Geyser conversion to solar

[Justice MM]

Hi. I am considering retrofitting the current 200-L electric geyser into solar, and I am stuck with two options. The first one is to replace the existing AC element with the dual element (DC and AC) and connect directly to the solar panels. This in my research is a widely used technology. The other option is to keep the geyser as it is and install a small specially purposed inverter and connect that to the panels. I have been told this technology is relatively new and it comes with its own challenging, mainly the frequent failing of the inverter components. Lastly is there any other technology out there, except the unsightly vacuum system? If there, which system is better and what to watch out for on the chosen system.

 

Thank you in advance.

[De0n19]

How about using a standard grid tied inverter with export power limiting, you can switch on your geyser at midday with a timer to use the solar power and the rest of the day your house loads can also make use of solar energy. Your geyser would probably take like 2 hours to heat up, so plenty of solar energy for other stuff to run then.

Edited September 18, 2021 by De0n19

[hoohloc]

On 2021/09/16 at 12:08 PM, Justice MM said:

Hi. I am considering retrofitting the current 200-L electric geyser into solar, and I am stuck with two options. The first one is to replace the existing AC element with the dual element (DC and AC) and connect directly to the solar panels. This in my research is a widely used technology. The other option is to keep the geyser as it is and install a small specially purposed inverter and connect that to the panels. I have been told this technology is relatively new and it comes with its own challenging, mainly the frequent failing of the inverter components. Lastly is there any other technology out there, except the unsightly vacuum system? If there, which system is better and what to watch out for on the chosen system.

 

Thank you in advance.

Your first option is the easiest and probably less expensive way to go. I replaced my 150L geyser, resistive element with Geyserwise PTC element and now I can power up my geyser from my solar system, the whole day. I use a CBI Astute controler to switch off the geyser at 16H00 everyday and back the next day at 06:00. Next step is to insulate my geyser and hot water pipes. I'm also looking at installing a gas water heater for those cloudy days and early morning showers in winter. 

[TimCam]

As hoohloc says the Geyserwise PTC element is a good start, and is about 15% more efficient than your current resistive element.

Have a look at the link below. Depending on your geyser size, select the appropriate wattage.

https://www.geyserwise.com/products/elements/2200-w-ptc-ac-element/

Gas is an option too, but then plumbing is needed, and using a gas geyser is a totally different experience, which some people don't like.

[Justice MM]

Thanks a lot. I am sitting with the quote I will check the spec for the element.

[Newbie Dave]

Hi Justin MM 

I installed 4x 330w panels in series and this is wired directly to the  3kw element  on my 150l geyser. it is controlled by a electronic thermostat that switches a  30amp solid state relay.  it works well for me   in the Western Cape. it is my diy  off grid geyser. I have installed a double pole isloator and a 10amp 10x38 fuse for overload protection.  There will be the odd day that you wont get hot water but so far my wife and daughter are quite happy with the set up. 

This is my first attempt at solar and looking forward to installing  a 5kw inverter  with 6 x 550  panels to go off grid with  10kw  hubble batteries  before year end. This is a great forum and a big thank you to all who share their wisdom and knowledge so freely.