How many panels would one need to power a 200l geyser?

 No - I think for your purposes you are ONLY going to run the electronics and lights in your house from battery and panels.  There is a kind of a rule in this game - if it makes heat it is hell - hellishly difficult to find a panel and battery solution. 

Think about it - one morning you switch on the kettle; someone has just taken a bath (if it was my wife even a 200l geyser is now kaput); she is now busy with the hair dryer; and someone is ironing a shirt.

Here we have EASILY 1.5 Kw + 3Kw + 1.5Kw + 2 Kw = 8 Kw.  8000 Watts - to cater for this from panels you need 24 330 Watt panels. TWENTY FOUR. But that is optimal conditions which you never have so probably closer to 30 panels. And in the morning even that is no good. And 10 (ten) Pylontechs in series. And goodness knows what else to cater for such a monster system.

BUT the kettle and hairdryer and iron are drawing power for only 3 minutes. Then the rest of the day your 24 panels sit idly by except the 10 or so which warms the geyser over a few hours and then you are back to using only 1 panel for your electronics.  

And if this was an evening scenario and you do not have all those batteries the water is cold in the morning DISPITE your solar efforts.

 

So the solution most often pursued is to get a solar hot water system that DIRECTLY heats the water from sunlight. These things are called collectors and simply heats the water as it circulates in black copper piping underneath a glass covered panel. On a hot day it BOILS the geyser. If you already have a geyser it can be connected to a collector on the roof.

These systems have been shown to be very cost effective and are much more efficient than PV panels per Kw sunlight HARVESTED. It falls back on electricity only when required. And as for the hairdryer and kettle and iron - you use mains when available ie you anticipate the loadshed. Since those few items are only used a few minutes per day you find their total impact on your electricity bill is minute but whenever they ARE used there is an incredible spike in consumption and your system wont cope. In a way this simulates the problem Eskom is dealing with at large scale.

 

 

So that has given me perspective, thanks Clivevan.

My investment is not going to yield much help in terms on ROI.

For now my priority is to ensure continued power when Eskom goes off, hopefully for not more than 5 hours.

With that in mind, I have decided I will get a Growatt 3kva unit with 2  X 100ah gel batteries. I will just need to make sure that I do not discharge them below 40%.

Bundu Power has it for about R7 100 and the batteries are R2 800 each. Hopefully they have stock tomorrow.

Then I will need to get some accessories to do the install. My sparky asked for battery fuse and holder plus 35mm cable. He said 4m but that in my opinion is too much. The inverter and batteries will be close to each other. 2m should do it I think.

We already have the additional DB and breakers, change over switch.

Hopefully we can get this done on the weekend.

Thanks for all the advice.

On 2022/04/28 at 5:02 PM, Kavesh said:

So that has given me perspective, thanks Clivevan.

My investment is not going to yield much help in terms on ROI.

For now my priority is to ensure continued power when Eskom goes off, hopefully for not more than 5 hours.

With that in mind, I have decided I will get a Growatt 3kva unit with 2  X 100ah gel batteries. I will just need to make sure that I do not discharge them below 40%.

Bundu Power has it for about R7 100 and the batteries are R2 800 each. Hopefully they have stock tomorrow.

Then I will need to get some accessories to do the install. My sparky asked for battery fuse and holder plus 35mm cable. He said 4m but that in my opinion is too much. The inverter and batteries will be close to each other. 2m should do it I think.

We already have the additional DB and breakers, change over switch.

Hopefully we can get this done on the weekend.

Thanks for all the advice.

Hi There Kavesh

Do you have an update on your installation and how it went? I am super interested.

Regards,

On 2022/05/06 at 12:00 PM, uDuWaR said:

Hi There Kavesh

Do you have an update on your installation and how it went? I am super interested.

Regards,

Hello

There has been a delay due to lack of stock of the inverters. I have now managed to purchase a 3kva Growatt inverter and 2 100ah gel batteries.

Hoping my sparky is available this weekend to complete the job.

I have already sorted my essential load and will be converting the some florescent tubes to LED which will lighten my essential load further.

I will update once its done.

 

OK so the inverter is now installed, 

 

Can you believe that I am waiting for load shedding now:-)    To test the system.

I have connected all lights to the inverter and key plug points that do not draw much power, to power wifi, laptops and cellphones.

I will be replacing the last few of my florescent tubes to LED soon, to make my lights load lighter.

These normal long tubes actually are a heavy draw, 2 x 5 foot double tubes in my garage draws 1amp of power.

We did a test  on some LED downlights, 16 downlights draws 0.5amps.

Obviously during load shedding I will not keep everything on, will manage that myself.

I will update once I have had load shedding.

 

Edited May 30, 20224 yr by Kavesh