[psyguy]

Are panels cheaper than the servo motor & Arduino used in this tool? Not to mention that at mass produced scales chip costs are usually 1/5 the price of an Arduino. What if every panel used these tools, we could increase the amount of power we gather from solar.

[bushbaba]

Yes. A 400w watt panel is 250$. When you account for labor and cost of all. The parts for a moving panel that can withstand high wind speeds…Placing more fixed panels is cheaper.

[yjftsjthsd-h]

> A 400w watt panel is 250$.

Wait, panels are that cheap? Could you point me to a good place to buy them?

[kurthr]

https://watts247.com/product-category/solar-panels/new/palle...

I don't know what, where, or how many you want, but these are by the pallet (~30ea) and about $6500. You can get much cheaper with used ones.

You get conservatively ~3hr of effective peak power per day (so a 400W panel will give you 1200Wh). You also need a DC converter for these to charge a battery or go to AC. Of course you'll want to mount them at the correct angle with a good view of the sun.

[ncmncm]

You generally have to buy them by the pallet-load, FOB ("free on board") at the source, which means you arrange shipping. Home Depot marks up 4x for local purchase.

But used panels, at 80% rated output, are even cheaper, as low as $150. A few of those will fail, so you keep spares. They are often repairable in a few minutes if you are not afraid of a soldering iron, e.g. replace a diode or MOSFET.

Any roofer will put in mounting brackets, and almost any electrician is happy to put in the panel.

[walrus01]

Decent vendors such as sunelec.con will easily quote you a price for a one pallet load LTL freight shipment of a pallet of, say, 22 panels. Not like you have to arrange your own freight and often they get a better price because of they great monthly spend with the major us48 state LTL freight carriers.

Be sure to specify if you need liftgate service at the destination or not, because that will affect cost, otherwise by default a pallet by LTL freight will need a loading dock to receive.

[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.

[fy20]

In Europe they are even cheaper as we don't have high tariffs on Chinese panels. I can buy a 350W panel for €150 including taxes, or €100 if I go to the equivalent of Craigslist and don't care about warranties.

[hedora]

Our solar panels are rated to 115mph winds. What are these servo mounts rated to?

Also, installation of the panels currently costs more than panels. They don't say (or I didn't find) how efficient the optimal fixed mount is, but the agent starts at 80%, so assume some fixed position is 80% of optimal. They increase that to 96%, so they reduce the number of solar panels by about 13%. If the installation labor cost increases more than ~26% because of the servo mount, then the servo mount hardware and frame would need to be cheaper than fixed mounts for it to break even. Similarly, the amount of aluminum being consumed by solar panel installions is non-trivial, and the movable frame is likely to increase that.

However, this is still a cool hobby project with a nice writeup.

[ehnto]

> Also, installation of the panels currently costs more than panels.

That's partly the racquet people set up to snag government grant dollars, but still true.

[rockostrich]

Maybe not bulk cost upfront, but surely the maintenance cost tips towards fixed place panels.