Loadshedding solutions

[Pure Savage]

1 hour ago, ChrisF said:

 

They are running diesel and gas generators non-stop at the moment.

 

no need for large battery back up systems.  Reduce the generator output in sync with the available PV and ramp up the generators when the pv reduces.  Every home that can supply a few kW.h per day saves a few liters of diesel/gas ......

Agreed, if they gave away the 2 way meters, thats 200l of diesel, how long does that last running those big generators for pumps?

[Pure Savage]

43 minutes ago, Johnny82 said:

Bad weather days 🥴 last year in June and July my monthly production from solar went from 450-550kWh in Jan/Feb to 270kWh mostly due to winter time where the sun rises later and the sun angle to the panels are not ideal. I only got about 60-70% of peak capability in the middle of the day, some days the batteries never got any extra charge as the solar production never exceeded the demand. Some days the batteries got full for about an hour only, other days only up to 70% somewhere during the day.

For interest sake, this is my system's production from last year - red line is total consumption, blue indicates how much was generated by the solar panels.

Saw an article where they state its around a 50-65% drop in winter. My trees in the garden may get a pruning. Hoping as our consumption is lower should hopefully get by in winter, will be interesting.

[dave303e]

20 minutes ago, Johnny82 said:

Absolutely. I am in Parow close to Tygerberg High School and I know our place is not ideally located with Tygerberg koppie blocking early morning sun (in winter the panels only really start producing around 11am) and I also don't have enough roof space facing the right way, so not all my panels are ideally placed. I know more is possible with my setup, but I have to live with what is possible. 

Last year approx 45% of my total usage was self generated and the power does not go off during load shedding, so the boss and the kids are happy and not complaining that the internet and the PC went off any more 😆

I just hope like hell someone is kicking architects when they don't adjust rooflines for solar optimization...

[bleedToWin]

If the city gave the feedback infrastructure for free and only paid for your monthly units that exceeds 100 monthly everyone would sign up and happily contribute even those that won't ever see a cent. They could greatly reduce their offering per unit over 100 and people would still do it.

Edited January 30, 2023 by bleedToWin

[Frosty]

3 hours ago, Johnny82 said:

Absolutely. I am in Parow close to Tygerberg High School and I know our place is not ideally located with Tygerberg koppie blocking early morning sun (in winter the panels only really start producing around 11am) and I also don't have enough roof space facing the right way, so not all my panels are ideally placed. I know more is possible with my setup, but I have to live with what is possible. 

Last year approx 45% of my total usage was self generated and the power does not go off during load shedding, so the boss and the kids are happy and not complaining that the internet and the PC went off any more 😆

When you say they aren’t ideally placed, are they facing more than one direction? 

[mazambaan]

12 hours ago, bleedToWin said:

If the city gave the feedback infrastructure for free and only paid for your monthly units that exceeds 100 monthly everyone would sign up and happily contribute even those that won't ever see a cent. They could greatly reduce their offering per unit over 100 and people would still do it.

It seems a no brainer to me but there is obviously a technical element to it which is not easily explained to politicians. My guess is that this concept of many domestic users feeding in requires a bit of load factoring, grid modelling etc and I doubt whether CoCT has the capacity to do this themselves and such specialists are not exactly thick on the ground IMHO (experience from 10 years ago). Now I'm guessing they would have to go to tender for these services and who is going to draw up the brief?

Domestic input has been a bit of an issue in parts of Hawaii (Musk's boet I believe) and one can imagine domestic input waning as domestic power requirements climb in the late afternoon.

Too timid by CoCT I think.

[Johnny82]

12 hours ago, Frosty said:

When you say they aren’t ideally placed, are they facing more than one direction? 

Jip, the house is built NW to SW to have a nice view of our mountain, with the result that there is only a little bit of roof space facing north-ish. So we had to put the one string on the one section of roof facing slightly NW, and the second string facing more east as it was the only space available. 

[Johnny82]

15 hours ago, dave303e said:

I just hope like hell someone is kicking architects when they don't adjust rooflines for solar optimization...

Haha, 40-50 years ago when our place was built there was no need for considerations for solar installations...

[Frosty]

Just now, Johnny82 said:

Jip, the house is built NW to SW to have a nice view of our mountain, with the result that there is only a little bit of roof space facing north-ish. So we had to put the one string on the one section of roof facing slightly NW, and the second string facing more east as it was the only space available. 

That’s similar to my place; running NW to SE. I also have it split on two sides. But that’s because I have a solar geyser and the pool heating equipment on the NE facing roof.

[Schnavel]

My house was built in the early 1900's and it's almost as though they built it with solar in mind! Roof faces almost due north and the pitch is almost perfect for the latitude required to get optimal solar.

[The Ouzo]

9 minutes ago, Schnavel said:

My house was built in the early 1900's and it's almost as though they built it with solar in mind! Roof faces almost due north and the pitch is almost perfect for the latitude required to get optimal solar.

Due north, in the southern hemisphere, has always been the optimum direction for winter warmth in homes.

My parents property face a few deg NE, when the house was going to be built my dad insisted they angle it exactly north, hence is sits slightly skew on the property. This was more than 50 years ago.

[Hairy]

15 hours ago, dave303e said:

I just hope like hell someone is kicking architects when they don't adjust rooflines for solar optimization...

Might I suggest you also then ensure that you buy a property large enough to be able to orientate your house optimally to allow for the ideal placement of the house ...... 

[Hairy]

15 minutes ago, Schnavel said:

My house was built in the early 1900's and it's almost as though they built it with solar in mind! Roof faces almost due north and the pitch is almost perfect for the latitude required to get optimal solar.

If the site permits, North facing is always how you want to build a house in SA.

[TheoG]

33 minutes ago, Schnavel said:

My house was built in the early 1900's and it's almost as though they built it with solar in mind! Roof faces almost due north and the pitch is almost perfect for the latitude required to get optimal solar.

Mine is also facing almost exactly north, single slanted roof to one side, so I have plenty of space for panels.

Roof angle is 17.5 deg, a bit steeper would have been better but I cant complain.  We are 3 units in the complex facing north and the other three are the opposite, facing south.  Would be a big issue for them to go solar .

Blue circled is my house, the 2 geyser panels is shown in blue also, red arrow facing north, so almost perfect for 3 of our complex units.

Edited January 31, 2023 by TheoG

[lechatnoir]

11 minutes ago, The Ouzo said:

Due north, in the southern hemisphere, has always been the optimum direction for winter warmth in homes.

My parents property face a few deg NE, when the house was going to be built my dad insisted they angle it exactly north, hence is sits slightly skew on the property. This was more than 50 years ago.

my roof pitch is N/S, so opted for panels west-facing. It does mean i get solar energy until sunset. though that is pretty weak as it sets, it's still something. it means battery is 100% at sunset. 

[lechatnoir]

one more thing, overcast (not heavily) days are good for solar radiation and charging batteries. 

On sunny days, my battery charging picks up from 9ish and ramps up pretty fast (west facing panels), but on cloudy days, that can be as early as 7am. if it stays overcast, it never gets very high as if it was full sun of course.

Spoke to my installer, and we figured out that it was the scattering of UV rays that brings on charging earlier.