Extra panels or Solar Geyser?

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Crusader1982

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I currently run a Hybrid solar system with an 8Kw Inverter, 3 x 5Kwh Batteries and 16 x 455W panels.
This system is just not enough for my household. Currently, I am switching the 2x geysers on for only 2 hrs per day which gives enough hot water.
I am probably 10 units short per day on average, taking into account that we get some cloudy days.
I was wondering what would be more beneficial between going to two Solar geysers for the house and flat, or if I should add more panels?
If so, how many panels would give me the same result as the two solar geysers in trying to gain that 10 units per day?
I am trying to establish which route will make more financial sense?
 
Panels - will help more in winter too.
10kWh shortfall, 3-4x540W+ panels on a good day will make up that shortfall.

The question is how many more panels can your inverter take?
 
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More a question of when you're drawing the extra 10 units.

During the day then get 4 more panels. 1.8 kWp will get you 10 units over the course of the day.

At night, or partially night and partially day, get an extra battery. Only you know your usage patterns.

I run the geyser 1 hour in the morning and 1 hour in the evening off batteries, and 3 hours during the day off pv, and use zero Eskom. 14 x 455 panels and 4 x 4.8 kWh batteries.

With 2 geysers you could do the same if you get the scheduling and timing right...
 
More panels get my vote but I haven't done the math to see how many more you can add.

From my unscientific observation a geyser takes 2-4kwh to heat per bath/shower so thats about 600w of panel per 5 hour solar cycle.

So call it 2000-3000w of PV panels for a family of 4.
 
rh1 said:
@Snyper564 solar thread goes into this topic. He has both. He stated he should never had invested in the solar geyser.
Click to expand...
This is one of the more unique situations, If you are this far in and you are trying to make up for "cloudy days" I would honestly say first make sure your system is optimised are you getting shade on panels thats a massive issue your system is bigger than mine with one less battery you should me thumping way more than I can.

I dont think you can add more panels your system might also be maxed panel wise so go solar geyser?

I think maybe heat pump in this situation might be better. Gonna need more input from others.

Please show what a your system typically produces a days something sounds off.

If you trying to compensate for cloudy days nothing at this point makes financial sense pay eskom and call it a day will never make your money back any way,
 
B-1 said:
More panels get my vote but I haven't done the math to see how many more you can add.

From my unscientific observation a geyser takes 2-4kwh to heat per bath/shower so thats about 600w of panel per 5 hour solar cycle.

So call it 2000-3000w of PV panels for a family of 4.
Click to expand...
take shorter showers ? I have a 250L geyser and it takes around 1unit to heat it to 40c in winter.
 
Crusader1982 said:
I currently run a Hybrid solar system with an 8Kw Inverter, 3 x 5Kwh Batteries and 16 x 455W panels.
This system is just not enough for my household. Currently, I am switching the 2x geysers on for only 2 hrs per day which gives enough hot water.
I am probably 10 units short per day on average, taking into account that we get some cloudy days.
I was wondering what would be more beneficial between going to two Solar geysers for the house and flat, or if I should add more panels?
If so, how many panels would give me the same result as the two solar geysers in trying to gain that 10 units per day?
I am trying to establish which route will make more financial sense?
Click to expand...
how big is ur house? That's too much electricity usage. What appliances are you using? solar is a lifestyle change, maybe look at reducing your usage.
16 panels are generating let's say 5000 watts of electricity on average during the day(let's day between 10 and 4 pm), are u using all of this? maybe use the excess to heat water during the day.
Since u said u are using a hybrid system, are u selling your excess?
 
Snyper564 said:
This is one of the more unique situations, If you are this far in and you are trying to make up for "cloudy days" I would honestly say first make sure your system is optimised are you getting shade on panels thats a massive issue your system is bigger than mine with one less battery you should me thumping way more than I can.

I dont think you can add more panels your system might also be maxed panel wise so go solar geyser?

I think maybe heat pump in this situation might be better. Gonna need more input from others.

Please show what a your system typically produces a days something sounds off.

If you trying to compensate for cloudy days nothing at this point makes financial sense pay eskom and call it a day will never make your money back any way,
Click to expand...
exactly, I think he is not using his system to its full potential.
 
My plan is to switch the geyser during the day, when there is surplus power using a sonoff POWR320D and home assistant. Geyser will not be used when there is no sun, unless of course, switch it on manually or from home assistant.
 
joker08 said:
take shorter showers ? I have a 250L geyser and it takes around 1unit to heat it to 40c in winter.
Click to expand...
Not a good idea to run a geyser below 40°. All shorts of nasties could start making their way into your water.

I think op needs to post his settings and some graphs showing usage. Inclined to believe an extra battery will make a bigger difference. He could use it during the day to compensate for grid and still get it charged up for night time by optimising his schedule and using timers...
 
I really appreciate the feedback ladies and gents.
I have no doubt that usage can be optimized. I think the biggest issue is running the aircon through the night. This is unfortunately non negotiable.(wife)
One of the adjustments I was thinking of was to change the geysers to "essential." This would allow me to run them during loadshedding straight off the PV when the grid is off.
 
shadow_man said:
Panels - will help more in winter too.
10kWh shortfall, 3-4x540W+ panels on a good day will make up that shortfall.

The question is how many more panels can your inverter take?
Click to expand...
Company said that they could run as many as 36 panels.
Think I will look at a few extra panels. Appreciate the help. Thank you.
 
@OP if you are running an 8K Sunsynk you have around 3kWp still to add, I suggest that you order panels whilst they are still available and get an installer booked soonest.
 
How many people is this and daily consumption? We're about 10 kW per day, 2.5 people.
 
More batteries will also help when you get a 24 hour Eskom cut and there isn't much sun to help you.
 
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