Please describe how sunshine alone will sustain this unchanged.

Because you’re ignoring the hugely inefficient baseline of how much sunlight we have historically been able to harvest.

From this page, sunlight-to-biomass efficiency of wild plants is less than 1%. For crops specifically bred over thousands of years to grow as much useful biomass as quickly as possible in each season, the number ticks up to 2%. But even that number also fails to account for the periods in which fields lay fallow between seasons, or for crop rotation.

Then, once you have that biomass, converting it into a useful form of fuel for burning, or food for biomechanical energy, has huge efficiency losses along the way.

Meanwhile, solar panels achieve approximately 25% solar efficiency.

That’s how we can collect far more energy from the sun today than at any point in the past. Biology is inefficient compared to photovoltaics.

Nuclear plants that are already running are very cheap to continue running.

That’s mostly beside the point, though, because, as you explain, they’re very expensive to construct, and that’s before even getting to the ones that never get completed because the cost overruns get the project canceled.

So I’m always in favor of running existing nuclear plants as long as possible, but am pretty skeptical of building any new nuclear plants.

Most usable energy on Earth comes from fusion of hydrogen into helium in the Sun, creating radiation that hits the Earth. That’s solar energy, of course, either thermal or photovoltaics, but also the wind caused by uneven warming, the evaporation and condensation of water that flows downhill for hydro power, the chemical bonds formed by photosynthesis making renewable biofuels or older fossil fuels.

Some portion of energy on Earth is gravitational potential energy and the kinetic energy of stuff moving around settling into a lower energy state: the moon dragging the oceans around, the heat of the Earth’s core spinning and tectonic plates moving from the momentum of all the dust that got pulled into what is now a planet. Geothermal and tidal energy mostly come from these planet scale phenomena.

Some portion of energy is the release of energy stored in nuclei formed from some past supernova, of less stable isotopes of atoms heavier than iron. Some portion of geothermal is traceable to this kind of nuclear decay, and obviously we can isolate and enrich those nuclear elements into fission fuel for nuclear power, as well.

Hard to categorize the second and third categories into solar power, though. Yeah, it comes from astronomical phenomena tracing back to how our solar system and planets were formed, from the materials they’re made out of, and found their way into their current shapes and orbits, but is that solar power?

New nuclear plants take like 10 years to build, and need to plan out a 50+ year useful life in order to be worth the up-front construction costs.

I wonder what the state of energy production in 2075 will be, where a nuclear power plant designed in 2025 and completed in 2035 will still have 10 years in order to break even on cost, competing with whatever the state of the art is on generation in 2075. Fusion? Widespread solar+wind+geothermal+batteries? Something we haven’t even dreamed of?

That’s why I’m skeptical of nuclear fission these days. It locks us in too long.

since there are many jurisdictions that won’t build nuclear capacity for political and societal-preference reasons, rather than technical ones

Most jurisdictions aren’t allowed to build nuclear, for nonproliferation reasons. That’s because nuclear technology can be used for nefarious purposes, and requires a highly functioning security apparatus in order to enforce safety requirements. So as a society we’ve tried to keep it out of the hands of those that the great powers have decided can’t be trusted with the tech.

Which then raises the uncomfortable question of whether we should trust ourselves, the current great powers, with this technology? If we plan out a 50-year useful life for a power plant, do we trust that the governments and companies operating that plant (and its supply chains and its waste management) will still be doing things safely in 50 years?

These days, I’m less sure.

I’m not discouraging the research. I’m just pointing out that this technology is very much unproven, and that they’ve got a long, long way to go. I wouldn’t get hopes up until they actually build prototype engines with sufficient thrust and power to make the calculations work.

If everything goes according to plan, they’re hoping to build working models in 2034.

That’s their pitch deck for raising money, at least. This is a startup trying to raise money from lenders and investors, before they’ve proven that this concept can work.

That’s still just a 2-seater. There are many things where scaling upwards runs into the square cube law. Increasing the lift or the thrust of this design would increase the weight even more.

My ability to build a scale model of a bridge that can hold up scale models of automobiles doesn’t actually prove that my design is viable with those materials at full size. It’s the same for aircraft wings, engines, and actual flight.

The contracts I’m describing are just long term contracts. Buyer and seller negotiate a long term price, and that’s the market price on that timeframe, no government involvement. Sometimes the spot price moves up or down, but the contract price is stable. It’s like buying a futures contract and just taking delivery regardless of how much the price moves: you paid a single price a long time ago, and all the fluctuation in the meantime doesn’t affect the price you actually paid for the right to take delivery.

It’s not really a subsidy to have long term contracts. It’s just a manner to have predictability, and make it easier to plan things in the future. Some of it is a risk shift on quantity or prices, on who bears the risk if production or demand don’t match up, and whose responsibility it is to make those two number match, by cutting power to customers or paying people to disconnect their powerplants from the grid.

But the long term contracts are often there for price and volume stability. Spot prices will still fluctuate, though, especially if it’s unpredictable how much energy different renewable sources will generate at specific times in the future, or how much different customers will want to consume at specific times in the future.

Either way, it costs a lot of resources to match up supply and demand, and you’ll either use prices to help push the numbers together or you consume a lot of resources trying to mandate those numbers come together. Trying to fight price swings will cost resources in some other way.

It’s not even limited to Europe, either. It’s just a Double Auction format, designed to find a clearing price where there is as much produced as there is purchased, at the same price for all market participants, for that particular time slot. Different grids use different time resolutions, from 5 minutes to 60 minutes in most places.

It is fair for everyone to be paid the same price for the same product at the same time. And the price will need to be high enough to actually attract producers for the demand at that moment. Those with very cheap marginal production costs (solar, wind, nuclear) can then get paid for making energy plentiful, while higher cost fossil fuels will still be incentivized to meet demand when those aren’t enough.

Basically, I don’t see any other way it would make sense. Giving less money to renewable/low carbon producers would set us back, and disincentivize buildouts of those sources.

Part of it is the sheer diversity of options and trim levels that are all under the same make and model of the Ford F-150. Taking a look at the Ford F-150 trim levels, there are basically 4 gasoline engines, 2 flex fuel engines, 1 hybrid drivetrain, 1 diesel engine, and a now discontinued EV powertrain. There are about 5 body/cab options, and several suspension options.

In contrast, take, for example, the GM BEV3 platform. It’s the Chevy Equinox, Chevy Blazer, Cadillac Lyriq, Cadillac Optiq, Honda Prologue, and Acura ZDX. I’ve driven several of these and they’re all basically the same with different options. There’s less diversity in those models than there is for the Ford F-150.

That’s basically correct. Passenger rail was a highly regulated industry, and it was always more profitable to transport freight over the same lines. Eventually, the private passenger rail companies were basically all losing money, and filed for permission to discontinue passenger service (in the previous regulatory framework, companies needed government permission to make any changes to service), so that Congress basically created Amtrak to take over the prior passenger lines. As it stands, though, Amtrak needs to lease/license access to tracks it doesn’t own, so it’s hard to increase speeds or service, as the track owners would need to give permission for the upgrades to the track or the effect on timetables. That’s even true of the Northeast Corridor, where Amtrak owns most of the track, but some segments are owned by freight rail companiex CSX and Norfolk Southern.

I like the graph but hate the colors. Too low contrast where correlating the lines to the actual country/category represented takes a lot more examination.