Geyser timer solution for solar

Splinter said:
This is a good point - but really only applicable when you already have solar I reckon.

If you are starting from ground zero, it might be more cost efficient to go for a heat pump?
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Depends, my solar cost 100k before I added another battery, thats 50% for the heat pump, so dependant on your needs and usage it may be better to spend the admitidely considerable amount extra and do it properly, or enjoy the small win with the heat pump.

My entire house runs on Solar no essential/non-essential with Eskom breaker OFF i.e I do not use eskom at all, the geyser is set to max temp ~70, and runs during the day via automation and stays more than hot enough for the next days usage.

My use case is that of not having a family to cater for.
 
denmendez65 said:
Yeah, for my situation I still have the whole house roof, my 6.5kWp of panels is on the garage roofs. So in my case I would get more panels for 25k. But i think most dont have that luxury so they have to focus on efficiency, especially with water heating. Which is where a Heat pump wins hands down.

Unless you put 10 geysers in series :ROFL:
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3 (750l) in series should be good enough for a few days. If not, you can always add more without breaking the bank.
 
wingnut771 said:
3 (750l) in series should be good enough for a few days. If not, you can always add more without breaking the bank.
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750l? You get those? 2000 litres is better :) . I am hoping to add the element this weekend. So far so good with the test.
 
Lupus said:
I have 9.2 and 15 was a struggle, can't check my history for last month as solar assistant crashed, but I think some days I even had 11
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That's 5, maybe 10, days a year. Those 5 days grid power does its thing. If you had 6kwp more that would've been 10kwh on those low days which would still have essentially covered your water heating.

And then there are 360 other days in the year.
 
denmendez65 said:
750l? You get those? 2000 litres is better :) . I am hoping to add the element this weekend. So far so good with the test.
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I would actually like a 750L geyser, 9am and automation has already turnedt he geyser on, by 11am geyser will be at temp and 15kwh batteries will be full, could be dumping that energy into more water.

1765263670342.png
 
Speedster said:
That's 5, maybe 10, days a year. Those 5 days grid power does its thing. If you had 6kwp more that would've been 10kwh on those low days which would still have essentially covered your water heating.

And then there are 360 other days in the year.
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Until substation burns down. You have a valid point but most want to be insulated from the problems of the grid, even during bad weather.
 
denmendez65 said:
Guys on here with 9 to 10kWp of panels struggled to hit 15kWh just a few weeks ago. Throw in family of 5 with a geyser consumption of 10kWh a day and you only have 5 left for the house. With a HP it would be 3kWh for the geyser and 12 left for the house and battery.

Production drops a ton in bad weather.
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You've got the wrong comparison. It's 10kwp panels with a heat pump, or 16kwp panels without.

If 10kwp delivered 15kwh, 16kwp would be 24kwh. So even on the bad days solar is winning.
 
Speedster said:
That's 5, maybe 10, days a year. Those 5 days grid power does its thing. If you had 6kwp more that would've been 10kwh on those low days which would still have essentially covered your water heating.

And then there are 360 other days in the year.
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sometimes it can be 10 days in a row, sure I've not seen that since 2023 but it does happen where we just have a thick cloud layer doing sweet bugger all but block sun for a long period of time.
It is why JHB actually experiences more rain than London does, we just get it in about 3 months vs over the whole year, we apparently have 90 days of rain a year in JHB, CPT is around 60 to 70
 
Zuner said:
I would actually like a 750L geyser, 9am and automation has already turnedt he geyser on, by 11am geyser will be at temp and 15kwh batteries will be full, could be dumping that energy into more water.

View attachment 1869759
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What's your temp at? You can add a geyserwise and then dynamically pump up the temp if there's excess solar available.
 
Zuner said:
I would actually like a 750L geyser, 9am and automation has already turnedt he geyser on, by 11am geyser will be at temp and 15kwh batteries will be full, could be dumping that energy into more water.

View attachment 1869759
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I am hoping to achieve that with my Jojo tank. Supply the bathrooms and geyser with luke warm water (some 30 degrees celcius). At the moment my batteries are full at 8:30. The earliest I have ever seen so other than the pool pump there is nothing really using the power. There is 2 teenage cousins staying over for the next 2 weeks so they are running the TV and PC the whole day so they can use the power guilt free lol. Otherwise the solar is idling most days.
 
denmendez65 said:
I am hoping to achieve that with my Jojo tank. Supply the bathrooms and geyser with luke warm water (some 30 degrees celcius). At the moment my batteries are full at 8:30. The earliest I have ever seen so other than the pool pump there is nothing really using the power. There is 2 teenage cousins staying over for the next 2 weeks so they are running the TV and PC the whole day so they can use the power guilt free lol. Otherwise the solar is idling most days.
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I've got two extra teens staying over right now as well. But the one uses a tablet and the other has a laptop. But at most my usage at night was 800w so battery bank can easily handle it. Wingnut will be happy to know I went down to 50%
 
Lupus said:
I've got two extra teens staying over right now as well. But the one uses a tablet and the other has a laptop. But at most my usage at night was 800w so battery bank can easily handle it. Wingnut will be happy to know I went down to 50%
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No man, you can do better, increase water temp to 70c.
 
Lupus said:
Got 16 panels, I could put up more, but the shade on one part of the house is persistent for quite some time. JHB parks aren't known for trimming trees or doing maintenance. But even if I added another 8 for 25k they'd still not be as efficient during cloudy weather as the heat pump, it might push me up to 400w meager generation
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My current panels are almost perfect north facing. Any extra panels I will put on part of the roof which is at a 45 degree angle to these, making them 45 degree NE. These should pick up the lower sun orbit in winter better.

Of course, CT has abysmal cloud cover in winter, so the absorption levels will still be low - but more panels help with eking out more of the limited solar radiation, I reckon.
 
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Splinter said:
My current panels are almost perfect north facing. Any extra panel I will put on part of the roof which is at a 45 degree angle to these, making them 45 degree NE. These should pick up the lower sun orbit in winter better.

Of course, CT has abysmal cloud cover in winter, so the absorption levels will still be low - but more panels help with eking out more of the limited solar radiation, I reckon.
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1765264588538.jpeg
 
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