How to Get Solar Ready
We’re working towards a fairly substantial remodel that is going to include upgrading our existing 100A panel to 200A. We’re not looking to do solar immediately as we have a giant green ash tree on the south of our lot that we’re currently babying with treatments and whatnot since it’s a very nice tree. It will presumably some day succumb to emerald ash borer at which point solar might be in the books.
So, while we’re making a giant mess, what all is worth installing now to be “solar ready” and what can we kick down the road? Based on quick reading the basics are empty conduit + pullstring from the panel to the attic, maybe also to the exterior wall above the low-slope first story addition roof. Any provisions at the panel itself? (Aside that we’re possibly also interested in emergency generator/ battery backup down the road).
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Around here, if you want to do net metering and your array is above a certain size you have to have a separate meter for the array. So the wiring goes from the array to the meter and then from the meter to the panel.
It's all location dependent. You're going to need to check with someone who knows what your local utility requires, which might be an electrician, a solar installer or the utility. Also be warned that requirements change frequently. As solar has become more popular our local utility has gotten fussier about what they accept.
As an installer, the system from panels to near the BOS (balance of system) near the meter (exterior) and load center (breaker box, interior) will mostly be the same no matter where. You'll need to purchase a combiner box for the roof to incorporate with shingles near the top of the array for shortest distance down to BOS. It needs to be metal conduit. 3/4" can accommodate a pretty large bundle of wires for a large array. You will do this now so the crew doesn't need to be crawling through the attic messing up the insulation. If you choose to go with micro inverters (attached to pv panels vs the large inverter down at the BOS), we just take the conduit through the attic and out high up then down to near the meter. For now you can just have it out through the attic wall and capped. Let the crew decide the nicest path down to the meter.