Author Topic: New Solar install - Cape Town  (Read 12347 times)

sheedl

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New Solar install - Cape Town
« on: May 15, 2013, 12:09:28 AM »
I'm planning on making a grid tied solar install for my house in Cape Town.
Due to costs, I can't really install a small system, as shipping / clearance is a huge cost over the entire system.

With that in mind, I'm planning on a 30 panel / 300W setup using Poly panels.  Mono panels aren't really worth the extra 15% in cost over poly imho, but feel free to change my mind with facts  8)

Currently panel cost in China for low qty (eg a palette of 20 panels) before shipping is:
700RMB / panel for 300W 37v @ 8A (Poly)  1957*992*50mm
900RMB / panel for 300W 37v @ 8A (Mono) 1957*992*50mm

My plan is 30 panels in 2  x 15 string's so voltages will be roughly 570DC / 8A

Will wire panels -> DC isolator switch -> 3 phase inverter -> grid for a grid-tie solution.
This is what the current grid-tie solutions appear to be doing, although it is illegal without the relevant permits in place. I'd like to be legal, but Cape Town doesn't want to support solar producers, so I may end up just dropping off grid completely with a battery setup, and Eskom for emergencies. 

The house is currently 3 phase, so I plan to stick with that.  I do realise that I could do a 1 phase inverter, and put  the output on 1 phase, but the cost for 3 phase isn't that much more in the 10KV input range, so I think better to stick to the same wiring where possible.

Inverter  will be  a grid tied inverter 10KV 3 Phase (as my house is 3 phase).
Startup voltage is 350V, max voltage is 1000V, so well within limits.

Open voltage on panels is similar to load, so thats ok also.

Our current usage is about 15,000W  daily, a 9KW system should be able to get us about 25KW in winter and 40-45KW in summer in theory, so we'll have plenty of excess.

We do have an analogue meter, so that can run backwards if we do run that into the grid.
I realise that I'll need to make sure that the excess isn't too excess, as otherwise Eskom will be interested why the bill is in minus points, but I'm not so worried.

Phase one of install will be panels  + inverter for grid tie.
I'd love to go completely off grid, but funding doesn't really cut it just yet.

Any comments from the peanut gallery as to what I plan so far?

Phase two will probably be the addition of a Sunny Island 6A + Automatic switchbox + battery charger + batteries.
With that I can add off grid capabilities.

I have a blog post here - http://www.computersolutions.cn/blog/2013/05/going-solar/ with details on inverter and panels if people want more info.

Oh, and thanks to M.J for the forum and youtube videos.


SeanB

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Re: New Solar install - Cape Town
« Reply #1 on: May 15, 2013, 12:48:01 AM »
Eskom will probably soon allow a grid tie system to be connected, they are running out of peaking options fast, and the ones that will work are not on the table for other reasons. Grid tie with a feed in tariff will do something, even if the system is not subsidised.

kibi

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Re: New Solar install - Cape Town
« Reply #2 on: May 16, 2013, 01:25:01 PM »
What you are planning makes sense to me. You might as well stick with three phase as you are one of the lucky few to have it. My previous home in Zimbabwe was three phase too.
I share your sentiments about the poly panels. I recently bought 1KW worth of poly's for the very same reasons that you are thinking. The benefits of mono's don't outweigh their higher cost. A mono panel of the same power might be marginally smaller than a poly, but nothing to cry about.
Battery backup can be retrofitted at some later stage if Eskom becomes unreliable. In Zimbabwe you wouldn't even think for a nano second about a grid tied system as ZESA are more off than on. People go for off grid over there and use ZESA to charge in the rare event that it is available.
Your conservative estimation of the production of your 9KW system is a good way to start. Just beware though a 9KW system on a fine Cape summer's day could produce 75KWh in a day.  75-25 = 50KWh back to Eskom, illegally. This is my only concern. However on cloudy days you may not even make your 25KWh, so as long as there is some sort of balance between meter readings you should be OK.

sheedl

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Re: New Solar install - Cape Town
« Reply #3 on: May 16, 2013, 08:47:17 PM »
Those are my thoughts too, but I figure at some point Eskom  / Cape Town municipality will allow grid tie.
Obviously, I'm not holding my breath on that!

