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Just getting started into solar


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Hey there everyone! First post coming up - be gentle!

Current set up
No Solar or inverters or batteries
1 x 2.2 kW petrol generator

During power outages: 

We plug the generator directly into the mains (mains switch is off and earth is on, turn geyser, pool, stove off at DB) via an extension cord from the garage into the house
We leave the lights and plugs on and keep the security items on, wifi, laptops and fridge on. We manage the loads if we need to turn the dishwasher, TV or washing machine on. So those are our essentials. We haven’t measured anything, we just go by how the generator sounds, if struggles, we turn some things off - very scientific ;)

So I’d like to get into solar because I’d like to save some money on Eskom, eventually have a quieter option than the generator for back up power and I just think solar is cool. 

The plan

This is how I was thinking about doing it and would appreciate some feedback on it.

  1. Separate out the DB to include the items we currently run on the generator during power outages - start measuring the output of this. But possibly should measure before, we may split things out on the DB differently. Would be interested in an estimate on how much it costs to split stuff out onto a separate DB.
    A win would be for it to be easier to switch to generator power but we wouldn't do this if we weren't going to do something more (like solar) later.
  2. Get an appropriately sized inverter and panel set up - one of those inverters that can automatically switch between grid power and solar when it gets shady. Not sure if this requires a battery or not - so I’d just get what I can get away with here. 
  3. The initial idea would be to use the solar set up during the day and save some Eskom pennies, but when there is a power outage, just connect to the generator instead. A manual way to switch over would suffice
  4. Eventually when I have money for enough battery power, when there is sun, then that will charge my batteries which will become my backup power. If there is no sun, then I can use the generator to charge my batteries. 

I realise that I have probably missed some steps I don’t even know about. Or problems I haven’t thought of. Maybe I’m thinking about this backwards? So would appreciate any thoughts. I also don’t want to be feeding back into the grid. Is this a suitable plan?
 

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Good idea with determining essential load avg as well as peak. 

40 minutes ago, MKRandburg said:

 

  1. Separate out the DB to include the items we currently run on the generator during power outages - start measuring the output of this. But possibly should measure before, we may split things out on the DB differently. Would be interested in an estimate on how much it costs to split stuff out onto a separate DB.
    A win would be for it to be easier to switch to generator power but we wouldn't do this if we weren't going to do something more (like solar) later.

All the bips and bops was about R2000 to get my essential load (all plugs and lights) moved from my main DB to a new surface mount DB. Diy job. 

This included a new ELCB, changeover, bi pole breaker, 40A trip breaker, case. 

Remember about R2000 for a electricity COC. 

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1 hour ago, swazz99jhb said:

Good idea with determining essential load avg as well as peak. 

All the bips and bops was about R2000 to get my essential load (all plugs and lights) moved from my main DB to a new surface mount DB. Diy job. 

This included a new ELCB, changeover, bi pole breaker, 40A trip breaker, case. 

Remember about R2000 for a electricity COC. 

Hmmm I'm not sure if I could do a DIY on it. Quite handy but nervous around electricity. So R2000 for parts, R2000 for COC and then labour?

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22 minutes ago, Brani said:

Are you plugging the generator into one of the plug sockets? 

yip. I know it's not a good idea. But we are very careful every time we do it. We have a protocol we follow. Another reason to have a good excuse to separate it out.

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2 minutes ago, MKRandburg said:

Hmmm I'm not sure if I could do a DIY on it. Quite handy but nervous around electricity. So R2000 for parts, R2000 for COC and then labour

No idea. I used Frans +27 82 804 1294 whose team did an excellent job finishing off what I started. 

I'm close to Randburg, so I'm sure they'll be able to assist. 

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18 hours ago, MKRandburg said:

Hey there everyone! First post coming up - be gentle!

Current set up
No Solar or inverters or batteries
1 x 2.2 kW petrol generator

During power outages: 

We plug the generator directly into the mains (mains switch is off and earth is on, turn geyser, pool, stove off at DB) via an extension cord from the garage into the house

You've been told this already, but this is not a safe practice. There is a reason why such arrangements are called "suicide plugs". 

Also it's a pain. Why not have something that just kicks in when it's needed and turns off when it isn't. Then if there's load shedding in joeys whilst you're down on the coast then you don't have to interrupt your fishing to wonder if your deep freeze will be OK or if your kids did things in the correct sequence.

