October 1, 20223 yr I'd like to hear from everyone what their average kWh eksdom usage was before and after having solar installed We had solar installed mid August but decided to do my first reading in September and compare it to the same month of last year. For the month of September we used a total of 21 kWh compared to 512kWh for the same month in 2021. The 21kWh mostly contributed to the grid prickle charge set on the inverter. We still use a electric stove and oven,3 aircons 1 electric geyser and 1 flat panel solar geyser with a electrical element that we can use if the water did not heat properly during the day.Not bad Imo. the above mentioned is connected to the non essential load with the ct clamp in place to allow excess solar to feed non essentials. Our system consist of: 14x 545w canadian solar panels 8kw sunsynk inverter and 3x 5.12kWh navitas batteries.
October 1, 20223 yr Had my system since Aug 2021. It was installed as a standalone off-grid solution from the start. i.e. I have a change over switch, either Solar system or Grid. My monthly usage before I had solar installed used to be 180-250kWh, so never was a wasteful consumer. With solar now my average has gone up to above 300kWh and Jun and Jul I actually exceeded 500kWh running a electric fan heater during the day to increase the inside temperature. I am on prepaid now so if I see my usage after sunset is pushing the battery below a certain limit then I sometimes switch to the grid to conserve the battery for the night. That gives me an average of 10kWh grid per month, and that is mostly from May to Aug. Now that our solar starts early in the morning as we go into summer, I really don't need any grid power. The only proviso is I have to recharge the prepaid once in three months at least, else they disconnect it. Add a R50 voucher every second month or so and use the grid just so that their "high tech" machinery doesn't trigger a disconnect. System specs are in my signature
October 1, 20223 yr 1 hour ago, TiaanSmit said: I'd like to hear from everyone what their average kWh eksdom usage was before and after having solar installed We had solar installed mid August but decided to do my first reading in September and compare it to the same month of last year. For the month of September we used a total of 21 kWh compared to 512kWh for the same month in 2021. The 21kWh mostly contributed to the grid prickle charge set on the inverter. We still use a electric stove and oven,3 aircons 1 electric geyser and 1 flat panel solar geyser with a electrical element that we can use if the water did not heat properly during the day.Not bad Imo. the above mentioned is connected to the non essential load with the ct clamp in place to allow excess solar to feed non essentials. Our system consist of: 14x 545w canadian solar panels 8kw sunsynk inverter and 3x 5.12kWh navitas batteries. September 2022 in JHB South has been an excellent month for Solar PV - my best month so far (system installed in Nov 2021). I had a 666.7kW of load, with only 16.9kWh coming from the grid. Most of the 16.9kWh was used on the 1st Sept, then the trickle feed used the rest. Tip: >1 flat panel solar geyser The normal (Eskom) recommendation is to use a timer to heat the water using electricity at 4pm-6pm and again at 4am-6am. Normally the sun will heat the water to above the thermostat setting of 60°C so the 4pm-6pm cycle won't kick in. What I recently did, was to use the solar geyser to store PV energy. My battery is normally full by 12pm-1pm and since I'm not yet grid feeding, the afternoon PV electricity is "wasted". What I did was I changed the 4pm-6pm cycle to 10:30am-6pm. Normally by 10:30am, my PV is generating about 4.5kW (see signature below for my system details). Typically ~3.5kW is going into the battery and ~1kW is going to running the house. I turn on the electric element in the solar geyser an 10:30am, this uses 3kW to force the temperature to 60°C in 1 to 2 hours - effectively storing 3 to 4kWh of PV in the geyser. The sun in the afternoon then boosts the temperature from 60°C to 70/75°C. Since the geyser is at 70/75°C even if we use hot water at night, we hardly ever need the 4am-6am boost. This helped me.
