DIY Solar Kits

[thoner7]

So we are still working to get power to our property and one of the things we have looked into is solar. The Tax Credits in NY make it almost a no brainer.

I have found a few websites online that offer "kits" with everything you need to install the system. These would save me money but its not very much. I am considering doing it though, not for the dollar savings but for increasing the size of the system. In particular, the 10 kwh kit from this website would save me $1500-2000, BUT would increase the size of the system by over 25%. This might be excessive for my usage, but I'm sure I could use the electricity in one way or another. https://tandem-solar-systems.com/home-solar-kits/

I've watched some videos online about installs, but they focus on the tracks and mounting the panels. That looks super easy. But what about the wiring? Anyone have any experience?

[oldtrapper]

30% federal tax credit. ;-{>8


Off grid? Batteries?

[thoner7]

Plus NY has an additional 25% tax credit. So 55% off. Then there is Grant money on top of that.

I'm just wondering how hard they are to install. I'd almost rather try my hand at this, save money, and hire out something else I was planning on doing

[Mosseyme]

The wiring is something I have been wondering about as well. In an off grid system where you are trying to produce as much as possible and lose as little as possible in transfer, what would be the best plan for your internal wiring. I am thinking we should go with 12 gauge at least if not 10 on the inside and no less than 10 gauge coming from the battery banks to the house on the outside. Also I am thinking we will do all the perimeter wiring behind the chinking so conduit or Romex. I am leaning toward conduit due to the thought of ever having to get behind that chinking for a problem. What have you guys done. Romex would be so much easier in the short term so I just don't know. Since we have hope to do some chinking this season I need to get this figured out.

[oldtrapper]

I have a couple of DIYer friends who have done it. Just work. When I do it, I will have an electrician make the final connections. ;-{>8


Gotta add, there appear to be large, cost saving changes to battery technology right around the corner.

[donjuedo]

The wiring inside the walls should be normal, just as if grid connected. Losses there are not significant.

As far as 120/240 wiring, the only change I might make would be to separate loads at the breaker box, so some might run from a generator, for example. But even then, I would still lean toward having the whole house running on the generator, if it's going to run at all.

Thoner, this is something you can do yourself. Just start with a basic book on home wiring from Lowes or Home Depot, to learn code basics. Ask questions here. Watch details you're unsure of on YouTube.

[thoner7]

Hey thanks for the feedback. I can and have run simple circuits, adding outlets and over head lights to bedrooms and stuff. I'm just not sure what degree of wiring solar entails and if any specific knowledge is needed.

In using some calculators online, it seems like best bang for your buck is putting them on the roof of my pole barn. Should be simple enough to rack them but tieing in the wiring to the meter and stuff.... I'm not sure. YouTube hasn't been much help.

[donjuedo]

Oh, wiring the meter. I have been assuming strictly off grid.

Power companies have two reasons to add requirements. One is safety. Short version: they don't want solar panels powering the grid when a line goes down and killing a lineman. Two: requirements discourage loss of their business to solar users. It may sound paranoid, but there are plenty of stories out there of frustrated customers of the power company, getting the runaround or not hearing back at all. And many succeed anyway. A licensed electrician is needed to make the meter connection, but he can cut through red tape, too.

[donjuedo]

Solar panel connectors are pretty standard nowadays, for solar panels. I vaguely recall a name like MC4, but don't quote me on that. It doesn't matter, though. You connect the male connector from one panel to the female connector of the next (just snap together). That forms one "string" of 2 or 3 or 4 panels or so.

When you have a few strings to connect in parallel (male connector to male and female to female), then you can cut off ends and wire together in a combiner box (a simple steel box sold by that name). You might need an extension wire or two with those solar connectors, in order to reach your combiner box.

From the box, you run off-the-shelf wire to the charge controller. From the charge controller, run more off-the-shelf wire to the batteries, and so on.

[thoner7]

So that sounds pretty simple. Just simple wires and pigtails at the junctions I assume? The kits come with wiring diagrams so I should be able to handle that I would think

[rreidnauer]

The only warning I'd offer is, when you start stringing together panels, you get into a deadly voltage/current scenario pretty quick. It's not like there's a switch to turn a panel off. And DC is far more dangerous than AC. Just the four panels I'm currently running puts out 96 volts open circuit, and can develop 10 amps @ 72vdc. If I hooked all 12 of my panels in parallel, I have a 60 amp welder. (yes, you can do that with solar panels, as shorting them does not harm them) Battery banks are even more dangerous, especially when you go 24v and bigger. Higher the voltage, the higher the risk of a DC electrocution. A 48vdc battery bank should be treated like 480v three phase.

