Generator or Inverter for residential use?

vassen

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Dec 12, 2006
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I
The last two unbearably cloudless days has had some positives as far as generation went. New record today, albeit very slight. I look set for a very low Eskom bill for the month though, so there’s at least that.

View attachment 999092
really envy you people that can feed back. Most I got to was 33.3kwh.
 

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vassen

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That’s very impressive actually, considering you not feeding back
Yeah. I’m sure id be able to get to 40 on a clear day, if I increase loads further. But probably won’t be able to test. Going to get rid of my microinverter and getting another 5kw in parallel. Got a really good deal of just under R18500 for the 5kw.
 

gbyleveldt

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Yeah. I’m sure id be able to get to 40 on a clear day, if I increase loads further. But probably won’t be able to test. Going to get rid of my microinverter and getting another 5kw in parallel. Got a really good deal of just under R18500 for the 5kw.
Ah, the joys of Sunsynk. I’m stuck at 5kW on my Goodwe. That being said, I genuinely have no need for more; I very seldom hit 3kW on the backup side with the system running since August.

That is a smashing deal on the inverter though
 

vassen

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Ah, the joys of Sunsynk. I’m stuck at 5kW on my Goodwe. That being said, I genuinely have no need for more; I very seldom hit 3kW on the backup side with the system running since August.

That is a smashing deal on the inverter though
Yip a deal I couldn’t resist. :sneaky:
The excess is more a nice to have for me. But main reason is the extra mppt.
The microinverter is not really working out and sunsynk has basically said they can’t really do anything cos it’s not their product. So now I enable it in the mornings and disable once my battery reaches 90% otherwise I end up feeding in... which I guess I’m getting charged for. So found a tentative buyer for my microinverter, which means the sunsynk actually ends up costing me even less.

I must admit the microinverter is a decent product. For a lot of the day, it just sits at 1200w production. For a grid tie solution, it would work really well. No long dc cables to worry about.
 

signates

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Yip a deal I couldn’t resist. :sneaky:
The excess is more a nice to have for me. But main reason is the extra mppt.
The microinverter is not really working out and sunsynk has basically said they can’t really do anything cos it’s not their product. So now I enable it in the mornings and disable once my battery reaches 90% otherwise I end up feeding in... which I guess I’m getting charged for. So found a tentative buyer for my microinverter, which means the sunsynk actually ends up costing me even less.

I must admit the microinverter is a decent product. For a lot of the day, it just sits at 1200w production. For a grid tie solution, it would work really well. No long dc cables to worry about.
That's a very good price on the 5kw.

My summer consumption is about 20% more than winter due to aircons running most days and every night. Average consumption is 60kwh per day in January compared to 45kwh in September. Working from home also doesn't help. Fireplace is used for heating in winter instead of heaters or aircons. I buy about R3k worth of wood that sees us through winter and for summer braais. Still have about 500 pieces of wood left from the last winter.

Currently looking to source another 6 x 305w Canadian solar panels to add to MPPT 1 but first have another project I want to start next week. This should also help with winter production and would balance my system nicely for winter and summer production.
 

gbyleveldt

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Yip a deal I couldn’t resist. :sneaky:
The excess is more a nice to have for me. But main reason is the extra mppt.
The microinverter is not really working out and sunsynk has basically said they can’t really do anything cos it’s not their product. So now I enable it in the mornings and disable once my battery reaches 90% otherwise I end up feeding in... which I guess I’m getting charged for. So found a tentative buyer for my microinverter, which means the sunsynk actually ends up costing me even less.

I must admit the microinverter is a decent product. For a lot of the day, it just sits at 1200w production. For a grid tie solution, it would work really well. No long dc cables to worry about.

Im curious if such an inverter, hooked up to a geyser with a 1kw element would make any sense? I think it would be a better solution than EV tubes, especially on colder days
 

Sinbad

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Im curious if such an inverter, hooked up to a geyser with a 1kw element would make any sense? I think it would be a better solution than EV tubes, especially on colder days
No it wouldn't.

Evacuated tubes are a much more efficient way of collecting heat, and as they are vacuum filled they do not get affected by air temperature.
Solar panels are only about 20 percent efficient
 

gbyleveldt

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No it wouldn't.

Evacuated tubes are a much more efficient way of collecting heat, and as they are vacuum filled they do not get affected by air temperature.
Solar panels are only about 20 percent efficient
Yeah I get that EV is more efficient at converting IR radiation to heat than PV. But I still needs heat to, well heat. PV doesn’t need IR to generate electricity; it can be a cold day but beautiful weather (think winter, when you want a hot geyser) and it’ll run at over 100% of its designed generation.

