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Load shedding now + solar later


WAP

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Good day everyone.

I am convincing myself i need an inverter, batteries and later on solar as well. I have no idea where to start. Who to contact for quotes on parts and installation etc?

Can anyone give me some guidance? Installers and suppliers i can contact.

Below i have attached my current usage as measured over the last 2 years with a Engage Efergy meter. Could someone make out from the below what i would need to include the whole house on an inverter and batteries. I have 2 x 200L geysers. At the moment i am using a generator to power the whole house except the geysers in load shedding or power outages.

Thanks in advance

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Welcome here, good choice. There are many examples on here of different systems. You certainly have the basic info shared above to make some informed choices. You can search on here for some info. Many systems were documented with pictures, including my own. Be prepared to drink from the solar hose so to speak. You will get many suggestions from members on here. Keep in mind that every persons own needs vary, what works for me may not work for you.

As part of the Energy info, you should have the daily demand graph as well. This will tell you the kW peaks that your system needs to cater for. I shared a way to design a system on here in Solar planing and design guide, should you want to read up a bit.

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It is important to know what time of day (or night) your usage spikes are and if you possibly have such graphs that definitely would be beneficial in calculating your inverter size, battery size, (and later solar size), etc.

 

Solar will only take you so far during the day, for both summer and less so much in winter (taking an average of 7.5 hours of solar sun in winter and maybe 8.5 or 9 hours during summer), and this is where your battery decisions comes into play, which also drive the factor of lithium vs gel vs lead acid, should they be able to communicate with one-another and even the inverter, etc ...

 

If you do plan on up-scaling later on, like adding panels, more batteries, blending Eskom, etc. rather look at getting a proper Hybrid Inverter now (possibly one that can run parallel for larger scaling later), than being stuck with something you will most likely end up selling again 3 months or 4 months down the line.

 

By the looks of it with 2 x 200L geysers your usage is surprisingly low, unless they are already converted to solar / gas?

 

I average on 50kW ~ 60kW daily ... (used to be lower), but once you realize that "free-powa" is a nice thing, you'll soon be turning every device on in your house almost daily ~ well that was in my case ... 😂

 

Basics first ...

 

  1. Replace all light-bulbs with LED
  2. If possible look at geyser conversions (I found that the best option is the EV Tubes, where your existing geysers are converted to "solar" - with 30 tubes you should be able to easily share the load between 2x 200 L geysers with a smile + your maintenance on them is very low compared to other options)
  3. If possible look at gas - stove / hob replacements

 

Just with the above 3 items alone you will already cut probably about 50% on your electricity bill (and solar / battery / inverter size alone).

 

This most definitely will bring down your usage, so you can "scale" for much smaller systems and calculate accordingly.

 

Some might argue rather scale bigger so you can cater for the electric stove, etc ... but just the above items #2 and #3 will ensure hot water even during load-shedding, hot food and coffee during those dark nights, and will teach you to change your lifestyle accordingly, and may even reduce your usage habits further.

 

* That's just my opinion of where I started from

 

PS: I had wasted thousands on useless installers, etc... etc ... and ended up doing everything myself - I do have some background though, but got a lot of help on this forum ~ watch out for replies form others who will tell you who to look for (installers) and who to duck and dodge!

 

Best of luck to you on this journey!

Edited by RabidBunny
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Thanks for the replies thus far. 

Whole house is led lights, 2 x 200L geysers not solar or gas, gas hob, 1 single person.

This is what my peaks look like when the domestic is here.

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And this would be a normal day 

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And now like today after the power came back from load shedding i guess the geysers kicked in and the washing machine and the kettle to peak at 5.3kw.

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I would ideally like an inverter like the Sunsynk 8kw and lithium batteries. Have no idea on how many panels of what size i would need.

Thanks again 

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I would recommend the 5kw Sunsynk with that kind of usage ,to justify the extra cost of the 8kw inverter you have to be spending quite a bit of time above 5kw throughout a day. As many LiFePO4 batteries as you can afford ,same for solar .Depending on your roof space available you can go up to 6500w as a North facing array or more if you have east/ west roof split. Personally i would prob go for 2 UP5000 or US3000C as a start with space /cabinet to upgrade to 4 or more overall in the future if the budget does not allow for it to happen all at once. 

