Solar Power Thread

It's a slow post-long-weekend Tuesday, so here's a graph of the solar PV power generated and exported in March 2014.

The line graph axis is left; the bar graph axis is right.

march2014-s.jpg
 
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I've just seen an interesting policy doc (not yet released, so can't share) which affects grid-tied SSEGs:

1. Municipalities to remove bureaucratic obstacles to connection of SSEGs to the grid. Recommends simple registration with no fees.
2. For RE systems up to 5kW: no compensation for feed-in (ie exporting power to the grid). "Net infeed into the network will not be compensated by the municipality in any month."
3. For >5kW SSEGs: Install 4Q meter at consumer's expense. Consumers to be credited with energy exports at the Eskom MegaFlex rate.
4. Policy is to move away from IBTs (Inclined Block Tariffs).
5. Abolish any price differences between prepaid and postpaid per kW charge.
6. Introduction of TOU tariffs in 2015. TOU = Time Of Use. So different prices for peak and off-peak consumption, priced to encourage load shifting to off-peak times.
7. Geyser control systems to be mandatory, but consumers can elect to pay a monthly fee (R50-R100) to not have ripple switches. Fines to be introduced for faulty or disconnected ripple switches.
 
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Sinbad said:
Nah even ripple switches are fine. Then again I don't use electrocity for water heating
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I would rather have them enforce solar heating for new buildings or some other method. I can just imagine being load shed from 2-6 and then having the ripple control kick in.
 
any14 said:
When the power fails, I manually flip a switch on the Victron to inverter mode. Only lights and some plug points are connected in this mode so stove, geyser, pool pump are disconnected.
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This is what I'm looking at doing as well. May I ask how this was achieved? Basically I want all lights and two plug points working (one which my TV, decoder, HTPC is using and another one in a different room with only a TV)
 
Don't know if someone mentioned a Solar sterling.The most efficient energy generators from solar heat.Also google solar ovens.There some 2Kw dishes at R2500.Care don't use near Lapa.Huge fire hazard...:D
 
Magnum said:
Don't know if someone mentioned a Solar sterling.The most efficient energy generators from solar heat.Also google solar ovens.There some 2Kw dishes at R2500.Care don't use near Lapa.Huge fire hazard...:D
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Nobody has mentioned those things because it would be off topic in the 'Solar Power' thread.
 
From Arthur's comment about the rule chages -- It's not all that good you know on the tariff front :
- <5kw no payment for exporting to the grid --> so basically you only get to give them electricity for free..
- >5kW you get the MegaFlex tariff* --> unfortunately in Summer at around midday, that's around R0.50/kWh (and only c. R0.30 on Sundays)
~(but in the 2 winter peak months, it can be over R2.00/kWh!! -- Wind anyone??)

Maybe I missed it earlier in the thread, but I see Arthur and Isheed are Cape Town - so are you guys on the the SSEG (small scale embedded generation). You pay R1.09 for electricity you use, but do you PAY or GET R0.56 for electricity you generate? It's never been clear to me that?! Also you cannot generate more than consume, but it's not clear whether that is over a day, a month or a year?

Maybe worth thinking about heading towards off-grid, but only for selected appliances --> e.g. having something intelligent that uses your power when it can, but switches stuff on/off to the grid when it can't... I wonder if that's possible?! Will have to bug the guys at homebug.co.za and see if their load-clipping technology is up to much :)

*Eskom tariff schedule here:
http://www.eskom.co.za/CustomerCare/TariffsAndCharges/Documents/ScheduleStdPrices2014_15.pdf -- see page 6 for the 'peak/off-peak' wheel, bottom one. Page 24 for the Megaflex tariff.
and Cape Town here:
https://www.capetown.gov.za/en/electricity/Elec tariffs 201415/Schedule of Consumptive Tariffs.pdf
 
Arthur said:
4. Policy is to move away from IBTs (Inclined Block Tariffs).
5. Abolish any price differences between prepaid and postpaid per kW charge.
Click to expand...

IBT's were just introduced to Tshwane last year.
It's a money making scam of note.

6. Introduction of TOU tariffs in 2015. TOU = Time Of Use. So different prices for peak and off-peak consumption, priced to encourage load shifting to off-peak times.
Click to expand...

Ah, yes of course ... municipalities will want to pay IPPs the lowest rate possible during the day so that all the solar power guys don't make much out of it.
 
L for Lawrence.


From Arthur's comment about the rule chages -- It's not all that good you know on the tariff front :
- <5kw no payment for exporting to the grid --> so basically you only get to give them electricity for free..
- >5kW you get the MegaFlex tariff* --> unfortunately in Summer at around midday, that's around R0.50/kWh (and only c. R0.30 on Sundays)
~(but in the 2 winter peak months, it can be over R2.00/kWh!! -- Wind anyone??)

Maybe I missed it earlier in the thread, but I see Arthur and Isheed are Cape Town - so are you guys on the the SSEG (small scale embedded generation). You pay R1.09 for electricity you use, but do you PAY or GET R0.56 for electricity you generate? It's never been clear to me that?! Also you cannot generate more than consume, but it's not clear whether that is over a day, a month or a year?

Maybe worth thinking about heading towards off-grid, but only for selected appliances --> e.g. having something intelligent that uses your power when it can, but switches stuff on/off to the grid when it can't... I wonder if that's possible?! Will have to bug the guys at homebug.co.za and see if their load-clipping technology is up to much

*Eskom tariff schedule here:
http://www.eskom.co.za/CustomerCare/...ces2014_15.pdf -- see page 6 for the 'peak/off-peak' wheel, bottom one. Page 24 for the Megaflex tariff.
and Cape Town here:
https://www.capetown.gov.za/en/elect... Tariffs.pdf
Click to expand...


