Hi All

Hope you are well. I had a question. How do you know if we are saving once solar is installed. I am not seeing changes on my electricity bill. My geyser is still on eskon but I have installed a timer to control when my geyser is switched on and switched off.
I have a 5kva inverter and 4.8kva battery. I run the house on solar during the day (switching back to eskom when using high wattage appliances like an iron or running multiple appliances at once when need to).

 

Kind regards

Deepa

10 minutes ago, raatkirani said:

Hi All

Hope you are well. I had a question. How do you know if we are saving once solar is installed. I am not seeing changes on my electricity bill. My geyser is still on eskon but I have installed a timer to control when my geyser is switched on and switched off.
I have a 5kva inverter and 4.8kva battery. I run the house on solar during the day (switching back to eskom when using high wattage appliances like an iron or running multiple appliances at once when need to).

 

Kind regards

Deepa

Several points in no particular order:

How long ago did you get solar installed? Electricity billing is typically 30 to 60 days in arrears, so you wouldn't see an instant change on your bill.

Also if there are fixed charges for the connection to the grid, those won't drop away.

The jury is out on whether or not timers on geysers save money. I think there's an argument that the geyser has to work hard twice a day, rather than just draw smaller amounts throughout the day - and the two come to roughly the same. Me no electrician, and if I'm wrong, somebody will correct me.

Start reading your own meter. Read it for a week and extrapolate that to a month. If that's not showing a decrease then there's something not lekker with your installation or with the settings.

Part of maximising the benefit of a PV system is to do as much electrical work as you can when the sun is up. At night you do as little as possible - that makes the battery last longer and reduces your draw from the grid. My house after about 17:00 we have fridges, TV, wi-fi, lights, fridges - no heating water, very little use of kettles and microwave. All the heavy lifting, so to speak, must get done during the day when you are getting free power from the sun.

40 minutes ago, Bobster. said:

Several points in no particular order:

How long ago did you get solar installed? Electricity billing is typically 30 to 60 days in arrears, so you wouldn't see an instant change on your bill.

Also if there are fixed charges for the connection to the grid, those won't drop away.

The jury is out on whether or not timers on geysers save money. I think there's an argument that the geyser has to work hard twice a day, rather than just draw smaller amounts throughout the day - and the two come to roughly the same. Me no electrician, and if I'm wrong, somebody will correct me.

Start reading your own meter. Read it for a week and extrapolate that to a month. If that's not showing a decrease then there's something not lekker with your installation or with the settings.

Part of maximising the benefit of a PV system is to do as much electrical work as you can when the sun is up. At night you do as little as possible - that makes the battery last longer and reduces your draw from the grid. My house after about 17:00 we have fridges, TV, wi-fi, lights, fridges - no heating water, very little use of kettles and microwave. All the heavy lifting, so to speak, must get done during the day when you are getting free power from the sun.

I had solar installed about mid May. Winter i didnt see any difference as yet. My geyser is outside though and not inside my ceiling. I need to replace my geyser blanket as well.
Let me do that and check the meter during a week.

I think I also need assistance with my inverter settings. I suspect something is not right there. I also do the same try to make use of sunlight as much as possible and keep tv, fridges for the night. Any recommendations for best settings for luxpower?

10 minutes ago, raatkirani said:

I had solar installed about mid May. Winter i didnt see any difference as yet. My geyser is outside though and not inside my ceiling. I need to replace my geyser blanket as well.
Let me do that and check the meter during a week.

I think I also need assistance with my inverter settings. I suspect something is not right there. I also do the same try to make use of sunlight as much as possible and keep tv, fridges for the night. Any recommendations for best settings for luxpower?

Not familiar with the inverter settings but if most loads use PV during the day and charge batteries and the grid charge timer is off and you discharge the battery having the fridge and TV on battery power you must see less grid used. 

If the battery cannot get through the night have the timer to use grid say from 02h-07h when there is PV power. 

29 minutes ago, raatkirani said:

I had solar installed about mid May. Winter i didnt see any difference as yet. My geyser is outside though and not inside my ceiling. I need to replace my geyser blanket as well.
Let me do that and check the meter during a week.

I think I also need assistance with my inverter settings. I suspect something is not right there. I also do the same try to make use of sunlight as much as possible and keep tv, fridges for the night. Any recommendations for best settings for luxpower?

