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Comment by bryanlarsen | Hacker News Reader

Moore's law will eventually stop, too. But people have been predicting the end for 50 years and it still looks like it has at least another 10 to go. It seems quite clear that solar costs will continue to drop exponentially until the end of the decade, which is all the author's assumptions need.

Land in a desert can cost as little as a few hundred dollars per acre, so it's far from being a dominant factor. And in other places solar is often a secondary use of the land.

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The article suggested local production, good luck buying land anywhere close to NYC at 100$/acre.

Mores law also failed several times. More revised his initial 1965 estimate for a doubling every year in 1975. He predicted various doubling rates with the weakest form being transistors on a single chip every 2 years starting in 1980.

So, it’s current form isn’t an exponential increase in density but in terms of transistors on a single chip. If density actually doubled every 2 years then starting from 1971 an Intel 4004 @ 188 t/mm then we should have hit 6 million t/mm in 2001 and 197 t/mm in 2011. Except chips only broke 6 million in 2012 (11 years late) and are nowhere near 197 million t/mm in 2022.

You're definitely not going to power all of NYC by rooftop solar, but also look at the size of the warehouse roofs (empty, no solar) in NJ just across the river, and out on long island. And Staten island. Etc.

Empty land is not necessarily a requirement.

Parking lot per-row shade structures that integrate PV panels on top are also a thing now, and there are sure a shitload of parking lots in NJ and out on long island.

Rooftop solar is far more expensive than solar put on land. The cost of rooftop solar (particularly homeowner solar) is usually hidden by implementing a big subsidy to wealthy consumers that is paid for by less wealthy consumers - sort of a reverse robin hood scheme.

We are well past the point where anyone can argue we should subsidize rooftop solar because we need to help build a fledgling industry - yet I see solar advocates continue to advocate for this wealth transfer from the poor to the well off.

Why is rooftop solar more expensive?

Mounting structure is there, grid supply is there, no issues with weeds/grasses, generally up in the air etc.

Rooftops are unused space.

You can see the cost differences here:

https://www.lazard.com/perspective/levelized-cost-of-energy-...

Rooftops are unused space, but the land use is generally a small part of the cost. Utility scale solar has real economies of scale compared to one-off small installations on someone's roof.

I'm not from the area, but isn't Manhattan well known for its tall buildings? How would those buildings' shade affect solar panels closer to ground level, e.g. warehouse roofs and parking shade structures?

You can get land in upstate NY for $1000/acre. There's a lot of cheap rural land even on the east cost.

Arguing that Manhattan is expensive therefore PV doesn't work is like arguing Manhattan is expensive therefore agriculture doesn't work.

Edit2: Closest found was 9k per acre a little over 250 miles away.

250 miles is a totally normal distance for high voltage AC electrical transmission lines.

Running normal high voltage lines 250 miles isn’t free, and that cost should be part of the comparison used.

Also, the cheapest land I found was 4k/acre, still well above pfdietz’s estimate.

I don't think I've posted any land cost estimates, elsewhere in this thread I mentioned how many warehouse roofs in NJ, Staten island and long island have no solar on them.

You can find much cheaper than that. For example, at $1128/acre:

https://www.zillow.com/homedetails/0-Ward-Loomis-Rd-Oxford-N...

(~214 miles from Oxford NY to Manhattan by road)

(search in Zillow by county)

Moore's law already stopped - since Intel's 10nm process was delayed by 5 years. The exponential grown continues, but a lot slower than predicted by Moore.

Even that "exponential" growth is a not a thing anymore. There are factors which make it less obvious (growing TDPs of modern CPUs and GPUs; going wider, i.e. increasing the number of CPU cores, instead of faster; making chiplets and building cpus out of them instead of big single dies), but these factors only postpone the inevitable (there's only so many levers you can pull and most of them have already been pulled). We're a couple years away from the silicon limit, the 2nm situation already looks grim.

I mean, it is our best/easiest bet for future power generation. I can totally see why more money keeps being pumped into it.

Either more efficient panels, cheaper panels, or simply a greater manufacturing capacity are all fine for securing the energy needs of the planet.

And we won’t have to worry about running out anytime in the next billion years or so.

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