My tiny project in sunny Ecuador

[ecusolar]

Ready for discussion

Ok Jason, I'm ready with copying the posts and the thread is open for discussion.

Thanks again for the invite, I hope I can bring in something useful to this board.

Thanks for the attention
Joe

[ecusolar]

Ebay DIY solar cells and sellers review

I promised in the first page a small review of the cells I bought in Ebay, here we go:

I bought the cells for the first part of my little project from 3 different sellers with 3 different qualities but always 108 3x6 cells, enough for to make 3 panels of 60W each purchase.
The prices here are shown with USA shipping included (dicember 2009), I had to pay about 35$ for each package additional to get them shipped to Ecuador.

rebeccayi0904:

108 cells (Everbright) 3x6 priced 159.95$ (buy it now)
Quality: Clipped tapped
Extras: silver solder, flux, bus wire, tabbing wire, 4 extra cells, 5% discount coupon

The double packaging was by far the best of all, in attach you see a photo.
The cells arrived in very good condition only one got a little crack on the way.
Only point that make some of them B quality where some sharp edges.
Panel Voltage at sunny noon: 21V


Evergreen*world:

110 cells (Evergreen) 3x6 priced 132.80$ (auction)
Quality: Fully tapped, split B grade
Extras: 3 6A Schottky diodes

Double packaging in 30 units each box, came only 90, still waiting for 25 cells which are on the way after claiming the missing cells, good communication during the issue.
The cells arrived in advertised condition most split a bit some split in the middle.
Panel Voltage at sunny noon: 20V


Fred480v:

108 cells (Evergreen) 3x6 priced 172.71$ (buy it now)
Quality: untapped
Extras: solder (not silver), flux, bus wire, tabbing wire, 3 extra cells

Double packaging in two 54 cells wrapped and secured with rubber bands.
The cells arrived in very good condition no one got cracked on the way.
I would call these cells A-grade as there have not been any visible damage
Panel Voltage at sunny noon: 20.5V
I wished that this package came with 3 feet more tabbing wire and more solder which should be silver solder.


Summery:

I liked the clip tabbed dark blue shining Everbright cells from Rebecca, they are easy to clean if you have rests of flux ore finger prints on them. You also save half of the soldering work as you can solder the plus wires easily to the short pre-tabbed neg wires.
This package from Rebecca came with so much bus wire that I could finish the panels with the split cells from Evergreen*world which don

[ecusolar]

Gov law

I don't plan only to charge the batteries with the panels, I will use three or 4 panels for the backup batteries (sure they will be deep circle) the rest of the panels I will connect direct to my inverters (grid tied and off grid). In the not to far future if the law will be confirmed to me I will go for a 2 KW grid tie inverter with enough panels.

I was working in this days more in infos about solar here in EC and found a law from 2006 (don't upload it as it's in spanish) that says that the goverment pays for each KW generated by solar tech 0.50 US$.
I have to visit the folks that manage these energy buys and find out what's the need to get qualified.

Actually I'm buying cells enough to built 9 more panels, in total I will have 18 x 60W for the moment.

If the law will be confirmed and I can qualify I can make enough bucks with the 18 panels to cover all my monthly energy needs and after three years about, my system will be paid by it alone.

Let's see if that works out

I thought I should at least upload this image for better understanding.

So, they pay 52 cUSD/KWh and I have to pay in my bill 12 cUSD/KWh.

At the end I have to generate much less energy than I use to cover my monthly bill.

[ecusolar]

Morninstar 15M controller 48V

I bet on this Morninstar controller some days ago and wan it for just some bucks.

http://cgi.ebay.com/ws/eBayISAPI.dll...EOIBSA:US:1123

It's the one with monitor integrated, I think it's a steal but:

It works on 48V, 3 of my 60W panels make 60V, is that enough or should I connect 4 panels?

What means in the add positive ground?

Will I have with 3 panels (180W) the almost same outlet of 180W at 12V charge?

[ecusolar]

Vacuum

As you saw in my proove in a previous post I didn't experience condensation in my panels but to avoid it in the future I built a vacuum in the panel.

Once that it is sealed completely and the silicon dry I used a medical needle and pushed it though the silicon under full noon sun, than I connected a vacuum pump and sucked as much air as I could. Than I took off the needle and cured the hole which gets closed only by the own silicon pressure with silicone.

That way it shouldn't present any condensation.

[ecusolar]

I will make the rest of the panels in the next week, I decided to keep the design, so all will look the same.

I'm actually with a friend who has a workshop (I made him the website) and we are discussing how's the best to mount the panels.

I'm almost sure that I will not use any frame at all but a solid built mount.

Maybe later I will upload a draft how this will work.

