Upgrades to Solar. Suggestions needed

[Pho3nix]

Hi guys,

So considering a few minor improvements even though I still plan to move within the next year.

Have a 5kW Deye battery, 4x550w panels and a singular 5kW 1C battery running the house at the moment. Geyser and oven aren’t connected at the moment. My thinking at the moment is adding another 4 panels, changing the geyser element to a 2kW version.

Oct Elec bill for September usage is R1750 for 550 units.

Below are some stats over the last month and a view on geyser usage.

EWeLink for last month

September

October so far

2 Decent-ish sunny days

Or is this a fools errand at this point in time.

 

[Lupus]

A 2kw element will take longer to warm the water up, could be up to 50% longer so yeah it'll be inverter friendly but it might run longer and will still use about the same amount.

 

[Pho3nix]

A 2kw element will take longer to warm the water up, could be up to 50% longer so yeah it'll be inverter friendly but it might run longer and will still use about the same amount.

Would it not be kinder to the inverter so then I could move that usage over to daylight hours?
Everyone usually bathes/showers before 9:30.

 

[_Jakes_]

A 2kw element will take longer to warm the water up, could be up to 50% longer so yeah it'll be inverter friendly but it might run longer and will still use about the same amount.

I've got a 2.5kW element, In the summer I run it for 1 hour in the morning and 1 hour in the afternoon before the kids take a bath. In the winter I run it for 2 hours in the morning and still an hour in the afternoon.

 

[Tomtomtom]

Hi guys,

So considering a few minor improvements even though I still plan to move within the next year.

Have a 5kW Deye battery, 4x550w panels and a singular 5kW 1C battery running the house at the moment. Geyser and oven aren’t connected at the moment. My thinking at the moment is adding another 4 panels, changing the geyser element to a 2kW version.

A 150 L geyser is a ~7 kWh battery you already own. It's a no-brainer to hook it up to absorb the solar power you're currently wasting after 1pm when your battery is full.

I would just do that first, and see how it goes. Work out if you need more panels to cover your hot water in summer. It would likely be at most 2 more.

 

[Lupus]

Would it not be kinder to the inverter so then I could move that usage over to daylight hours?
Everyone usually bathes/showers before 9:30.

Yeah it'll be, but it'll still take longer to warm up. 9:30 at night or morning?

 

[Pho3nix]

Yeah it'll be, but it'll still take longer to warm up. 9:30 at night or morning?

9:30 in the morning. Kids are 6:30 or so. Wife 7:30 and I usually take a shower around 9:30 or 10 depending on my day.

 

[Lupus]

9:30 in the morning. Kids are 6:30 or so. Wife 7:30 and I usually take a shower around 9:30 or 10 depending on my day.

That should be fine then, just monitor it. Geysers can stay hot for a long time.

 

[Tomtomtom]

9:30 in the morning. Kids are 6:30 or so. Wife 7:30 and I usually take a shower around 9:30 or 10 depending on my day.

If you get the geyser above 60 degrees by 4pm, it will still be above 50 degrees the next morning.

You might want to prioritise "recharging" the geyser before your battery when the sun comes up.

 

[wingnut771]

What element does geyser have now?

 

[Tacet]

Why do you want to add more panels? You're currently wasting solar capacity.

What inverter do you have? I don't see any geyser or oven consumption on your power graphs, so I suspect that your inverter is only feeding critical loads, and that you're not pushing power back to the non-essential loads. If the inverter (e.g. Sunsynk, Deye, Luxpower) supports pushing power back to the non-essentials, either your CTs (current transformers, need to be clamped around the council breaker live) is not installed or the configuration is wrong.

If you can fix the above, then changing the geyser to a 2 kW element will make sense, and then would be a good time to decide whether additional panels are necessary. I suspect that it would be - I doubt that your current installation will recharge the battery and recharge a geyser (I'd estimate 6-8 kWh for a family, mine for me is 4 kWh) with your current panels. But it would be better to base the decision on data after you've started pushing excess solar capacity to non-critical loads.

 

[leon.davibe]

Hi guys,

So considering a few minor improvements even though I still plan to move within the next year.

Have a 5kW Deye battery, 4x550w panels and a singular 5kW 1C battery running the house at the moment. Geyser and oven aren’t connected at the moment. My thinking at the moment is adding another 4 panels, changing the geyser element to a 2kW version.

Oct Elec bill for September usage is R1750 for 550 units.

Below are some stats over the last month and a view on geyser usage.

EWeLink for last month

September

October so far

2 Decent-ish sunny days

Or is this a fools errand at this point in time.

No point in adding more panels if you arent using alm the solar from current panels

ie battery is full 1pm and you lose production from that point on, so getting more load to prevent battery from getting full to utilise what you have first before adding more

Natutally more battery can also solve that problem but costs more
So get geyser in play first cause it is 6-10kwh battery allternative

 

[Lupus]

If you have 21 to 24k laying around heat pump, yeah it's a bit noisy but it uses 900 to 1200w

 

[denmendez65]

Why do you want to add more panels? You're currently wasting solar capacity.

