Starship’s been in development for over two decades and the design keeps being changed and failing.
Soyuz has a very impressive record, Starship has been horrifically mismanaged by comparison. The falcon heavy flew 14 times and SpaceX is all in on a heavy launch vehicle because what? Even if they hit every target perfectly from now on it was a wasteful project.
The design changing and the development _failing to meet its stated deadlines_ is not a good argument for the system never working. Especially given we know the deadlines were unrealistic to begin with, yet significant milestones have been achieved in (deadline-ignoring) impressive time frame - like landing a second stage rocket from orbit within 8 years of development (by a private company, not a national effort).
Not paying off isn’t the same thing as never working.
Opportunity cost is a real thing. The obvious alternative buying stock (or handling out dividends to investors who buy stocks) would have created a new revenue stream larger than a working starship in 2027 represents.
Thus even if nothing else fails, the project was a poor investment. The market just isn’t big enough that making launch cheaper would be worth it at this point, profits might grow in the future but the deficit keeps growing in the meantime.
> Starship’s been in development for over two decades
What? The first version of something that looks anything like Starship was the ITS announced back in 2016, later "BFR" in 2017 and the stainless steel version (which is now flying) in December 2018.
Eight years is very reasonable for a fully reusable heavy lift system - something no one has built before.
The Space Shuttle took roughly 12.5 years from formal concept studies to its first flight (and 9 years from official program approval)
Space Shuttle was an even harder project. Amendments to the Starship project were all directed towards making it fly better. Modifications which various departments demanded from the Shuttle project made it a worse and worse spaceship. They even had to let go of the emergency recovery capability, which eventually led to death of 10 astronauts.
In this context that would mean running the same intervention at scale 30 times without each run impacting the next. Maybe that is possible, but it seems unlikely to me especially if the intervention has a half life on the order of a single generation as life experience and social norms change.
The question I was raising was locality though, it was temporal. Such experiments take time to conduct, and running a couple dozen or more times takes even more time.
The question I was raising was whether said results would be useful beyond a decade or two into the future, not across different cities today.
Then you're still misreading my point. Such tests take a decent amount of time to design, get approved, execute, and analyze.
Say it takes a year even when 30 runs are done in parallel while keeping proper control over population distributions, variables and controls, etc. If the results are only useful on the timeline of a generation or two, it would only make sense to run such studies on events pretty likely to happen.
Testing interventions of a hundred year pandemic event wouldn't be useful if the results became invalid after a generation, for example. Unless you're willing to run such studies every generation knowing that roughly 1:5 would be useful. That'd depend on how expensive and invasive the intervention study is in the first place.
We don’t need to invest an ever increasing amount in solar panels to transition because existing panels degrade slowly. Scale things out another 20 years and at current rates solar will have squeezed out just about everything else.
Sure, we can always move faster but hydro and wind limit how much solar we actually need. Batteries have cycle limits so even if wind is unreliable producing power at 2AM just to increase battery lifetimes makes sense.
20TW is roughly current world marketed energy consumption. But, on Earth, solar power plants have a capacity factor around 20%, so you need 100TW of solar panels to produce those 20TW. Moreover, we should expect human energy consumption to continue to grow, not suddenly become constant, especially since solar energy is so much cheaper than older sources of energy; 20 years from now we might need four times that much, depending on how AI works out. In that case you'd need to produce about 400TW÷20 years = 20TW/year.
Hydropower is already scaled nearly to its limits, and wind energy is useful and important, but is dropping in cost much more slowly than solar, and it's tapping a much smaller resource.
> 20TW is roughly current world marketed energy consumption. But, on Earth, solar power plants have a capacity factor around 20%, so you need 100TW of solar panels to produce those 20TW.
This confuses primary energy with work. 1 TWh of solar can displace multiple TWh of primary energy. This depends on details, of course; in some cases it makes sense to directly convert solar output resistively to heat even if that takes a second law loss.
This is a good point; in particular, electrification of transport will reduce the figure substantially, especially because car engines are usually less than 30% efficient. But electrical power is already about a third of the total, isn't it?
You're right, that's less than a fifth. Thank you.
So, the other 82% of primary energy consumption could be reduced by about 60%, except for the part that's already used for heating (how much is that?), and by about 75% when it's being burned in the inefficient internal combustion engines commonly used in cars and the like.
Ballparking, this seems like fueling the current economy purely with electricity, and counting "primary energy usage" as the output in the case of solar panels (rather than "the sunlight hitting them" as you advocated elsewhere, which is a defensible convention but not one anyone uses) would cut primary energy usage by about a third.
> except for the part that's already used for heating
Heat pumps are ~300% efficient on average across most of the globe outside of a few areas. Even just cooking with resistive heating uses less fuel because you’re not heating up air to supply oxygen to a fire.
