A newbies DIY solar install

[Jchonline]

Interesting my house is 4800 sq ft 4 ppl and we run about 35 kw a day in the summer. Well since you are grid tied it can just be sold back, but you will be doing them a huge favor!

 

[RalphVa]

We get the utility fuel cost for not making what we produce in excess. About .03/kwh.

Guess panel costs are WAY down from when we put ours in around 5 years ago. No way could we have paid out such a large project with that little bit of credit.

 

[RalphVa]

Big houses have big electric bills. 4,500 sq/ft finished space, 2 fridges, 2 freezers, 3 kids, washer/dryer that runs non stop, etc etc. System will cover all summer usage and with summer credits may cover winter as well. Even in the swing months when air/heat is not used I average about 65 kwh/day

Our house is around this size, and our average kw usage is short of 2.5 kw. Only the 2 of us though, and we run thermostats about 74 F in summer and about 64 F in winter. Have 2 fridges, 2 freezers, big ice maker that uses as much as a frig, washer/dryer. 4 ton main heat pump, 2 ton upstairs heat pump and 2 ductless units for the basement.

 

[beowulf]

I asked the solar installers I got bids from what percentage of their bid was for the equipment and what percentage was for installation. I was told that 40% of the cost was for installation. So, I contemplated doing it myself as the total bid was $29,200 and I checked it all out and figured I would be able to handle it, and there are companies catering to DIY solar installers. But I changed my mind when I was told that the equipment would not be warranted if I did it myself. So, I had it installed. Also, this was done when the tax credit was 30% on the total cost. If I did it myself I would have only received the tax credit on the equipment cost - so that was another reason I had it done.

 

[Industrial Toys]

My criteria would be to have a system without integrated inverters in the panels, so YOU could use the power if needed in an outage. Maybe not immediately, but having the possibility there. Being able to tap into the DC from the panels.

 

[jk96]

My criteria would be to have a system without integrated inverters in the panels, so YOU could use the power if needed in an outage. Maybe not immediately, but having the possibility there. Being able to tap into the DC from the panels.

In the last 6 years here I can't remember more than 3 or 4 outages with the longest being this winter for maybe 3 hours so usage during an outage just isn't a factor for me.

Oh and the 30 seconds our lights flashed on and off when the house was struck by lightning and it grounded out in the walkout garage through the hvac unit. That was fun.

 

[jk96]

Our house is around this size, and our average kw usage is short of 2.5 kw. Only the 2 of us though, and we run thermostats about 74 F in summer and about 64 F in winter. Have 2 fridges, 2 freezers, big ice maker that uses as much as a frig, washer/dryer. 4 ton main heat pump, 2 ton upstairs heat pump and 2 ductless units for the basement.

2.5 Kilowatt hours? Per hour?

 

[jk96]

Currently working through the application for our electric coop for the approval to grid tie the solar before I finalize the purchase. One question I have for those who have done a ground mount system before is the location of the invertors and auto shutdown box? Did yours go at the panels or house? For my installation it looks like the sequence would be panels to rapid/auto shutdown box to invertors to manual disconnect to utility. Panel location is about 540 feet from the house and invertors are outdoor rated. With that said would it be better to locate the invertors & shutdown box indoors for better efficiency out of the heat? My electrical service enters the house into a utility room in the basement where my electrical panel is located. Just thinking it may be best to also place the shutdown modules and two invertors on the basement wall as well as opposed to outdoors on the house. Would make for a cleaner install as well without all of the components on the outside of the house.

 

[bmaverick]

My criteria would be to have a system without integrated inverters in the panels, so YOU could use the power if needed in an outage. Maybe not immediately, but having the possibility there. Being able to tap into the DC from the panels.

And that's how I'm setup. Power goes out, got enough juice to run the 230V well-pump down 200Ft.

My panels put out 24VDC. Thus, it's easy to branch the battery bank to charge 12VDC series batteries in pairs, and then use another tap to be dedicated as 12VDC. From 24VDC, it's easier to reach 230V.

I made this some time back. For 24VDC charging and 12VDC access when the power is out. The Renology charge controller does Lithium Iron batteries too!

 

[ponytug]

Going 540', I would consider upsizing the conductors to reduce losses, but more than that, I would think about DC.

If you have no shade, you might want to consider running the DC back to the house, and converting it there, if you can arrange your DC to be as high as possible for your inverter input, but below, 600V. (I think that is from a common insulation limit on wires, but there is also an NEC burial limit for depth, as in you have to deeper if at, or over, 1000V.) You will have lower power loss in the transmission. (Loss goes as current squared times resistance, so doubling the voltage quarters your losses) I would check your local codes and AHJ to be sure.

I'm not a solar expert, but that's the advice we were given, and it made sense to me.

YMMV

All the best,

Peter