May I please have some advice on the best solution for my loadshedding needs. I live in a small coastal town in the Western Cape, on the way to Hermanus.

The roof is 45 degrees facing due north and I have space for 12 * 420W panels. Considering my loads, I need a 5kVA inverter/charger and 7.5kVA LiFePO4 battery. The 5kVA inverter/charger is likely adequate. But to scale up on batteries later, probably the way to go is 2 * 3.8kVA batteries for now?

I’ve been told that the communication and compatibility between the batteries and inverter is critical.

What is suggested ito equipment brands, reliability and suppliers please?

Any idea of budget for a total package?

27 minutes ago, Cory said:

I’ve been told that the communication and compatibility between the batteries and inverter is critical.

It's important. Having good comms between batteries and inverter means you can make best use of your system (EG on mine I can "reserve" some of the battery for use during outages, but to do that, the inverter must reliably know the state of the battery). 

So don't just buy batteries advertised as having "CAN bus" or whatever. Dig a little more and check what works with what. And check from both ends, if I may put it that way. I have a Goodwe inverter and a Freedom Won battery. The Goodwe doesn't have any settings for Freedom Won, but Freedom Won knows all about Goodwe inverters, and via the comms can set the inverter optimally. When the FW was installed, the technician just made up a cable, plugged it into the battery and the inverter and within a couple of minutes the battery had adjusted everything to it's liking - charge voltage, charge current, the whole shooting match.

So, again, yes, comms are important.

A lot of folks use software like Solar Assistant to mediate between battery and inverter, but, again, the support is not there for every combination of battery and inverter.
 

Just get an 8kW Sunsynk inverter & a supported LFP battery. Grow from there. I agree with the statement above regarding CAN compatibility between bands. It's something to be aware of.

Edited July 12, 20222 yr by WJP

Hi Cory

Bobster is quite right about the inverter and battery compatibility.

However, regarding your question on sizing the solar solution, many things must be considered e.g.

- what is your current usage and when in the day;

- to what extent will your family adapt their electricity consumption behavior or should life continue as is;

- are there appliances that you can replace to lower your peak power consumption;

- sounds like loadshedding is your concern rather than cost saving, or maybe both;

Etc.

I assume you need a ballpark figure. I brought my utility down from about 650kw p/m to between 20 and 100kw p/m with a R90k investment. Loadshedding impacts me little. However, I did put a lot of effort and research into my setup where others paid about 50% more for a similar set-up.

10 hours ago, Pieter Lourens said:

Hi Cory

Bobster is quite right about the inverter and battery compatibility.

However, regarding your question on sizing the solar solution, many things must be considered e.g.

- what is your current usage and when in the day;

- to what extent will your family adapt their electricity consumption behavior or should life continue as is;

- are there appliances that you can replace to lower your peak power consumption;

- sounds like loadshedding is your concern rather than cost saving, or maybe both;

Etc.

I assume you need a ballpark figure. I brought my utility down from about 650kw p/m to between 20 and 100kw p/m with a R90k investment. Loadshedding impacts me little. However, I did put a lot of effort and research into my setup where others paid about 50% more for a similar set-up.

Hi Pieter

If I may ask, I know (from my question on another thread) that you also have the 6kw Solis 5g inverter, but what else did you install? Reason for asking is I also spend roughly R90k and was just wondering if I got it wrong.

I installed:

Solis inverter, 2X4,8kW Pylontech UP5000 with 4 535W JA solar panels. Added 1 panel recently (yes I did not really factor in the losses in the system). And then of course all the required brackets, fuses and breakers.

@Cory, if it helps. With my system (5 panels now), with average daily consumption of +-13kWh (Solar geyser and solar swimming pool pump), we went down to using about 500W ONLY from grid daily. This is however a sunny July day in Middelburg MP. On stage 6 we had certain days of 4 hours at a time loadshedding with the system providing more than enough. 

 

Hi @Rolo

You are quite right, I have the Solis RHI 5G 6K inverter.

My configuration is as follows:

• 1x Solis RHI 5G 6K inverter
• 10x 330W panels on MPPT 1 (azimuth = 30 degrees, 30 degree inclination)
• 4x 330W panels on MPPT 2 (azimuth = 210 degrees)
• 1x 4.9kW Pylontech UP5000 battery
• 2x 330W panels on Geyserwise AC/DC geyser element (150 liter geyser)
• 2x 395W panels on second Geyserwise AC/DC geyser element (150 liter geyser)

From a consumption perspective:

• All lights are LED
• All appliances are A+/A++ rated
• We use a gas stove
• We have a 1.4kW kettle (used quite frequently)
• I have the geysers on a timer and will only top-up with AC power between 8am and 4 pm)
• We do not use heaters or air conditioners

Our peak consumption average between 2kW and 4kW and may go up to 6kW for a short period in a day.

