Installing the panel (27-28 June)

[mtbandy]

I've been taking lots of pictures the last couple of days, and thought I might as well do regular diaries whilst I'm installing and tweaking my small photovoltaic system. I know this is tiny compared to some of you guys who live totally off grid and need the power to survive, but I'm just doing it for a bit of fun and to prove to others that we can generate our own usable amounts of power!

Anyway, onwards...

The last couple of days have consisted of working out a way to mount my 50 watt panel onto the garage roof, in a semi-permanent way. Drilling through the roof was out of the question, so plan B was to use sand bags to hold down a steel frame. Unfortunately, the whole mess would be in clear view of several neighbours, so a neater solution was required.

I got hold of some steel angle section from the local steel merchant, and welded this frame together to hold the panel.

Last night I slapped a thick coat of paint on it, and it came out alright.

One of my better welds (we only bought the mig welder on Monday)

This is the frame screwed to a concrete slab on the roof. It's a 600x600x50 slab. Getting the slab onto the roof was extremely difficult - in the end I lashed a rope around it, angled the ladder to that it was at a shallow angle, climbed onto the roof and hauled the slab up the ladder. If it had slipped off half way, then the amount of damage to the greenhouse would have been ridiculous!! But fortunately it worked quite well.

Me bolting the panel on :-)

Wiring it all up at the panel end...

I really don't understand why they need that diode there...

Wiring completed and ziptied to the frame

In come the wires... There are two power cables for the PV panels, and an unused TV antenna cable. I still don't know how I got away with drilling this hole!

The PV 'Array', In theory there's 55 watts there - but I've never seen more than 1.8 watts from the smaller panel. Minutes after installing, the large panel was putting out 42 watts, hopefully I'll be able to hit 50 or more when the sun is out in full and shining directly on the panel.

Hope you all enjoyed reading my first real diary entry! It's all good fun so far, see even us on-gridders can have fun making our own power! Tomorrow I'm driving to Manchester to collect some deep cycle Yuasa 90Ah batteries, that AbyssUnderground/Andy spotted going cheap on eBay. I'll probably use either 1 or 2 on the system for now. Looking forward to getting those!

[fungus]

The frame looks very nicely made, pretty good welding. The diode looks like a bypass diode for use in higher voltage systems with panels in series, if one panel is putting out lower current then the diode will conduct and not drag all the other panels down to that amperage. I would like a few of the batteries there but too far to pickup

Coming along nicely! Seems like it'll all be up and running soon.

[ghurd]

Looks good!

Thats right about the diode.  It only helps with 48V systems.

I suggest cutting it out, before it can cause problems later. Not common, but it happens.

About 3.2A is the best it'll do.

Keep an eye on the zip ties.  UV eats up the standard type.  Expect to replace them in a year or 2.  Maybe cover then with black tape?

Keep a close eye on the married cable too, unless you know for sure it is sunlight rated.

G-

[AbyssUnderground]

Looking nice! I just wish I had that sort of PV instead of the rubbish 38w running at just 20w most of the time. Keep it up :-)

[tecker]

Looks fine and a good step forward . I can't help but caution the use of a heavy concrete block on the roofing. Any time installs are made on flat roofing the balast is removed down to base material and a curb is constructed larger than the size of the   device and the curb is bonded with the same material the roofing membrane is made of if not the corners settle into the membrane and a costly leek that tends to migrate to other parts of the roof .Sorry for a butt in but an older roof can go bad Quickly .  

[tecker]

Looks like tar and gravel so sweepit to the membrane and coldtar several layers of  heavy felt to the clean surface make a frame with 2X10 pressure treated and set to the felt squares  with cold tar put the block on that and good to go.

[mtbandy]

Thanks for the replies, and for the advice regarding the roofing.

I'll have to do something about that then, the roof is felt sealed with tar, with gravel on top. All I did was sweep away the gravel for the slab, but it wasn't quite level so I packed it with gravel, and did wonder about it digging in. I'll have to follow your advice there and sort it out quickly!

On a related note, we do have a nasty leak in that roof already, and it has been there for about 3 years :-( it's just getting worse, and I wondered if there is any easy way of finding/fixing it being as no-one else is going to. From what you said above, I'm wondering if it has been caused by using ladders on the roof. I suppose finding it is the main problem, the roof leaks in about 3 places inside and the plasterboard has come down...

[tecker]

Your best bet to fix the leaks is to buy a roll of torch down roofing it looks alot like roll roofing but thicker the tar is on the back and your rent a large propane torch and torch the back until it melts and seat it in place some one with some pointers is a good idea or a book with pictures . I've done it several times It's not to bad .

[pepa]

most roof leaks are located at the points of flashing. check the flashing near the water damaged area for cracks and seperation of material. once the water gets under the roofing material it will follow the path of least resistance and show up in several areas at the same time. pepa