With regard to https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg if the capture and separate elements can be decentralized, then distribution and one storage phase are eliminated.

In other words, if a refueling station can do solar or wind capture and electrolysis on-site, the economics are better. This would be unlikely for stations in urban or high-density areas, but for rural and suburban locations it might be a win.

Check my math:

Say a fueling station needs to serve (only) 100 cars per day, providing 50kWh per car. That's 200kW average generation power needed. Ballpark, a 1 m2 solar panel can generate 200kWh/year, or 23W average. (quora answer, 2018). You need .. really? 9100 m2 of area, which is .91 hectare or 2.25 US acres.

A 200kW per day (73000kWh/year) wind turbine might stand 25m tall. (uk wind energy report, 2014) Will these function in suburban to urban settings? Would they be accepted by the public? In the US, siting rules are a mess, but one example I found called for 2500 feet (760+m) distance to property line and 1.5 times turbine height to overhead utility lines. (NCSL, 2016)

Given these fairly large size requirements, unless I slipped some decimal points, it doesn't seem likely to work out.

https://www.quora.com/How-many-kWh-will-1-sq-meter-of-solar-...

https://cdn.ymaws.com/www.renewableuk.com/resource/resmgr/Do...

https://www.ncsl.org/research/energy/state-wind-energy-sitin...

This is the point (one of the points) that Vaclav Smil makes about renewables: abysmal energy density of production (in Watts/square meter: more like 'intensity' than 'density' to me).

The only thing that beats oil is nuclear fission. With everything else, production takes up land that could be used for something else, or isn't being used for something else because it has problems such as distance or inhospitable climate or unfriendly (steep or unstable) terrain. All of which drive up maintenance costs or make the land also unusable for energy production.

There are no good solutions apart from the one that coal companies astroturfed us into nearly banning in the 1960s.

What you're calling "energy intensity of production" doesn't look like a very important parameter. There's plenty of unused land that could host solar or wind installations and transporting electricity really is a solved problem.

I understand the impulse to defend nuclear power against seemingly irrational criticism, but that shouldn't distract you from the incredible advances that other technologies have been making. Nuclear has had its time, and today it's just not a competitive way of making electricity anymore.

Beside, you're never going to convince people that nuclear is perfectly safe - it just isn't. Even if you can completely rule out catastrophic failure, you still have a bunch of people who need to go to work every day and work with radioactive materials. Yes, it can be done safely, but personally I'm happy I don't have to (and I do work with other toxic crap in the lab on a regular basis ;)).

So, at the end of the day, you're going to need to make an argument that goes like "... but nuclear power is worth it because we have no better alternatives" at some point. But look at this report on levelized cost of energy (LCOE) [0]. Wind and solar are absurdly cheap! We need to focus on solving the intermittent supply issue now, and that looks to be totally doable, if expensive, with current technology. But it's only getting cheaper (see literature I've cited in a different post in this thread).

Of course, calculations might change if there's some sort of technology breakthrough in nuclear technology - as in any technology.

[0] https://www.lazard.com/perspective/lcoe2019

> Even if you can completely rule out catastrophic failure, you still have a bunch of people who need to go to work every day and work with radioactive materials.

This is argument from extremes.

Coal plants kill a lot more people simply by operating: they release radioactivity (and toxic heavy metals, and PM2.5 particulate).

Gas extraction, processing, and transport also kill people (often the people who were occupying the land that the gas drillers want.) Ditto for oil. Wind turbine construction and maintenance also kills people. Solar panel construction involves working with toxic chemicals in far greater quantities than nuclear fission.

You expose fewer people to smaller risks with nuclear than with its alternatives.[1]

Also, wind and solar are dependent on either storage, for which we have no good grid-scale, months-long options yet, or globe-spanning petawatt transmission networks, if you're not going to accelerate climate change.

Don't get me wrong. I love solar PV - the only energy production method that relies on modern physics. I love wind, too, because it doesn't involve boiling water to make steam to drive turbines, which seems hopelessly steampunk to me these days. I'd also love to see a worldwide transmission network - that level of international co-operation would be awesome.

[1]. Gawd, I sound like a shill for nuclear. 2002 me would be horrified. But learning about climate change (and wanting industrial civilization to continue) forced me to confront my priors.

> Nuclear has had its time, and today it's just not a competitive way of making electricity anymore

I just don't agree with this. The tech has not been there, and even as that has slowly changed, the regulatory environment has lagged and obstructed horribly. These are problems, but they can change over time.

I believe it is in fact possible, given enough resources and effort, to truly perfect nuclear power - that being, after all, the real source of all these "renewable energy" options. And when we do, we should embrace it, not dismiss it out of hand based on some outdated superstition.

I don't have anything at all against wind and solar, but it's not a 1000-year strategy. Yes, we need to take urgent action to address climate change, and these may well be - ok, fuck it, are - our best short term options. But going forward, when we then need to look at how we'll increase society's power budget by 10, 1,000, 1,000,000 - nuclear is the only way[1], and we should start working on that, and sweeping away these old stereotypes, today.

[1] also open to space-based energy harnassing techniques, but i am trying to limit my thinking to known-viable ideas

Maybe above 60° latitude Sun energy is hard to harvest, an wind energy could be too unstable. This is where nuclear power would be in place.

Even though not so many people live so far up north, it's a significant part of densely populated Europe.

concentrating diffuse stuff is the new paradigm. the age of diffusing dense stuff is over.

Wind turbines can coexist with agriculture without many issues. Pretty common here in Denmark. The biggest problem with building wind turbines on land here is probably NIMBY-ism.

> if a refueling station can do solar or wind capture and electrolysis on-site, the economics are better.

Are the economics better than just placing that solar or wind plant on the grid and using electricity for battery-powered cars? You still have big losses in electrolysis, compression and then power generation in a fuel cell.

I would like to have seen more elaboration on transmission losses in the power grid. For example, if we imagine solar cells in Sahara generating energy for Europe, is power grid transmission feasible or does hydrogen look better in comparison?

I linked a paper talking about that. Losses are likely on the order of 5% per 1000km. I would think long distance transmission lines could transmit power both east and west which solves some of the time shifting issues. And south to north which solves some of the issue with low irradiance during the winter at high latitudes.

AKA Germany would probably be better off investing solar farms in southern Spain and connecting via long distance transmission lines. Only 1600km or so. Also consider sunset is an hour later in south west Spain.

The problem with generating power in the Sahara for use in Europe has little to do with transmission losses and much more to do with the capital cost of building high capacity power lines over thousands of kilometers. There's also the cost of protecting those lines, since they would have to pass through several different countries that are not always politically stable.

Good point. But that could also ve an argument for hydrogen?

It could be an incentive for political stability in those regions if they benefit from it.

That's what DeserTec planned to do some time ago. Power line transmission would be possible, but political situations were too unstable, so the project for canceled.

How efficient is electrolysis compared to making hydrocarbons?