Eskom has physically checked the values one time in the last year, so as long as I manage to keep them at bay I should be ok for the interim, until I can move to phase two - aka full off grid.   I'm perfectly fine giving them free electricity in the interim.

Best worst case, I can unplug one string, and run off 4.5KW so we're +- not in excess, or set the timer on the solar heating to be on 24/7 so we waste too much electricity (this would really make me unhappy though, as its waste for the sake of it).

Worst worse case, I need to go full offgrid, and spend the extra for the battery side asap.

I visited the Solar Trade Show here in Shanghai yesterday, and saw a number of decent chinese Li backup implementations that were viable options.  I'm a big proponent on Chinese stuff, mostly as there is good product if you look for it - just avoid the dross ;)

Some photos of the show here - http://www.flickr.com/photos/sheedl/sets/72157633500979664/

Some interesting inverter producers that I hadn't heard of - I suspect Ginlong will be one to watch in the near future as they had nice product design, decent looking hardware and people that knew what they were talking about.

Some of the entrenched people weren't there - didn't see SMA, and as we only got there in the afternoon, we missed out on a whole wing of stuff.  I was mainly interested in inverters, so concentrated on looking at those..

Lots of people will be coming out with grid tie + battery charge "on/off grid hybrid" systems soon.  Quite a lot of the manufacturers had stuff in the pipeline for later this year / early next year. Will be interesting to revisit solutions based on that in a year or two.

Doesn't affect my purchasing decisions now though, as I'd rather put in something, and update later if the price is right.



sheedl

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Re: New Solar install - Cape Town
« Reply #4 on: May 17, 2013, 08:09:42 AM »
The council is pretty fast these days - I got a reply back regarding legalities a day after I asked.
I wish all the departments were this fast.  Usually I need to ask about 5 times for a reply that will be "sent after lunch, i promise"  ;D

In short -

Its doable / legal, as long as i don't feed back in, or i have a prepayment meter.  (I'm not too keen on that, so will set the inverter to not feed excess to grid for now, till I can afford the 2nd phase of world domination^H^H^H er, i mean batterys + off grid inverter setup).

Below is the official line on this:

Quote
Following is the City’s current position regarding grid connection of small scale renewable electricity generation.
 
The City is unable to accommodate reverse power flow at the present. It is working  across numerous fronts (technical standards, meter solutions,  back end business (billing) processes, legal/legislative issues etc etc ) to be able to accommodate full reverse power flow in the future. Presently the plan is to compensate the generator one “one for one” offset basis per kWh consumed. This may change, but the City will not be able to refund the generator more than the tariff rate at which the consumer purchases electricity from Eskom.
 
Installations will not be allowed to feed power back onto the grid until  the city’s back end billing  processes can accommodate everything required by net metering.   It is quite difficult to put an accurate time frame on when net metering will be allowed, other than to say that in the future it is expected to be common practice.
 
PV  and other renewable energy installations may currently run connected to the grid  and offset instantaneous consumption as long as there is never any reverse power flow.  One of the ways this may be achieved is through careful balancing of load with generation. Written permission to connect in parallel with the grid must be obtained and one would be required to comply with the City’ requirements in this regard.
 
There is  one exception regarding allowing reverse power flow (although it  is not very attractive) : current prepayment meters  decrement both on forward and reverse power flow- for residential applications consumers with  prepayment meters may connect renewable energy generation to the grid and then with careful load balancing reduce the amount of instantaneous reverse  power flow to a minimum. This is a temporary solution – in the future when a suitable metering solution is identified the City will require the prepayment meter to be replaced with a bidirectional prepayment meter.
 