October 1, 20223 yr Author 5 hours ago, system32 said: September 2022 in JHB South has been an excellent month for Solar PV - my best month so far (system installed in Nov 2021). I had a 666.7kW of load, with only 16.9kWh coming from the grid. Most of the 16.9kWh was used on the 1st Sept, then the trickle feed used the rest. Tip: >1 flat panel solar geyser The normal (Eskom) recommendation is to use a timer to heat the water using electricity at 4pm-6pm and again at 4am-6am. Normally the sun will heat the water to above the thermostat setting of 60°C so the 4pm-6pm cycle won't kick in. What I recently did, was to use the solar geyser to store PV energy. My battery is normally full by 12pm-1pm and since I'm not yet grid feeding, the afternoon PV electricity is "wasted". What I did was I changed the 4pm-6pm cycle to 10:30am-6pm. Normally by 10:30am, my PV is generating about 4.5kW (see signature below for my system details). Typically ~3.5kW is going into the battery and ~1kW is going to running the house. I turn on the electric element in the solar geyser an 10:30am, this uses 3kW to force the temperature to 60°C in 1 to 2 hours - effectively storing 3 to 4kWh of PV in the geyser. The sun in the afternoon then boosts the temperature from 60°C to 70/75°C. Since the geyser is at 70/75°C even if we use hot water at night, we hardly ever need the 4am-6am boost. This helped me. I did the same. Set the geyserwise controller to heat from 11am to 4pm. To 55 degrees. The flatpanel pushes it beyond 70 degrees on most days mid to late summer the geyser averages 85 degrees. Winter months will be a different story since I've not been through a full winter with solar I reckon my geyser timers will need to be adjusted to kick in slightly later. We heat 1 geyser at 6 in the morning for the hairsalon. Even though it's on Non essential it draws about 10% battery power to heat up to 45 degrees.this usually leaves us with 63% average soc in the morning. By 10:00 our batteries are fully charged. Some days even earlier than that.
October 6, 20223 yr I have Municipal account data since June 2008. Our monthly electricity use has been fairly stable till June 2022 when my PV panels became a factor. Average monthly usage based on 30.5 days for 24 months till June 22 (before PV) was around 425 units or then about 14 units per day. Were only 2 persons in the house and use power conservatively. Since June 2022 this has decreased slowly to 9.36 units per day for Sept 22, that equals a saving of 4.64 units or 33% I have been considering this, it seems a relatively small saving if I consider that many days the solar provides nearly all the electricity the house needs during daylight hours. If I then convert the saving to Rand it actually looks worse (4.64 X 2.88 = R13.38 pd = R408.18 pm) This would be a pretty reasonable saving, but it is not true when I look at my account as there are all kinds of Factors effecting the actual amount, of which the crucial one is a fixed charge portion of the electricity account. There has also been a tariff increase. My monthly saving has in actual terms taken from my account only been about R150 pm. The fixed portion of the electricity account is only set to increase as more people decrease their electricity consumption. Only my stove and oven are outside the inverter, so that is a given that I can not influence and for the past month I have done everything possible to run the house fully from the sun, even my geyser when I am at home. Although the monthly saving is not crucial, it does play a role and seems to be much less then I had reasonably anticipated. In coming month I expect to increase my saving somewhat, but will see. I also notice I seem to be using much more grid electricity then others, but “if you use little you can only save a little” I must compare the readings from my inverter to those provided by the City. I pay the City of Cape Town.
October 6, 20223 yr @RodbuilderIt would help to know more about your system, especially the capacity of the battery. When I took the plunge, we were using 13 to 14 kWh per day. Since installation (just over 3 years ago) our average - including overcast days, a couple of failures of a different brand of battery, and some forced recharging whilst I was on holiday and had to ensure our housesitter had power - is 2.4 kWh per day. On sunny days like we've been having in Gauteng the last while, it is handily under 1 kWh per day. You can see my setup in my signature. One signficant thing I have found when comparing with other laypersons who have gone to the solar route is the 10kWh battery. A lot of folks go for 5kWh, it's cheaper, and that's the direction the salesperson nudged them. But 10 kWh gives me a lot more flexibility, because I will usually get through the night on the battery. If it is 100% SOC by about 15:30, I should get through to at least 7 the next morning. Now Our water heating is done by a heat pump. This draws less power than a 2kw geyser element, and for less time. So the drain on the battery is not too great If I had a 5kWh battery, I'd be close to using the useful capacity over night. I usually have 50 < SOC < 60 after the water heating. So 5 and a bit kWh left. A 5kWh battery would be run down to the point where the BMS would stop it discharging, and at that point the system would resort to grid power (assuming there is grid power). We have a full gas stove. The electrical load for cooking a meal is negligible. We have made some changes to our habits to make the best of the PV system. So we never run the dishwasher or the pool pump at night. We only heat water whilst the sun is up, and we have good insulation fitted to the geysers so that they retain heat (heat pump switches on at midday, is usually done by 13:00, and we still get a hot shower at 8 or 9 pm). So I think you need to get a handle on when you use power, and ensure that you are making best use of PV. What inverter do you have? Many of them offer a graph tool that you can use via an app or online. Here's my graph from yesterday Note that we don't have a lot of heavy loads (yellow line) after hours. Only the early morning water heating, but we found out by trial & error that we can get away with that (though maybe we wouldn't with a 5kWh battery). When I first got this tool, it was invaluable for seeing what I used, when, and what the impact on the system was. NB! This is actually a quiet day in our house, No dishwasher for a start. But hopefully this illustrates the sort of tool I'm talking about and how useful it can be for optimisation. Until you have a handle on what is using how much power and when, you can't make best use of the system. You should be doing better than you are, but we need more information before we can give you helpful advice. A lot of people get caught out by those flat charges. Here in Johannesburg we currently have the option of a pre-paid meter which has no flat charges per month but a higher charge per kWh. A lot of people I know could save money just by converting to that prepaid tariff. Edited October 6, 20223 yr by Bobster. clarity
October 6, 20223 yr I need to go out but quick response, I'll add more later. Main differences between us:- I need to warm geyser from PV, can do most days but today not, raining and heavily overcast and I need to be home to keep an eye on it. I have only 5.5 kw battery, I know that is not enough to carry me through the night, but often switch off grid around 04h00 and then charge battery from PV. Is a bit tricky as around 07h15 I make breakfast, coffee machine, kettle, toaster etc. I have that taped but wifey not so much. I could run around 6 hours at night, but that leaves no load shedding margin. Obviously we have electric stove and oven which runs outside inverter. I don't know quite how much that uses but probably around the same as the geyser My guess is that is already a major part of the issue. I can see Sunsynk app details. 10 X 640 panels, also facing N.E. Sunsynk 8 Kw Hybrid Hubble 5.5 Kw battery At the moment I am trying to learn how, what this all works to decide what I want to do about it. Not keen to spend more unless it clearly pays for itself. As to Pre Paid meter, I don't like that idea, just another hastle and wont change that unless clearly worth while.