I deemed it not to be worthwhile to contribute the *R14 a day just for the privilege of my providing free power to the provider*, so didn't go SSEG. It works out cheaper that way for me.

Math would work out as:
Pay R14 a day.
Pay R1.09 (need to check on the rates) for KW consumed.
Get credited R0.56 for KW generated, but if it goes into credit, all credits null and void.
Rather a bad deal imho, the electric bill would go up, rather than down.

So, instead I get to waste whatever excess I have in summer, as it would literally cost me money to give it to Eskom/ City of Cape Town. I'll probably stick my remaining panels up at some point in the summer, as winter we don't generate at much as I'd like.

I'm planning to get 3 x inverters and some batteries quite soon though, so may just quit using CoCT Electricity if they get too silly with demands.

So far, have generated 4MW since Nov 18th 2013. We just turned over from 3999 -> 4MW early evening.
 
lsheed_cn said:
I deemed it not to be worthwhile to contribute the *R14 a day just for the privilege of my providing free power to the provider*, so didn't go SSEG. It works out cheaper that way for me.
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I thought you said you were net-metering (using the grid as a battery)? Must have been Arthur! So what is happening with the electricity you produce right now? Do you have to turn a heater on just to use all the excess? (maybe the inverter does that itself?!).

If you were feeding the grid for free/no-pay, then that would work... but you still need a grid-tied to make sure you don't electrocute someone when they think the grid is down.

If you aren't feeding the grid you must have a lot of fun switching over the incomer every time you do/don't have enough power to run something... e.g. run the washing machine on solar, but then what if a cloud comes over? When the heating element comes on it would brown-out surely?

lsheed_cn said:
So far, have generated 4MW since Nov 18th 2013. We just turned over from 3999 -> 4MW early evening.
Click to expand...
Good job! 4000kwhr -- but how much did you save? IE - what proportion of the production can you effectively use?
I'm asking because I'm trying to get an idea of how to make that better for everyone!
 
You can buy switches/limiters that won't export power. Google AT Switch or Grid Tie Limiters

eg -
http://www.sustainable.co.za/microcare-grid-tie-limiter-solar-inverter.html
http://www.exsolar.co.za/products/grid-tie-limiter/

I have some details on my http://goingsolar.co.za site.

Product Example from Ex Solar in Somerset West - http://chtech.co.za/wordpress/smart-energy-controller/

...and to quote from that page - "The problem however is that the South African government has not come to the party in terms of allowing the feed-in of unused solar energy back into the Eskom grid. Eskom has however announced a feed-in tariff structure that is actually quite laughable – not forgetting the fact that you have to purchase a new 4-quaddrant meter AND pay a premium rate to have this facility available at your house. These additional costs make it totally unfeasible to install a solar system and rely on Eskom rebates to finance the project."
 
YingYang said:
This is what I'm looking at doing as well. May I ask how this was achieved? Basically I want all lights and two plug points working (one which my TV, decoder, HTPC is using and another one in a different room with only a TV)
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I had to rewire my DB box. Added an external DPDT 60A Industrial switch (about R250):

Raw mains goes to the one set of poles, output from inverter to the other. The "common" side feeds the circuit breakers I desire to be powered (like lights)
 
Okay, the question: battery replacement costs, and how often. biometrics mentioned 5 years, other people have mentioned 4 years, so this seems consistent. But what are the costs?
 
Our holiday home only has single phase 60amps of power, we want to put a jacuzzi with a heat pump, i have been thinking if we had it running of solar we would never have to worry about tripping the houses power + saving money. Question how much is this going to cost? what do i need?
 
phaktza said:
Okay, the question: battery replacement costs, and how often. biometrics mentioned 5 years, other people have mentioned 4 years, so this seems consistent. But what are the costs?
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I have a small system I put together 10 years ago so by now the panels are much more efficient for the same cost. But at a minimum you need:

1. Solar panel - R3,500 (mine is 85 W but you'll get 200+ W now)
2. Regulator - R500
3. Battery - R1,000
4. Invertor R2,000

I'm sucking these numbers out of the air (as it was 10 years ago) but around R7,000 for a 200 W 100 Ah setup. This will run things like lights, modems, phones, laptops for a few hours. Forget about heating or big screens.

Note I use the expensive sine wave invertor vs square wave as it's preferred by electronics. R2,000 vs R400.
 
biometrics said:
I have a small system I put together 10 years ago so by now the panels are much more efficient for the same cost. But at a minimum you need:

1. Solar panel - R3,500 (mine is 85 W but you'll get 200+ W now)
2. Regulator - R500
3. Battery - R1,000
4. Invertor R2,000

I'm sucking these numbers out of the air (as it was 10 years ago) but around R7,000 for a 200 W 100 Ah setup. This will run things like lights, modems, phones, laptops for a few hours. Forget about heating or big screens.

Note I use the expensive sine wave invertor vs square wave as it's preferred by electronics. R2,000 vs R400.
Click to expand...

Those costs are not bad, and to be honest I'm happy with my ADSL, a few lights and my phone to continue working. If that is the approximate outlay I would be happy to do this!

In the event that grid power is disconnected how to you go about switching off your geyser and fridge?

In addition to a solar geyser, gas geyser for the kitchen and gas hob I think I could incur large savings for minimal outlay.
 
phaktza said:
Those costs are not bad, and to be honest I'm happy with my ADSL, a few lights and my phone to continue working. If that is the approximate outlay I would be happy to do this!

In the event that grid power is disconnected how to you go about switching off your geyser and fridge?

In addition to a solar geyser, gas geyser for the kitchen and gas hob I think I could incur large savings for minimal outlay.
Click to expand...

My setup is not connected to the db, I just run some extensions.
 
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