Considering Solar but not totally off the grid.

[SelwynAS]

Good morning

We are seriously considering going solar, and our electrician (who we have used or years and knows out electrics very well) has recommended Sunsync 5Kw inverter and batteries with 9 x 460 or 525 watt panels.

I have calculated that Highest consumption over last 12months 30Kw and average of 27 per day. We live in Gauteng on the East Rand. Our roof considered for the panels faces 330degrees North, which gets sun almost all day. Now during load shedding we run 6900kva generator and by turning off pool pump and solar geyser, the genny seems to idle for most of the time. The only strain is shown the water tank pump kicks in and returns to "normal" once water stops running. Does this system sound practical to be able to run for stage 6 load shedding during the day, from solar panels only -assuming full sun - and not use the batteries at all. He advised we should handle this with ease and have spare to charge batteries. In addition to this question are there any other questions i should be asking before coughing up all this money?

[WannabeSolarSparky]

Aim for stage 8 or 10 loadshedding

Sunsynk5k with a battery or 2 (Ideally 2) will go a long way with mitigating loadshedding for sure.
Just manage your loads nicely and be sure your electrician splits your essentials and non-essentials nicely to suit your usage patterns.
And make sure he installs the CT Clamp correctly

Edited April 14, 2023 by WannabeSolarSparky

[SelwynAS]

8 hours ago, WannabeSolarSparky said:

Aim for stage 8 or 10 loadshedding

Sunsynk5k with a battery or 2 (Ideally 2) will go a long way with mitigating loadshedding for sure.
Just manage your loads nicely and be sure your electrician splits your essentials and non-essentials nicely to suit your usage patterns.
And make sure he installs the CT Clamp correctly

Ok thanks for the heads up. Our electrician did mention to split the load like pool pump and geyser.

[frivan]

Panels facing north have the best return on investment. However, I have some panels facing north-east and some facing west. This makes the solar day a little bit longer. A VSD pump also takes away the dips on startup.

[Scorp007]

9 hours ago, SelwynAS said:

Good morning

We are seriously considering going solar, and our electrician (who we have used or years and knows out electrics very well) has recommended Sunsync 5Kw inverter and batteries with 9 x 460 or 525 watt panels.

I have calculated that Highest consumption over last 12months 30Kw and average of 27 per day. We live in Gauteng on the East Rand. Our roof considered for the panels faces 330degrees North, which gets sun almost all day. Now during load shedding we run 6900kva generator and by turning off pool pump and solar geyser, the genny seems to idle for most of the time. The only strain is shown the water tank pump kicks in and returns to "normal" once water stops running. Does this system sound practical to be able to run for stage 6 load shedding during the day, from solar panels only -assuming full sun - and not use the batteries at all. He advised we should handle this with ease and have spare to charge batteries. In addition to this question are there any other questions i should be asking before coughing up all this money?

9 x 460W panels will provide a maximum average of 21kwh a day year round in Gauteng. You mention your average is 27kwh a day. So panels cannot provide your use. 

You can have a maximum of about 14 x 460W panels on a 5kW Sunsynk. This will sort you out on full sunshine days. There are however a number of summer days where you might only yield 10% of the 21kwh a day that 9 panels will provide. 

You will also find at times you cannot use all the PV due to full battery and low load switched on. This will further hamper you to meet your demand. 

Edited April 14, 2023 by Scorp007

[GreenFields]

Repeating a bit of what was said before, but I just want to differentiate a bit between these lines of thinking, whether we're talking of mitigating loadshedding during the day, or moving towards off-grid operation.

The OP seems to be asking more about daytime use during loadsheding. If your biggest daytime use is a water tank pump - let's say a 750W pump surging on every so often and then running for a few seconds up to a few minutes - geyser and pool pump and probably stove not in use - just baseload of say 1kW...

My 2c, for this a 5kW inverter with 4kW of panels is plenty, even overkill on most days, but nice to have the extra panels for cloudy days, and because you then CAN help run the geyser and pool pump on sunny days when the grid is on, or put it on AUX.

If you want to lean more towards off-grid independence, and add more batteries for the evening and for kitchen usage, then a 5kW is a little light, but it WILL take you a long way compared to having nothing at all. Maybe if you max out on the 6.5kW of panels the inverter can handle it would help, but to go off-grid it's probably better for this level of usage to upgrade up to an 8kW inverter and maybe double up on the panels.

[Arandoza]

Once you install solar and see the cost savings,you will probably want to grow the system

You will probably also start shifting your loads to daytime to save even more  

So I tend to agree with @Greenfields go bigger if you can, start with the panels and batteries that you need for night time use, and when its cloudy. When cloudy the batteries need to be able to carry the loads, as the clouds pass by, especially if you are running higher daytime loads, and load shifting. But consider planning for adding additional panels and batteries and maybe a second parallel inverter.

Many people install a system and then see the huge reduction and then want to upgrade or add to the system but are limited by their initial choices. Also keep eskom on prepaid, its good backup, and add the generator as a final backup. Also have a bypass inverter switch(s) installed, in case the inverters require repairs or maintenance, so one can simply work around them, if ever needed.

Load shedding is not the only problem we sit with, cable theft, failing infrastructure, pylons having their metal stolen, etc. and you may find you want enough battery capacity to carry you thru the night with ease

 

[Bobster.]

Right now we have 9 to 11 hours a day without grid, so you have to have enough battery to be able to sustain a 4.5 hour outage at night, and then recharge. 

This depends on your loads at night. IE After useful PV in the PM and until useful PV the next day.

This system will make a difference, definitely. Early on you are going to be on a learning curve as you see how much electricity you use when, and work at moving loads around to make best use of PV whilst still charging up the battery. 

Good move on going for the lithium battery. Lead+acid or gel batteries will not last long with things as currently stand. 

Your usage is about double mine & you have half the battery. I get through the night on battery and still have some in hand. With 5kWh I'd be right on the edge if there was a load shed round 6 or 7 and there wasn't enough PV to service the loads. 

Remember that you usually get 90% useful battery capacity as the BMS will not let it discharge past 90% of capacity. 

 

[SelwynAS]

Hi Everyone

Thank  you ALL for your responses and advise. It is not an easy decision, and I feel it could very easy to overspend on a system, but reading all the above, we feel  - as pensioners - we cannot justify spending more money. We seriously looking at retiring to the Cape,  in the next year or two, and need to consider a small system there as well. I feel the advise and specs suggested by our electrician should allow us to cope for now. We have a solar geyser, a gas stove and replaced all our lights with LED so our consumption should not increase. Before making our decision, we will take note of what was said and record out meter reading daily at 6am and 6pm to see what power is used daily and overnight. The convenience of not having to star the genny or cannot use it as its too late at night will be a bonus for us. Again tx for all the advise - lots to chew on