[hedora]

$3 per watt, installed on your roof is typical these days:

https://www.remodelingcosts.org/solar-panel-costs-increase-s...

That includes labor, mounting hardware, inverters and grid tie in. It also assumes high efficiency panels.

Watch out before buying older technology (lower efficiency) panels. Some have significant efficiency losses per degree Celsius increase in temperature.

[zbrozek]

I bought 42 Sunpower X21-335 panels used for about $4700 shipped to my door a few years ago and couldn't be happier. As far as I could tell they weren't actually ever unboxed.

[ncmncm]

For the numerically challenged, that is $4700/42 = $112 each.

$112/335W = $0.33 per watt. Installed, well under $1.

[zbrozek]

Yeah, the whole system has been fantastic. I'm so glad I did it. DIYing it was also fun.

[yjftsjthsd-h]

> $3 per watt, installed on your roof is typical these days

Which is why I was so fascinated by someone saying that you could get panels at 250USD/400W=0.625USD/W; I suppose it's possible that all the other stuff (electrician, mounting, inverters) is the difference, but a factor of 5? That feels like an chance to do something hacky and come out way ahead (like, say, DIYing a panel to run your computers, thus cutting out rewiring the house and needing an inverter).

[jseutter]

Yes, a factor of 5 is fairly close. The prices of panels and inverters has dropped, while the price of labor and wiring has stayed constant or increased. The end result is the factor of 5 that you mention, and DIY systems are becoming more popular.

One of the factors in cheaper solar is that the panels have gotten bigger. Panels grew from 250w to 300, 350, and now to 400w and 450w. The 450w panels are 82 inches by 42 inches, so taller than the average person. Larger panels require less mounting and less labor, so even if they cost more they might be slightly cheaper to install.

I think that utility scale solar will eventually beat residential solar on price because of less labor per watt to install. I sometimes think about a solar system that could be set on top of a house in a few hours and would contain the inverters and interlocks and be wired into a single breaker in the house electrical panel. A truck operator/installer and electrician could do two installs a day and the labor price would be significantly less. We are so far from this currently, with site surveys, permitting processes, individual panels in custom configurations and so on that result in several days of work spread out over months. I don't know if it could ever happen, but it is fun to think about at times.

[laurencerowe]

> I think that utility scale solar will eventually beat residential solar on price because of less labor per watt to install.

Utility scale solar beats residential solar by a huge margin already. New utility scale solar projects on the California grid are priced around $20/MWh [1] compared to feed in tariff rates of $0.08923/kWh = $89.23/MWh [2].

As a renter who can't have solar installed on my home I find it pretty objectionable that my electricity rates subsidise expensive toy systems of homeowners.

[1] https://www.pv-magazine.com/2021/09/30/us-utility-scale-sola...

[2] https://www.pv-magazine.com/features/archive/solar-incentive...

[35mm]

In the US a large part of what you’re paying for is the sales and marketing cost.

Prices in the UK & Europe are lot lower per watt.

[swiftcoder]

Like, drastically lower. You can buy a 450 watt panel at a retail outlet for less than $200.

For example, https://www.leroymerlin.es/fp/88110787/panel-solar-risen-445...

[ncmncm]

Effectively, US solar panel cost is scaled by import duties.

[PinguTS]

> $3 per watt, installed on your roof is typical these days

In Germany, around 2019/2020 depending on the size of the installation it was around 1€ to 1,30€ fully and professionally installed on your roof. Right now with the increasing demand and very bad availability we are back at about 1,50€ to 1,80€ per Watt.

[dn3500]

I paid $1.47 per watt for 3200 watts last summer but that's in Mexico.