Grid Connect PV systems

Post by **Johny** » Wed, 16 Mar 2011, 14:28

Mesuge - I keep forgetting you're not in Oz. Can you fill out your country in your profile so I don't have to go searching through your posts to figure out where you are (please

)? (This sounded like an order but it's more a begging type tone).

Post by **Adverse Effects** » Thu, 17 Mar 2011, 17:55

a4x4kiwi wrote: I prefer no electronics at all.

that has to be the silliest statement i have seen

the panels are Electronics
the converter is electronics
the controller is electronics

as for the small panels in my pic you dont have them running the full length of the array you have them tacked on to the end of the main panel

They use the thermal expansion of liquid to move a hydrolic actuator

so you want to use a system that relies on pressure that moves a piston up and down a cylinder

problems with that are

leeking conectors
leaking shaft seals
leaking piston seals
cracking chambers
moving joints that need to be greased
not to mention if the conrod starts to rust it can lock the system up and stop it moveing at all
and what happens if you get something like a cold wind blowing over the tank that should be heated by the sun? it will ether not move or it will move the wrong way or move to far

Post by **Richo** » Thu, 17 Mar 2011, 20:58

It's easier just to fix them all in place and shine a mirror on the panels to double your power

Post by **markrmarkr** » Fri, 18 Mar 2011, 00:06

Goodness,
con rods, connecting rods, seals cracking chambers... I just had a moment of deja-vu. What was the name of that ancient device people used to use to power their cars???

Post by **EV2Go** » Fri, 18 Mar 2011, 01:22

How about building a parabolic dish? that way you could use the refracted light as well as the direct light.

Post by **EV2Go** » Fri, 18 Mar 2011, 01:24

Johny wrote: Mesuge - I keep forgetting you're not in Oz. Can you fill out your country in your profile so I don't have to go searching through your posts to figure out where you are (please)? (This sounded like an order but it's more a begging type tone).

It's all in the sig...
Czech EV Club | blog, gallery, video | http://old.elektromobily.org

Post by **Johny** » Fri, 18 Mar 2011, 14:13

EV2Go wrote:It's all in the sig...
Czech EV Club | blog, gallery, video | http://old.elektromobily.org

Oh

Post by **Tassie Mike** » Mon, 21 Mar 2011, 03:47

Thanks people, the replies are indeed edifying!

Here in Tasmania we are at 41 degrees south and the sun competes with the cloud more than in say Northern NSW, buying just one more panel is a good argument, but this thing will shift all 12! --- so if the net gain is, say 30% thats about three and a half panels.

OK yep I imagine leaks and rusty rods are a problem I had not thought of that!
More thinking is required!

My experience with electronic shifters was dismal to say the least, thats why I am looking about!

Post by **Adverse Effects** » Mon, 21 Mar 2011, 09:55

there is realy no electronic in it

co control boards at all

you simply hook both the small panels to the motor (1 in reverse with a few diodes to stop the current going back the wrong way

i am no electronic genius but that would work wouldn't

Post by **Tassie Mike** » Mon, 21 Mar 2011, 13:23

I think you are right, it would work, a toothed belt and some micro-switches!!

It should return to "Start" at the end of its days movement,, I think I can do that !

Thanks Adverse

Post by **bga** » Wed, 23 Mar 2011, 23:53

No adverse effects...

Hmm, some small PV panels probably would work fine. You could use some reliable old electromagnetic 'amplifiers' (er relays) to reduce the size of the control panels and allow a night time reset for the next day.

I think the way to look at it is the marginal gain. If it's worth 3 or so panels, that's about $1500 these days, so the tracker has to be considerably less than this to make it worthwhile not simply buying some more panels.

If it's within 15 degrees it'll work pretty good.

I'd thought anout mounting pairs of panels on a rotating pole sticking through the south roof at the lattiude angle and rotating to track the sun. It would probably be so visually offensive, maybe even worse than a windmill, that the neighbours would make me take it down.

Flat panels on the north face work well and don't have any rusty mechanisms under them.

Post by **T1 Terry** » Thu, 24 Mar 2011, 04:16

The brother in law who lives on the side of the Huon Valley in Tassie has a rather agricultural set up but it works for him. The panels are mounted on a length of water pipe so the can be tilted east to west. One of the upright poles is adjustable to allow for summer/winter sun angle. There is a shaft at 90 deg to the axle shaft with a rod connected. The bottom of the rod is welded to a plate that fits onto an old wheel and tyre. This wheel and tyre fits in a garbage bin. Water if fed into the garbage bin from a spring at a regulated rate causing the tyre to float, this tilts the panels. The flow rate has been set to tilt the panels from east to west at a speed that follows the sun. In the evening the plug is pulled on the tank (rubbish bin) and the water irrigates his vegie garden. This drops the tyre to the bottom of the bin and the cycle starts again the next day. A possible refinement would be a lumitron to control the flow valve and an auto flush unit to drain the tank when it's full

His positioning sensor is 2 pieces of plate mounted one above the other. the top one has a 6 " hole and the bottom on a cross painted on it. The sun shines through the hole and forms a perfect circle centred on the cross when the panel angle is correct.
Hows that for farmer rough

but it works, his other power supply is a Pelton wheel (looks like a heap of spoons mounted radially) connected to a car alternator but this is only run in the evenings if the solar input has been poor. The water to drive the pelton wheel comes from a spring fed dam higher up on the property.

