[kayaeb]

Is it though?

Renewables that are popular now, like solar and wind, are weather dependent, which means the grid needs to handle variable input, which it's not designed to do and would need major fixing. Also means you need to store the energy for when it's not abundant, Germany does this by pumping water into mountain lakes to produce hydro on demand, but they've run out of lakes, so you need batteries. Batteries of a grid-size magnitude need carbon-expensive materials and have their own plethora of problems.

These two problems are only feasibly conquerable in a reasonable timescale by a few countries, for others they are prohibitively expensive, far beyond the small subsidies proposed in things like the Paris Accord. Now, sure, USA, Europe could implement these, but it's not going to fix the problem if Asia, Africa don't, and additionally it's going to add significant economic and geopolitical pressure between these nation-blocs, those who are hamstringing themselves and those who aren't.

Hydro has serious geopolitical issues as fresh water supplies grow more tactically necessary, consider Egypt / Ethiopia right now with the Nile, or China's tibetan plateau snow-seed cannons to capture water before it reaches India.

Tidal has extremely short lifespans, any moving system in salt water is difficult to keep going for more than a few years.

Geothermal is good, but also one of the most expensive and a bit of a "slow burner," not going to be powering anything serious with that without sinking billions into the plant.

The only real solution I see is nuclear, but that's a naughty word for some reason.

[fsloth]

As near future sci-fi options go from 100ft up I don't see anything too problematic with hydrogen economy. Except for transport infrastructure.

Or, we remain with carbon based fuels, except they are synthesized from atmospheric carbon in regions with plenty of solar energy.

These approaches surely have challenges, but I would like to know what are the biggest ones?

[Zigurd]

Ammonia is more practical than hydrogen. Just not as sexy. Should be rebranded as the "hydrogen-nitrogen economy."

[petre]

Ammonia has issues like being toxic and higlhy volatile.

I think DME has some potential as an alternative fuel because it can be produced through CO2-to-DME hydrogenation or by using syngas/manure and burned in cleaner diesels (no particulate emissions).

[dragonwriter]

> Renewables that are popular now, like solar and wind, are weather dependent, which means the grid needs to handle variable input, which it's not designed to do and would need major fixing.

Non-renewable plants have variable output even if it is not dependent on weather, and the grid in fact deals with variations in total and per-plant inputs whether or not solar or wind is attached. If there are problems with that, the need to address them is independent of the use of solar and wind.

[kayaeb]

Not on the scale of "we need to move the bulk of the energy from Texas to New York for 3 hours, then when the sun sets shift state-level power supply routing from the cornbelt to cover the drop."

Handling a plant going offline is totally different from the logistics of shuttling variable regions of production across the entire country.

[dragonwriter]

> Not on the scale of "we need to move the bulk of the energy from Texas to New York for 3 hours, then when the sun sets shift state-level power supply routing from the cornbelt to cover the drop."

Sure, but that's why you favor a regionally balanced mix of renewables, with regional peaker plants (which may not be clean/renewable, but are better than relying on dirty sources for your core needs) not geographic concentration of single sources.

[wlll]

> The only real solution I see is nuclear, but that's a naughty word for some reason.

I am sure that if you put your mind to it you can think of some reasons people might feel uneasy about nuclear power. It’s not like incidents involving it are that far in the past.

[kayaeb]

if you look up deaths by energy production method, nuclear is far and away the safest, in every single country by orders of magnitude, even wind is deadlier.

[pfdietz]

The claims that solar and wind are deadlier use cooked statistics (very old numbers for wind, and dodgy assumptions about rooftop solar that don't apply the utility-scale fields that are now dominating).

[kayaeb]

I'm not sure if "accidents" count as "cooked" statistics... modern nuclear plants are much safer than 20th century ones as well, so if we're updating numbers I think nuclear is still an extremely safe contender (and if you split nuclear deaths by country, USA is an order of magnitude again safer than all nuclear). Maybe I misinterpret what you mean by cooked though, I would be interested in reading more about it, if you have a good piece? Wind also relies on pizoelectric elements, I'm not sure what their carbon footprint is compared to nuclear fuel, probably would be less in the future if like CA/OZ stepped into the rare-earth supply chain.

And new types, like thorium salt reactors don't have classical issues like uranium waste products and much much smaller possibility of runaway reactions. And France has been "5 years away" from fusion reactors for like 30 years on a shoestring budget, with real money that could be a possibility in maybe another 30 years and also dodges all the horror-story problems.

Overall, I agree, modern solar, especially reflector-steam plants shouldn't be lumped in with silicon panels, especially when talking about total carbon footprint. But I do think nuclear carries a lot of unfair baggage that has kept us on oil for way longer than we should have been.

[GekkePrutser]

Right now yes. But we're creating waste that remains harmful for thousands of years and store it in facilities with a 100-year service life.

It's the same kind of "leaving problems to the next generation" of current fossil-fuel use except this one is a lot more generations away.

[kayaeb]

This isn't the case with thorium salt reactors or, if we had enough funding to finally crack it, fusion.

[kvetching]

Renewables are crony capitalism. Without consistent government subsidies, incentives, grants, etc...they are not profitable.

[dragonwriter]

No, renewables are public goods as they have positive net externalities, that is, a substantial share of the benefits of their use accrues to people outside the transaction. Well, relative to fossil fuels, at least; it's more accurate to say that fossil fuels are public harms with a substantial net negative externality.

Government action in the form of subsidizing the former and/or taxing the latter is necessary to internalize the externalities so that the relative net cost (benefit) is born by (accrues to) the participants in the transaction.

https://en.m.wikipedia.org/wiki/Pigovian_tax

[amiga_500]

Fossil fues are subsidized because the users don't pay the true cost.

[VyperCard]

Yeah they are also directly subsidized.