Solar Power Systems

[srothman]

I was listening to a chap on the radio the other morning about how he installed a solar power system in his home and how he is now fully self-sufficient so far his electricity is concerned. He isn't even connected to the power grid anymore. He has a household of 4 and his installation will pay itself off over a period of between 4 and 5 years, depending on the increases imposed by Eskom.

Has anyone here followed that route? Perhaps a hybrid-system? I know solar-powered water heating systems are becoming more and more common, but has anyone here taken it further than the hot water?

 

[Sinbad]

A year ago I investigated just putting my pool pump onto a solar solution.
R50k. Couldn't believe it.

The tech is still stupidly expensive, and it's not that cheap to maintain either. Batteries need replacement every couple of years...

 

[Cius]

It is still expensive unfortunately but I suspect that will change in the next few years. The cost of solar panels has been coming down by about 25% per year for last 8 years as I understand it and manufacturing of Solar panels has just trebled as it has finally surpassed the cost of Diesel generators. Large portions of countries like India are using Diesel generators for power due to their national grid being unstable in the more remote regions. The fact that solar is now more cost effective than Diesel was a big watershed as many people are now switching over.

I suspect that within 10 years solar will be cheaper than nuclear power but doubt it will pass coal any time soon. Still, once it is even threatening passing coal the price of coal would drop due to the drop in demand due to people switching over.

Either way it is inevitable that Solar will be the new normal source of power within a century or so with power plants probably being located in space. Countries like Israel and her allies in the US are spending a lot of money on Solar power as once solar becomes cheap enough the oil price will drop and Israels biggest headaches will vanish rather quickly along with all the oil revenue of Iran and countries like that. The rest of the world is also looking increasingly to alternative energy sources due to the wildly fluctuating oil price and the negative effects that is having on the world economy. The pressure has reached a high level and hence the development is now happening slowly but surely. Continued price drops in solar panel production, battery production, and control systems will continue and hopefully also a disruptive innovation or two that takes us into a new technology realm that is in the order of 10 times more efficient (for either gathering or storing energy) and we are there.

Still, for now it is probably not economically viable to switch to Solar. Hopefully within 3-5 years though it will be.

 

[isie]

A year ago I investigated just putting my pool pump onto a solar solution.
R50k. Couldn't believe it.

The tech is still stupidly expensive, and it's not that cheap to maintain either. Batteries need replacement every couple of years...

I would love to go majority solar , but as you said tech is insanely priced,

 

[Arthur]

The main pain is batteries. Glass jar deep cycle batteries have a 15 year lifespan, but are insanely expensive.

 

[Skerminkel]

Economies of scale will always make the grid cheaper than going solo. The most cost effective is to go for a hybrid system. Use the sun or heat pump to heat your water and you will probably cut your bill by 50-70%. Next step is to insulate your house properly and save another chunk on heating and cooling.
Cooking on gas also saves in pre-heating your stove.
Then, change your habits. Shower in the evening when you have hot water in the geyser. That way you don't have to set it to heat early in the morning. There are loads of other tips on reducing your energy demand available on the web and in books.
Only after the above, start considering storage of energy to get off the grid. It will probably never make economic sense.

Sorry if you know all this. I simply cannot resist the opportunity to promote sensible home energy use.

As this is a MyBB discussion, I assume you guys are drawn to all the gadgets and tech available. Rest assured, there are loads available even before you go off grid!

 

[froot]

I was listening to a chap on the radio the other morning about how he installed a solar power system in his home and how he is now fully self-sufficient so far his electricity is concerned. He isn't even connected to the power grid anymore. He has a household of 4 and his installation will pay itself off over a period of between 4 and 5 years, depending on the increases imposed by Eskom.

Has anyone here followed that route? Perhaps a hybrid-system? I know solar-powered water heating systems are becoming more and more common, but has anyone here taken it further than the hot water?

