Solar Water Heating what are my options?

[Draigman]

I'm trying to reduce my Eskom usage. Using solar for the geyser is an obvious starting place.

I done a bit of research and my options seem to be between PV solar heating and a Vacuum Tube system.

The vacuum tube system seems a bit antiquated with all the new tech on the market. A couple of my friends used this system and they had some bad experiences with the water overheating.

I see that there are a couple of players in the PV market, Geyserwise and Power Optimal. Both look good on spec and the only real difference I can see is that Power Optimals Elon system doesn't require any changes to made to the geyser element. 

Anyone have any advice to point me in the right direction?

 

[Gerrie]

On 2021/08/19 at 7:02 PM, Draigman said:

The vacuum tube system seems a bit antiquated with all the new tech on the market.

Both systems has a place in the market and in my opinion there’s no right or a wrong between the two. If you are planning on installing a inverter it might be worth fitting a big enough system that could also be used to dump excess PV power into, but this normally require a reasonably big size inverter especially if you have more than one geyser. In my own situation I have one evacuated tube geyser and one normal electrical geyser that I dump some excess PV into, but I think I choose the evacuated tube geyser because it can manage without electricity and timers and always have hot enough water for showers.

[Draigman]

Thanks for you reply Garrie.

The reason that I am not thinking of Vacuum tubes is 2 people I know had boiling water blowouts due to excess heating of the water. One of them also had to add and a addition 12 volts pump for some circulation problems. Also we get serious hail storms here in the raining season, I'm talking about tennis balls size hail that punches hold in windows, dented my Landrover 100 body work and dented outside metal tables. Not sure tubes could handle that!
I'm not proposing a high capacity solar installation as i've done detailed load calculation for day and night consumption so I don't anticipate having a high degree of surplus PV power for the geyser.

The PV direct solar systems I am looking at also claim to perform (at a reduced level) on days that are not FULL sunshine. The Elon system appears to offer the better cost option.

https://www.poweroptimal.com/

I'm looking for people who have installed either this system or the geyersise solution to get their opinion.

[roadkill]

On 2021/08/23 at 6:26 AM, Draigman said:

Thanks for you reply Garrie.

The reason that I am not thinking of Vacuum tubes is 2 people I know had boiling water blowouts due to excess heating of the water. One of them also had to add and a addition 12 volts pump for some circulation problems. Also we get serious hail storms here in the raining season, I'm talking about tennis balls size hail that punches hold in windows, dented my Landrover 100 body work and dented outside metal tables. Not sure tubes could handle that!
I'm not proposing a high capacity solar installation as i've done detailed load calculation for day and night consumption so I don't anticipate having a high degree of surplus PV power for the geyser.

The PV direct solar systems I am looking at also claim to perform (at a reduced level) on days that are not FULL sunshine. The Elon system appears to offer the better cost option.

https://www.poweroptimal.com/

I'm looking for people who have installed either this system or the geyersise solution to get their opinion.

Did you ever come to a decision on this? Also looking at Elon. I am also not a fan of evacuated tube. I had one at my last place, geyser top mount. When the water gets too hot it simply dumps out the water as it cannot temperature control any other way, maintenance long term is also a hastle. It will perform better overall on heating, but in the long run, in my opinion, you will get way more reliability and less hastle out of a PV system