Planning a solar system

[Next Thing]

The reason I said to use a "average" type value is that usage is never exactly the same day 2 day. My 2 cents is that once you have a figure add some over sizing then on a panel size increase it even more to cater for a % of degregation over the years.

 

[AchmatK]

The reason I said to use a "average" type value is that usage is never exactly the same day 2 day. My 2 cents is that once you have a figure add some over sizing then on a panel size increase it even more to cater for a % of degregation over the years.

If you going to spend R100k on solar, the last thing you want to do is skimp on doing the proper calculations.

A proper energy audit using something like an efergy is money we'll spent and the first thing anyone will tell you before trying to size your system.

First is understand your electricity usage patterns. Second, reduce consumption where you can, led lights, replacing appliances with energy sufficient ones, etc.

Only then can you start looking at inverters, batteries, panels.

I ran my efergy for over 4 years before eventually being able to afford to put in solar.

 

[maxxis]

If you going to spend R100k on solar, the last thing you want to do is skimp on doing the proper calculations.

A proper energy audit using something like an efergy is money we'll spent and the first thing anyone will tell you before trying to size your system.

First is understand your electricity usage patterns. Second, reduce consumption where you can, led lights, replacing appliances with energy sufficient ones, etc.

Only then can you start looking at inverters, batteries, panels.

I ran my efergy for over 4 years before eventually being able to afford to put in solar.

+1. Kept my eye on the Efergy during the day and at night. Made notes of the readings and determined my average usage.

Also looked at my meter daily to see what my daily usage was.

Finally my budget. The outcome was a 5kw inverter with 10kw storage.

 

[Next Thing]

IMO and yes I am a numbers person.

Nighttime is a period of minimal usage. You need to understand what your end objective is

a) Do you want to be 100% offgrid ( keeping in mind that the last 20 to 30% escalates costs ) or are you willing to be semi ongrid.
b) Are you willing to do other prework before you size your solar with easy wins
i) Take big ticket items off electricity to ( example gas ) : Geysers/Stove/Heaters
ii) Take the smaller items to better technologies : LED lights etc> Generally buying better dishwashers/washing mach/ tumble driers isnt really worth it if you cange your mindset on when to run them.

A lot of it is a mindset change. Pack a dishwasher. Run it during the daytime. Washing and Drying the same
Dont turn everything on at 9am. Stagger it during the day
If it can be done during the day do it then. That will only affect your invertor and panel size, not your battery requirement.

Panels are cheap. So if you can live with 70 to 80% offgrid you can save on your solution cost

For example our family load in a big house for family size of 5 + onsite domestic
After 5pm and before 8am the usage is minimal compared to during the day.
At most I use the batteries down to 30% SOC with multiple targets during the night so we always have enough to cater for a 3 or 4 hour power outage.


I oversized on panels (8.4kw, max of about 7.4kw in my EW config ) so I don't have to worry about what I do during the day and I know that if I need to be totally offgrid I just need to spend another R50 to R70K on additional batteries.
Also by oversizing on panels even on a cloudy day I generally generate enough for my daily usage ( with minimising the big ticket items ) and some battery charge.
It takes a cloudy+rain day for me to really not generate any pv at all which is actually not that often in GP.
If Eskom/Nersa goes ahead with this stupid rates for solar only it may pay me to buy the extra batteries and to wire in my Generator anyway to cater for the case where I may have 3 or 4 days with minimal generation which are few and far between.

 

[thehuman]

Except in this instance it wouldn't be much help. There are 2 buildings on the property which are all included in the same municipal bill. So while it gives a very rough idea, it doesn't provide enough precision to make informed decisions regarding sizing of panels and batteries. The most important bit I'm after is to see what the actual nighttime usage figures are.

Not getting 2x extra clamp meters is a blessing, now you can monitor one phase at a time , when ready move it to another phase and monitor it , could maybe get away with putting a inverter only on one phase, and maybe later on rest.

 

[Next Thing]

IN Addition. If you are looking at more than 1 invertor in parrallel, then keep in mind each invertor has an inbuilt running cost that will be drawn ,in the case of the cheaper invertors, directly from the batteries. You could be drawing for 50w to 150w per invertor. I would rather look a single larger invertor than multiple smaller invertors to minimise this hidden tax.

Also look at the maximum current draw per battery. It doesnt help only putting one battery in when its max power draw is , ( for example ) , 2kw when you may need a 5 of 6kw spike at night or even during the day ( when no grid is available ).
Like I said its a mindset change and being more aware or what you do when.

 

[TheChamp]

IN Addition. If you are looking at more than 1 invertor in parrallel, then keep in mind each invertor has an inbuilt running cost that will be drawn ,in the case of the cheaper invertors, directly from the batteries. You could be drawing for 50w to 150w per invertor. I would rather look a single larger invertor than multiple smaller invertors to minimise this hidden tax.

