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Comment by 2trill2spill | Hacker News Reader

The article you cited said we need 43,000 square miles of solar to power the earth costing 5 trillion dollars, I consider that to be a huge amount of land and money. That would be half the area of Minnesota the state I live in devoted entirely to solar panels. Sure it wouldn't all be in one place but that is still a significant amount of land world wide that have to change land uses.

Also isn't that article also assuming that all of the solar panels would be in the Sahara desert? Where solar power is extremely efficient. If we spread these solar panels across the world we would need significantly more because they would located in places much less suitable for solar power.

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Yet the UK, not exactly blessed with excess sun, has already reached a point of generating more by renewables than fossil. With little noticeable impact on anyone anywhere aside from a few windmills in hilly spots, or visible a mile or so off some areas of coastline, and a fair bit of roof mount solar.

If that is all the space required to power the planet I find cause for much hope. I doubt there would be much impact on anyone once you distribute across all the countries. How much area is available globally that is currently empty roof? Car parks as others have noted. What of offshore, covering reservoirs, road and rail side verges and medians, wind, wave and nuclear. How much scrub and desert that provides little for us or the local flora and fauna?

Unless Minnesota plans on actually powering the world it doesn't seem a reasonable comparison or objection.

> Yet the UK, not exactly blessed with excess sun, has already reached a point of generating more by renewables than fossil

Sorry, but more of what precisely?

Not all kinds of energy, surely?

Nuclear + wind, solar and hydro has now achieved parity (and just surpassed) coal, oil and gas for electricity generation. Both in capacity and actual generation achieved. We have a way to go to match Orkney, but electric is progressing nicely down the route to fully renewable, even with the Tory changes of subsidies.

https://www.bloomberg.com/news/articles/2018-11-06/britain-n...

Are you counting nuclear as renewable then? Not totally off-base since uranium in seawater replenishes at a rate higher than we could ever extract it at world scale for a few billion years.

Nuclear comes out pretty well on CO2. I figure it has to be part of the mix as we move away from fossil, even if we eventually just use it to buy 40 years and ultimately move entirely to non-nuclear renewables.

Aha. That explains it.

I assume wind and solar are < 1% of that "renewable" total.

No need to assume (especially with such a low number).

http://gridwatch.co.uk/ has nuclear, solar and wind at 18%, 6% and 15%. Wind reached 37% this year, https://www.independent.co.uk/news/uk/home-news/wind-power-r...

According to http://electricitymap.org UK has most installed and used capacity in gas power plants.

Well a much publicised yearly report commissioned by Drax (UK's largest coal and biomass station) this week from Imperial College and sourced from Nat Grid thought otherwise.

https://www.drax.com/press_release/capacity-renewables-overt...

Who's most up to date or accurate? Given the steady drop of fossil capacity, perhaps electricitymap that seems to be volunteer run simply hasn't caught up yet?

There's over a 5GW difference in amount of installed wind power between that site and the "over 20GW" claimed in the Imperial report. Solar varies by a similar percentage.

There have been other reports on the same lines throughout this year of the dropping off of fossil and rise of renewables, for both generation and capacity. Even with the distraction of fracking and changes to feed in tariffs.

That's the maximum net generating capacity, but you can't just turn it on, it generates what it generates based on the wind/sun. If you want to see a live breakdown of power generation to the UK grid it's here http://gridwatch.co.uk/

"Yet the UK, not exactly blessed with excess sun, has already reached a point of generating more by renewables than fossil."

Natural Gas is still the biggest source of electricity generation in the UK, by some margin. But it is declining, slowly.

By the early 2020s, it's likely that wind turbines will have overtaken nuclear as the #2 source.

UK electricity generation mix: https://www.ofgem.gov.uk/data-portal/electricity-generation-...

I think they must be including nuclear in renewables (32.97% non-renewables w/o nuclear, 21.69% renwables w/o nuclear, 36.79% renewables w/ nuclear).

Correct. Nuclear + renewables as against fossil.

May I recommend euanmearns.com as a reliable claim-debunking source? Also manicore.com some of the contents is in English.

Considering the US alone uses about 4K SQMI for parking, that really doesn’t seem like too much.

https://www.nytimes.com/2012/01/08/arts/design/taking-parkin...

10x the total parking spaces seems pretty damn huge to me, I've seen some big carparks.

In addition, carparks in the US could be argued to be an ecological and sociological disaster.

If you could somehow have cars without carparks (maybe the car folds up, I dunno), it would be one the biggest quality-of-life improvements in my lifetime. Probably about on par with the smartphone for me personally, probably a bigger improvement for people who are very poor.

Self-driving cars will alleviate this problem, since the cars will just rent their time out (like Uber/Lyft today) and after they drop you off at your destination they zip off to pick up the next human. Even if you choose to own your own car, the car itself could go back home during the day while you're at work.

Though if owned self driving cars are used we have to choose between keeping parking spaces and increased traffic congestion. If there is no parking space, the car will have to arrive at work when you are leaving (which is usually the same time as everyone else) meaning two extra rush hour journeys each day.

That's already the current situation. Generally all traffic congestion is into a city area in the morning and outwards from a city center in the evening. There isn't typically congestion in both directions. Either way, between that and being able to get work done in your car (so you could leave earlier). I don't think it's too bad.

That is only true because lanes are built for the rush. When I've seen reversing direction lanes (in for the morning rush, out for the afternoon), the opposite direction now has congestion because of all the people working different shifts who can't take that lane.