Also, reducing fossil fuel refining and transportation is a surprisingly large fraction of that primary energy supply with 40% of global shipping by weight being oil. Think of it this way if you’re buying 10 gallons of gasoline a week that’s 6.2 lb/g * 10 * 52 = 62 * 52= 3,200 lb a year in fuel ie the weight a car shipped from some oil field to a refinery then to you.
You have some good points, but I think there are some flaws in them.
Heat pumps are probably now economic only in niche scenarios, even at current PV module prices; they cost dramatically more than the solar panels they displace. And they're really only applicable to climate control, not to other applications of heat, such as cement kilns, electric arc furnaces, or baking bread. I do use one to heat my bedroom in winter, but I don't think they are really relevant to the future.
It is true that electric cooking is more efficient, especially when the heat can be produced in close proximity to the food, as in induction stovetops, crockpots, and microwave ovens. I don't know how to size this, but I don't think it's very large.
40% of global shipping by weight is fossil fuels, not just oil (https://billmckibben.substack.com/p/the-happiest-number-ive-...) but that's by weight, not energy consumption. The vast majority of fossil-fuel shipping is shipped by shipping ships, not by railroads, tractor-trailer trucks, stepvans, small boats, or personal cars, and, if I'm understanding https://unstats.un.org/unsd/energystats/pubs/documents/2026p... correctly, only 2.5% of the global total energy supply ("TES", the UN's term for world marketed energy consumption) is the bunker fuel that powers those ships. (I had guessed 3%.)
So, completely eliminating fossil fuel shipping will save about 1% of total energy consumption.
> I don't know how to size this, but I don't think it's very large.
It covers every use case for high temperatures and more impactful the higher temperature you want. Melting iron using fossil fuels at 1,500 °C also means wasting high temperature exhaust air.
It's quite common in such situations to use the outgoing hot gas to preheat incoming air. This kind of technology goes back more than a century. This cannot be 100% effective (entropy created in the process has to go somewhere) but can greatly reduce the energy needed.
Pre heating air is very much a thing, but it only buys you so much.
Really high efficiency home furnaces require cooling the exhaust gasses low enough for water to condense but that low temperature heat isn’t particularly useful at a smelter where low relatively temperature waste heat is plentiful.
There’s other issues like introducing drag which requires either a large chimney with hot exhaust gasses or fans to force airflow etc.
In the end the only thing that matters for these calculations is relative efficiency where electricity wins by ~20% or so in the real world plus fuel lost in transit.
The better home tech analogy would be air-to-air heat exchangers. These exhaust air from inside a house, replacing it with a stream of outside air, and transfer almost all the difference in heat energy from one stream to the other.
At home, air to air heat exchangers run into humidity issues. If it’s 100f at 98% humidity you don’t get even vaguely close to 70f 50% humidity by using cooler internal air to cool hot humid air.
At home the benefit is non zero, but you still need extra energy for the kind of gap I am talking about.
Further for a furnace the transfer is zero sum, remove 1g of water from the exit stream move 1g to the input stream and now there’s an extra gram on the output stream canceling out the transfer.
More fundamentally, current numbers come from what is actually happening not what could in theory be done.
If the thermodynamic states of the two gas streams are swapped then in the limit no extra energy is needed. If humidity is converted to some bound state and then back this is, ideally, completely reversible.
Now, in combustion the gas streams are not identical in composition and mass, so there is some unavoidable loss, but the efficiency gain can be very large. Recuperation had a huge effect on the efficiency of blast furnaces.
> that low temperature heat isn’t particularly useful at a smelter where low relatively temperature waste heat is plentiful.
I suggest you read through the links pfdietz provided, and understand them, because you are mistaken about this point. It is not a peripheral issue; it has been central to thermodynamic machinery since Stirling.
Feel free to quote any part that actually disagrees with what I said.
Coal is the only fossil fuel with minimal hydrogen turning O2 into H20. Latent heat of vaporization for water is very high, but you can only extract that by cooling the exhaust gasses below its dew point. Preheating alone doesn’t let you extract that energy from exhaust gasses.
You may be computing Carnot efficiency backwards; heat pumps are less impactful for producing higher temperatures, not more. Also, there are practical difficulties with trying to build a heat pump that can function at several hundred degrees.
Aside from pfdietz's good point about regenerators, resistively melting iron with electricity doesn't require any high-temperature exhaust air.
My point was people natural gas smelting is a long way from the 98% efficiency you see in high end home natural gas heaters. Latent heat of vaporization means it takes far less energy to warm the incoming air than you can extract from the exhaust.
> 20TW is roughly current world marketed energy consumption
Primary energy for solar panels is the sunlight hitting them not the electricity they produce. Fossil fuels care about primary energy because you pay for the fuel. Further, roughly 40% of global shipping by weight is moving fossil fuels.