Also look at the maximum current draw per battery. It doesnt help only putting one battery in when its max power draw is , ( for example ) , 2kw when you may need a 5 of 6kw spike at night or even during the day ( when no grid is available ).
Like I said its a mindset change and being more aware or what you do when.

The current draw is actually very low, around 20W mostly, inverters that can be paralleled are not cheap so there is really no issue in regard to the internal power draw, it's really insignificant.

I have an old, heavy 2000W, omnipower unit, here's the standby draw, 150W sounds very extreme.

 

[Next Thing]

The current draw is actually very low, around 20W mostly, inverters that can be paralleled are not cheap so there is really no issue in regard to the internal power draw, it's really insignificant.

I have an old, heavy 2000W, omnipower unit, here's the standby draw, 150W sounds very extreme.

Since that is labelled as the Sonos plug for your TV , are you talking idle current supplied to appliances ?
I was not referring to that. I was referring to the actual power used by the invertor to actually run.
Most Voltronic based invertors use the battery to actually supply this.
Some of the grid tie units use 20w to monitor the grid supply to see if the grid is active which is seperate to the above

 

[Crusader]

The Garden Route installers don't mess around with pricing. Other installer got back to me and estimates a 5kW solar panel system with 8kW Sunsynk and 2 x 5kW Freedom Won batteries plus install will be around R209 000. Ouch.

 

[AchmatK]

The Garden Route installers don't mess around with pricing. Other installer got back to me and estimates a 5kW solar panel system with 8kW Sunsynk and 2 x 5kW Freedom Won batteries plus install will be around R209 000. Ouch.

Seems within the range

My DIY install consisting of 8kw sunsynk, 10.37kw solar panels and 14kWh pylontech batteries came to R230k.

 

[Crusader]

Unless something changes our solar plans are on hold until sometime next year. Guess I have more time to gather data now.

 

[Mike Hoxbig]

Unless something changes our solar plans are on hold until sometime next year. Guess I have more time to gather data now.

That sucks. You got us all excited for you over nothing...

 

[Crusader]

That sucks. You got us all excited for you over nothing...

Sorry. I was all excited too. Property owner wants more time to sort things out, get a contract etc. Good news is that in all likelihood there's a high chance that we'll converting both buildings to solar, so a much bigger install might be in the cards. Hopefully it will make the installer fees slightly cheaper with sharing the travel and accommodation portion.

 

[RonSwanson]

The Garden Route installers don't mess around with pricing. Other installer got back to me and estimates a 5kW solar panel system with 8kW Sunsynk and 2 x 5kW Freedom Won batteries plus install will be around R209 000. Ouch.

Start a spreadsheet (if you haven't already)

• Get more quotes, and take your time. Make it clear to all incumbents that you are serious, yet you have standards;
  • Send out a specification that includes
    • Your current monthly (and daily if possible) usage
    • Your home's plans, including desired spots for panels
    • Anything that can assist them in making a stab at your current consumption;
• Make decisions on exactly who it is that you actually want to do business with. The right company will hit you in the face. It did, to me at the time.
• Keep sending out feelers;
• Don't be discouraged by assholes. I encountered quite a few along my own journey.
• Decide (and write down in your spreadsheet) what exactly it is that will make you walk away.
• You know what is negotiable, and what isn't.
  • Make the rules, and write them down. (This is probably the most important step, do it in your spreadsheet).
  • Evaluate each proposal with an open mind
  • Record why it was rejected
  • Give reasonable feedback on each proposal, even if it is ridiculous. Record your feedback.
  • Keep going. There are many companies.
• Make adjustments to your original specifications in the light of new information (that you can trust).
• Be open to different and new ways of doing things;
  • Evaluate new and radical proposals against a sound technical test suite (which you would have developed by now);
  • Where there is doubt, question, and question again. It may be tiresome, but no-one ever got fired for asking questions,
• Make your choice only once it feels right. You will know when that happens.

Good luck!

 

[Crusader]

Start a spreadsheet (if you haven't already)

• Get more quotes, and take your time. Make it clear to all incumbents that you are serious, yet you have standards;
  • Send out a specification that includes
    • Your current monthly (and daily if possible) usage
    • Your home's plans, including desired spots for panels
    • Anything that can assist them in making a stab at your current consumption;
• Make decisions on exactly who it is that you actually want to do business with. The right company will hit you in the face. It did, to me at the time.
• Keep sending out feelers;
• Don't be discouraged by assholes. I encountered quite a few along my own journey.
• Decide (and write down in your spreadsheet) what exactly it is that will make you walk away.
• You know what is negotiable, and what isn't.
  • Make the rules, and write them down. (This is probably the most important step, do it in your spreadsheet).
  • Evaluate each proposal with an open mind
  • Record why it was rejected
  • Give reasonable feedback on each proposal, even if it is ridiculous. Record your feedback.
  • Keep going. There are many companies.
• Make adjustments to your original specifications in the light of new information (that you can trust).
• Be open to different and new ways of doing things;
  • Evaluate new and radical proposals against a sound technical test suite (which you would have developed by now);
  • Where there is doubt, question, and question again. It may be tiresome, but no-one ever got fired for asking questions,
• Make your choice only once it feels right. You will know when that happens.