T1 Terry

Post by **reecho** » Wed, 04 May 2011, 04:50

I have 5.22Kw of HHV (18x290W) panels and a SMA Sunnyboy 5000TL inverter.

I upload my data live to....

http://pvoutput.org/intraday.jsp?id=1261&sid=972

Just received my latest bill and its over $300 in credit after 60 days..

Plenty of capacity if an EV sneaks into my garage...

Post by **bga** » Tue, 14 Jun 2011, 07:07

Not all panels are created equal!

I was up on the roof over the weekend and was comparing the complexion of the various solar panels. One set has taken on a decidedly yellow colour from the silicone potting goop ageing. I was a bit surprised because the panels have only been up for about 12 months.

So far, it hasn't significantly affected the output, but I suspect that this set may last less than 5 years. The other set still looks perfect.

I'm not going to get too upset; The PV panel industry is evolving at such a rate that 5 years is a long time, so I'll see what's available when the time comes.

Post by **jonescg** » Fri, 17 Jun 2011, 18:26

As for battery storage, wouldn't nickel-iron batteries be the better option? Sure they are three times more expensive, but last at least 4 times longer than lead acid, and they don't have any really nasty heavy metals.

I was doing some back-of-the-envelope calculations for setting my house up with solar panels and a large Ni-Fe battery array. This way you can go completely off-grid and the 'gummit can 'garn 'git stuffed!

I was hoping to run all of the lights in the house on 240 V DC, but I don't know if that's practical. It's OK on low voltage DC house setups like my parent's old place in Queensland. This way if the inverter failed you at least have lights.

Of course a 240 V battery bank would mean 200 individual NiFe cells, so that takes up a bit of space.

Also, I have to stop spending money on my electric race bike and buy the house I'm living in... one thing at a time

Post by **antiscab** » Fri, 17 Jun 2011, 19:04

Nimh cells from Vectrix's are available,

30Ah nominal,
you could easily have a usable 20Ah 250vdc battery for $2500.

Matt

Post by **jonescg** » Fri, 17 Jun 2011, 20:51

I was thinking of these guys:
http://ironcorebatteries.com.au/page8.php

Oh, sorry I couldn't get to the meeting on Tuesday. I was going to ask about branch support for the TTX-GP...

Post by **Johny** » Fri, 17 Jun 2011, 21:02

jonescg wrote: I was thinking of these guys:
http://ironcorebatteries.com.au/page8.php

I gather they do not need any sort of balancing and prices are comparable to hi-end LiFePO4 with an almost forever life. Sounds good for PV storage.

Post by **electriker** » Wed, 21 Sep 2011, 02:38

Richo wrote:
It's easier just to fix them all in place and shine a mirror on the panels to double your power

I'm actually trying that out by recycling old CDs, using a paper guillotine to cut them into hexagonal shape (like a large astronomical telescope mirror)

and mounting on a PVC pipe frame. Pretty cheap and disposable.

My preliminary results show a rectangular array smaller than the PV panel gave a measured 10% boost in output.

Joe

Post by **glenn_aircooled** » Sun, 16 Oct 2011, 14:32

I have become interested in the idea of tracking with my 1.5kw PV system. Probably the biggest drawback being the extra Roof weight and complexity. I already have 8 PV panels and a Solar Hot water unit up on the North facing roof.
The Mirror option may need trying out :)

Glenn.

Post by **glenn_aircooled** » Sun, 16 Oct 2011, 14:45

A sad story about procrastination - I got my PV system put up on the roof when they offered the 60 cents rebate. I am still paying it off, pays for itself wit hthe savings

I immediately told every one I knew to take up the offer.
My Father thought it was a good idea - got some quotes for 2kw, but kept
thinking how he'd like to go completely Off Grid. So kept looking for good price for some one to do that. Was also waiting for the promised better Panels to come out.....looked and waited right up till they announced the end of the 60 cents rebate.
So Now I pay $80 for 3 months of Electricity [ family of four]Previously it would have been about $440., I also pay $360 paying off my PV system - which just happens to be at break even - that will continue for another year - then I own it outright.

My Father still pays his $340 per quarter electricity and grumbles to himself at every Power bill how he waited too long.

Post by **gttool** » Mon, 17 Oct 2011, 01:22

ours was $1000 average and now $200 could not complain either

Post by **electriker** » Mon, 17 Oct 2011, 01:38

When the Commonwealth introduced their solar rebate scheme, KRudd wanted to have 20% of all power generated renewably. (What I call the R%)

Here's my effort, month by month:

It's pretty hard to get an exact figure, but I think I'm about $200 ahead in my income stream over that period ... I've sold $200 more electricity than I've bought.

Joe

Post by **SamD** » Mon, 17 Oct 2011, 18:43

Hey Glenn, you may want to give this mirror idea a go - it's not complex and you will pick something up - however small.

http://samdidgaf.blogspot.com/2011/08/s ... ector.html

Post by **glenn_aircooled** » Wed, 19 Oct 2011, 01:44

Thanks Sam