Electromechanical  credit meters running in the reverse direction are not acceptable to the City. They are not designed to run backwards and are not certified to do so. Some may be accurate and others may not. The City is not in a position to test the accuracy of each individual meter. The City is not prepared to have bi-directional residential credit meters installed for the purpose of net metering as it has a general policy to move away from credit meters to prepayment meters for residential applications.
 
The City has chosen the set of standards and specifications with  which the developer/supplier  must prove  compliance.  These standards are still being developed and track national developments.
 
Regards
 
Brian Jones
 
Brian Jones
Head: Green Energy
Electricity Services

SeanB

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Re: New Solar install - Cape Town
« Reply #5 on: May 17, 2013, 11:30:10 AM »
Simplest ( yet probably never thought of by the metros) would be a second meter to measure the amount you feed in, then offset this at a rate against your bill. Will be doable with current system by a simple tariff charge in the negative ( computers don't care about negative numbers being an issue) range so the 2 offset each other. The customer just has 2 meters on different rates, simple and easy. They may pay a consultant a 6 figure fee to figure this one out, but I will allow them the use of the idea for a fee to be determined later of course.

sheedl

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Re: New Solar install - Cape Town
« Reply #6 on: May 20, 2013, 03:33:19 AM »
Had some further correspondance with the Council -
Quote
Hi Laurence

Appended e-mails refer. I would advise as follows:
 
You may connect a residential PV panel in parallel with  the City’s grid if you can live with your prepayment meter (you will be required to have a prepayment meter installed if you don’t have one) decrementing on both forward and reverse power flow.  With careful shifting of load to coincide with maximum pv production, under the tariffs proposed for the next financial year (they have not yet been adopted)  the breakeven point is in the region of about 150 kWh per month reverse power flow- bear in mind that the proposed small scale embedded generation tariff has a daily service charge and the normal  domestic tariff does not.
 
Ryno van der Riet copied to herewith can provide details of the technical requirements. There is also an application form.
 
To be legal the installation has to be approved by the City.
Feel free to contact me should you have any further queries.
 
Regards
 
Brian
 
Brian Jones
Head: Green Energy
Electricity Services
7th floor ENS House
No 2 Lower Loop Street
City of Cape Town 8001
P.O. Box 82
Cape Town 8000
Telephone :(021) 446 2015
Fax :(021) 446 2066/446 1987


 

Will update this thread further when I get more details.

Obviously this doesn't make much financial sense currently due to the following -

You get charged to grid connect (R14 daily at current rates for 2013.  R14 x 30 = R420 minimum charge over and above your bill)
You don't get paid for electricity paid back into the grid over and above what you use.

This is unfairly penalizing grid-tie producers as other pre-pay customers don't get penalized.  Eg - if you use minimal electricity, your bill is your bill, not bill + minimum fee's.  If they're claiming that this is a maintenance fee for upkeep of the grid, then its quite onerous! 

A fairer way would be to do what other countries do to encourage supply - pay you a lesser fee for generated electricity.  Eg if Eskom charges you R1.40 a KW, then pay R0.40 for your power.  This would encourage larger installations, and lessen the load - Eskom would get the benefit of cheaper electricity that they immediately can sell to your neighbours at R1 profit! (it costs them about R0.70 for running the diesel powered generators, vs about R0.50 for coal.
Longer term this is the way to go, as it encourages self production, and both parties benefit. 
Its also better for the planet (over the lifetime of the panels), as we burn less coal in South Africa, so less pollution.

Sadly, its doubtful that we'll go that route, as Eksom is rather short sighted, and all this will do will encourage those with the money to go completely off-grid, thus depriving the greedy incumbent with less.   





SeanB

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Re: New Solar install - Cape Town
« Reply #7 on: May 20, 2013, 11:34:39 AM »
well this is the same entity that signed a deal to sell power with no escalation clause, and where they sell 10% at below cost.

sheedl

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Re: New Solar install - Cape Town
« Reply #8 on: May 20, 2013, 03:01:20 PM »
More info -

Quote
The City is not in a position to purchase excess energy above what the consumer consumers- the consumer is to be on average a net consumer not a net generator. There is at present no other source of funding to finance RE production therefore the proposed tariffs will pay a reduced rate for excess energy generated- in the region of 45c per kW (estimated to be same cost that energy would alternatively have been purchased from Eskom by the munic). The tariffs have been set so that people without generation will not be subsiding those who do.
 