Good luck!

Some awesome advice there.

I've already crossed 2 installers off the potential list. One kept me waiting for 3 weeks before sending a quote and the other just ignored all the info I gave them.

I think the extra time will be good to get a better picture of our actual usage patterns.

 

[Heisenborg]

One piece of advice....

When you are spending ~100k, then cheapest isnt always best. Get someone with a good track record and some example installations.

And ask anything and everything here. Just did it myself. Glad i paid a bit extra and got amazing service.

Dirkman did mine. They are enterprise level guys, so you know you getting top top quality

 

[RonSwanson]

Some awesome advice there.

I've already crossed 2 installers off the potential list. One kept me waiting for 3 weeks before sending a quote and the other just ignored all the info I gave them.

I think the extra time will be good to get a better picture of our actual usage patterns.

It's important to keep the list / spreadsheet, and the decisions and reasons. I ended up going with a supplier that I had crossed off many months prior.
It turned out to be the best provider (after all the sharks tried to feed), and to this day I am very happy, despite the small initial inconvenience.
The most important part is not to lose hope. With all the fly-by-nights I don't blame people who do, but it's something that one wants to guard against.

There are some amazing service providers out there, and very often the best SP are far too busy, which translates in a perception of poor service (yet is a guarantee of quality). Once a serious dialogue is established though, it does get better.

I can draw parallels with the restaurant industry, just because they are full does not mean that the quality of the product / wine pairing / additional selections are affected in an way. In fact a full restaurant (with a queue of hopefuls outside the door) is, in some ways, an endorsement of the quality and enjoyment that people are prepared to wait for.

 

[Mike Hoxbig]

It's important to keep the list / spreadsheet, and the decisions and reasons. I ended up going with a supplier that I had crossed off many months prior.
It turned out to be the best provider (after all the sharks tried to feed), and to this day I am very happy, despite the small initial inconvenience.
The most important part is not to lose hope. With all the fly-by-nights I don't blame people who do, but it's something that one wants to guard against.

There are some amazing service providers out there, and very often the best SP are far too busy, which translates in a perception of poor service (yet is a guarantee of quality). Once a serious dialogue is established though, it does get better.

I can draw parallels with the restaurant industry, just because they are full does not mean that the quality of the product / wine pairing / additional selections are affected in an way. In fact a full restaurant (with a queue of hopefuls outside the door) is, in some ways, an endorsement of the quality and enjoyment that people are prepared to wait for.

To add to this, plan for how you want your system to work. Ask lots of questions, both here and to your provider/installer. Write everything down because you will end up forgetting something.

When they do finally come out to install, don't rush the job. It's labour intensive and you want it done properly. Again ask lots of questions, refer to your notes and make sure it's installed how you want it to be based on how you want it to operate. A lot of chancers will just get everything sort of working and leave it at that.

It's a lot of money that you're spending so make sure it's done right. And don't be intimidated by the information overload. That will come naturally once you start asking questions about how you want your system to work...

 

[rh1]

Hi Crusader ... I have a domestic 3 phase supply and went with a Sunsynk 12kw 3 Phase inverter in Sept 2021.
My usage is around 30kwh per day. I have a peak in the morning between 4 and 7 when the two geysers come on.

I have 4.3kw (name plate capacity) of panels, which on an average sunny day gives me about 20 kwh per day, and a cloudy day about 12kwh. A really rainy day gives me 5-6kwh.

I have one 5.5kwh battery (Hubble AM2) which cushions the production and load during the day. I dump excess power to to the geyers during the day and so the water is hot for the early evening showers.

Because I have only one battery, I save the battery at 90% charge until midnight in case of a power failure. After midnight it slowly drains to 25% until around 5am. Then the sun comes up and by around 9.00 am I am producing 2.5kw.

The inverter comfortably handles the load and is more than sized for my needs.

I could do with another 4.3kw of panels and another 1 battery in the short term (3 total in long term). This will more or less free me from the grid for 85% of the year (not totally on cloudy days). I am based in JHB.

How much did this setup cost, ballpark figure?

 

[furpile]

Is this the correct Efergy to get? We are moving soon and I want to start measuring as soon as possible. I see stock is only due in May though. Anywhere else with stock or another product to use?

EFERGY Standalone Home Hub Kit - Electricity Energy Power Wattage Monitor Watt Meter​

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