About a year ago a guy on MyBB got a quote for a 4-person household with solar + battery swopouts. The quote was somewhere between R100k-150k. The major problem is that solar panels are still expensive. Batteries aren't cheap either... you're looking at around R1500 for a decent battery (deep cycle), and you need a few of those.

 

[etwylite]

I believe the vast majority of people have a misperception of PV and that going off grid is the only goal.

A scalable PV install is optimal. Start small with built in scalability and add on as and when required/viable.

Personally, I use eskom to my advantage. My system has few batteries (only for 4 hrs backup) because of their expense and I merely spin my mechanical meter backwards with a bi directional inverter thereby accumulating "credits" which I draw down against. Although we dont have a feed in tariff system in place eg Germany where i would get paid for excess credits, as long as I dont run into a creditsystem with Eskom, I'm fine.

That way my system was way cheaper and made economic sense .
BTW. PV panles can now be bought for R12/watt where a year ago it was about R18/watt

PM if theres anything in particular you wish to know

 

[Sinbad]

You spin your meter backwards? Isn't that theft? After all, you're not providing energy to the grid...

So R12/watt...
My average consumption is 40kwh/day - I'd need 5kw for 8 hours a day to maintain that... R60k worth of panels. More if I want to allow for cloud etc...?

 

[Freaksta]

I believe the vast majority of people have a misperception of PV and that going off grid is the only goal.

A scalable PV install is optimal. Start small with built in scalability and add on as and when required/viable.

Personally, I use eskom to my advantage. My system has few batteries (only for 4 hrs backup) because of their expense and I merely spin my mechanical meter backwards with a bi directional inverter thereby accumulating "credits" which I draw down against. Although we dont have a feed in tariff system in place eg Germany where i would get paid for excess credits, as long as I dont run into a creditsystem with Eskom, I'm fine.

That way my system was way cheaper and made economic sense .
BTW. PV panles can now be bought for R12/watt where a year ago it was about R18/watt

PM if theres anything in particular you wish to know

Could you expand on where you say you accumulate credits, I'm not sure I'm understanding correctly!

 

[Freaksta]

You spin your meter backwards? Isn't that theft? After all, you're not providing energy to the grid...

So R12/watt...
My average consumption is 40kwh/day - I'd need 5kw for 8 hours a day to maintain that... R60k worth of panels. More if I want to allow for cloud etc...?

While thisis true, i think the main point was that you shouldn't think about going all out at once! Start with what is easy and more affordable! Get your geysers off the grid, replace lights bla bla bla

 

[Alton Turner Blackwood]

I believe the vast majority of people have a misperception of PV and that going off grid is the only goal.

A scalable PV install is optimal. Start small with built in scalability and add on as and when required/viable.

Personally, I use eskom to my advantage. My system has few batteries (only for 4 hrs backup) because of their expense and I merely spin my mechanical meter backwards with a bi directional inverter thereby accumulating "credits" which I draw down against. Although we dont have a feed in tariff system in place eg Germany where i would get paid for excess credits, as long as I dont run into a creditsystem with Eskom, I'm fine.

That way my system was way cheaper and made economic sense .
BTW. PV panles can now be bought for R12/watt where a year ago it was about R18/watt

PM if theres anything in particular you wish to know

I read that twice and still don't know wtf you're saying :wtf:

 

[Cius]

We got one of those OWL energy monitors and it is awesome. Allowed me to finally see what different appliances where costing me on a real time basis. At first we just installed it on the main board watching the immediate costs but later on I made a special short extension chord with a seperate live wire so that I could check individual appliances. Its difficult to figure out how much energy something like a dishwasher, a geyser, or an oil heater uses as it is not constant energy draw. It turns on and off. Checking one appliance at a time allows one to see overall trends and figure out the average cost of different dishwasher cycles for example.

 

[etwylite]

I read that twice and still don't know wtf you're saying :wtf:

Apologies, i assumed some knowledge on the issue.

Simply put there are many more economical ways to implement a PV solution than simply off grid.

@Sinbad Providing energy to the grid is exactly what Im doing. Please do not accuse me of theft.