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1 hour ago, Nexuss said:

I would recommend the 5kw Sunsynk with that kind of usage ,to justify the extra cost of the 8kw inverter you have to be spending quite a bit of time above 5kw throughout a day. As many LiFePO4 batteries as you can afford ,same for solar .Depending on your roof space available you can go up to 6500w as a North facing array or more if you have east/ west roof split. Personally i would prob go for 2 UP5000 or US3000C as a start with space /cabinet to upgrade to 4 or more overall in the future if the budget does not allow for it to happen all at once. 

I agree with Nexuss, your normal usage does not seem to peak much above 4kW by the looks of it. I'd in your case also look at the 5kW inverter, as 2x of them is roughly the cost of 1x 8kW and they can run parallel.

 

Your usage seems to be very low during the majority of the day and mainly spiking at wake-up time and bed time ... assuming that is kettle / geysers.

 

Your average per day seem to be hovering around the 20kW mark, which means you're pulling less than 1kW per hour spaced out over 24 hrs.

 

I'd say to start of with 1x 5kW battery should be able to carry you through 3 hours of loadshedding permitted the geyser doesn't run through that same period. Important note, if you chose to piggy-back your geyser on solar have a plumber replace your geyser element with a 2kW, the usual 4kW drains a battery like a hot knife through butter.

 

6 x 410W panels should also suffice for the size you're looking at and to cover most of your daily load (and charge the battery).

Edited by RabidBunny
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1 hour ago, 87 Dream said:

As said by most of the replies on here. 5kW would be ok for your inverter needs, however, there is a major scenario that no one has picked up on. The capacity of a said 5kW inverter when all your loads are on at the same time. So your 2 X geysers need to be staggered by the looks of your data one of your geysers has a 3.5kW element. If you have this geyser on at the same time as the kettle you at above 5kW. This graphic that you show is a graphic in isolation. 

This is a non-issue as you should not have your geysers on the essential side of the inverter.

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5 minutes ago, Nexuss said:

This is a non-issue as you should not have your geysers on the essential side of the inverter.

Not for everybody. I consider my hot water as an absolute essential, so do many other people. There is no thing like it should not be on the essential side. I planned to have mine so designed the system around that. Requirements rule.

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18 minutes ago, Sarel said:

Not for everybody. I consider my hot water as an absolute essential, so do many other people. There is no thing like it should not be on the essential side. I planned to have mine so designed the system around that. Requirements rule.

Yes i agree with you,my statement/advice is more aimed toward the lower end budget,which most of us are on haha!, If you want geysers/aircons/microwave/kettle and other large draw items on the essential side i would prob go for 2x 5kw Sunsynks or the 8kw. I guess it all comes down to budget then. 

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It is always, your budget vs requirements. We all want everything, but the budget is the one item that is determinate, or the significant other 😬. Same for my budget, I wanted other things, but do not have the money 😕 

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Back to on topic. A few principles are in order. First, try to reduce consumption. Then try to schedule loads so not too many of em overlap too much. Then decide what is essential loads for you. Then calculate how much inverter you need. Simple enough eh 😅

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2 hours ago, 87 Dream said:

As said by most of the replies on here. 5kW would be ok for your inverter needs, however, there is a major scenario that no one has picked up on. The capacity of a said 5kW inverter when all your loads are on at the same time. So your 2 X geysers need to be staggered by the looks of your data one of your geysers has a 3.5kW element. If you have this geyser on at the same time as the kettle you at above 5kW. This graphic that you show is a graphic in isolation. 

Pretty darn sure that on many other given days this sub 4kW peak is sometimes scratching above 5kW at the correct timed use of appliances. 

I always say, do not give me the best data that makes you make a smaller choice of inverter because it makes better financial sense. Rather make a better inverter choice based on system peak demands. I think that your data is too narrow & I know what a geyser looks like on a power graph & your geyser is at 3.5kW & most kettles are in the range of 2kW. So unless you will have discipline your system will need to be managed. If you opt for a larger 8kW system you have the breathing space. 

But, this equipment is not cheap so by all means buy the best your budget allows but make sure to buy quality. 

Welcome on here, many threads to read & gain an understanding of what's the best fit for you & your household. Couple of Clubs here in isolation, there is the Sunsynk, Deye, Voltronics (Axpert), Growatt & the Victron mafias here🤠. Will take you time to figure out where you best fit in on this playground. However, feel at home & feel free to share & to gather advice. We learn from the most knowledgeable & most novice as we explore.