I agree, to the extent that car-parks take up valuable space in cities. I assume that solar would not have that same problem.

If some other type of energy generation system used as much land as solar there is no way environmentalists would have ever supported it (rightfully so, I would say). I think solar was just not practical until very recently to actually be used at grid scale. So in the past saying one should stop burning coal and use solar was just a way of saying stop using power altogether and do some kind of back-to-the-land thing.

Efficiency has always been the smartest and cheapest approach, using lots of tech we already understand. It's always worth mentioning, especially as it's a multiplier of other greener sources.

The article was talking about the need for WORLD energy production, whereas I was comparing it to the amount of land used for parking in the US alone. If you spread that much land use among the entire world it isn’t that crazy.

Moreover re: the other comments about parking being an ecological disaster, I agree, but that’s more because of the car-dependency that parking comes with than the pavement itself. Pavement is ALSO a problem, particularly re: surface water permeability and flooding. But most solar and wind installations don’t require the same vast expanses of impermeable surface.

Lastly, remember that wind, at least, can and is often installed off-shore, so when you consider the surface of the ocean as a viable place to distribute some of this land use its even less concerning - at least relative to the continued burning of fossil fuels and associated greenhouse gas emissions.

Force all the malls and shopping centers to have solar roofed parking lots? Yes please.

"The article you cited said we need 43,000 square miles of solar to power the earth costing 5 trillion dollars"

Neither of those numbers seem out of reach to me.

I assume a large amount of solar can be placed on existing rooftops or other pieces of the (already) built environment.

I also note with interest that the most recent Iraq war cost somewhere between 2 and 3 trillion dollars and that bill was mostly footed by a single country which was hardly impoverished as a result.

I do question the externalities and pollution and embedded carbon costs of 43k SQMI of solar panels, however - I think that's the logistical issue that's most pressing.

>I do question the externalities and pollution and embedded carbon costs of 43k SQMI of solar panels, however - I think that's the logistical issue that's most pressing.

YES! especially considering the life cycle of PV - it is short!

Here is some great stats to consider: https://youtu.be/V2KNqluP8M0?t=454 (alarmist tone + admittedly biased toowards nuclear - for a reason - the numbers are sound)

In the same way you're conflating fission with fusion (I'll support funding for the latter, but not the former) when you advocate 'nuclear', you're also conflating PV with with solar thermal under the very broad heading of 'solar'.

My expectation is that most large solar plants will not be PV.

Good point. But do subsidies, research funds, and general sentiment support that? I primarily see investment in PV - not solar thermal. Got a preference I can look at suggesting you are correct?

No idea about subsidies, research, and gen-pop attitudes around the two.

Solar thermal has a couple of advantages - peak supply extends through into peak demand (around sunset), because it's basically its own storage system - efficiency is around 70% (compared to PVC which is ~ 15%, and is expected to rise very gently - as you noted in another thread). The lack of sensitivity to technology improvements makes it more attractive to investors, which is convenient as it's obviously a larger capex per installation. (I suspect R&D for pvc is higher per, say, unit of technology - though this isn't a big concern in terms of capex per user.)

Either way, most nation states have electricity grids that lend themselves to larger power generation installations, than a totally distributed system (where someone else looks after short term storage and baseload) - plus larger installations (solar thermal) work well in regions where there are disparate climates within the reach of long-haul power cables. (Definitely the case in AU for most major metropolitan areas - there are solar-thermal-favourable sites within a few hundred kilometres of the larger population centres.)

I've just done a pvc vs cst - and the latter's numbers really make a mockery of the anti-solar apologists' estimates on surface area required to provision estimated power requirements.

Also there would be national security concerns. You can't just put all solar panels in Sahara because some local African dictator or strong man can just decide to sabotage or just simply turn off the electricity as a power play. Each country would have to have these panels installed on its own territory to be able to have any sovereignty and not be easily blackmailed. You can't put all your eggs in one basket, especially if the basket is an area of Earth where there is very little law and order and constant revolutions, uprisings, terrorism and general political instability.

You can't just put all solar panels in Sahara because of so many more important reasons, mainly energy transportation. Power lines will never be that efficient, and battery storage would be prohibitively expensive (and I am not even sure there would be enough rare metals on earth to build that many batteries).

We worked hand in hand with middle east dictators for centuries now, to get their oil. Oil is interesting because it is cheap to transport (pipelines).

Also counts against nuclear reactors: do you really want to give the same strongmen and dictators the first step towards nuclear weapons?

Well, I mean we shouldn't export nuclear tech to really unstable third world countries. That's obviously a bad idea. But I see no problem in building nuclear plants within borders of western stable democracies. I was replying to a suggestion that it would be trivial to generate all of the world electricity by covering Sahara with solar panels. Was just pointing out how silly that sort of thinking is.

So how do you the third world obtaining power?

Perhaps you're not in California, but, in California, I can definitely find more rooftop area for solar than I need. Like, a lot more.

43k sq mi comes to about 15 sq meters per person, worldwide. It's big, but it's not unimaginable.

The habitable land area of Earth is about 40M sq. mi. So we're talking on the order of .1% for solar power. It's not insignificant, but I hardly think it qualifies as "huge".

You could stick a lot of on inhabitable land too.

I think you meant "uninhabitable", but either way, it works.

Words... speak... hard.

Alas, not a lot of insolation in Antarctica or Siberia.

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