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Thread: solar systems

  1. #1
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    solar systems

    The electrical bills are climbing at 15% per year ... load shedding is a reality and will be for some time ... looking at who is being awarded contracts for a "greener" solution ... maybe investing in your own system might be a worth while option.

    Another thing to consider ... EV's and chargers ... if the price of fuel increases at the current rate and ICE vehicle will not only be more expensive to buy ... but your fuel bill will kill you ... then there is services and maintenance to take into consideration ... it might still be cheaper than electricity ... unless you can produce your own electricity to charge your vehicle of offer the service to your neighbours ... like cellphones they predicated 900k sales ... but in fact it hit something like 135 million sales within a short period of time ... and I am sure the government will help by bumping up the petrol tax (money for cream on the scones)

    Moms school bus is a good example where you could save big ... low daily mileage ... can be plugged in while not in use and then be used at night to power the house if you find the home battery is low ... considering what size of the vehicle battery (from 30kwh) in comparison to a backup house battery from (2.4 kwh)... you could probably run your house for a few days.

    If you are smart ... charge your vehicle while at work ... then use it to power your house at night and probably the whole weekend ... just leave enough to get back to work ... buy a car with biggest battery even if it it doesnt fit your budget ... it might other cost saving benefits.

    People are going to say ... but you need to buy a new battery after a couple years ... well you spend R300k on a entry level vehicle at the moment and pay it off over a 3-5 year period ... then replace it ... rather than replacing the battery just buy a new car with a brand new battery.
    Comments are based on opinion...not always facts....that's why people use an alias.

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    Now that we have that out the way ... lets look at how to go about "investing" in a solar system ... as mentioned above ... we all know why a solar rebate system is not being rolled out ... we will be making the billionaires even wealthier in this country ... like in Australia ... which now has an abundance of electricity ... looks like you will have to fork out a few tens of thousands for a basic system.

    There is a catch and I am starting to see it more frequently ... people install a system with expectation of this long term investment ... 2-3 years down the line ... that investment becomes a door stop or if you luck and have lead acid batteries ... you can still recover a few pennies for the lead at the scrap yard ... I dont know know of a place that wil not charge you to dump lithium batteries ... in fact you might have to pay a hazard fee (need to do a little research with regards to disposing lithium batteries)

    I am glad I have not invested in solar yet ... it is going to require a bit of research ... to find a system which will be upgradeable ... a system which will allow you to add rather than have to replace the entire system if you invest buy an EV and then another EV at a later stage.

    I suppose what we should be asking ... how much will it cost to charge an EV ... 10amps x 230v = 2300 watts x 10 hours = 23 kwh x R2.02 = R46.46 per day x 5 = R232.30 x 4.33 =R1005.90 per month ... would that even be a consideration for an expensive solar system ... buying an EV with a big battery could save you buy batteries for the house.

    just a few thought going though my head this morning.
    Comments are based on opinion...not always facts....that's why people use an alias.

  3. #3
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    Hi
    You need to be careful and split the 2 scenario's out as discussed above.

    Installing PV panels provides a return on investment in around 5 years - The PV panels will give you 20 years , brackets and mounting structure if chosen correctly will be 20 years and the inverter +/- 7 years.

    The storage is another story and depends on what you are trying to achieve , in this country we want it as back up power and there is no return on investment , but if you can use a portion or all , to store energy and supply usage when the sun goes down then there is a return .

    If your PV inverter can just sit feeding onto the "Live Busbar" and the battery storage system sit on the network as an independent inverter and storage system also on the " live busbar" then you have options.

    Installing 5Kw of PV panels along with a reasonable inverter should cost around 100K and produce around 30KHW per day - 900KWH per month in near perfect conditions. - using your rate at 2.02/kwh translate to a savings on electricity bill of R 1 800.00 per month. It would pay for itself in +/- 5 years , in near perfect conditions and without taking electricity increases into account and if you are presently using 900Kwh per month during daytime.
    If the client is only using 600Kwh per month and no storage to feed the installation at night then you may as well install 2,5KW of panels at a cost of +/- 50K and maximize the potential return.

    We are busy installing 5KW of PV and 13,5KWH battery for a client on a new house that in his present house uses 3K a month on electricity.
    The battery system will be adjustable via the app to reserve storage for a grid outage and the unreserved portion to feed his network at night. Depending on requirements and load shedding this will enable him to obtain a return on investment into the battery.
    The reserved portion of the battery will recharge from the grid when it comes back on and the unreserved portion will only recharge from the PV .

    We convinced them to rather spend money on LED lighting , new fridges energy saving, and solar geysers . The energy savings will already be cheaper than installing PV to run energy hungry appliances .

    In my opinion there is no " one size fits all " when advising on a PV and storage system. It is dependent on the requirements and budget.

    At my office I need battery backup to enable work to continue and along with solar allows me to almost run independent of the grid.The return on that investment will be in the region of 16 years , it is done out of necessity.
    At home I am not to bothered about storage. All I need is my alarm to stay on and not beep in the middle of the night to remind me about load shedding. My storage cost is minimal and the PV would then give me a 5 year return.

  4. #4
    Diamond Member Justloadit's Avatar
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    What throws the spanner in the works with hybrids, is that the loss of mains power is an unknown, and a reserve amount of stored energy must be kept for this purpose, and this is then the reason that your ROI is delayed.
    a power loss on a sunny day is not an issue, but if it is raining or during the night, then you have to be vigilant to ensure that you have sufficient energy.

    I also have an issue with users who do not want to change their lifestyles when installing solar hybrid systems, so end up still using a good portion of mains.
    However this is still a major savings of no less than 50% of their utility bill.
    By changing your lifestyle you can increase the savings to almost 90% with out making no changes to the system.

