Solar power - how does one begin

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macbeth

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Looking to start installing solar power panels etc at my home. Want to do the diy way, but not sure how to begin.
What do i need to look out for? Any advice from those who have already done it?
How easy is it to put a pool pump onto a solar system?
Any suggestions for the most price competitive suppliers in gauteng?
thanks
 
There's a few things you need to consider when installing a solar system:

a) the best position for your solar panels. They better the angle and sun coverage, the more juice it pumps out. If you have a branch that bugs 5% of the panel, you can lose up to 30% of the panel's output.

b) voltage and current regulation - you can't run the cables straight into your battery array, so you will need a regulator to do it for you. The correct term for it escapes me now.

c) Battery array - you need an array of batteries that will suit your needs, but this depends on what equipment you want to run from it.

d) Obviously the power is now stored in 12V DC batteries... so you need to invert the power back to 240VAC, so an inverter you shall buy (once again the specs depend on what you want to run)


e) Solar panels itself... the size depends on what you want from it.
Powering a pool pump is a pretty expensive thing to do - assuming your pump is 1.5kW, that means it costs you ~R2/hour of running... but a setup big enough to output 1.5kW can cost you about 20k, so you'll spend 3-4 years paying it off.

Now you can do it yourself, but are you tech-savvy?
 
I'm not too concerned about the 3-4 years - as long as it saves money long term.
As for me, tech-savvy - well...I can change a plug and know a little, but probably nowhere near the level of an electrician...
thanks...very interesting indeed. At the moment when I search a bit on the net it feels like its a big hit and miss, difficult to decide who is a decent supplier and who not...
 
Well, your first question would be to detirmine the pump motor size.
Next would be how long you would like to run the pump.
Next, if you happy with the pool pump, would you like to expand it to the rest of the house?
How much north facing roofspace do you have?
Is Netmetering allowed in your area?

The reason for all the questions is that solar stuff is pretty expencive, so you would like to start with your ultimate design, then cut it up in smaller blocks and start working from there.

Ultimately, battries is your most expencive and ineffient part of the solar system, and if you can run without it, makes the installation so much cheaper.

If you allowed to do export power back onto the grid (Netmetering) in your area, you off to a good start.
Then you only need solar panels and a grid tied invertor. All the power the solar panels generate is used, either by yourself or exported back onto the grid.

If netmwtering is not possable, then battries and an invertor would be the way to go.

Have a look here for some more detail...
http://www.powerforum.co.za/
 
froot said:
There's a few things you need to consider when installing a solar system:

a) the best position for your solar panels. They better the angle and sun coverage, the more juice it pumps out. If you have a branch that bugs 5% of the panel, you can lose up to 30% of the panel's output.

b) voltage and current regulation - you can't run the cables straight into your battery array, so you will need a regulator to do it for you. The correct term for it escapes me now.

c) Battery array - you need an array of batteries that will suit your needs, but this depends on what equipment you want to run from it.

d) Obviously the power is now stored in 12V DC batteries... so you need to invert the power back to 240VAC, so an inverter you shall buy (once again the specs depend on what you want to run)


e) Solar panels itself... the size depends on what you want from it.
Powering a pool pump is a pretty expensive thing to do - assuming your pump is 1.5kW, that means it costs you ~R2/hour of running... but a setup big enough to output 1.5kW can cost you about 20k, so you'll spend 3-4 years paying it off.

Now you can do it yourself, but are you tech-savvy?
Click to expand...
A charge controller.

OP, I'm not trying to put you off or scare you here, but be warned, going solar is very expensive! Just an example, I grabbed the first hit from google to gauge the price of a 200w panel from here[/ and it'll set you back R2 233. That's for one panel only. You'll probably need about 20 or 30 (at least) depending on your needs.

A 102ah deep cycle battery can easily cost R1 500, and (again, depending on your needs) you'll need a lot of those as well. Also, batteries have a finite lifespan of around 5 to 10 years depending on various factors.

If money is no object then by all means go for it! :)
 
You do also get 12V pumps that can operate on solar. I have lost my bookmarks else I would have given you a link.
 
2 types of Solar:
- Grid Tied (where you basically feed into grid daytime and your meter goes "backwards", then at night you roll forward again)
- Off Grid (where you have solar + batteries etc)

You need:
Panels.
Inverter (these are typically different for on/off grid, although there are hybrid ones).
Batteries, Charge controller (assuming off grid).

I'm busy installing a grid tied system at my house.
I have special needs, so mine isn't your average install.

I have 30 panels @ 300w for 9KW.
A 3 phase 10KW grid tied inverter.
No batteries (as I can't afford to go that route yet).
I sourced, ordered all my stuff myself from China (I work there most of the year), and am self installing.

More details on mine here - http://goingsolar.co.za

Can answer questions if people are interested.
 
Last edited:
Sinbad said:
Batteries are useful for keeping the lights on when you have power cuts. Ideally, you want both.
Click to expand...

True, but for the OP I think it makes much more sense to grid-tie and to schedule the pool pump to run at 12h00, when solar generation is peak and most of the household are at work/school.

Ideally I'd like a combined system: grid-tied AC, with a separate (battery backed-up) DC circuit for lights, with a couple of 5 V regulators for USB powered devices. The problem with that is that you'll have to build a totally separate DC distribution circuit, and that will have to be fairly thick cable. You'll also need separate conduit (you're not allowed to run AC and DC in the same conduit), and the law is quite strict on DC breakers as well.
 
