Solar Power Thread

The pro's are you can be independent of Eskom.
The cons are the cost of fossil fuels make the exercise very expensive.

A modern diesel generator uses between 0.28 and 0.4 litres of fuel per kilowatt hour produced.
Using the 0.28 figure, at the current price of diesel that works out to R2.89 per kWh excluding the losses in charging the batteries which is a tad higher than the ~ R1.20 per kWh consumers are paying municipalities for electricity.
What would be funny is if/when the electricity tariffs pass the R3/kWh mark and people start using diesel generators at home to go off the grid.

Even if electricity hits R3/kwh it will still cost less to use eskom than Diesel.
Your batteries will cost you at least R500 per month in maintenance.

thanks for your replies.

I have already reduced my consumption by installing insulation in the ceiling / double glazing / CFL lights / gas stove / LED LCD TV / solar geyser. looking at replacing my old fridge/freezer with a new modern A+++ version. however there are somethings that are difficult to save power on like my 1.1kw pool pump which runs 8hrs a day in summer & 6hrs in winter. any ideas?
 
thanks for your replies.

I have already reduced my consumption by installing insulation in the ceiling / double glazing / CFL lights / gas stove / LED LCD TV / solar geyser. looking at replacing my old fridge/freezer with a new modern A+++ version. however there are somethings that are difficult to save power on like my 1.1kw pool pump which runs 8hrs a day in summer & 6hrs in winter. any ideas?

Pool pump is a bugbear for me too. I don't think there's any way round it, unfortunately. Gotta just build it into the capacity planning for the solar system.
 
Nice explanation.
Do the basics right first. Insulation, Natural/passive cooling.

And Heat exchangers? Don't you get a dual function one? part air-con/part geyser?

I thought about this as well. It doesn't seem that this product exists and I think it simply boils down to the complexity of having your hot water tank in the same place as the heat pump for your air conditioner.
 
thanks for your replies.

I have already reduced my consumption by installing insulation in the ceiling / double glazing / CFL lights / gas stove / LED LCD TV / solar geyser. looking at replacing my old fridge/freezer with a new modern A+++ version. however there are somethings that are difficult to save power on like my 1.1kw pool pump which runs 8hrs a day in summer & 6hrs in winter. any ideas?

The pool is a tough one. The best I was able to think of was to find ways that would reduce the pump usage. The goal would be to minimise the amount of crap that falls in the pool in the first place. For this I thought that having one of those fine mesh covers over the pool would be the best option(the one that kinda makes the pool look like a trampoline). This would protect the pool from leaves bugs etc and that would reduce the amount of hours that the pump must run. You will probably want to run the pump multiple times a day for less hours to ensure that you maintain even chemical distribution but would not need to run for as many hours as the creepy wouldn't have to pick up all the leaves etc.

Another advantage over and above the lower pump run time would be a warmer pool as the fine mesh traps the heat better as well as lower evaporation. Oh and off course it protects you from drowning kids too:D
 
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My creepy picks up dust a lot more than it picks up leaves etc.. I have a surface skimmer that works very well to keep leaves out of the equation.
 
My creepy picks up dust a lot more than it picks up leaves etc.. I have a surface skimmer that works very well to keep leaves out of the equation.

Yeah bud it does this by pumping water. Remember that the fine mesh cover would sit just on the waters surface and between the meniscus created in the mesh and the mesh itself it would significantly reduce the dust. Short of putting a solid sheet across the pool I doubt there would be a perfect solution.

I have seen guys put the "bubble wrap" covers on their pools. That may work better.
 
Reducing pumping hours would have another negative side effect for me - pool is solar heated. So if I cut it down any more than I have, the water would be too cold for my SO!

So as I said, I'm just going to accept that extra kilowatt, 6 hours a day, and build it into the capacity of the solar system once I get there.
 
Sho, isn't 6 hours a day a lot? Our pool is quite large and it runs only 2-3hours a day! Pool is just a money pit ;)
 
It could run less, but then it wouldn't be as warm. Also, then the pool cleaner leaves gaps.
 
Reducing pumping hours would have another negative side effect for me - pool is solar heated. So if I cut it down any more than I have, the water would be too cold for my SO!

So as I said, I'm just going to accept that extra kilowatt, 6 hours a day, and build it into the capacity of the solar system once I get there.

True. I didn't think of the solar system. Perhaps have it run 45, minutes out of each hour for the six sunny hours of the day? I would be worried about the heat and lack of moving water cooling the pipes. I have images of exploding hot water on the roof.:D
 
True. I didn't think of the solar system. Perhaps have it run 45, minutes out of each hour for the six sunny hours of the day? I would be worried about the heat and lack of moving water cooling the pipes. I have images of exploding hot water on the roof.:D

Mine empties when the pump turns off...
If I wanted to reduce the time I'd rather remove from the beginning and end of the run period as these receive less heat than at midday.
 
Mine empties when the pump turns off...
If I wanted to reduce the time I'd rather remove from the beginning and end of the run period as these receive less heat than at midday.

See and you thought you wouldn't have ideas :p I would appreciate it if you could experiment and provide us details with the best pump hours vs hot water vs clean pool?

It might be useful to the rest of us what you learn.
 
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What would be the best way to cool the house? Inverter aircon?
Take a look at evaporative coolers. Not great at the coast or in high humidity, but perfect in many places. You can't dial in a temperature, but the big plusses are (1) much cheaper to run than compressor aircons, and (2) run with open doors and window - you always get fresh air, and dust in the house is minimised - great if you hate that "aircon stuffiness".
 
damn guess the pool is the bitch to save on.
mine is a 30kl saltwater fibre glass pool with 6 solar panels.
barely uses any chemicals, I run the pump for 8 hrs to take advantage of the sun.
in winter I run it for 6 hrs minimum so that the pool cleaner can clean the entire pool properly and circulate the water through the filter a few times.
 
Found a shocker, scuse the pun. Little bar fridge I use for drinks when we have folks round for a braai, but I just left on cos it was just a tiny fridge... 130W 24x7 = over R110 a month!
 
Found a shocker, scuse the pun. Little bar fridge I use for drinks when we have folks round for a braai, but I just left on cos it was just a tiny fridge... 130W 24x7 = over R110 a month!

that seems a bit high is the fridge compressor running 24/7. If so it's probably because the coils at the back have no access to fresh air. Otherwise it's just busted and never turns off.

You will be surprised how much energy a fridge will use when it is put into a confined space. They just aren't designed to work like that.
 
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