Solar geysers - are they a scam?

SauRoNZA

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Hi I'm thinking of heating my water with solar but my problem is that I have a 4kw element in my 200l geyser. I only have a 5kw inverter which can power the 4kw element and can blend solar and grid.

The problem is obvious that I cannot use anything else with the geyser on. The best option I think is to upgrade to a 8kw sunsynk and put the geyser on the non essential side but my inverter is only 4 months old and could last 10 years before it needs replacing.

I could downgrade the element to a 2kw one and connect it to my 5kw inverter.

I'm just not sure what the downside is to downgrading my geyser element.

Why not put in a smaller element?

Or even one that can run directly off solar PV? Makes much more sense.

 

NightCrawlerNic

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I think the issue with most solar geezers' is that some dont have a non return valve. I found that our the hard way. I would have my water temperature at 40 when i go to sleep and when i wake up it would be 20 odd.

Mine is fitted with the valve, then i installed a timer with schedule for 30 minutes in the morning and 30 minutes in the evening and its working perfectly. I however have to manually switch it on during manually during cloudy days.
 

Paul_S

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Why not put in a smaller element?

Or even one that can run directly off solar PV? Makes much more sense.


It's still more efficient to heat water using evacuated tubes or flat plat collectors but if one already has excess solar PV generation then it makes a lot of sense.
However I'd rather run a low power 230VAC element off an inverter because then your panels can be used for other loads besides just heating water.

 

isie

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I think the issue with most solar geezers' is that some dont have a non return valve. I found that our the hard way. I would have my water temperature at 40 when i go to sleep and when i wake up it would be 20 odd.

Mine is fitted with the valve, then i installed a timer with schedule for 30 minutes in the morning and 30 minutes in the evening and its working perfectly. I however have to manually switch it on during manually during cloudy days.
Non-return valve missing I see is common now in many geysers not just solar (call it being cheap or shoddy plumbers etc) But whenever we have a water issue will always hear some guy complain his element packed up because the gesey emptied out.

You could add in the timer to go on midday -since a thermostat won't switch on to heat water up if its already at the set temp - unless the thermostat isn't working and it just heats up - but then you have another issue.

Can i suggest you get rid off your timer switch and invest in a geyserwise or similar.
you wont regret it
 

qscwbt

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SauRoNZA

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It's still more efficient to heat water using evacuated tubes or flat plat collectors but if one already has excess solar PV generation then it makes a lot of sense.
However I'd rather run a low power 230VAC element off an inverter because then your panels can be used for other loads besides just heating water.


Yeah if you are going to go the full inverter whole home route it makes sense to do that and just use the more efficient element.
 

Solarion

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I thought solar geysers worked with batteries. Stores up the energy and uses those to heat the water?
 

SauRoNZA

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Non-return valve missing I see is common now in many geysers not just solar (call it being cheap or shoddy plumbers etc) But whenever we have a water issue will always hear some guy complain his element packed up because the gesey emptied out.

You could add in the timer to go on midday -since a thermostat won't switch on to heat water up if its already at the set temp - unless the thermostat isn't working and it just heats up - but then you have another issue.

Can i suggest you get rid off your timer switch and invest in a geyserwise or similar.
you wont regret it

The problem I’ve found with timers is that it’s all very static.

Geyserwise wins for having the temperature threshold of 5 degrees, although I find 10 degrees to be far more efficient t.

Best of both worlds is a smart switch that can do the geyserwise threshold but also do things like automatically go off when you leave the house etc.

Mine turns on at 07:00 and off at 21:00. If I leave the house it turns off and when I come back the thermostat turns on.

If it reaches 55 degrees it turns off until it drops to 45 and then turns back on again, which in summer pretty much means it never goes on in the day.
 

Speedster

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I thought solar geysers worked with batteries. Stores up the energy and uses those to heat the water?
I guess you probably get some that work that way, the most efficient ones have a flat plate or evacuated tubes that catch heat from the sun to heat up the water that is circulated through it.
 

Solarion

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I guess you probably get some that work that way, the most efficient ones have a flat plate or evacuated tubes that catch heat from the sun to heat up the water that is circulated through it.

There are these Lithium Ion batteries coming into operation now in many parts of Logistics. Was talking to someone recently and he said during their tea break the electric forklift drivers would simply plug the forklift into a charger and in 10 mins the forklift was fully recharged as opposed to something like 2-3 hours for the old lead acid batteries.

The Lithium Ion is so small they are putting counterweights into the battery bay where the old batteries were. These new batteries are like two shoe boxes size worth and incredibly powerful. Maybe they will be a game changer in solar powered products?

Edit: Newer forklift.

iu
 

Speedster

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There are these Lithium Ion batteries coming into operation now in many parts of Logistics. Was talking to someone recently and he said during their tea break the electric forklift drivers would simply plug the forklift into a charger and in 10 mins the forklift was fully recharged as opposed to something like 2-3 hours for the old lead acid batteries.

The Lithium Ion is so small they are putting counterweights into the battery bay where the old batteries were. These new batteries are like two shoe boxes size worth and incredibly powerful. Maybe they will be a game changer in solar powered products?

Edit: Newer forklift.

iu
Lithium ion, specifically lithium iron phosphate (LiFePo4), are already standard in solar applications.
 

NightCrawlerNic

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I am changing my batteries from gel to lithium. Gell takes longer to charge and gives me issues the moment it reaches 50%. I am hoping the lithium will last longer.
 

zolly

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Our solar geyser gives us hot water for free during the whole of summer. We turn it on once a day during winter in the morning for a couple of hours.

In terms of cost savings it shaves off about a third of our electricity costs.
 

Maurice Kitching

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Our solar geyser gives us hot water for free during the whole of summer. We turn it on once a day during winter in the morning for a couple of hours.

In terms of cost savings it shaves off about a third of our electricity costs.
Ours never on from September to May. For 4 months of the year on for about 30 mins per day and only if someone wants to shower in the morning.
 

dj2381

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I am busy doing renovations at home and have been thinking about getting a solar geyser for a while now, so now is as good a time as any, can any of you guys in CT recommend an installer?
 

zolly

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I am busy doing renovations at home and have been thinking about getting a solar geyser for a while now, so now is as good a time as any, can any of you guys in CT recommend an installer?

I will chat to my brother. We had a guy come over in October and put one in at our new house.
 

zolly

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I am busy doing renovations at home and have been thinking about getting a solar geyser for a while now, so now is as good a time as any, can any of you guys in CT recommend an installer?

So we had our plumbing guy come do our install. They've also done a bunch of other work around our house.

 
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