> solar power plants have a capacity factor around 20%
This varies widely by technology and location. ~30% isn’t uncommon in the US. Capacity factor 29.7% (average 2015–2017, MS1) https://en.wikipedia.org/wiki/Mount_Signal_Solar tracking vs fixed makes a huge difference. Rooftop solar sucks vs grid scale in terms of production but you save on grid transmission losses the numbers aren’t directly equivalent.
Further PV panels degrade every year, but you see 30 year old panels still in use.
> human energy consumption to continue to grow
> 20 years from now we might need four times that much
Population growth + Electric cars + AI changed US electricity consumption from 4.03TWh in 2018 to 4.19 TWH in 2025. That’s less than 0.6% per year, suggesting 4x increase in primary energy consumption from AI in 20 years as a meaningful possibility is insane. https://statbase.org/data/usa-electricity-consumption/
Yes, single-axis trackers often get capacity factor over 25%, and solar farms in sunny places very commonly use them. But the picture isn't so sunny everywhere; solar capacity factor in China, Germany, and the Netherlands has been a dismal 10%. So 20% is a ballpark figure, and it's possible to do better under favorable circumstance.
It is true that it would be insane to expect the US to lead the transition to abundant renewable energy, but that doesn't mean the transition won't happen. It just means it will leave the US behind. The US's electricity production (though not energy production!) doubled in the 01960s and then stopped growing, and China's electricity production has doubled over the last 10 years and continues to grow rapidly. Worldwide, we should expect cheap solar panels to lower the cost of electrical energy, opening up new uses for it.
The Netherlands is an extreme edge case for solar. They are focusing on wind for obvious reasons so it’s a moot point. Most of the north is low enough population density that hydropower is plentiful for their needs.
The Netherlands is much worse than average, but they're not an extreme edge case. Norway is the extreme edge case, and they're also focusing on wind. (Parts of Antarctica get more sun than most of Norway.)
I have no idea why China has such a dismal capacity factor! I suspect they have a shortage of transmission capacity between the sunny places and the populated places. Let me know if you find out.
Those latitudes are pretty close, but that doesn't tell the whole story.
At noon on the equinox, Amsterdam gets 80% of the sun that NYC does, and Fairbanks gets 56%. But, at noon on the winter solstice, Amsterdam gets 55% of the sun that NYC does, and Fairbanks gets 7% ofthesun NYC gets. So, in terms of insolation above the atmosphere, Fairbanks is dramatically worse than Amsterdam. If the sine of the sun elevation was the whole story, to survive the winter on solar, you'd need 8× the solar panels in Fairbanks you'd need in Amsterdam, which would need less than 2× New York.
In fact, cloud cover is very important, and I think it narrows the gap a bit.
So, at the current production rate, we can produce solar cells that deliver 20TW/year in about 15 years. Eventually, we’ll have to replace lots of them, but given that the rapid growth of installed panels makes the majority of panels new, I think we can mostly ignore that in this calculation.
We need to produce enough solar panels to generate net new 20TW every year; 20TW/year as a measure of energy production doesn't make sense as the Watt is a measure of energy transfer. In other words, we need to increase production by 20TW per year every year for 20 years in order to hit the 400TW that we need to be producing all the time (in this model where global energy demand is 400TW)
Thank you. One minor detail: producing 20TW per year is in order to have 400TW of generation capacity installed, but only producing 80TW because of the 20% capacity factor.
Rooftop solar has both economic efficiency disadvantages (generally poorer siting, being dangerous and expensive to install) and advantages (no transmission losses, no added load on transmission and distribution systems, and in some cases elimination of inverters and other power electronics). It isn't clear to me whether it comes out to be overall more or less economically efficient, and I suspect that it probably depends on local circumstances, and especially on whether you can reduce or eliminate inverters.
However, the most persuasive case for rooftop solar is basically political rather than economic: it reduces or eliminates the building's dependency on utility-scale generation, transmission, and distribution. This dependency can bite in the form of unreliability (like California's intentional power outages during the now-yearly summer brushfire season, or the "load shedding" rolling blackouts South Africa had for several months last year), in the form of extortionate energy prices due to monopoly rent extraction (California being the poster child here at the moment, extorting 29.75¢/kWh from resident), or in the form of systemic fragility (currently there are blackouts in Kyiv because Russia is blowing up the power stations, which amplifies the coercive effect of Russian attacks on Ukraine).
I want to say, I greatly appreciate your help in getting these figures right.
That’s because there were so many rooftop solar subsidies, removing them gutted rooftop insulations. You will see many highly optimistic calculations because people are trying to sell you solar panels but they leave out details like the time cost of money. 30k upfront at even 5% annual return is a lot of money let alone borrowing 30k at 6%.
