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The cost of the panels is already such a small fraction of residential install cost. My panels were definitely under a buck a watt (maybe 15% of the total cost)

The cost of the panels is already such a small fraction of residential install cost. My panels were definitely under a buck a watt (maybe 15% of the total cost). The installation cost (i.e. paying for a team of a dozen guys to dangle in harnesses on my steep roof for three days) absolutely dominated the invoice (50-60%). The second most expensive was the batteries (about 20%). The remainder went into the hundreds of other parts (inverter, cut-off, conduit, circuit breakers, cables, MPPTs, brackets, safety stickers…) needed for a functioning & legal system. And a couple hundred bucks of fees to the city for permitting and inspection, and a couple hundred bucks for the off-shore engineers to draw the system design docs. I won't make a profit for decades, unless the price of grid power shoots up. It would make more sense in a place with higher power costs. But I can keep the lights on if there's a power outage, without the maintenance costs (and noise) of a hydrocarbon-fueled generator. If you're installing solar for monetary gain, don't put it on your roof, buy/lease cheap land and build a solar farm. My electricity provider even lets you buy in on syndicated solar farm deals, if you don't want to manage the process yourself; you get the generated kWh credited back on your power bill!

slyall 4y ago
There was a story last week about commercial solar farms having panel flat on the ground and some people posted about putting home solar setups flat (or slightly elevated with a brick and tied down). Saving money with the setup beats getting the last percent out of the install. Although probably only some rural home-owners are going to be able/allowed to just put the panels flat on the ground. https://news.ycombinator.com/item?id=33926683 https://news.ycombinator.com/item?id=33926683
- 0cf8612b2e1e 4y ago
  For a residential install (10s of square meters, not thousands). I would still feel more comfortable laying down some concrete first to minimize the chance of spoilage from vegetation. Plus something cheap for elevation from any flooding (bricks, cinder blocks, etc).
  - Casteil 4y ago
    Yep, as soon as you start talking about flat panels on the ground, you start introducing problems with moisture, and/or snow/ice buildup in the winter. Might be ok in some areas, but not at northern latitudes, and definitely not their winters.
- krallja 4y ago
  Haha, love it. Sure, you're losing a few percentage points of efficiency, but not THAT much, as long as you're within a couple dozen degrees latitude of the equator (COS(X) ≈ X for small values of X). And if you're far from the equator, why are you messing with solar anyway??
Casteil 4y ago
I'd gotten a couple quotes for grid-tied solar installations recently.. and they were pretty outrageous @ over $5/watt installed (with no battery backup & no option to stay on with the grid out). So now I'm in the process of putting together a 1.8kW solar system for the roof of a cargo trailer. Not the biggest solar setup, but I'm also not a huge consumer of power - this should offset a significant portion of my consumption in summer, and it's also expandable to ~2.7kWh (though I should've bought a 6th panel for that). I've paired the panels up with a 3kW hybrid inverter and a 5.1kWh LFE rackmount battery. Should do pretty well together, and like you said... I'll be able to keep the lights (+fridge/furnace) on if there's a power outage - a huge plus. Total cost for the main components and most of the necessary wire/hardware? ~$4000, before any tax credit.

slyall 4y ago

There was a story last week about commercial solar farms having panel flat on the ground and some people posted about putting home solar setups flat (or slightly elevated with a brick and tied down). Saving money with the setup beats getting the last percent out of the install. Although probably only some rural home-owners are going to be able/allowed to just put the panels flat on the ground. https://news.ycombinator.com/item?id=33926683 https://news.ycombinator.com/item?id=33926683

0cf8612b2e1e 4y ago
For a residential install (10s of square meters, not thousands). I would still feel more comfortable laying down some concrete first to minimize the chance of spoilage from vegetation. Plus something cheap for elevation from any flooding (bricks, cinder blocks, etc).
- Casteil 4y ago
  Yep, as soon as you start talking about flat panels on the ground, you start introducing problems with moisture, and/or snow/ice buildup in the winter. Might be ok in some areas, but not at northern latitudes, and definitely not their winters.
krallja 4y ago
Haha, love it. Sure, you're losing a few percentage points of efficiency, but not THAT much, as long as you're within a couple dozen degrees latitude of the equator (COS(X) ≈ X for small values of X). And if you're far from the equator, why are you messing with solar anyway??

Casteil 4y ago

I'd gotten a couple quotes for grid-tied solar installations recently.. and they were pretty outrageous @ over $5/watt installed (with no battery backup & no option to stay on with the grid out). So now I'm in the process of putting together a 1.8kW solar system for the roof of a cargo trailer. Not the biggest solar setup, but I'm also not a huge consumer of power - this should offset a significant portion of my consumption in summer, and it's also expandable to ~2.7kWh (though I should've bought a 6th panel for that). I've paired the panels up with a 3kW hybrid inverter and a 5.1kWh LFE rackmount battery. Should do pretty well together, and like you said... I'll be able to keep the lights (+fridge/furnace) on if there's a power outage - a huge plus. Total cost for the main components and most of the necessary wire/hardware? ~$4000, before any tax credit.