October 6, 20223 yr 2 minutes ago, Rodbuilder said: Obviously we have electric stove and oven which runs outside inverter. I don't know quite how much that uses but probably around the same as the geyser Well, on my system the swimming pool and the guest geyser are not backed up, but whilst the grid is up they run off of PV and/or battery. They are not backed up by the inverter, but also not completely isolated from it. One tool I have to mitigate against this is that I can put a rule on the inverter that allows the batteries to discharge only so far when the grid is up. This is set to 40% DOD (IE 40% left), and so I will always have at least 40% (probably 30% actually useable) when the power goes down. If you look at the graph I posted, you will see the pool pump turn on about 10am. Actually this is being supported by PV. On an overcast day it would start pulling from the battery until that 40% DOD protection kicks in. If I were to run it at night, it would draw from the battery whilst there was grid power. It only completely disconnects from the inverter when the grid power is off.
October 6, 20223 yr One thing you can look at to manage your battery for maximum ROI while maintaining charge for loadsheds - SolarAssistant with the Maintain SOC setting - the % and times assumes that I will either be loadshed or power will be out till 8am when panels will take over. As the night progresses if there was no outage or the loadshedding was extended it switches between utility and battery If there is an issue with cloud for the day i'll switch to Utility charge to build battery before the daytime sessions
October 6, 20223 yr Thanks. I know that I can set certain parameters based on times. I first need to understand all this stuff before I attempt to "fiddle" with it😉 One problem I see is that I will always be at risk if I do not buy another battery but its a bit steep to throw in another R30 000- With Solar assistant, can I do the changes from my desktop? It does not seem that the Sunsync interface can do that, I have to go to the machine and do it there.
October 7, 20223 yr I need some assistance to get my system registered in Cape Town, please see Sorry to hijack thread but is urgent to me and can not find the support I need! Ekskuus!
October 7, 20223 yr 19 hours ago, Rodbuilder said: Thanks. I know that I can set certain parameters based on times. I first need to understand all this stuff before I attempt to "fiddle" with it😉 One problem I see is that I will always be at risk if I do not buy another battery but its a bit steep to throw in another R30 000- With Solar assistant, can I do the changes from my desktop? It does not seem that the Sunsync interface can do that, I have to go to the machine and do it there. with solar assistant you can make changes from your phone / desktop
October 7, 20223 yr You are correct, as far as I know, the Sunsynk interface does at this stage not have that ability and I managed to obtain fairly high level access. I presume some additional hardware is required, can't just plugin a RJ45 network cable?
November 3, 20223 yr Author On 2022/10/01 at 11:00 AM, TiaanSmit said: I'd like to hear from everyone what their average kWh eksdom usage was before and after having solar installed We had solar installed mid August but decided to do my first reading in September and compare it to the same month of last year. For the month of September we used a total of 21 kWh compared to 512kWh for the same month in 2021. The 21kWh mostly contributed to the grid prickle charge set on the inverter. We still use a electric stove and oven,3 aircons 1 electric geyser and 1 flat panel solar geyser with a electrical element that we can use if the water did not heat properly during the day.Not bad Imo. the above mentioned is connected to the non essential load with the ct clamp in place to allow excess solar to feed non essentials. Our system consist of: 14x 545w canadian solar panels 8kw sunsynk inverter and 3x 5.12kWh navitas batteries. Update***** For the month of October we used a total of 26kWh from Eskom compared to 580kWH for the same month in 2021. September = 21 kWh October = 26 kWh The goal is to remain under 1 kWh Eskom units per day. Not sure how it will play out in winter.