I'm not trying to scare you off, but I also want to make sure you understand it isn't like playing with 110v house current.

[loghousenut]

He's not full of sheep dip on this one. I had the pleasure of burning my wedding ring off me with a 12 volt battery once. HOT DANG!

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[donjuedo]

Pigtails would work, but the combiner box probably has terminal strips/blocks/bus. Still, it's simple.

Rod's right about the voltage getting up there. In the cold, the panel voltage goes up. That's just trivia in your case, as the seller of the kit has already worked out such details, selection of the charge controller in particular.

[rreidnauer]

If you really want to have some fun, try installing a regular 110v house light switch to turn the panels off. (have a fire extinguisher ready)

[thoner7]

I guess I will have to install them in the dark

[StressMan79]

I guess I will have to install them in the dark

You are generally ok (against arcing) with "low voltage" (under 50 vdc) which is why dc systems are usually only 48 volts.

[solarpower]

What's the going rate for purchasing panels? I was under the impression you can find them for .50/watt.

[project]

What's the going rate for purchasing panels? I was under the impression you can find them for .50/watt.

http://sunelec.com/solar-panels/

[donjuedo]

By the pallet, the price I see there today is $0.28/watt. I bought 2 pallets awhile back, and each was 225 watts, not the 300 watts on the site today.

The last time I suggested sunelec.com on this site, they were terribly unresponsive, but IIRC, it eventually worked out. I would still do business with them again, as long as the prices are rock bottom low.


Peter

[loghousenut]

I remember when we thought $1 a watt was too good to be true.

That back when we used real American dollars and not these new teenyweeny metric dollars.

[rreidnauer]

It should work, but it will increase heat significantly, likely shortening lifespan.

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[thoner7]

So I'm researching solar diy kits again. I'd like to put them on my roof. But I'm concerned about the wiring. Like how exactly do you may the connections? What kind of wire stubs are on each panel?? How do you wire it back together before going to the panel.

I can't find any info online all they talk about is wiring in parallel or in series.... I don't care about that

[rreidnauer]

I've seen a couple different ways panels come. Some with a screw or threaded post and nut, but mostly with a pair of 3~4 foot wires stubbed out of a junction on the back, with MC3 (old type) or MC4 connectors on the ends. The connectors can be cut off if you wish, and use weather tight connectors directly into junction boxes, but better to buy the associated MC3 or MX4 pigtails and wire those into a junction box or electrical trough. Then you can change out panels quickly by just unplugging the MC connectors

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[thoner7]

I've seen a couple different ways panels come. Some with a screw or threaded post and nut, but mostly with a pair of 3~4 foot wires stubbed out of a junction on the back, with MC3 (old type) or MC4 connectors on the ends. The connectors can be cut off if you wish, and use weather tight connectors directly into junction boxes, but better to buy the associated MC3 or MX4 pigtails and wire those into a junction box or electrical trough. Then you can change out panels quickly by just unplugging the MC connectors

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Ok, so each panel connects to a fairly idiot proof connection. And at some point all those wire go to a junction box where it then goes to the panel and backfeeds or is used etc.

Would you say that if I built my own house and wired at least half of it myself, it would be fairly easy to do?

[loghousenut]

Any fool of our caliber can do it. Get a look at Home Power online magazine and you'll get a handle on it.

[rreidnauer]

Give me more info Throner. Grid-tied or off-grid (battery bank)? If off grid or hybrid, bank voltage? Panels voltage? MPPT or PWM type charge controller? Housed wired for AC, or both AC and DC?

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[thoner7]

Give me more info Throner. Grid-tied or off-grid (battery bank)? If off grid or hybrid, bank voltage? Panels voltage? MPPT or PWM type charge controller? Housed wired for AC, or both AC and DC?

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I would do grid tied.

[thoner7]

Give me more info Throner. Grid-tied or off-grid (battery bank)? If off grid or hybrid, bank voltage? Panels voltage? MPPT or PWM type charge controller? Housed wired for AC, or both AC and DC?

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I would do grid tied.