Quote

 

We leave the lights and plugs on and keep the security items on, wifi, laptops and fridge on. We manage the loads if we need to turn the dishwasher, TV or washing machine on. So those are our essentials. We haven’t measured anything, we just go by how the generator sounds, if struggles, we turn some things off - very scientific ;)

So I’d like to get into solar because I’d like to save some money on Eskom, eventually have a quieter option than the generator for back up power and I just think solar is cool. 

The plan

This is how I was thinking about doing it and would appreciate some feedback on it.

  1. Separate out the DB to include the items we currently run on the generator during power outages - start measuring the output of this. But possibly should measure before, we may split things out on the DB differently. Would be interested in an estimate on how much it costs to split stuff out onto a separate DB

This is the way it is usually done. Your DB is split into essential and non-essential loads. The essential loads are always backed up by the solar system. There is usually a current limit on this. Mine is 20A (momentary bursts up to 30A are tolerated) which is more than your genny is putting out. And you can go bigger than that if you want (and if you can afford it).
 

Quote
  1.  
  2. Get an appropriately sized inverter and panel set up - one of those inverters that can automatically switch between grid power and solar when it gets shady. Not sure if this requires a battery or not - so I’d just get what I can get away with here. 
  3. The initial idea would be to use the solar set up during the day and save some Eskom pennies, but when there is a power outage, just connect to the generator instead. A manual way to switch over would suffice
  4. Eventually when I have money for enough battery power, when there is sun, then that will charge my batteries which will become my backup power. If there is no sun, then I can use the generator to charge my batteries. 

So up until point 3 you are talking about running in grid-tied mode. To get to (4) you will need a hybrid inverter - these are common these days. But if you run without batteries then when grid goes down your system stops working, even on a bright, sunny day, and you will have to resort to the genny.

But some inverters have the ability to switch the genny on for you. So if you get the genny wired in properly and get the right inverter and get the DB split done you will have some protection when load shedding happens. Maybe then you decide to forego the batteries. 

As regards load: The DB Split usually puts geysers, electric stoves and the pool pump on the non-essential side since these are known guzzlers of power. The guy who installed my system said that he liked to have the whole kitchen, except lights, on the non-essential side but I said I'd manage that situation. Because if you have the kettle, the microwave and, say, a toaster all running at the same time then for a short period of time the current gets quite high. There are usually many things in the kitchen that have a high draw, hence my installer's preference. But we manage this now. A gas stove helps because we don't have to use the electric kettle when there's load shedding or at night (though sometimes the hair drier, a deeply evil device, gets plugged in). 

Anyway, it sounds like you are aware of limitations and up to a bit of load management.

So my system, just as a starting example, can run the whole property (pool pump and all, one geyser on a heat pump) for a whole day if we have good weather*. It discharges the battery through the night and then starts recharging when the sun comes up. If there's a load shed we have only the essential loads (any time of day) but that gives me a constant 20A. The batteries when fully charged give me 10Kw/h. Since you don't want to run them flat that's really 9kw/h. Unless the weather is foul we will get through a 2 hour load shed no problem. And when there is load shedding and the weather is foul I can pre-emptively charge the batteries from grid, but I do this less often now that Jhb is on 2 hour load sheds like the rest of the country. When the grid drops the inverter kicks in very quickly. If you are close to an LED lamp you may detect a flicker, but you won't, for example, see a flicker on the TV screen. The system is effectively silent. If you get close to it you may hear some relays clicking, but no fans or warning beeps.

* we are still connected to the grid, and use a little every day. But on a good day (like today) "a little" is about 0.7 kw/h. 

 

Quote

I realise that I have probably missed some steps I don’t even know about. Or problems I haven’t thought of. Maybe I’m thinking about this backwards? So would appreciate any thoughts. I also don’t want to be feeding back into the grid. Is this a suitable plan?
 

 

Edited by Bobster
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19 hours ago, MKRandburg said:

I realise that I have probably missed some steps I don’t even know about. Or problems I haven’t thought of. Maybe I’m thinking about this backwards? So would appreciate any thoughts. I also don’t want to be feeding back into the grid. Is this a suitable plan?

With any sort of alternate power, even a solar geyser, you have to modify your habits to make the most of it. You have a solar geyser? Don't shower in the morning when there's going to be all that hot water in the afternoon. Etc.

Start with some simple disciplines. Don't fill the kettle all the way up in the morning and then boil it 3 or 4 times before you actually make a cup of coffee. Don't heat your water to the point where you need to crank up the cold tap to be comfortable - then you've wasted energy making that water too hot to use. Everybody should do these things anyway because they will bring some relief to your wallet. 