Do you have any sort of tool that you can access that shows what the system is doing? Something like this

I watched this very regularly when I first got my system. Especially the yellow line, which is the loads. I am quite familiar with the loads in my house by now. You can see the house just ticking over at night. Then 6:30 the heat pump turns on. Just on 7 there is a spike that is the kettle. The next spike is the dishwasher heating. 10:30 the pool pump switches on. Etc. So if you see something happening during the night, you can investigate and see what it is (and people you thought you knew will start calling you things like "nazi"). 

These tools are very useful early on because they give you a view of the flows of power and WHEN it is flowing. A part of having a PV system and maxmising the benefit is changing your routines so that you don't waste the battery at night and then have to recharge it. This is easier with 10kWh (which I have) than with 5, but you can still do some optimisation.

If you look at the stats on the inverter, how many kWh's of solar has it produced? This is energy that is reducing your utility bill. Then compare that with an estimate of how much you should be producing monthly and see if you are utilizing the available PV well. Your geyser is your biggest single energy consumer in the house - not having it backed up and using solar power means you're missing a large opportunity to reduce your Eskom consumption.

My view on geyser timers without the solar benefit is that they only save you energy if you use hot water at specific times in a day. Keeping a geyser constantly hot increases the losses as losses are proportional to the temperature difference between the water and the ambient air. If you only shower at night then being able to get the heated water up to temp just before you shower reduces the time for losses. Then after your shower the water temp can remain cold with very few losses over night and during the day. Unfortunately if you need hot water available all the time then a geyser timer doesn't help you much as you can't leave the water at low temps to reduce losses.

If you have solar to supply the geyser then a timer helps tremendously as you can heat the water during the day with excess solar.

As mentioned by a few members already, try getting some data, that will go a long way to start visually understanding your solar setup.
Check your inverter, most today have some sort of data logging that you can view.
Else at the very least try graphing your eskom bill or bought units ti visually start seeing your usage.

e.g. below, my last 6 months eskom purchases, being in Cpt this winter has been a bit harsh with clouds and rain, so ended buying quite a bit of power
My usual summer months I average less than 2 units per day from eskom.

Grid use for 2022:

This year to date:

Winter 2023 was a rather wet and cloudy affair compared to previous years.

Since I do not export to the grid, as soon as the batteries are full the mppt units pull back. So Solar totals can be much higher if allowed to export.

From the start of 2023 I've gotten a lot 'smarter' in managing loads with automation and scheduling. Home Assistant pulls data directly form the Victron Cerbo and now switches the geysers, pool pump etc on and off. This is where the savings happen. Switching your big consumers to times with ample sunlight and free power.

More panels are going up over the summertime to help with generation in winter. Currently got 5760W on the roof and they have been there since 2014. Going to add another 4kW. 

2 hours ago, JaseZA said:

My view on geyser timers without the solar benefit is that they only save you energy if you use hot water at specific times in a day. Keeping a geyser constantly hot increases the losses as losses are proportional to the temperature difference between the water and the ambient air. If you only shower at night then being able to get the heated water up to temp just before you shower reduces the time for losses. Then after your shower the water temp can remain cold with very few losses over night and during the day. Unfortunately if you need hot water available all the time then a geyser timer doesn't help you much as you can't leave the water at low temps to reduce losses.

This is pretty much what happened with us. We have a bit of an advantage, it turned out, in having a heat pump. We worked out two time slots a day which give us enough hot water at the right times for the two of us to shower. A big fat blanket on the geyser and lagged pipes (also already in place) help reduce losses. Our housekeeper has been told that if she wants to use hot water, she needs to do it early in the day.

The other thing that we need hot water for, of course, is dishes. We leave that up to the dishwasher, which we are now maxing out. Everything we can fit in there goes in, and we run it nearly every day. It's in economical mode which uses less than 0.9 kWh for a full load, and about 9l of water (try washing a full dishwasher load with 9l of water). Of course we don't run this at night, we run it when the sun is up.

@raatkirani don't feel discouraged. We all have been through this curve of understanding what loads there are and how we can move them around to make best use of the system. It's quite usual. Also see my comments about my dishwasher. For all your appliances read the manual and understand the different modes.

Edited October 9, 20232 yr by Bobster.