“Rules” are still being established but I expect limits will be set on the size of generation that will be allowed eg. 3kW for a single phase connection.
 
When the tariffs have been approved a guide will be posted on the City website. Business processes still have to be implemented to accommodate bi directional billing etc and it will be a while before the tariffs are actually practicably implementable- but tariff setting is a once a year exercise and we might be able to implement the tariff for non residential applications this coming year.
 
Regards
 
Brian

and from Ryno -

Quote
A three phase bi-directional prepayment meter is not yet commercially available.
 
The following will apply to new residential grid connections: Residential, until a new metering solution is adopted with the consumer being required to be on the domestic net metering tariff or other approved tariff arrangement. Only on the basis of being cost responsible for installing a new split prepayment meter with passive common base (if credit meter currently installed or not in place already), which decrements on reverse power flow and must be on domestic (not lifeline) tariff. No refund will be payable for decremented units and it will be in your interest to consume all renewable energy. If/once the new split bi-directional prepayment meter is available, we will pick up cost of new prepayment meter, if you move to residential net metering tariff. Compliance with technical specifications.
 
Application detail as follows:
GEN/EMB - Application for the connection of embedded generation. Refer to CCT website http://www.capetown.gov.za/en/electricity/Pages/ServiceApplicationForms.aspx

Clearance by other City of Cape Town Departments required. Their requirements are as follows:
2.1        Planning and Building Development Management (Various offices and queries to Peter Henshall-Howard):
a.         All PV roof top installations: No building plans are required to be submitted provided the panel(s) in its installed position does not project more
than 1,5 metres, measured perpendicularly, above the roof and/or not more than 600mm above the highest point  of the roof.
Full building plans, including an engineer’s endorsement, are required if the panel(s) in its installed position projects by more than 1,5 metres,
measured perpendicularly, above the roof and/or more than 600mm above the highest point  of the roof. Note that a relaxation in terms of
the Zoning Scheme Regulations is also required.
b.         PV Installations on the ground: No building plans are required to be submitted provided the panel(s) in its installed position does not project
            more than 2.1 metres above the natural/finished ground level. Full building plans are required where any part of the installation projects more
than 2.1 metres above the ground level.
                                    c.         Other: Clearance required for other embedded generation such as wind.
2.2       City Health Specialised Services (Shannon Maree and Ian Gildenhuys):
a.          Air Quality and Mechanical Engineering (Noise) Units have no objection to not being consulted with these type of applications with the
proviso that no diesel fuelled mechanical engine generator forms part of the installation.
b.         Should a mechanical engine which burns fuel or generates noise be incorporated in the installation, such applications should be referred to
            City Health.
2.3       Environmental Management Systems and Audit (Keith Wiseman):
a.         Large scale PV installations would require environmental authorisation (EA) in terms of the NEMA 2010 EIA Regulations if they generate
> 10 MW electricity, or <10 MW but cover an area of 1ha or more.
b.         Electrical transmission infrastructure that may be associated with a large scale PV system would require EA if it has a capacity of 275 kV or
            more within an urban area, or more than 33kV outside urban areas.
c.         The airport would count as inside an urban area.
d.         Large scale roll-out of SWHs wold not require EA. There may however be heritage compliance issues in some areas of the City.
e.         Household installation of PV would not require an EA unless it exceeds the electricity generation threshold mentioned above, which seems
            unlikely.
SSEG ENA G83/1-1 Appendices.
Declaration by professional engineer/technologist of SSEG installation compliance to G83/1-1 & NRS 097-2-1.
Inverter type testing by 3rd party test house such as Bureau Veritas [examples of SMA and MLT Drives attached].
Electrical installation Certificate of Compliance.
SSEG electrical network drawing.
Inverter programed to NRS 097-2-1.
Site layout.
Operations and Maintenance Procedure.
NERSA requirements are that City of Cape Town is responsible for registering installations less than 100 kW exporting to the grid, in line with “Standard Conditions for Small Scale (less than 100kW) Embedded Generation within Municipal Boundaries”. Retrospective requirements might be required in future. Note licencing and registration requirements in terms of the Electricity Regulation Act (ERA).
 
