angle in overcast dim rainy conditions, but that can create other problems it you don't keep an eye on them.
Love the big sheds you have. My new motto - you can't have too much solar or big enough shed. It's all too hard. Mike.
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 796
Posted: 01:14pm 27 Apr 2024
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Thanks Mike. Having these nice 440W panels makes me wish I'd chased bigger ones earlier. I have virtually filled that side of the roof now and would hate to have to undo all the work and fit bigger ones ... so I think they'll stay and I'll find somewhere else if I end up with more.
There's still 40 metres of fence in line with that shed wall ... so I could start filling that too. Haha
I'm still learning the ropes and have probably hung on too long with the heaters ... so by the time I turn them off the battery doesn't have time to recover as much as it needs. I'll get the hang of it eventually and then try and automate it somewhat.
One of our problems is that the house is very open so it is hard to divide off and just heat or cool one area ... plus there's five of us here and that's harder again.
Our air heater is still performing well but it will make a huge difference to have the big new one on the roof. Still have to finish it but am actively working on it again now that the solar is getting there.
I do enjoy the space here but can see the advantages of a small block. Wouldn't need a tractor and slasher and rideon and all the other work involved in maintaining a large block. Maybe eventually we'll downsize ... though shifting that Warpverter would be a major undertaking. Perhaps we'll subdivide and just keep the house and sheds.
I never expected to be able to run electric heating with solar but seeing we have plenty of space ... and panels are cheap enough if you keep an eye out ... it may be perfectly feasible for several months of the year. And the money saved from power bills can pay for new batches of panels.
I do know a guy online who has lots of panels (cheap secondhand) and several inverters and a heap of forklift batteries who runs an all electric house with three ovens and a jacuzzi on his system. Crazy.Cheers, Roger
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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