How cheap does solar get, and what does that change?
One number sits under this whole argument: the price of a solar panel falls by a roughly fixed percentage every time the amount installed doubles, and it has been doing that for fifty years. The people on record here agree about the number and disagree about almost everything downstream of it -- what the grid ends up looking like, whether the forecasts are worth making at all, and whether the arithmetic that said none of this could work was wrong or merely early. Two dated forecasts are here, and the person who made the earlier one has already said in public that it was too cautious.
25 dated claims from 6 people · 5 views · 1 change of mind · most recent 3 Sept 2026. Every line below links to the person’s own words.
The views
What is a view?
Our reading of what a group of claims have in common, one level
above a korrent: a korrent is our reading of what somebody said, a view is our
reading of what several korrents share. The claims are printed under it, so the
sentence can be checked against them.
Nobody is filed under a view — claims are. A person is named here because a dated
claim of theirs sits under it, and somebody whose claims sit under two views
appears under both.
PKPaul KrugmanBut politics aside, what’s notable about that 2001 report, put together by men who regarded themselves as hard-headed realists, is that it envisaged an energy future reliant almost entirely on fossil fuels plus a bit of nuclear energy.paulkrugman.substack.com
Trade economist, Nobel laureate in 2008 for his work on…
Their wordsBut politics aside, what’s notable about that 2001 report, put together by men who regarded themselves as hard-headed realists, is that it envisaged an energy future reliant almost entirely on fossil fuels plus a bit of nuclear energy.
CHCasey HandmerPer doubling of production, costs have fallen a consistent 30-40% since 1970, but it’s only in the last few years that this price has become competitive with legacy electricity generationcaseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsPer doubling of production, costs have fallen a consistent 30-40% since 1970, but it’s only in the last few years that this price has become competitive with legacy electricity generation
Ramez NaamThe data paint an incredible picture: One that shows the price of solar electricity from utility-scale systems dropping by anywhere from 30-40% with each doubling of cumulative solar deployment.rameznaam.com
Author and clean-energy investor who has been publishing…
Their wordsThe data paint an incredible picture: One that shows the price of solar electricity from utility-scale systems dropping by anywhere from 30-40% with each doubling of cumulative solar deployment.
CHCasey HandmerA number of commentators have consistently predicted that solar cost improvements will level out “this year” since about 1990, and yet if anything deployment, cost decline, and the learning rate have only improved.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsA number of commentators have consistently predicted that solar cost improvements will level out “this year” since about 1990, and yet if anything deployment, cost decline, and the learning rate have only improved.
Ramez NaamWe can use the last decade to predict the future prices of solar power. Not by looking at the cost of solar as a function of time, but by looking at the cost of solar as a function of cumulative scale of the solar industry.rameznaam.com
Author and clean-energy investor who has been publishing…
Their wordsWe can use the last decade to predict the future prices of solar power. Not by looking at the cost of solar as a function of time, but by looking at the cost of solar as a function of cumulative scale of the solar industry.
DMDavid MacKayI am sure that photovoltaic panels will become ever cheaper; I’m also sure that solar panels will become ever less energy-intensive to manufacture, so their energy yield ratio will improve.inference.org.uk
Physicist
Their wordsI am sure that photovoltaic panels will become ever cheaper; I’m also sure that solar panels will become ever less energy-intensive to manufacture, so their energy yield ratio will improve.
CHCasey HandmerBy 2045, natural gas will be used as LNG primarily for high performance supersonic aviation, shipping, and industrial heat.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsBy 2045, natural gas will be used as LNG primarily for high performance supersonic aviation, shipping, and industrial heat.
PKPaul Krugmanthere are many people who still refuse to believe that renewables can be practical even as renewables keep growing around the world, in fact accounting for the bulk of growth in electricity generationpaulkrugman.substack.com
Trade economist, Nobel laureate in 2008 for his work on…
Their wordsthere are many people who still refuse to believe that renewables can be practical even as renewables keep growing around the world, in fact accounting for the bulk of growth in electricity generation
CHCasey HandmerFollowing current trends to second order, >95% of humanity’s energy needs will be downstream of solar panels by 2042, just 19 years away, and alongside enormous expansion in direct use of electricity, fuel consumption will grow to more than $25T/year in equivalent dollars.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsFollowing current trends to second order, >95% of humanity’s energy needs will be downstream of solar panels by 2042, just 19 years away, and alongside enormous expansion in direct use of electricity, fuel consumption will grow to more than $25T/year in equivalent dollars.
Ramez NaamThis incredible pace of solar cost decline, with average prices in sunny parts of the world down to a penny or two by 2030 or 2035, is just remarkable.rameznaam.com
Author and clean-energy investor who has been publishing…
Their wordsThis incredible pace of solar cost decline, with average prices in sunny parts of the world down to a penny or two by 2030 or 2035, is just remarkable.
