Guidance on Solar Configuration

[PB15]

Hi All,

I have been reading most of the discussions here for last couple of months and now finally made up my mind on the installation. I want to achieve the following and reduce the electricity bill

1. Power during load shedding

2. Daytime energy savings and

3. Use the battery to meet the evening demand

We are a family of 4 (us two and two kids) and a family of two (tenant) in the cottage.

I am thinking of the following configuration

1. Sunsynk - 5Kwh

2. Panel - 455w * 12

3. Battery - 7,2Kwh

Please let me know if this should be sufficient to generate enough power during the summer and winter. I am aware that I will still have to use grid for the shortfall, but I am hoping it won't be too much.

Here is the list of some of the things we use, 2 geysers (200L which I recently retrofitted to solar geyser and 150L), 2 fridges, 2 washing machines, 2 microwaves, 2 electric ovens, 2 toasters, 2 TVs, 2 electric kettles, 2 irons, 2 grinders, pool pump, electric motor, electric fence.

[system32]

>Here is the list of some of the things we use, 2 geysers (200L which I recently retrofitted to solar geyser and 150L), 2 fridges, 2 washing machines, 2 microwaves, 2 electric ovens, 2 toasters, 2 TVs, 2 electric kettles, 2 irons, 2 grinders, pool pump, electric motor, electric fence.

Q1. What's your monthly & daily kWh usage?
Q2. Have you made your home efficient?
Q3. Which direction(s) (North or East+West) will the panels be installed and what angle?
Normally with a smaller inverters, you need to split the DB into essential and non-essential loads.
Q4. Which appliances will you run on the "Essential Load" (Will stay on during Load Shedding).

If you have excess solar, you can use a simple timer to heat your geyser(s) during the day and run your pool motor.

AFAIK, the SunSynk 5k can handle more than 5kW pass through (quite a bit more).
Essential loads will draw power from the battery at night down to a programmed SoC, then switch to grid.
In the event of load shedding essential loads will continue on battery until a programmed shutdown SoC is reached.
Non essential loads (connected on grid side) will still be powered by excess solar during the daylight up to 5kW.

 

[Kalahari Meerkat]

8 hours ago, system32 said:

Non essential loads (connected on grid side) will still be powered by excess solar during the daylight up to 5kW.

Assuming the grid is up, when the grid is down, so will be the non-essential loads, whether you have excess power or not...

[system32]

This thread, similar to your sizing, has some good tips:
https://powerforum.co.za/topic/12034-to-buy-a-second-battery-or-not/

 

[GreenFields]

Personal opinion would be to keep the tenant's household only on the non-essential side, with no battery backup, and let them organize their own loadshedding solutions like a trolley with inverter, or something similar. At most maybe just give them LED lighting on backup if you can. The 5kW inverter will be overwhelmed very quickly once everybody tries to turn on their loads.

[PB15]

Thank you all for the feedback.

@GreenFields: You are right. The plan is to split the load in essential and non-essential for both the main house and the cottage. The LEDs and Fridges are considered as essential.

I am also planning to change the thermostat 150L geyser in cottage to 2Kw so that it can run on Solar during the day.

However the one thing I am not sure about is, can I stop the supply to non-essentials in the cottage when enough energy is not generated especially during winter and on cloudy days as the main house is the primary focus and excess solar energy (non essentials) can be used in the cottage.

[PB15]

@system32

Q1. What's your monthly & daily kWh usage? [PB] The main house daily usage is about 16Kwh during summer. I am hoping it would be about 60% more in the winter. My 200L geyser is converted to solar. The daily usage in cottage is about 9Kwh during summer. I don't have the stats for winter period but 150L geyser is conventional.
Q2. Have you made your home efficient? [PB] The lights are changed to LED, we use gas burner stove.
Q3. Which direction(s) (North or East+West) will the panels be installed and what angle? [PB] The panels will be installed in East+South directional. Not sure about the angle.
Q4. Which appliances will you run on the "Essential Load" (Will stay on during Load Shedding). [PB] Here is the list of essential appliances and the count. It includes some of the appliances in the cottage.

If you have excess solar, you can use a simple timer to heat your geyser(s) during the day and run your pool motor. [PB] The poop pump runs between 10am and 4pm everyday and I am planning to change the thermostats on the geyser to run it on solar (non-essential).

 

Hope this helps.

[Scorp007]

On 2022/04/11 at 5:20 PM, PB15 said:

@system32

Q1. What's your monthly & daily kWh usage? [PB] The main house daily usage is about 16Kwh during summer. I am hoping it would be about 60% more in the winter. My 200L geyser is converted to solar. The daily usage in cottage is about 9Kwh during summer. I don't have the stats for winter period but 150L geyser is conventional.
Q2. Have you made your home efficient? [PB] The lights are changed to LED, we use gas burner stove.
Q3. Which direction(s) (North or East+West) will the panels be installed and what angle? [PB] The panels will be installed in East+South directional. Not sure about the angle.
Q4. Which appliances will you run on the "Essential Load" (Will stay on during Load Shedding). [PB] Here is the list of essential appliances and the count. It includes some of the appliances in the cottage.

If you have excess solar, you can use a simple timer to heat your geyser(s) during the day and run your pool motor. [PB] The poop pump runs between 10am and 4pm everyday and I am planning to change the thermostats on the geyser to run it on solar (non-essential).

 

Hope this helps.

Loads give a guidance but one of the major loads is that pool pump running 6hrs. You will have to make a call if 6hrs is a need or a want when on solar. Luckily it can run during sun periods.

Edited April 13 by Scorp007

[Bobster]

On 2022/04/11 at 5:20 PM, PB15 said:

Q3. Which direction(s) (North or East+West) will the panels be installed and what angle? [PB] The panels will be installed in East+South directional. Not sure about the angle.

You mention load shedding, so you're in SA. I would hope, then, that the above is a typo. That you mean East and NORTH. I have seen some south facing panels, but that's hardly an optimal orientation in the southern hemisphere.
 

[system32]

On 2022/04/24 at 11:49 AM, Bobster said:

You mention load shedding, so you're in SA. I would hope, then, that the above is a typo. That you mean East and NORTH. I have seen some south facing panels, but that's hardly an optimal orientation in the southern hemisphere.
 

The reason to have EAST+WEST facing is that you generate PV solar electricity for longer periods - early morning and late afternoon.

I have 2 strings - both facing North.
Yesterday (4 May) - PV started generating at about 7h45 and stopped at 16h45 - if the strings were EAST+WEST they would start/stop an hour earlier & later.
I would generate less overall PV electricity, but I would have PV electricity for longer period.
This has an impact on the size of your batteries.

If you selling to grid, then NORTH is probably best.
If you have a battery and charging for usage at night, then EAST+WEST probably better.

Happy for gurus on forum to correct me and advise.

[Bobster]

9 minutes ago, system32 said:

The reason to have EAST+WEST facing is that you generate PV solar electricity for longer periods - early morning and late afternoon.

You are right, and I understand that. But PB15 mentioned that "The panels will be installed in East+South directional", which seems strange in SA.