Most modern solar systems will give you some kind of monitoring tool. so early on you should use that and see what your load is at different times of day and then you can do the analysis of why things are as they are. You can then start "moving" loads. EG I have a heat pump, which is more efficient than a geyser element, but I don't let it run all day. It's on a timer and turns on twice a day - which gives us quite enough hot water when we need it, and means I have solar power available for other jobs during the sunny hours. The pool pump is on a timer so I can control when that runs and try to avoid too many big loads at the same time. The timer for my dishwasher is a nagging husband type. I tell them you can run it from this time to that time, not at 4 in the afternoon please.

Generally I try to do as much "heavy lifting" as I can during the day. Then at night it's just the fridges and the TV and maybe a bit of microwave. 

You literally have to make hay whilst the sun shines.

Edited by Bobster
seplling
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Thank you everyone for your responses. The reason I mentioned plugging the generator into the mains is because the first step I'd like to make on the way to doing solar would be to stop doing that. So the first step would be to split the DB and then have some kind of switch to run those essential appliances directly via the generator during power outages and not run around the house doing all the checks we have to so we don't burn our house down or worse. 

The second point I'd like some clarity on, is: can I buy one inverter that initially I can just draw solar power from during the day and it's smart enough to switch over to grid power when there isn't enough sun and then when there is a power outage I can switch the abovementioned switch to generator power? And then later when I want to expand I can add batteries to it? Is this possible?

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Hi MKRandburg

 

I would look in to the SunSynk brand of hybrid inverter, depending on the loads either the 5 Kw or the 8 Kw inverter. They will do exactly what you are looking to do. I think there are a lot of people who are running these on this forum so help should not be far away. 

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23 minutes ago, Greglsh said:

Hi MKRandburg

 

I would look in to the SunSynk brand of hybrid inverter, depending on the loads either the 5 Kw or the 8 Kw inverter. They will do exactly what you are looking to do. I think there are a lot of people who are running these on this forum so help should not be far away. 

Fantastic, that is great news.

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2 hours ago, Buyeye said:

The above mentioned inverter can also connect to your generator if your generator supports that. 

I'm pretty sure my generator doesn't support much, it's one of those cheapy, pull start guys. But I'm guessing there must be a way I can still connect it in, when required but in a some more manual way?

 

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Hi

The SunSynk/Deye Inverters are true hybrid Inverters that can either automatically start your generator if it supports it - or you can manually start it and feed the power in via the AUX port on the Inverter - You have many options to choose from . You can also put your entire house on inverter if you wanted to if you do not want to split out the loads . 

I have the 8 KW Deye Inverter with 22 X 415 W panels and 20 KW of Battery (2 X Dyness F10 Powerboxes) so my whole DB is on the inverter .

Also have a 5500W generator that I manually start if the battery is flat , the sun does not shine and Eskom decides to hide the power . I start it manually and the Inverter picks up the feed automatically once the Mains is down .

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20 hours ago, Bobster said:

But some inverters have the ability to switch the genny on for you. So if you get the genny wired in properly and get the right inverter and get the DB split done you will have some protection when load shedding happens. Maybe then you decide to forego the batteries.

I'm pretty sure if you have an inverter without batteries, but with generator, you're still up the creek without a paddle when the power fails, you'd have to start the generator manually, since the power is gone and without batteries, I have yet to see an inverter run on its own without the grid being there...

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I was looking at an earlier post of yours re "Geysers/hot water".

I found it considerably more effective to heat water with "Heat collectors" rather than with PV's - I have a combination of 1200L geysers, and in process of adding another 500L-800L (we use ALOT of hot water being a Birthing Centre) and don't even want to imagine the number of PV's needed to heat so much water.

VERY EASY to install some or other kind of RetroFit onto existing geysers. Vacuum Tubes more effective at higher temperature35C-80C, and flat panels more effective from 25C- 65C

Correct me if I am wrong, but calculated each 200L stores +- 12kW-16kW of energy. Batteries or Super Caps are not the "only" way of storing "household" energy! Should be a drive to install bigger geysers, rather than small geysers which "warm faster"....almost like saying we should not build bigger dams so that they can fill faster!!!