We have EV tubes installed and it works brilliant in summer, but not so much in winter (when you actually prefer warmer water). Even on a cloudy winter day the PV system will at least generate some power where the EV system doesn’t do anything.

Just an observation I made having both systems installed and made me curious. Again, I agree EV is more efficient but I think it’s moot when considering real world use in practice. Itll be interesting as an experiment
 

vassen

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That's a very good price on the 5kw.

My summer consumption is about 20% more than winter due to aircons running most days and every night. Average consumption is 60kwh per day in January compared to 45kwh in September. Working from home also doesn't help. Fireplace is used for heating in winter instead of heaters or aircons. I buy about R3k worth of wood that sees us through winter and for summer braais. Still have about 500 pieces of wood left from the last winter.

Currently looking to source another 6 x 305w Canadian solar panels to add to MPPT 1 but first have another project I want to start next week. This should also help with winter production and would balance my system nicely for winter and summer production.
I tend to use more in winter. Cooling doesn’t require as much power as for heating. Don’t have a fireplace so just use the aircons.

still need to try to figure out a way to use hot water for space heating. Then I can reduce my winter bill a bit. My last eskom bill came in at just under R400 mainly due to a few very cloudy days.

I saw someone was selling for second hand new panels on PF classifieds. Not sure if it’s still available.
 

vassen

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No it wouldn't.

Evacuated tubes are a much more efficient way of collecting heat, and as they are vacuum filled they do not get affected by air temperature.
Solar panels are only about 20 percent efficient
I tend to disagree.
On cloudy days, my evacuated tubes do nothing much to raise the temperature of water in the geyser. Maybe increases by 3-5 degrees over the day. I have a sonoff th16 in there so can actually see the changes over the day.
My 6.5kwp solar array on the other hand still gives me between 2 to 2.5kw during such conditions.

Over the last winter, the evacuated tubes would raise the water at most 20-25 degrees on a clear day. That’s around 4.6 - 5.8kwh of energy.
I’ve said many times that if I would do it again, I would just add the extra storage tank and add more panels instead of the evacuated tubes.

I also then would have to worry about water getting too hot when I go away for a few days or even like today where I had to go cover the tubes as the water was already at 80 degrees at lunch time.

Obviously, if one doesn’t have an inverter / solar pv, then the argument is totally different and evacuated tubes are better.
 

vassen

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Itll be interesting as an experiment
After the last winter of not getting enough hot water through the ev tubes, I then added the electrical element controlled with the sonoff+relay. It’s still connected on the non essential side so now if my batteries are full, I just turn the 2kw element on. This works a lot better for me.
 

Sinbad

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I tend to disagree.
On cloudy days, my evacuated tubes do nothing much to raise the temperature of water in the geyser. Maybe increases by 3-5 degrees over the day. I have a sonoff th16 in there so can actually see the changes over the day.
My 6.5kwp solar array on the other hand still gives me between 2 to 2.5kw during such conditions.

Over the last winter, the evacuated tubes would raise the water at most 20-25 degrees on a clear day. That’s around 4.6 - 5.8kwh of energy.
I’ve said many times that if I would do it again, I would just add the extra storage tank and add more panels instead of the evacuated tubes.

I also then would have to worry about water getting too hot when I go away for a few days or even like today where I had to go cover the tubes as the water was already at 80 degrees at lunch time.

Obviously, if one doesn’t have an inverter / solar pv, then the argument is totally different and evacuated tubes are better.
Interesting. When it was cloudy my 3.3kwp system dropped down to a couple of hundred watts
 

vassen

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Interesting. When it was cloudy my 3.3kwp system dropped down to a couple of hundred watts
The only time mine drops to less than 300w is if it’s rainy or really dark clouds. For light clouds it’s still decent production
 

calypso

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A friend of mine has just chucked out all of his flat-plate collectors to put up more PV panels as roof space is limited and making more electricity is more important than making hot water. He did the maths and that worked out for him. I've been thinking for a while, the high price of Tubes/Flat plate and the lowering price of solar panels, soon it won't make any sense to go Tubes/Flat plates.
 

Sinbad

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The only time mine drops to less than 300w is if it’s rainy or really dark clouds. For light clouds it’s still decent production
What type of panels do you have?
Mine were JASolar poly
 

vassen

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What type of panels do you have?
Mine were JASolar poly
6x 420w Canadians poly facing north
8x 390w JA mono facing west
4x 365w Canadians east facing on 1200w micro inverter.

i guess it also depends on the inverter mppt. I know a few people that are getting more power with the sunsynk compared to axperts and 1 that’s getting more than with victron. :ROFL: I don’t want to cause WW3... just what people tell me.

With me, I get around 90% of the rated power at peak
 
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