We are off the grid except for cloudy and rainy days, where we will need to invest in another UP5000 battery should we want to be truly off grid.

PS our bill went down from about 650kW p/m to less than 100kW p/m.

I hope that I answered your question

Sho, did you get ALL of that for the R90k? You struck one hell of a bargain 😆

Interestingly, I tripped my inverter when starting up a 2500W WOLFF lawn mower while grid was off (loadshedding). The start up of the motor was so high it peaked above the 6kw threshold of the inverter. Well that's what I think (with what must be said as very little electrical knowledge)

1 hour ago, Rolo said:

I tripped my inverter when starting up a 2500W WOLFF lawn mower

I could also be that your startup capacitor on the motor is finished. Friend of mine runs his lawnmower on a 5.5KVA Deye without issues

Due to the 2900rpm motors in lawn mowers they tend to take longer to start. If it was the capacitor it should not start at all. Start current for a 2.5kw can easily be far higher than what some 6kw inverters will provide. This is close to abuse. 😊

Start up current of a motor can be 6 times higher than normal running current.  

1 hour ago, iiznh said:

I could also be that your startup capacitor on the motor is finished. Friend of mine runs his lawnmower on a 5.5KVA Deye without issues

5K Sunsynk hasn't any issues with my 2500W Southern Cross mower, and I am servicing other loads simultaneously.

22 minutes ago, YellowTapemeasure said:

5K Sunsynk hasn't any issues with my 2500W Southern Cross mower, and I am servicing other loads simultaneously.

During loadshedding, the way @Rolo attempted it, or while the grid was present?

28 minutes ago, PowerUser said:

During loadshedding, the way @Rolo attempted it, or while the grid was present?

Both.

Thanks everyone for the info. Potential supplier helped to design my system for 6 * 460W PV, 5kVA Victron for Inverter & MPPT setup, 5kVA Freedom Won battery. Not off-grid but can handle 18 hours Power outage. That does require some discipline to run high current items during sun hours. Has anyone come across these two companies; Specialised Solar Systems and Energy Pivot?

On 2022/07/14 at 2:32 PM, Pieter Lourens said:

Hi @Rolo

You are quite right, I have the Solis RHI 5G 6K inverter.

My configuration is as follows:

• 1x Solis RHI 5G 6K inverter
• 10x 330W panels on MPPT 1 (azimuth = 30 degrees, 30 degree inclination)
• 4x 330W panels on MPPT 2 (azimuth = 210 degrees)
• 1x 4.9kW Pylontech UP5000 battery
• 2x 330W panels on Geyserwise AC/DC geyser element (150 liter geyser)
• 2x 395W panels on second Geyserwise AC/DC geyser element (150 liter geyser)

From a consumption perspective:

• All lights are LED
• All appliances are A+/A++ rated
• We use a gas stove
• We have a 1.4kW kettle (used quite frequently)
• I have the geysers on a timer and will only top-up with AC power between 8am and 4 pm)
• We do not use heaters or air conditioners

Our peak consumption average between 2kW and 4kW and may go up to 6kW for a short period in a day.

We are off the grid except for cloudy and rainy days, where we will need to invest in another UP5000 battery should we want to be truly off grid.

PS our bill went down from about 650kW p/m to less than 100kW p/m.

I hope that I answered your question

Pieter & @Rolo

Thanks for educating me on this. My worst winter consumption (when Eskom has to help my Geyserwise PV solar) is 310 units per month. Summer time it’s 220 units per month. Potential supplier suggests 2760 solar, 5kVA inverter and 5kVA battery. Any advice on that? Should I go smaller?

Edited July 30, 20222 yr by Cory

6 hours ago, Cory said:

Pieter & @Rolo

Thanks for educating me on this. My worst winter consumption (when Eskom has to help my Geyserwise PV solar) is 310 units per day. Summer time it’s 220 units per day. Potential supplier suggests 2760 solar, 5kVA inverter and 5kVA battery. Any advice on that? Should I go smaller?

Are you sure those consumption numbers are correct? You seem to be out by a factor of 10, or you have horribly under-specced your system. 

2 hours ago, Speedster said:

Are you sure those consumption numbers are correct? You seem to be out by a factor of 10, or you have horribly under-specced your system. 