That may be true wherever you live (probably in the US), but it isn't true worldwide. US$30k buys 200 kilowatts (peak) of unsubsidized mainstream photovoltaic modules. Even in the US it buys half that. That's a utility-scale power plant, not a household rooftop installation.
Meanwhile, household rooftop and balcony installations continue to proliferate rapidly in Pakistan, Germany, Australia, here in Argentina, etc.
Photovoltaic modules on their own don’t do anything. Planning, permits, installation, inverters, etc are all dramatically more expensive in rooftop solar. Grid scale also doesn’t need to worry about when the roof gets replaced or additional leaks.
But you don’t need to take my word for it even with a 30+% subsidy on most instillations residential solar in the US only represents ~15% of total solar capacity. Globally the numbers are even lower.
Photovoltaic modules produce a voltage or current on their own. It's true that you have to connect them to a load for them to do work such as washing your laundry or heating your oven, but that load can be very cheap. Like, a wire. None of the dramatically more expensive things you're naming are necessary.
In the US you have a negative 100% subsidy on solar panels in the form of tariffs, and the planning and permit prices you're talking about are additional similar negative subsidies, not actual costs. They don't exist in Pakistan, and they could be set to zero tomorrow at the stroke of a pen, which is what has happened with balcony solar in several European countries. That's why you're talking about nonsense prices like US$30k for a household system.
> None of the dramatically more expensive things you're naming are necessary.
Without labor your solar panels are still sitting in the box the showed up in. You can debate how much is actually necessary but economically it makes zero difference if a 3rd party or the homeowner does the install, labor is labor.
Similarly it’s not rooftop solar if the panels aren’t on a roof. Using up your yard for solar panels is an option but means more issues with shading and loss of yard space.
In the end it depends on how you transition. I worked a lot on this subject. If solar panels last 20 years, or 30 or 60 it's not the same thing obviously. But in some places they're already replacing them, not because the panels can't continue to produce, but because they have more efficient panels and they don't have an infinite amount of territory to build new solar farms. Currently most studies use 30 years for the lifespan of solar panels.
Now what people don't see is to build these panels we use fossil fuels directly and indirectly. The GW/y we're able to install is highly correlated to our use of fossil fuels. The only way to achieve that transition is to use clean energy to build more energy capacity, so that at the end of the transition clean energy is able to sustain a world with clean energy (we can ignore a bit of fossil fuels here and there, we'll say it's mostly clean energy).
If today, we stopped increasing the amount of solar panels installed per year, the total amount of solar panels installed would continue to increase for 30 years (with that lifespan hypothesis). And then be stable, IF at this point, we produce enough energy to sustain the system. I did the math on this some years ago, and I was really not confident we could reach the numbers. We would not be producing enough energy in 30 years to achieve the transition. In all my models, if we start to reduce our CO2 emissions, we start to reduce our production of solar panels, which stops the transition. Obviously I only talked about solar panels but it applies to all other sources of energy, wind and nuclear included.
Basically there is no simple solution to replace fossil fuels, but there are "less worst" scenarios depending on the amount of wind / solar / nuclear / hydro etc. countries do.
Your model counts how many panels we have to build. But a lot of what the existing panels produce is wasted today. If we could store it, we would get more useful energy out of the panels we already have, and we would need fewer new ones.
That is why I think the bottleneck isn't the panels, it's the batteries. Panels produce when the sun is up and overproduce, which leads to negative prices for the producers. Being able to store the energy produced during low demand helps stabilize the system, gives cheaper energy prices and a fair price to producers. What I'm actually saying is that building more solar panels makes no sense without storing the energy. Only by doing that will we manage to become more independent from fossil fuels, because then energy from renewable sources can meet demand much better.
Once you start changing the rules you’re no longer constrained by the old rules. Abandonware going free inherently means all the IP used by the game is free to use as part of the game. It doesn’t require individual assets to be free independent of the game.
iOS has been steadily offering more options over time. And yes taken individually customization seems like the correct choice basically every time but eventually you end up with a mess.
Consider the logic for tap’s could offer hundreds of customizations. That’s core functionality and I’m sure someone internally is thinking deeply about many of them. But if you offer zero customization most people just get used to how things operate so skipping that functionality isn’t terrible for the average user. Instead they offer options for people with disabilities which is a distinct group who can’t just adapt and thus a meaningful justification.
Inside a 401k dividends get reinvested, on top of that companies value income go up with inflation simply because they’re getting a similar cut of larger numbers.
That’s why long term stocks are a vastly better investment.
Soyuz has a very impressive record, Starship has been horrifically mismanaged by comparison. The falcon heavy flew 14 times and SpaceX is all in on a heavy launch vehicle because what? Even if they hit every target perfectly from now on it was a wasteful project.
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