November 3, 20223 yr On 2022/10/07 at 3:40 PM, Rodbuilder said: You are correct, as far as I know, the Sunsynk interface does at this stage not have that ability and I managed to obtain fairly high level access. I presume some additional hardware is required, can't just plugin a RJ45 network cable? I am not correct, the Sunsynk app does allow you to make setting from your software. You do need to obtain the required permissions from Sunsynk.
November 3, 20223 yr Hi Tiaan, I love the graph/report you have create. Would you mind sharing it. I would love to use this on my own installations etc. Kind Regards David Pretorius
November 4, 20223 yr 9 hours ago, MRE said: Hi Tiaan, I love the graph/report you have create. Would you mind sharing it. I would love to use this on my own installations etc. Kind Regards David Pretorius https://www.solar-assistant.io
November 20, 20223 yr System installed May/June 22 Am on grid and have been managing my Geyser to try to maximise solar use. I have many years of Municipal account data, and my electricity use has always been very stable at around 420 pm. Roughly 50% decline in units used from City but because of fixed portion of tariff not 50% reduction in Rand cost.
December 6, 20223 yr Author Update for November. November was a relatively good month with the exception of one extremely foggy day on 02/11/2022 Our batteries dropped below 50% SOC and the local municipal grid was off due to a substation that tripped when the power came back online after loadshedding. Total Eskom units used for November = 9.5kWh. We used 432 kWh for the same period in 2021. As mentioned in previous post's, the major contributing factor to our eskom usage is the grid prickle charge set at 20w. I'm looking forward to the winter month's to see how we can best optimize our system to limit eskom usage to sub 20kWh per month. One of the thing's I'm considering is moving aircon's, geysers, stove and oven onto it's own circuit with separate changeover switch from essential to non essential and vice versa but still keep the ct coil in place to allow excess solar to feed non essential load if I make the switch. Eskom usage summary: September = 21 kWh October = 26 kWh November = 9.5 Considerations - add more battery storage capacity for winter months.
December 6, 20223 yr I am on grid which has certain limitations, and I am registered with CtC witch is a terrible pain. Battery capacity is probably the key to maximising your usage saving in my situation and I am installing another battery today which will enable me to run on battery most of the night. I am firmly of belief that we will eventually not be saving much as CtC will simply re structure the electricity tariffs in such a way that they don't lose revenue. Most daytimes I can run whole day with the grid off, except for cooking times.
December 18, 20223 yr To further optimise night time battery usage, consider using a timer to switch off fridges / freezers from 22h30 to 6h00 when mostly not used. Might not seem like much, but may add up if you have a few of these in your household ...
December 19, 20223 yr Thanks. If I wanted to go to those length I would probably first have to address my stove and oven and get a gas electric hob or something like that. I don't think it is worth the cost, but what is the convenience worth..... A lot more. What I am trying to find out is if I can somehow get a Smart Switch to put the grid on/off?
December 19, 20223 yr 11 hours ago, DeonBez said: To further optimise night time battery usage, consider using a timer to switch off fridges / freezers from 22h30 to 6h00 when mostly not used. Might not seem like much, but may add up if you have a few of these in your household ... Not sure I would recommend switching off fridges/freezes due to possible food issues. When the device comes on, it will need to run for a while to get the temperature back to the thermostat setting, negating some of the savings. Below is the electricity consumption for my 300L vertical fridge and 300L vertical freezer - they overfull. I would save 0.41kWh (MAX)
December 19, 20223 yr Your system is relatively large for your average consumption - you should effectively be off-grid in the dry summer months. We are a family of 6. Our municipal consumption dropped 25% when I installed solar geyser (pre-feeding the second geyser plus Geyserwise controllers). Municipal consumption dropped by the same amount when we installed 14 x 455 kWp + 8kW + 10.2kWh. Total consumption went up, partly due to kids growing up, and partly because it is now "free".
December 19, 20223 yr System commission date: 3 December 2020. Also added a heatpump at the same time and have been replacing appliances ever since with A++ or A+++ models as they break. Sunsynk 8Kw, 7.2kWp installed PV and 10kWh batteries up to Aug 2021 and 15kWh after that date. Location Western Cape which explains the higher winter usage Electricity bill for 2020 was about R30k (from 1 Dec 2019 to 30 Nov 2020) for the year. This excludes fixed charges. To lazy to add the data into PoweBi, excel will have to do. Edited December 19, 20223 yr by I84RiS
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