87

Thanks that is exactly what i am thinking. I don't want a system specked on the what is the minimum i can get away with. I want to have breathing room. Buy once cry once.

I also don't want to have to juggle loads or wire in essential and non essential loads. Everything must work as if nothing happened. I don't want to tinker and adjust settings every other day. The system must be installed and I can forget about it. Only monitoring it. 

Any suggestions on who i can contact for quotes and installation ? I am in Secunda, MP

Thank you for all the responses thus far.

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Thank you again for the replies. I used the shower this morning during load shedding. Power only came back after 9. I can see the immediate spike to 3.47kW after power came back. I assume its the geysers as i was using the generator until after nine and on the db only the geysers were switched off while on the genny.

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5 hours ago, Sarel said:

Not for everybody. I consider my hot water as an absolute essential, so do many other people. There is no thing like it should not be on the essential side. I planned to have mine so designed the system around that. Requirements rule.

He should speak for himself, Hot water is absolutely essential 😂

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13 minutes ago, 87 Dream said:

This is divorce territory guys 🤣 I'd go so far as to say that there is hot water, then essentials there after. 

Yep that is the power curve of a geyser right there.

87

Hahaha divorce is ongoing atm. That's why i have such low consumption. I have 2 x inverter ac's as well. I have used them on the genny a few times. Maybe i must check the spikes when they are operating to get a better picture.

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But why two 200L geysers for 1 guy? I can understand that when you have excess pv power you can heat more water for the day when there is less usable sun. I'm also thinking/planning my pv system and I want to start with a 5kW inverter and when I need more I can add another inverter in parallel and if 1 fail I have a certain amount of redundancy while the failed 1 is being repaired. 

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10 hours ago, Vaal said:

But why two 200L geysers for 1 guy? I can understand that when you have excess pv power you can heat more water for the day when there is less usable sun. I'm also thinking/planning my pv system and I want to start with a 5kW inverter and when I need more I can add another inverter in parallel and if 1 fail I have a certain amount of redundancy while the failed 1 is being repaired. 

Afaik the two geysers has to be on at the same time. I have tried switching on or the other off and use it like that but then the water is not really warm. I have a heatpump that is connected to the geysers and that thing does not work at all. The plumbing diagram is all wrongly connected to the 2 geysers so i just use them with their elements. To re do the plumbing is a total nightmare so i just leave it off. I bought the house with the heatpump installed.

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On 2021/10/28 at 7:15 AM, Sarel said:

It is always, your budget vs requirements. We all want everything, but the budget is the one item that is determinate, or the significant other 😬. Same for my budget, I wanted other things, but do not have the money 😕 

I run the municipal lines directly to inverters [ through surge protectors, etc... ]; everything after that is essential ... 😬

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5 hours ago, WAP said:

Afaik the two geysers has to be on at the same time. I have tried switching on or the other off and use it like that but then the water is not really warm. I have a heatpump that is connected to the geysers and that thing does not work at all. The plumbing diagram is all wrongly connected to the 2 geysers so i just use them with their elements. To re do the plumbing is a total nightmare so i just leave it off. I bought the house with the heatpump installed.

Sorting out the plumbing will already drop your usage by 50% (only having the one 200L geyser running instead of two, water will heat up faster, and last longer and should be more than enough for one person).

It's not always a good idea to build (new) on-top of what is broken/non-functioning by the response above.

Rather have them properly sort out the geysers and plumbing - you'll already be in a better position to be able to do proper usage calculations thereafter.

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On 2021/10/29 at 6:27 AM, WAP said:

Afaik the two geysers has to be on at the same time. I have tried switching on or the other off and use it like that but then the water is not really warm. I have a heatpump that is connected to the geysers and that thing does not work at all. The plumbing diagram is all wrongly connected to the 2 geysers so i just use them with their elements. To re do the plumbing is a total nightmare so i just leave it off. I bought the house with the heatpump installed.

It sounds like the 2 geysers are connected in parallel. Would it be possible to close a valve on 1 of the geysers (the one you switch off). Running 2 geysers in parallel is very weird and (a bit stupid). As said you would save a lot by using 1 geyser because your standing loss will be a lot less. If you aren't technically minded it might be worth it to find a knowledgable person to check the system and your heat pump. In what area are you?

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