4 hours ago, raatkirani said:

Hi All

Hope you are well. I had a question. How do you know if we are saving once solar is installed. I am not seeing changes on my electricity bill. My geyser is still on eskon but I have installed a timer to control when my geyser is switched on and switched off.
I have a 5kva inverter and 4.8kva battery. I run the house on solar during the day (switching back to eskom when using high wattage appliances like an iron or running multiple appliances at once when need to).

 

Kind regards

Deepa

Welcome!

How many panels do you have and what are the specs of the panels? Good to know what sort of production you getting to also help with some suggestions.

Lots of good comments and questions already...do you have an idea of what your kWh consumption was like before you had solar installed?

Are you manually switching the breaker to supply the load from Eskom vs Inverter?

Hi @Bobster. Thank you so much I really need to do some homework how best to optimise etc

Thank you everyone too for your responses. Very helpful indeed.

@Carl Anthony I have 5 panels. 575 watts each. before i used to use around 750units a month in summer and almost 1000 units a month in winter.
I used to manually switch between Eskom and Inverter. Then the installer came and made a setting change on the inverter so that It shows eskom is sending power and triggers battery when there is loadshedding. So now what I do is around 6am I drop the AC In switch only during the day and then switch the AC IN switch back up around 5pm. I just have a feeling that something on my setting is not correct because Ideally I want to use sun during the day, use Eskom when I iron clothes as that pulls a lot of power, use some eskom in the evening and try to use battery early hours of the morning until the sun is up again to charge battery and power the house.
But I only have a 4.8kva battery and I don't have enough at the amount to increase my battery to 10kva.

I suspect i need a 10kva battery to keep be going through the night without eskom. but any recommendations would help.

I just thought I would see savings at the moment.
 

a

Edited October 9, 20232 yr by raatkirani
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56 minutes ago, Carl Anthony said:

Welcome!

How many panels do you have and what are the specs of the panels? Good to know what sort of production you getting to also help with some suggestions.

Lots of good comments and questions already...do you have an idea of what your kWh consumption was like before you had solar installed?

Are you manually switching the breaker to supply the load from Eskom vs Inverter?

Hi @Bobster. Thank you so much I really need to do some homework how best to optimise etc

Thank you everyone too for your responses. Very helpful indeed.

@Carl Anthony I have 5 panels. 575 watts each. before i used to use around 750units a month in summer and almost 1000 units a month in winter.
I used to manually switch between Eskom and Inverter. Then the installer came and made a setting change on the inverter so that It shows eskom is sending power and triggers battery when there is loadshedding. So now what I do is around 6am I drop the AC In switch only during the day and then switch the AC IN switch back up around 5pm. I just have a feeling that something on my setting is not correct because Ideally I want to use sun during the day, use Eskom when I iron clothes as that pulls a lot of power, use some eskom in the evening and try to use battery early hours of the morning until the sun is up again to charge battery and power the house.
But I only have a 4.8kva battery and I don't have enough at the amount to increase my battery to 10kva.

I suspect i need a 10kva battery to keep be going through the night without eskom. but any recommendations would help.

I just thought I would see savings at the moment.

4 hours ago, raatkirani said:

Hi @Bobster. Thank you so much I really need to do some homework how best to optimise etc

Thank you everyone too for your responses. Very helpful indeed.

@Carl Anthony I have 5 panels. 575 watts each. before i used to use around 750units a month in summer and almost 1000 units a month in winter.
I used to manually switch between Eskom and Inverter. Then the installer came and made a setting change on the inverter so that It shows eskom is sending power and triggers battery when there is loadshedding. So now what I do is around 6am I drop the AC In switch only during the day and then switch the AC IN switch back up around 5pm. I just have a feeling that something on my setting is not correct because Ideally I want to use sun during the day, use Eskom when I iron clothes as that pulls a lot of power, use some eskom in the evening and try to use battery early hours of the morning until the sun is up again to charge battery and power the house.
But I only have a 4.8kva battery and I don't have enough at the amount to increase my battery to 10kva.

I suspect i need a 10kva battery to keep be going through the night without eskom. but any recommendations would help.

I just thought I would see savings at the moment.

So you have the potential to produce about 2300w from panels depending on direction they are facing…so if your home load is at a constant during sun hours you should be producing about 12-14kWh (units) per day. Calc is kWp * (sun hours) 6hrs less 20% (for panel heat loss and cable length from panel to inverter and some other factors) = potential production per day.

