What about the big fusion reactor in the Sky? Shouldn't we go all in on solar? Why is so difficult to harness that source? Maybe the same obstacles make fusion so difficult to pursue.
The largest solar farm in the US, the Topaz Solar Farm in California, covers 25sq/km has a peak generation capacity of 550MW. The source uses the median of the 59 nuclear plants in the US to arrive at its 3.36sq/km (1.3sq/mile) per 1,000MW figure but the largest nuclear plant ever built, the Kashiwazaki-Kariwa plant in Japan, produces ~8MW on just 4.2sq/km of land which makes it twice as efficient in terms of land use as the median US plant.
That places solar at 13.75 sq/km per 1,000MW compared to nuclear's 0.525sq/km using the best case scenario for the density of existing sources. That doesn't even account for the variable output of the solar plant versus the consistency of nuclear generation. Solar is ultimately far too land hungry to ever serve as the world's primary source of electrity.
Source: http://www.nei.org/CorporateSite/media/filefolder/Policy/Pap...
Make everything out of environmentally friendly, lighter and long lasting aluminium rather than steel + concrete.
Have street lighting that is as bright as sunlight over entire cities, allowing us to no longer be dependant on time of day.
Growing food crops indoors with artificial light, saving massive amounts of land.
Desalination to make all our water. No longer extracting it from rivers and aquifers. A cleaner, less polluted water source.
A single energy source - today we use petroleum (cars), natural gas (cooking and heating), electricity (lighting etc.), diesel (transport) and many more in industry. All of those need distribution networks. A single cheap energy source could coalesce a lot of infrastructure.
Please, no. Some of what you said I'm onboard with, but definitely not this. The human impact of perpetual day is large and negative. The negative impact of massive artificial lighting on astronomy is also quite massive.
Will the heat from all that electricity generation affect the environment in significant ways?
At which energy usage scale humanity will be restricted by the planet environment capacity to deal with the generated heat?
I think we're a long way from that yet though.
The real annualized power of the Topaz Solar Farm comes to 6 megawatts per square kilometer, using its 2015 generation total of 1,301,337 MWh. At that areal productivity[1], if you could ignore intermittency, it would take ~95,000 square kilometers to supply the 2013 US electricity demand of 4,986,400,000 MWh.
The US Corn Growers Association estimated that 27% of US corn grown in 2011 was for ethanol, and corn covered 92 million acres:
http://www.ethanolproducer.com/articles/8611/world-of-corn-r...
Converting 27% of 92 million acres to square kilometers, the US is using about 100,500 km^2 to produce ethanol.
But you can't ignore intermittency, so (barring much improved storage, which may happen but can't be assumed) solar PV is not a drop-in replacement for nuclear power.
[1]Other areas of the US get less sun than central California, but newer farms with more efficient panels and single axis tracking increase areal productivity significantly over the fixed-tilt CdTe construction of Topaz, so I think that 6 MW/km^2 is a reasonable number to use.
Because there's a hard upper limit of 1367 watts per square meter.
And, practically speaking, you're not going to reach 10% of that (panel efficiency, angles, cloud cover, air transmissivity, weather, damage, dust/dirt, night/dawn/dusk, conduit resistance, storage loss, etc).
That means the only way to scale up is land surface area, about 10,000 square kilometers of solar panels for 1TW power production, covering about 0.1% of the USA.
(Don't get me wrong, I'm just presenting objective numbers. I'm thrilled about Tesla / Solar City pushing rooftop solar with "invisible" tiles, and think every home should be built with at least the whole roof covered with solar panels. Independence is a big deal, and having at least substantial off-grid power is important.)
We may have to do it eventually, seeing as climate science is drowning under a flood of irrationality and lies.
Still, the virtually unlimited energy available via this means is making it increasingly promising. Moving forward, storage technology will help overcome some of the limitations.
All we need to invent is the wireless energy receiver!
It isn't enough.
Well it is enough, but there isn't an efficient method to store or transmit the captured power. Solar is awesome, but the places it is most available also happens to be where it is least needed, in general, I'm aware of Saudi Arabia.
It should also be pointed out that Solar is the most [1] green house gas producing method of green energy. Wind, Nuclear, Hydro-Electric, and Tidal are all vastly more carbon efficient.
[1] https://en.wikipedia.org/wiki/Life-cycle_greenhouse-gas_emis...
... but still tiny compared to any form of fossil fuel or biomass!
Presumably the carbon footprint of solar is largely made up of fossil fuel used in the production and installation of PV panels themselves. This would decline over time as the grid, and vehicles, become greener. Eventually, new panels would be produced using energy from existing panels, closing the loop.
Wind, Nuclear, Hydro-Electric, and Tidal are all vastly more carbon efficient.
The difference is pretty small according to the table you posted. They're all much, much better than fossil fuels.
Coal: 770 Gas: 410 Rooftop solar: 26 Offshore wind: 8 Nuclear: 3.7
So, the word "vastly" above might be overstating things. Solar certainly isn't the most efficient, but it's pretty damn efficient compared to anything produced by biological processes.
I'm not comparing Roof Top solar to Coal or Natural Gas yes very clear winner there. I'm comparing it to Hydro-Electric, Nuclear, Tidal, and Wind where it is by far the dirtiest.
Thank you for making it clear that I was not being unfair, even in my pre-edited state.
They are a small difference compared to extractive mining. Statistics rhetorical tricks aside, the world would be much better off if we were using any mix of the non-extractive power technologies, even if that mix heavily weights rooftop solar.
Fundamentally the fact that rooftop solar is something I can put some money into tomorrow and see the results in six months means it is effective, which offends many people who would prefer that we spend our efforts in ineffective ways, either for ideological reasons (amusing that nuclear doesn't appeal to these types) or because they wish to maintain the status quo. Since the science shows that status quo is going to drown the island I live on inside of 75 years, I'm not a big fan of this point of view. My island is probably already dead, and the 80K people that live here need to find a new home in our or our children's lifetimes, but I am motivated to make choices that don't produce more stories like mine.
It doesn't have to do everything. But it's something, and something you can personally choose to do. As opposed to, oh, for example a geothermal facility, which I can't exactly put in my back yard.
If we could store energy cheaply and efficiently, we would not need fusion plants. We would just use solar power. And if we had fusion plants without a cheap and efficient way to store energy, there would still be energy problems like in transportation, wouldn't there? I mean the reason most cars for instance are not electric nowadays is not because we can't generate enough electricity, it's because we can't store enough electric energy in a car.
Perhaps we should not go "all on" anything. Solar is available now, it's getting cheaper by the day, and it's very easy to install and use. But it's intermittent, requires storage, it's not portable except at low levels, and energy density is not that great.
Fusion is obviously not available now. But when figured out, it would have all the strengths of classic nuclear energy without most of its weaknesses.
We should keep deploying solar as fast as possible, while aggressively pushing for fusion research.