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Hi Charyl

I have always wondered about the best way to go about this. I have 2 x 150L geysers in my house. To retrofit these with solar is about R15K per geyser with labour. Now my thinking and this could be wrong, is that is R30k, if you are going to install a PV system anyway, could you not add that money into a bigger inverter,from a 5kw to 8kw Sunsynk is about +_R10K, then R20k worth of panels. Then when the 2 geysers are hot the extra power can be used elsewhere, where as with the solar geysers once the water is hot the sun is wasted? Whats your thoughts?

 

P.S I think in your situation with that much hot water it might work the other way round.

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3 hours ago, Kalahari Meerkat said:

I'm pretty sure if you have an inverter without batteries, but with generator, you're still up the creek without a paddle when the power fails, you'd have to start the generator manually, since the power is gone and without batteries, I have yet to see an inverter run on its own without the grid being there...

That makes sense. A grid-tied inverter can't do that. But I know that there is a device that turns a genny on when the grid dies. I used to work at a hospital and they had that setup. If grid went down, something kicked the genny in - with a couple of seconds delay. I assumed that there must have been some switch held open by grid power and that closed when the grid went down and initiated whatever is involved in firing up the genny. 

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3 hours ago, Kalahari Meerkat said:

I'm pretty sure if you have an inverter without batteries, but with generator, you're still up the creek without a paddle when the power fails, you'd have to start the generator manually, since the power is gone and without batteries, I have yet to see an inverter run on its own without the grid being there...

Absolutely with the current generator anyway, I'm outside yanking on the cord to get it going anyway! hehe But I want to plan this thinking ahead. Decide what the small steps are going to be with the ultimate plan in mind for the end. however I just looked at the price of SunSynk Inverters, and that is perhaps a bigger step than I had initially contemplated... so I might need a plan B. Or take longer to get into solar.

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6 hours ago, MKRandburg said:

I just looked at the price of SunSynk Inverters, and that is perhaps a bigger step than I had initially contemplated... so I might need a plan B.

The Sunsynk tick’s most boxes but unfortunately it does not suit everybody’s budget so in case of a plan B the cheap Voltronic Axpert inverters are in my opinion still a good option if you need backup. I have an Axpert and it has been keeping my lights on for a few years now and it also saves me a few pennies every month. The only problem is you would need batteries with the Axpert as they cannot work without batteries.

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Thanks @87 Dream can you recommend a reliable shop? 
I think spending around R10k maybe R12k on the hybrid inverter is around my budget and then I need to figure out panels. 
But I was thinking about maybe a heat pump to start with.

But first before I get ahead of my self i'm buying one of those Efergy energy monitors to figure my usage. A friend was saying all his usage is a at night so this set up wouldn't suit him, so need to confirm I'm not in the same boat. I don't think so though, 2 of us and no kids. 

Appreciate the comments and feedback.

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1 hour ago, MKRandburg said:

Thanks @87 Dream can you recommend a reliable shop? 
I think spending around R10k maybe R12k on the hybrid inverter is around my budget and then I need to figure out panels. 
But I was thinking about maybe a heat pump to start with.

But first before I get ahead of my self i'm buying one of those Efergy energy monitors to figure my usage. A friend was saying all his usage is a at night so this set up wouldn't suit him, so need to confirm I'm not in the same boat. I don't think so though, 2 of us and no kids. 

Appreciate the comments and feedback.

If someone had given me this advice I would have better for it. If you get the sunsynk for R8k more then you don't have to worry about the heat pump if you overspec on the PV panels.

 

I'm in the position you will be in if you go ahead with that plan. I have overspecced on the pv panels but I have no way of feeding my excess pv production to my geyser. The problem is the geyser has a 4kw element with is too big for a 5kw inverter. 

 

So I have looked at installing a heat pump but they are expensive. So now I'm looking at an inverter that can power loads before the inverter. 

 

If you really want a cheap inverter you can buy my growatt spf 5000es it's 5 months old.

Maybe someone else can advise if a mecer infinisolar 5kw inverter might be a good option for you. Like this one https://www.diygeek.co.za/product/mecer-infinisolar-4kw-super-single-phase-5000w-mppt-bi-directional-with-grid-parallel-up-to-6-48v-dc-copy/

Edited by Buyeye
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What we have noticed with the geyser after some really long power outages is, with the 2 of us, we can go a whole day and a bit and still get 2 hot showers out of our geyser, so I am thinking I may rather go inverter and panels instead of the geyser. We are going to put the geyser on a timer and then also monitor the energy and see. Lots of data still need to gather

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