Freaksta and Skerminkel have it right. Be efficient as possible and reduce your resistive loads, ie electric geyser, stove, heaters and then look at a PV implementation.

 

[Other Pineapple Smurf]

I was listening to a chap on the radio the other morning about how he installed a solar power system in his home and how he is now fully self-sufficient so far his electricity is concerned. He isn't even connected to the power grid anymore. He has a household of 4 and his installation will pay itself off over a period of between 4 and 5 years, depending on the increases imposed by Eskom.

Has anyone here followed that route? Perhaps a hybrid-system? I know solar-powered water heating systems are becoming more and more common, but has anyone here taken it further than the hot water?

My previous employer spent a small fortune on getting off the grid, 3 years later and all the hi-tech German important equipment was sitting idle and we where running 100% off the grid. Beside the hight entry cost, the maintance is also high and when things go pear shape they really do.

Its one thing to convert your geyser but its another to try and go all the way.

 

[Other Pineapple Smurf]

About a year ago a guy on MyBB got a quote for a 4-person household with solar + battery swopouts. The quote was somewhere between R100k-150k. The major problem is that solar panels are still expensive. Batteries aren't cheap either... you're looking at around R1500 for a decent battery (deep cycle), and you need a few of those.

And those batteries only last 5 years if your lucky, but getting anything more than 3 years is good going.

 

[etwylite]

Could you expand on where you say you accumulate credits, I'm not sure I'm understanding correctly!

My normal consumption for arguments sake is 20KW/h a day. My system produces 18KW/h/day. My meter starts at 100 units, spins backwards with my daily output to 82 units and i then draw 20 units so that the meter ends at 102.

I am adding my 18KW/h to the grid "effectively" using it to store my output in place of a battery bank and then drawing from the grid when I need to. at the end of the month my meter sits at 2KW/h x 30 days and I pay eskom for 60 units although I have utilised 600. I have put 540 units into the grid.

In effect my system is paying for itself at the rate of 540 units x by my unit rate per month. this rate will accelerate with tariff increases.

A grid-tie system such as mine effectively take the expensive battery storage/maintenance issue out of the equation and places that burden on eskom. The con is I am not Fully independant of eskom.

 

[Arthur]

I installed a heat pump nearly three years ago, for hot water. Marvellous device. Even with that, we use around 50kW/h per day - big power eaters are washing machine (which runs on cold water mostly), dishwasher, oven, pool, and irrigation pumps. Cooking is on gas. It's a big double-story house. Municipal mains is single phase 60A, through a Syntell prepaid meter (was here when we bought the house). I have a MLT Drives PowerStar 12KW hybrid bi-directional inverter, which can export to the grid. Regrettably there's no advantage as my meter won't run backwards. The local City Electrical Engineer is too busy fighting corruption/incompetence to even give though to REFIT or a pilot project.

I am very close to getting 40 x 200W panels, but my biggest challenge is the storage/batteries. Any advice appreciated, etwylite.

 

[Skerminkel]

Another saving that works brilliantly for me: In our area there is a lot of invasive alien trees (black wattle, mostly). I installed a quality wood burning stove. Two bakkie loads of wood last me a year. Winter for warming, summer for braai. Just buy 6 months in advance to allow it to dry properly.

 

[Sinbad]

@Sinbad Providing energy to the grid is exactly what Im doing. Please do not accuse me of theft.

Defensive much?
I was not aware it was possible to provide energy to the grid via your home meter. The technicalities of this are too much for my mind to handle


Freaksta: I have a solar geyser and I have replaced most of my lights with CFL or LED. I have a few dimmable 50w downlights left, I am awaiting my suburb's local replacement program to come onstream to kill those off too.
We boil water in the kettle once a day, and put it into a hotpot (lasts all day)
We use heatpump aircons to warm the place up - much more efficient than element heaters..

Sadly, solar geyser, with three people in the house, doesn't provide enough energy to be non-reliant on eskom. Especially in winter.

My average usage is half what it used to be, but it's still high enough that the cost hurts.