What inverter do you have? I don't see any geyser or oven consumption on your power graphs, so I suspect that your inverter is only feeding critical loads, and that you're not pushing power back to the non-essential loads. If the inverter (e.g. Sunsynk, Deye, Luxpower) supports pushing power back to the non-essentials, either your CTs (current transformers, need to be clamped around the council breaker live) is not installed or the configuration is wrong.

If you can fix the above, then changing the geyser to a 2 kW element will make sense, and then would be a good time to decide whether additional panels are necessary. I suspect that it would be - I doubt that your current installation will recharge the battery and recharge a geyser (I'd estimate 6-8 kWh for a family, mine for me is 4 kWh) with your current panels. But it would be better to base the decision on data after you've started pushing excess solar capacity to non-critical loads.


View attachment 1857572

He has basically 2kWp of panels. If he runs a 2kW element plus some baseload, he will eat into the battery. The best situation is to have enough panels to supply everything off PV when he runs the geyser. Wasting generation is not a problem with panels being cheap. It will help him with the occasional cloud that covers the panels. I say he should add the 4 panels.

 

[Tacet]

He has basically 2kWp of panels. If he runs a 2kW element plus some baseload, he will eat into the battery. The best situation is to have enough panels to supply everything off PV when he runs the geyser. Wasting generation is not a problem with panels being cheap. It will help him with the occasional cloud that covers the panels. I say he should add the 4 panels.

Cheap is relative; while you may have enough funds to easily add 4 panels, not all of us have that luxury. Also, I asked what inverter it is with multiple reasons: to see whether the inverter can feed power to the non-essiential loads and to see how much solar capacity the inverter can safely handle. I also think that more panels will be required, but I don't like the mindset of "more panels, more battery, bigger inverter" that is so prevalent in the solar industry. I much prefer an approach of load analysis, followed by load optimization for solar purposes, and as a last step designing a system that then balances cost vs benefit.

For the OP to add panels right now is useless. He need to supply the geyser with solar first, otherwise he'll just be wasting more solar capacity.

 

[Tomtomtom]

I say he should add the 4 panels.

He said he's moving within the next year. No way he'll get his money back on 4 new panels with hardware and installation costs. For the new owner, or if he stays longer than a year, then yes, could make sense.

Meanwhile a new element is about R 300 and has a payback of a month or two. He should have done that yesterday already. Total no brainer.

 

[denmendez65]

Cheap is relative; while you may have enough funds to easily add 4 panels, not all of us have that luxury. Also, I asked what inverter it is with multiple reasons: to see whether the inverter can feed power to the non-essiential loads and to see how much solar capacity the inverter can safely handle. I also think that more panels will be required, but I don't like the mindset of "more panels, more battery, bigger inverter" that is so prevalent in the solar industry. I much prefer an approach of load analysis, followed by load optimization for solar purposes, and as a last step designing a system that then balances cost vs benefit.

For the OP to add panels right now is useless. He need to supply the geyser with solar first, otherwise he'll just be wasting more solar capacity.

So his batteries only start charging after the geyser is done? If he uses the battery at night, the battery will be empty in the morning. What time would that be? Looks like his batteries get full around 1pm. Thats a 5kWh battery. If he heats gesyer first, then the geyser gets hot at around 1/2pm. Zero battery charging.

He only has 3 hours to fully charge the battery. Any hint of cloud any they will never charge. A power outage at night will leave him in the dark.

 

[denmendez65]

He said he's moving within the next year. No way he'll get his money back on 4 new panels with hardware and installation costs. For the new owner, or if he stays longer than a year, then yes, could make sense.

Meanwhile a new element is about R 300 and has a payback of a month or two. He should have done that yesterday already. Total no brainer.

If hes moving out then he should do nothing. Why waste time and money on a place you will leave next year.

 

[Tomtomtom]

If hes moving out then he should do nothing. Why waste time and money on a place you will leave next year.

He's looking to reduce a R1750 electricity bill in the mean time.

For a cost of a R 300 element, he can probably displace up to 5 kWh per day heating his geyser over the summer. That'll be a R 400-500/month saving. Why would you not take that?

Obviously if he needs an electrician that could tip the balance, but spending up to R 2-3k he'll still have saved money a year from now.

 

[denmendez65]

He's looking to reduce a R1750 electricity bill in the mean time.

For a cost of a R 300 element, he can probably displace up to 5 kWh per day heating his geyser over the summer. That'll be a R 400-500/month saving. Why would you not take that?

Obviously if he needs an electrician that could tip the balance, but spending up to R 2-3k he'll still have saved money a year from now.

Will his battery charge in the last 3 hours of the day, thats the question. Because with a 2kW element, from the moment the geyser runs. The battery will get drained. It means he has to trade off running from battery at night and heating the geyser.

Keep the batteries full during the night. Then Use PV to heat the geyser (it will draw some 500W from the battery till 1 pm or so). Then he can charge the 2kwh or so used from the battery with the remaining sun of the day.

This can work, he will save some 500 rand maybe but his night usage will be on Eskom now.