My ideal will be a10 kva grid tied inverter with a battery bank, enough to run the whole house off battery for 12 hours... when I win the lottery.
 
lsheed_cn said:
2 types of Solar:
- Grid Tied (where you basically feed into grid daytime and your meter goes "backwards", then at night you roll forward again)
- Off Grid (where you have solar + batteries etc)

You need:
Panels.
Inverter (these are typically different for on/off grid, although there are hybrid ones).
Batteries, Charge controller (assuming off grid).

I'm busy installing a grid tied system at my house.
I have special needs, so mine isn't your average install.

I have 30 panels @ 300w for 0.9KW.
A 3 phase 1KW grid tied inverter.
No batteries (as I can't afford to go that route yet).
I sourced, ordered all my stuff myself from China (I work there most of the year), and am self installing.

More details on mine here - http://goingsolar.co.za

Can answer questions if people are interested.
Click to expand...

30 300W panels will give you 9kw. are you sure you are only using 1x 1kW inverter?
 
lsheed_cn said:
2 types of Solar:
- Grid Tied (where you basically feed into grid daytime and your meter goes "backwards", then at night you roll forward again)
- Off Grid (where you have solar + batteries etc)

You need:
Panels.
Inverter (these are typically different for on/off grid, although there are hybrid ones).
Batteries, Charge controller (assuming off grid).

I'm busy installing a grid tied system at my house.
I have special needs, so mine isn't your average install.

I have 30 panels @ 300w for 0.9KW.
A 3 phase 1KW grid tied inverter.
No batteries (as I can't afford to go that route yet).
I sourced, ordered all my stuff myself from China (I work there most of the year), and am self installing.

More details on mine here - http://goingsolar.co.za

Can answer questions if people are interested.
Click to expand...

i see the maths is better in your link. I still see a few issues and recommend that you get a expert advise before proceeding any further. (or maybe you were just trying to make the post more readable? In that case, carry on sir)
 
@lsheed_cn,
just be aware that it is still NOT legal in CPT to go Grid-tied.
Yes, there is a couple of tests running, but the council is dragging their flipping feet :(
Also note, that even if and when grid-tied is allowed, you will not be paid out if you export more power than you consume.
For that you have to register as a SSEG (Small scale electrical generator). You will pay R0.89/kwh and they will pay you R0.46/kwh :(

Ref: http://www.capetown.gov.za/en/electricity/Pages/ElectricityTariffs.aspx
 
@Wetkit - Unfortunately I'm well aware of whats possible, and whats not - I have *pages* of reference emails from CPT on my site about it!

It is legal to grid tie, but its a lot of forms, and even when you've done that, currently its not really worth it to go grid tied, as you get charged a daily fee just to connect to the grid. On top of that, you're not allowed to go into credit, so having solar and feeding back into the grid would actually cost you more than not feeding back into the grid (currently!).

It *will* change in the near future - I guesstimate sometime in the next 5 years or so.

If I could afford batteries at the moment, I would go that route. Mine will be an on grid, but not feeding into the grid system, and I'll have separate circuits for daytime use for things like washing machine, and dryer (our 2 largest consumers of electricity, other than the oven). My inverter can be programmed to do that, then, when CPT deigns to let us contribute, I can flip a switch and become a net exporter of electricity :)

Or, when I get a bit more cash, I can add a battery management system in, and have batteries.
I was looking at Lithium Ion or Lithium Sulphur based, but I'd need about 90k RMB (R150,000) for something suitable based on my research of what was available and pricing at the SNEC fair over in China last year ( http://www.snec.org.cn/default.aspx?lang=en ).

So far I've spent about R80,000 on panels, inverter, mounting etc (including shipping+taxes), which isn't bad, considering local pricing for what I have is about 250-300k...


--
@ElecEng -

Yup, I keep getting confused on the KW numbers (doh!)

My inverter is a _10KW_ 3 phase inverter, panels are 9KW total (30 x 300W), so sized correctly for my needs.
Assuming 5 hrs of sun a day, I should generate somewhere in the 40KW a day range being pessimistic, and we only use something like 15KW daily.

(We use 700w-800w an hour).

I have actual stats for a years worth of electricity use via my Flukso. Pretty cool to see that something like turning on a kettle chows enough electric that you can tell when it was turned on and off from the graphs.
 
I'm thinking of putting all lighting (and alarm and electric fence) in the house onto solar with battery.

Now at most total power use will be around 600W (adding all the lights W together if they were all on at the same time). General overnight use (the security lighting) would be between 200w to 250W for say 12 hours.

Have a flat roofed house with lots of unobscured line-of-sight to the sun during the whole day, garage roof (5mx4m) would be ideal (can house whole system there and close to house DB board).

So questions is so I can do basic costing (lets work on as if using 500W for 12 hours):

1. How many 200W panels would I need to load the batteries during the day with?
2. What type of charge controller would I need to look at?
3. How many batteries would I need?
4. What kind of inverter would I need?
 
rebel998 said:
I understand that pumping back into the grid is better but how sure can one be of getting "money" back?
Click to expand...

Almost no chance afaik. The laws being passed do not allow for being paid out, only for offsetting on a month by month basis, unless I'm very mistaken which has been known to happen on occasion :p
 
My old man went solar, can run a whole house (think 4 bedroom plus granny flat) on batteries in the evening, the charge controller is a fancy aussie one, the inverter is a fancy European one, the deep cycle batteries (bank of 24 enormous things), and a few rows of pv panels (grouped into 3 clusters) from China.
The geyser is solar with very very low heat loss and gas backup.
The total cost was about R130k, when the dollar was about R7, for the solar conversion which he did himself except connection to the mains. Pretty much everything was imported.
 
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