Based on your stated electricity bill your daily consumption is between 25-35kWh (units) per day.

If you are maximising your load during the day in theory your bill should be halved at least. Not taking into account what your settings are and if its set to charge the battery during the night from grid etc.

What appliances and electronics are running during sun hours?

What appliances and electronics are being run during the night?

You said the geyser is a non-essential, do you know what kW element you have and also what are the set run times you have for it? I have 2 x geysers…one is a 2kW 150L and the other a 4kW 200L both run on the system…I run them early morning from the grid so we have hot water for showers…these days with warmer temps I can run them for 2hrs and 90min respectively and that consumes about 10kWh (units) in winter they both run for 3hrs…MAYBE 2.5hrs each and then it consumes about 18kWh (units) for the morning run only. During the day the run off PV…so they set to run twice a day each with one run being free and the other from the grid.

Sorry I can’t help with the inverter settings not familiar with Luxpower.

1 hour ago, Carl Anthony said:

You said the geyser is a non-essential, do you know what kW element you have and also what are the set run times you have for it?

It's also worth pointing out that "non-essential" doesn't mean "doesn't load the PV system". In many cases the panels and batteries will try to power the geyser,or at least contribute what they can,whilst there is grid power.

My pool pump is non-essential. If it were to run at night, and the grid was up, it would draw from the battery. If the grid is down, it won't run at all.

Again, this is something that checking of data will make clear.

6 hours ago, raatkirani said:

I have 5 panels. 575 watts each. before i used to use around 750units a month in summer and almost 1000 units a month in winter

IMO you are under panelled.

Your consumption is about 25kWh a day in the summer. That's about double mine. Yet I have another kW of panels.

Result is I can power pretty much everything most days, and so my meter barely moves.

I have a 4.6 kW inverter, a little smaller than yours.

We have to work according to our budget and our roof space, but if you can get more panels (remember the tax refund) and move as many loads as possible to the day, you will reduce your grid usage and have more independence.

I'm not giving you a rule of thumb here in terms of the ratio of panel kW to house kWh. You don't have to triple your panels, but you could use more.

Perhaps it boils down what one wants to achieve. If you want to cover LS and introduce some saving only then 5x575W panels can produce 11kwh a day if all PV is used(not easy) . This can be a 40% saving from the 25kwh a day. 

You should be seeing savings. These are my calculations in Ekurhleni  arbitraging the IBT and fixed rates.

Savings = Actual load cost on Fixed rate - Actual grid Usage on IBT rate 

Blue background is actual savings based on usage 

 

Edited October 12, 20232 yr by Gary Waterworth

i got my solar in July  5kw Battery and 2.7Kw Panels and noticed the following,

Before solar my daily usage averaged 15-17Kw.  Heater and Cooker are the heaviest hogs starting at 530PM -through to 1159pm

With Solar and my system  set to prioritise load. I get 7kw during the day and 8-11kw at night

Overal change to bill was zero, before solar Eskom Bill R1000, Now Eskom Bill R1000. No change but  I assume i would have paid more without solar.

I then changed my system such that my system now prioritises home load, so far it looks good. over the last 30 Days, i am averaging 3-4Kw per day and 11-13 kw battery and solar. but then its summer as well. More sun more power. 10Kw Battery is the best. Thats a future wish for me.

 

3 hours ago, Magetsi said:

i got my solar in July  5kw Battery and 2.7Kw Panels and noticed the following,

Before solar my daily usage averaged 15-17Kw.  Heater and Cooker are the heaviest hogs starting at 530PM -through to 1159pm

With Solar and my system  set to prioritise load. I get 7kw during the day and 8-11kw at night

Overal change to bill was zero, before solar Eskom Bill R1000, Now Eskom Bill R1000. No change but  I assume i would have paid more without solar.

I then changed my system such that my system now prioritises home load, so far it looks good. over the last 30 Days, i am averaging 3-4Kw per day and 11-13 kw battery and solar. but then its summer as well. More sun more power. 10Kw Battery is the best. Thats a future wish for me.