Regards
Ryno van der Riet


Looks like I'll probably install my 3 phase system, and leave offline until I have a full offgrid implementation 2-3 months later when I can afford the next phase haha.

Adding battery + bms doubles the cost of the system, but it does let me go completely off-grid.   Will probably go with the 3 phase Li system I saw from Samil at the recent trade show. Thats coming out in September - preliminary pricing is RMB3 per watt sans Batteries, which is reasonable compared to other implementations I looked at.
Guess this means a full house system won't be setup until end of year, but at least I can stick some of the loads on the solar side until then (washing machines and dryers are the main target I have in mind!)

warlock

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Re: New Solar install - Cape Town
« Reply #9 on: July 15, 2013, 03:26:02 PM »
sheedl : Did you ever get all your PV panels ? If so were did you get them from and how much ?

sheedl

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Re: New Solar install - Cape Town
« Reply #10 on: November 06, 2013, 01:32:03 PM »
I finally got my panels, and started doing my DB board this week.
Panels were 24k rmb + shipping for 30 x 300w + taxes + misc fee's.  With my 10kw inverter was about 80k rand landed, as I got royally screwed over by the clearance agents. Otherwise would have been closer to 60k rand.

I have an update post here - http://goingsolar.co.za/2013/11/06/status-update/

Haven't mounted them yet, but should be this week, assuming it doesn't rain like today!
« Last Edit: November 06, 2013, 01:34:45 PM by sheedl »

sheedl

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Re: New Solar install - Cape Town
« Reply #11 on: November 10, 2013, 11:32:37 PM »
Update on my install - got half the panels mounted now.

http://goingsolar.co.za/2013/11/11/mounting-systems-and-panels/

Not live yet, but should be by tomorrow, weather permitting.

MJLorton

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Re: New Solar install - Cape Town
« Reply #12 on: November 11, 2013, 11:02:40 AM »
Hats off to you! Great system and great blog on the progress. This all helps other folks considering taking this route.

If I'm correct....the laws have change since your first post on feeding back into the grid...do Cape Town municipality pay for excess power now?

I missed all these posts as we were in transit here to the US at the time...

Cheers,
Martin.
Play, discover, learn and enjoy! (and don't be scared to make mistakes along the way!)

warlock

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Re: New Solar install - Cape Town
« Reply #13 on: November 13, 2013, 05:48:24 AM »
Out of interest, what has the panels cost you now per watt ?

sheedl

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Re: New Solar install - Cape Town
« Reply #14 on: November 25, 2014, 02:13:00 AM »
Its a year later now, and we've generated about 6.2MW (6200KW) with 16 panels on the roof (couldn't fit the 30 I bought!).
Averages out to about 17KW / day generation, which balances out the usage quite nicely (well, summer time we generate a lot of excess, and winter break-even, or 80% of usage).

Given that Eskom is busy with their new lets cut the electricity on a daily basis loadshedding shtick, I'm off to go buy the 3 inverters + 1 battery I'll need to go fully offgrid (daytime/ short periods of outage) today, from the nice Ex-Solar people in Somerset West.

So far, I'm extremely happy with the system, zero issues*.
It just works. I still need to put some monitoring in, but I finally have a laptop for that so will start uploading to pvoutput.org when I come back again from China in Jan next year.

*One panel is partially shaded by the chimney daytime, and shows slight burn marks on the shaded bits due to uneven load, keeping an eye on it, but it is working..

More info on my install up on http://goingsolar.co.za