I will make the rest of the panels next week as I don't have glass at the moment.

One note beside of all: If someone doesn't have the best solder skills go for already tabbed cells. I have pretty good skills but I asked one of my staffs to solder the tabs on a damaged cell, he did it but damaged the cell even more and it looked horrible.

[ecusolar]

Another panel

Today I finished another one what looks identical but has a little pvc tube in to let the panel "breath" like RCinFLA mentioned.

I think they aren't bad for the weather condition you find here in EC, we have garantized 8 month without rain and it's very dry (air huminity) during that time.

The raining season is just 4 month but sometimes it rains only once a week.
The weather is changing like everywhere due to all the stuff humans have done in the last 300 years.

Next prototype will be under vacuum and I guess it will be the final model.

Each one is marked and maybe I can post a follow up in some years when china panels cost 0.5 $ per Watt, lol.

BTW: the last one took me only 3 hours, I think it's getting better from now on.

[ecusolar]

Sealed DIY panel w/o vacuum

Ok, I finished the panel yesterday night and it's all dry now

Here I simulate the worst case what can happen in Ecuador, a sunny day with sudden rain.

I sprayed with a sprikler constantly for 15 minutes water, than let it sun dry and you see it has no fog in.

This panel wasn't made using vacuum, the next one I will try that out.

Here the price of the panel, it doesn't include the frame I will use a more solid mounting rag instead.

The panel gives 21 Volts, this time I used 36 and not only 33 cells.

[ecusolar]

Panel size

I'm still not sure what will be the best panel size:
1. the 3 by 12 cells
2. the 4 by 9 cells

Did someone read about that or have experience with both designs?

Actually I'm using 3 x 12 strings but need to use a cable to get pos and neg closed together.

[ecusolar]

Silicone "Frame" for sealing

I have no mayor updates today, the only thing I did was creating my "frame" for the sealant.

Here a photo to have an idea what I did.

It's a 3mm Iron lineal 1M long (I made two of those and two smaller ones to get one panel done at the time), I passed Silkasil to have a guide for the final sealing which will be done tomorrow (at least one panel).

It takes a little time to do that but I think it's worth to do, mostly because of cosmetic reasons.

To solder the cell strings I use a guide at one side, I have several pieces of MDF of 120 cm by 25 cm where I solder the cells, once they are done they will rest there untill I glue them to the glass buttom.

I use few silver solder to have a better heat transmission in the first contact but than I only use only the solder which is coming with the wire (on the wire).

[ecusolar]

TEDs

Holy, that's nice stuff.

here the price list of TEDs: http://www.theenergydetective.com/store/

[ecusolar]

Kill A Watt

Today arrived my Kill A Watt meter.

It's a very good tool, my 23" Samsung LCD screen is rated 108W but it only uses 70W.

The Sony laptop charger is 60W but when the battery is charged I could read 35W only.

My wife called me Mr. Watt-son today.

[ecusolar]

Economic aspect of DIY panels

Q: I just said making them won't save you any money over buying them

I think I will second that after finishing my project, it will be very difficult if not impossible to get closed to the quality of factory manufactored panels, starting with the Ebay cells which are mostly B-quality.

Anyhow, compiling a DIY system makes you to understand step by step what is all this about and at the end you might stick to install a system by yourself but buying factory parts it needs for your consume.

As I said before, I don't care too much how long the panels I'm making last (but hope at least 6 years) as China is in full production and will drop worldwide solar panel prices. Maybe in 5 or 6 years they cost the half of today and are soft string, who knows?

Not everything coming from China is bad, they produce the quality you want and have different export qualities with of course different prices and a not exportable local quality.

I know all this because I have a Chinese friend which imports/exports al kind of stuff.

[ecusolar]

Double purpose panel

As I said before I have a multi purpose for the DIY panel.

This is to generate Solar electrisity AND solar hot water in the same panel.

Here a picture of the construction of the panel you saw in the photo and where the water hoses/tubes will be placed.

I have more than enough space at home to place the panels so it's not my idea to save space but construction cost.

Also I was reading that cooler cells produce more energy than hot ones, that's why I want to measure the heat in the spaces of the panel.

The cost of the frame was 34$ the glass included.

The lower part of the panel will be a sheet of aluminium and isn't included yet.

[ecusolar]

DIY 33 cell Panel in plain sun

Here another photo of my first DIY panel in plain sun at 14:00 h (18V out).

The fan you see there is a 24 V cooling fan and it spinns from 6:30 to 18:30 h (Wow, 12 hours) when connected.

I took the decision not to cure this one with Sylguard (anyhow I have 8 more panels to built) as it will be a test panel for other additional aplications and measurements like heat inside etc.