Yes power cost at R23 000 per month looks too high. It works out at drawing 56A @ 230V for 24/7.

Edited July 30, 20222 yr by Scorp007

8 hours ago, Cory said:

Thanks for educating me on this. My worst winter consumption (when Eskom has to help my Geyserwise PV solar) is 310 units per day. Summer time it’s 220 units per day. Potential supplier suggests 2760 solar, 5kVA inverter and 5kVA battery. Any advice on that? Should I go smaller?

 

2 hours ago, Speedster said:

Are you sure those consumption numbers are correct? You seem to be out by a factor of 10, or you have horribly under-specced your system. 

Could it be 310 units per month, rather than per day?

If so, I don't think it's far out. Panels are around 6x460W, total 2.76kW, producing up to approx 400 units per month on average. Winter might be touch-and-go, also considering losses due to efficiencies, but as long as Eskom is available that's not too bad.

For the inverter and battery I wouldn't go lower. Without knowing your exact instant loads, if you're planning for running your house off it, even during loadshedding, then a 5kVA (4kW) inverter and 5kWh(4kWh with recommended 80% Depth of Discharge) battery are a little light. Probably okay as a backup with some careful co-ordination, but rather plan with expandability in mind. With Victron and Freedom Won you are choosing (perceived) quality over quantity. Lower-tier brands could offer more capacity headroom for the same money, but under circumstances that might not be the right choice.

12 minutes ago, Scorp007 said:

Yes power cost at R23 000 per month looks too high. It works out at drawing 56A @ 230V for 24/7.

Skuus man 🤦🏼. Had a power outage here 😝. Those are figures per month.

🤔🤔🤔

3 minutes ago, Cory said:

Skuus man 🤦🏼. Had a power outage here 😝. Those are figures per month.

In that case the inverter will work just fine🤔🤔🤔just expensive if compared to other options.

Edited July 30, 20222 yr by Scorp007

8 minutes ago, GreenFields said:

 

Could it be 310 units per month, rather than per day?

If so, I don't think it's far out. Panels are around 6x460W, total 2.76kW, producing up to approx 400 units per month on average. Winter might be touch-and-go, also considering losses due to efficiencies, but as long as Eskom is available that's not too bad.

For the inverter and battery I wouldn't go lower. Without knowing your exact instant loads, if you're planning for running your house off it, even during loadshedding, then a 5kVA (4kW) inverter and 5kWh(4kWh with recommended 80% Depth of Discharge) battery are a little light. Probably okay as a backup with some careful co-ordination, but rather plan with expandability in mind. With Victron and Freedom Won you are choosing (perceived) quality over quantity. Lower-tier brands could offer more capacity headroom for the same money, but under circumstances that might not be the right choice.

Thanks. Sorry guys. My finger trouble. These are monthly figures. Thanks is for the advice. I don’t intend to be off grid. The Cape coast are that I’m at gets long rainy days and a system that provides capacity for that is prohibitively expensive. My intention really is to be loadshedding proof, expandable as needs change. Geyser is already own PV, stove hob & kettle are gas. Electric oven Will stay on Eskom.

Edited July 30, 20222 yr by Cory

24 minutes ago, Scorp007 said:

Yes power cost at R23 000 per month looks too high. It works out at drawing 56A @ 230V for 24/7.

Lol yes, my bad 🤦🏼  It’s 310 and 220 monthly, winter and summer respectively. I’m on prepaid at R2/unit.

12 minutes ago, Scorp007 said:

🤔🤔🤔

In that case the inverter will work just fine🤔🤔🤔just expensive if compared to other options.

Off on the table is R135k installed. Suggestions on how to save on that please?

7 minutes ago, Cory said:

Off on the table is R135k installed. Suggestions on how to save on that please?

Without getting prices no 1 will be Synsynk / Deye 5kW. Then Solis RHI 6kW but just not sure if the Solis is not too slow to prevent feed back and tripping your prepaid meter even with the CT. No3 a Kodak OG 7.2 Max.

Edited July 30, 20222 yr by Scorp007

16 minutes ago, Scorp007 said:

Without getting prices no 1 will be Synsynk / Deye 5kW. Then Solis RHI 6kW but just not sure if the Solis is not too slow to prevent feed back and tripping your prepaid meter even with the CT. No3 a Kodak OG 7.2 Max.

I’ve seen a quote for 10 panels, 8kVA Sunsynk and 12kVA Revov battery for R183k. In relation, is the quote for my system unrealistic?