 

@Buyeye we have another cooker this side 😁

1 hour ago, hoohloc said:

@Buyeye we have another cooker this side 😁

Let me start with the OP. Your system is a good one. I have the same inverter and the setting you have to turn off is ac charging. Then the battery discharge to one that suits you, the weather and recommended depth of discharge eg. on sunny days mine is 90%. On rainy days like this week it's set at 50%. You shouldn't have to touch the change over switches unless there is a fault. You should only have to use the luxpower app. If you tick take load together the inverter will prioritize the load but may trip the prepaid meter if you have one.

If we were to size your system we could say it's a small system and your requirements are a medium sized one.

Since your current system cannot cover everything, you have to decide whether to budget to build it up to a medium sized one or reduce your usage.

You did not specify if the stove( not cooker 😁) and the geyser are electric. I would suggest looking into the cost of converting the stove and geyser to gas vs adding more panels and batteries. If a gas geyser is scary then reducing the electrical element to a size that can be powered by the inverter is also an option eg. 4kw to 2kw or 3kw to 1,5kw ect.

The question of how the stove and geyser are powered has to be addressed as they are 80% of your bill.

You can safely use the iron with the current system as most irons only use 2000 watts not constant. They come on and off.

Most of the points above also apply @Magetsi.

Edited October 12, 20232 yr by Buyeye

@Bobster. You have great stats on your system so you can as a test disable the timer for the heat pump and leave it on during a 24h period and check how many times it comes on to keep the temp at your normal setting.

Then compare it to if it was off say during the night and do one heating cycle early in the morning. 

The results might answer the doubt about timers saving a bit of power or not. Share your findings. 

On 2023/10/13 at 1:23 AM, Buyeye said:

Let me start with the OP. Your system is a good one. I have the same inverter and the setting you have to turn off is ac charging. Then the battery discharge to one that suits you, the weather and recommended depth of discharge eg. on sunny days mine is 90%. On rainy days like this week it's set at 50%. You shouldn't have to touch the change over switches unless there is a fault. You should only have to use the luxpower app. If you tick take load together the inverter will prioritize the load but may trip the prepaid meter if you have one.

If we were to size your system we could say it's a small system and your requirements are a medium sized one.

Since your current system cannot cover everything, you have to decide whether to budget to build it up to a medium sized one or reduce your usage.

You did not specify if the stove( not cooker 😁) and the geyser are electric. I would suggest looking into the cost of converting the stove and geyser to gas vs adding more panels and batteries. If a gas geyser is scary then reducing the electrical element to a size that can be powered by the inverter is also an option eg. 4kw to 2kw or 3kw to 1,5kw ect.

The question of how the stove and geyser are powered has to be addressed as they are 80% of your bill.

You can safely use the iron with the current system as most irons only use 2000 watts not constant. They come on and off.

Most of the points above also apply @Magetsi.

Iam happy on my end. Winter is just unavoidable and i have no more funds to upgrade .

On 2023/10/13 at 6:38 AM, Scorp007 said:

@Bobster. You have great stats on your system so you can as a test disable the timer for the heat pump and leave it on during a 24h period and check how many times it comes on to keep the temp at your normal setting.

Then compare it to if it was off say during the night and do one heating cycle early in the morning. 

The results might answer the doubt about timers saving a bit of power or not. Share your findings. 

Sorry for taking so long to get back to you on this.

I'm reluctant. I have a 4.6 kW inverter, and this is surprisingly easy to overload. One of the reasons I've had the heat pump on a timer is that this creates a time slot in the morning in which appliances can be used without us having to worry about the heat pump (which is backed up) running at the same time. And it creates another slot in the afternoon which I can use to heat the guest geyser using solar.

I also don't want to have it running at night, or not yet, because it will draw from the batteries.

But I have set it so that it turns on at 6:00 and will be left on until 15:00. We'll see how that goes.

I don't know if we'll get anything conclusive. There's only two of us, so not a lot of showering going on (keep your smart remarks to yourself). We run the washing machine on a cold cycle. Etc. Plus we have a lot of insulation on the main geyser and the hot pipes are lagged.

What I'd like to know is how to get these graphs and data from the inverter

I'm using a Kodak OG7.2 and the book describes how to connect.  This fails when scanning the 14-digit number as it is not recognised, either inserting manually or scanning the code

Btw:  My first system (now much extended) was fitted in 2015.   Over the years there has been a substantial decrease in electricity units used.  In summer we are down to 10 units a day.   So I'd say its working fine, apart from no blackouts