    I have been experimenting, and my recommendations for a hybrid is to get a DEYE , Sunsync or Victron.
    Then there is the size.
    If you have some form of water heating, whether it is solar or gas, and you have a gas stove, then you can get away with a 5kW system and about 2.7kWatt of PVs and 10kWatts Lithium batteries.
    If not then at a very minimum an 8kWatt system with about 4kWatts of PV, but I would recommend an 11kWatt system with 5 or 6kWatts of PVs at a minimum, and not less than 15kW of Lithium but better at 20kWatts
    I would also recommend getting a "Silent" diesel based generator between 11 and 15kWatt, as a back up if you can afford it. Anything smaller may create an issue with your inverter if you attempt to power the inverter with the generator.
    Another point, when shopping for diesel generators, make sure you get a good sine wave out, else it will create issues with the hybrids, as they will knock the incoming off as a bad supply.
    I found that 2 piston generators are not as good as 3 and 4 piston generators. The 2 piston due to the physics of the firing cycles, creates a distorted sine wave.
    The best way to test is to connect transformer based LED lighting, which is not dimable, and you will see the LED flashing when being supplied by a distorted sine wave.
    Victor - Knowledge is a blessing or a curse, your current circumstances make you decide!
    Solar pumping, Solar Geyser & Solar Security lighting solutions - www.microsolve.co.za

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    I agree it is no longer a plug and play suited for everyone ... what is best suited for you and your application ... only an installed system with monitoring of all components of your electrical installation not just the solar/inverter/battery system ... smart power meters are required at the main incoming would give you an accurate understanding of what is happening.

    Hence why I believe "the span smart DB" is the way forward ... this essential and no essential and hybrid inverters are going to become a thing of the past.

    With this kind of money you can see that there is gonna be some change happening ... rebates for individuals is unlikely ... is this going to increase the cost per KWH ... someone must pay back the money.

    https://techcentral.co.za/south-afri...y-deal/204264/

    Points to be noted:

    Are you looking for a battery backup system for load shedding or to keep your essential service operating (alarms etc) or

    A hybrid with solar and batteries or an off grid solar system with or without batteries to reduce you electricity bill and have a little backup for must haves.

    Do you want to go totally off grid and not even have a power cable coming onto the property or

    and for me the most important consideration ... expansion ... no matter which route I take ... I must be able to add components as I build the system ( hence Victron being the most expensive would be a no brainer) ... every site that I visit which already has a system installed ... I get the same response for solar experts ... you need to replace everything ... if older than 2 years ... its

    6.6 kw of solar seems to be the buzz figue which keeps popping up as I scratch.

    I am monitoring 2 systems ... one with solar and the other without ... completely different inverters ... and batteries ... and even the load profiles ... it is so interesting to watch how the 2 respond to load shedding and bad electrical supply voltages.

    I am looking forward to doing a full solar/hybrid inverter/lithium battery install to see how they all compare over a period of time (years).
    Comments are based on opinion...not always facts....that's why people use an alias.

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    Victron would be my first choice ... I have been doing some research into Sunsynk and I like what I see ... an installer I have been working with promotes Deye.

    But at the end of the day 1 think will determine which product regardless of cost ... support ... Victron have offered a 48 hr return replacement policy ... can they live up to it ... havent tried it yet.

    What I have noticed is to become a Victron distributor ... you need lots of connection ... or maybe a group of installers to move to various levels to qualify for discounts.
    Comments are based on opinion...not always facts....that's why people use an alias.

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    One of my concerns with regards to circuit breaker protection ... I see a lot of inverter supplier recommend 50% over rating the circuit protection ... I believe that is some what excessive.

    Surely a little research would indicate that circuit breaker selection should be done buy checking the breaker spec ... for example I would think a 50 or 60 amp would be a bad choice for a 5 kva inverter ... if you were concerned about inductive loads such as computers ... you would select a max 30 amp curve 2 breaker (designed specifically for that type of application) it would not only reduce the installation cost and save money ... it would also offer better all round protection.

    If you have motors connected for example then a 30 amp curve 1 or D curve would be more suitable ... once again ... maybe a fraction more expensive for the breaker ... but a significant saving on the rest installation.

    The only time I would consider it a wise decision ... selecting and installing 60 amp breakers and cabling ... if you plan to upgrade the system in the near future.

    We all know that with EV's coming sooner than later ... there is gonna be a lot of upgrading solar installations.
    Comments are based on opinion...not always facts....that's why people use an alias.

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    It been quite a solar/inverter/battery education weekend ... I think I have learnt a bit more about solar and calculations for solar panels ... battery backup ... reading the data loggers and charts will make a lot more sense ... time to go get some sleep .
    Comments are based on opinion...not always facts....that's why people use an alias.

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    the additional protection features of these Sunsynk TRUE hybrid are rather interesting.

    I am told it is not wise to install the 5 kva unit inside the house ... they sound like a drone when the fans are running.

    https://www.youtube.com/watch?v=a_QF...channel=Ellies
    Comments are based on opinion...not always facts....that's why people use an alias.

  10. #10
    Diamond Member Justloadit's Avatar
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    Quote Originally Posted by ians View Post
    the additional protection features of these Sunsynk TRUE hybrid are rather interesting.

    I am told it is not wise to install the 5 kva unit inside the house ... they sound like a drone when the fans are running.

    https://www.youtube.com/watch?v=a_QF...channel=Ellies
    I did note this with other manufacturers but my Deye on rare occasions, I can hear very faintly a fan kick in when the heat sink reaches about 50C.
    I was under the impression that the Deye and Sunsync are the same just branded differently.
    Victor - Knowledge is a blessing or a curse, your current circumstances make you decide!
    Solar pumping, Solar Geyser & Solar Security lighting solutions - www.microsolve.co.za

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