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Connecting several houses solar systems into an off grid uhm grid private

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So we are on a farm and have a system, with three rental units including our own house. Eskom line connection fee is more than the kwh related amount we consume. We want to go completely offgrid… because neighbours paid eskom r15k to go prepaid 3 years ago and they are still not converted…

Would it be feasible to install a system at each unit, and use the existing wiring to connect all the units into a private grid, so one could share excess power by prioritising load, battery then feedback to grid? And also use grid to charge batteries. Then if say someday we need more we can add panels or a new system anywhere on the grid…. Also it would then be feasible to utilise the various roof orientations better. 
 

i am assuming it can’t be done simply, as there is no global grid to push back to, the private grid will just be too erratic unless some systems are undersized and batteries oversized for instance. Maybe… and all the inverters probably need the same reaction time…

 

  • 1 month later...
14 minutes ago, Againstthegrains said:

Great Idea, but in South Africa it is illegal to transfer power over a property boundary. So a microgrid would be illegal. 

@Againstthegrains Are you 100% sure of this?  

How does an estate like Midstream work that is provisioning their own electricity? 

https://businesstech.co.za/news/energy/664139/this-estate-has-a-r200-million-solar-plan-to-cut-up-to-4-stages-of-load-shedding/ 

As long as the properties are all bordering each other and they are not going to be crossing any public/private property I don't know of any laws restricting the exchange of energy between properties. 

 

6 minutes ago, Sc00bs said:

@Againstthegrains Are you 100% sure of this?  

How does an estate like Midstream work that is provisioning their own electricity? 

https://businesstech.co.za/news/energy/664139/this-estate-has-a-r200-million-solar-plan-to-cut-up-to-4-stages-of-load-shedding/ 

As long as the properties are all bordering each other and they are not going to be crossing any public/private property I don't know of any laws restricting the exchange of energy between properties. 

 

They are a private estate. The same as a complex having 1 power supply point and arrange their own payment for unit holders. 

The same system can be done on the farm with a few units. Many homeowners do it for a garden flat. Private prepaid system. 

Where the problem comes in is when you start selling to a neighbour that has a munic/Esk connection. 

Edited by Scorp007

1 minute ago, Sc00bs said:

@Againstthegrains Are you 100% sure of this?  

How does an estate like Midstream work that is provisioning their own electricity? 

https://businesstech.co.za/news/energy/664139/this-estate-has-a-r200-million-solar-plan-to-cut-up-to-4-stages-of-load-shedding/ 

As long as the properties are all bordering each other and they are not going to be crossing any public/private property I don't know of any laws restricting the exchange of energy between properties. 

 

I think that's not right either. That would mean that I can sling an extension lead over the fence to my neighbour. City Power don't like that. OK... "City Power", maybe this is by-law thing in Johannesburg. 

Midstream in interesting, they have a micro-grid already. That allows them to have a big PV/Battery system that feeds their microgrid rather than having put solar on individual roofs and then find a way of sorting out demand. Also they are implementing smart meters and participation in the scheme is optional. 

It's a quite a different solution than @Andre grobler is enquiring about.

On 2023/02/05 at 7:27 PM, Andre grobler said:

So we are on a farm and have a system, with three rental units including our own house. Eskom line connection fee is more than the kwh related amount we consume. We want to go completely offgrid… because neighbours paid eskom r15k to go prepaid 3 years ago and they are still not converted…

Would it be feasible to install a system at each unit, and use the existing wiring to connect all the units into a private grid, so one could share excess power by prioritising load, battery then feedback to grid? And also use grid to charge batteries. Then if say someday we need more we can add panels or a new system anywhere on the grid…. Also it would then be feasible to utilise the various roof orientations better. 
 

i am assuming it can’t be done simply, as there is no global grid to push back to, the private grid will just be too erratic unless some systems are undersized and batteries oversized for instance. Maybe… and all the inverters probably need the same reaction time…

@Andre grobler

There is no doubt that it can be done, I think that the big questions are how much it would cost and who would be able to do it for you.

Just now, Sc00bs said:

@Andre grobler

There is no doubt that it can be done, I think that the big questions are how much it would cost and who would be able to do it for you.

Interesting things on the go in the OFS where farmers club together and the intension is to take over the lines from a substation and they all contribute to the mini network. 

Regulator is the stumbling block. At least LS is going to force new laws around who may/may not sell power. You can only keep a strong guy down for a period. 💪💪

3 minutes ago, Scorp007 said:

Interesting things on the go in the OFS where farmers club together and the intension is to take over the lines from a substation and they all contribute to the mini network. 

Regulator is the stumbling block. At least LS is going to force new laws around who may/may not sell power. You can only keep a strong guy down for a period. 💪💪

The rapid decentralisation of the South African power grid is here and businesses/households are being forced to decouple from Eskom for survival. It is happening a lot faster than people anticipate and our whole power landscape will be fundamentally different in 10 years time. 

28 minutes ago, Sc00bs said:

@Againstthegrains Are you 100% sure of this?  

How does an estate like Midstream work that is provisioning their own electricity? 

https://businesstech.co.za/news/energy/664139/this-estate-has-a-r200-million-solar-plan-to-cut-up-to-4-stages-of-load-shedding/ 

As long as the properties are all bordering each other and they are not going to be crossing any public/private property I don't know of any laws restricting the exchange of energy between properties.

 

You are not allowed to cross property boundaries; technically it's illegal to have an extension cord cross property boundaries - unless you have a license to sell electricity. (in the last instance, the extension cord might also breach some other laws as well...). From your article, Midstream Electrical Supplies distribute electricity in Midstream, I assume they have a license...

on this topic, although not answering the original post. 

 

IF myself and the neighbor decides to erect a pole/structure on the fence wall with 12/14/16/20 or hundred(this is for argument sake) solar panels (these very same panels will provide shade for his outside patio area by his pool) and we run the PV cables down to the wall with junction box installed. we both tap into this junction box to our own inverters....  can this work? 

47 minutes ago, Flouw said:

on this topic, although not answering the original post. 

 

IF myself and the neighbor decides to erect a pole/structure on the fence wall with 12/14/16/20 or hundred(this is for argument sake) solar panels (these very same panels will provide shade for his outside patio area by his pool) and we run the PV cables down to the wall with junction box installed. we both tap into this junction box to our own inverters....  can this work? 

The typical solution to entertain distributed solar strings is to use string inverters. These are gridtied  pv only inverters, ac-coupled to the 220vac reticulation. 

Now your entering microgrid territory however. 

Edited by BritishRacingGreen

3 hours ago, P1000 said:

You can't connect multiple MPPTs to the same string, that won't work, they will fight each other.

The solution to MPPTs are that each MPPT has its own panels and they charge a common set of batteries. Both inverters then share the batteries and each inverter is connected to each dwellings loads. 

Not worth it. The sum total of power is the same for 2 free standing systems or sharing. You only save a bit on the structure for both sets of panels. 

Charging the neighbour for power used is just easier. 

Having a common generator and charging users in a shared complex like mini factories or shopping centre is just easier. Who can police people for doing it? 

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