CHCasey HandmerOn the flip side, these captive solar power plants will be curtailing approximately 75% of their generated power and will be able to provide net power on all but a few days per year.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsOn the flip side, these captive solar power plants will be curtailing approximately 75% of their generated power and will be able to provide net power on all but a few days per year.
CHCasey HandmerFor loads below $1000/kW, intermittent operation with some modest solar array oversizing is the winning strategy. Above $1000/kW, we charge and discharge batteries daily to run them.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsFor loads below $1000/kW, intermittent operation with some modest solar array oversizing is the winning strategy. Above $1000/kW, we charge and discharge batteries daily to run them.
CHCasey HandmerA battery that’s discharging every day gets great utilization, but one that’s only there in case the sun doesn’t come up for two days in a row, barely gets used.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsA battery that’s discharging every day gets great utilization, but one that’s only there in case the sun doesn’t come up for two days in a row, barely gets used.
CHCasey HandmerThe logical end state of this displacement is not some hybrid grid with around 20% solar backed up by spinning generation, but a much more dynamic, versatile grid with around 200% solar generation and hours to days or weeks of battery storage, fully decoupling time of generation and consumption.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsThe logical end state of this displacement is not some hybrid grid with around 20% solar backed up by spinning generation, but a much more dynamic, versatile grid with around 200% solar generation and hours to days or weeks of battery storage, fully decoupling time of generation and consumption.
CHCasey HandmerThe only highly populated industrial country unable to trivially meet its electricity and synthetic fuel needs with solar alone is the United Kingdom, due primarily to a high population density and high latitude.caseyhandmer.wordpress.com
Physicist, formerly at NASA's Jet Propulsion Laboratory
Their wordsThe only highly populated industrial country unable to trivially meet its electricity and synthetic fuel needs with solar alone is the United Kingdom, due primarily to a high population density and high latitude.
DMDavid MacKayif we covered the windiest 10% of the country with windmills (delivering 2 W/m2 ), we would be able to generate 20 kWh/d per person, which is half of the power used by driving an average fossil-fuel car 50 km per day.inference.org.uk
Physicist
Their wordsif we covered the windiest 10% of the country with windmills (delivering 2 W/m2 ), we would be able to generate 20 kWh/d per person, which is half of the power used by driving an average fossil-fuel car 50 km per day.
DMDavid MacKayWhile wave power may be useful for small communities on remote islands, I suspect it can’t play a significant role in the
solution to Britain’s sustainable energy problem.inference.org.uk
Physicist
Their wordsWhile wave power may be useful for small communities on remote islands, I suspect it can’t play a significant role in the
solution to Britain’s sustainable energy problem.
DMDavid MacKayJust like Britain, Europe can’t live on its own renewables. So if the aim is to get off fossil fuels, Europe needs nuclear power, or solar power in other people’s deserts (as discussed on p179), or both.inference.org.uk
Physicist
Their wordsJust like Britain, Europe can’t live on its own renewables. So if the aim is to get off fossil fuels, Europe needs nuclear power, or solar power in other people’s deserts (as discussed on p179), or both.
Noah SmithBecause solar has, broadly speaking, won the technological race. Intermittency was the last big problem, and batteries have gotten good and cheap enough to make solar reliable.noahpinion.blog
Economics writer; author of the Noahpinion newsletter
Their wordsBecause solar has, broadly speaking, won the technological race. Intermittency was the last big problem, and batteries have gotten good and cheap enough to make solar reliable.
HRHannah RitchieBut, China mainly dominates these markets because it has produced a long-term industrial strategy for these technologies and has honed an optimised, modern supply chain as a result.sustainabilitybynumbers.com
Data scientist at Our World in Data and author of Not the End of the World
Their wordsBut, China mainly dominates these markets because it has produced a long-term industrial strategy for these technologies and has honed an optimised, modern supply chain as a result.
HRHannah RitchieThat’s because most clean energy jobs are in deployment and maintenance rather than manufacturing, and since higher costs slow down the rollout of renewables, increasing prices reduces the total number of people working in clean energy (even if the number working in manufacturing increases).sustainabilitybynumbers.com
Data scientist at Our World in Data and author of Not the End of the World
Their wordsThat’s because most clean energy jobs are in deployment and maintenance rather than manufacturing, and since higher costs slow down the rollout of renewables, increasing prices reduces the total number of people working in clean energy (even if the number working in manufacturing increases).
MacKay concluded that Britain cannot live on its own renewables at current consumption. Handmer agrees the UK is the hard case and reaches the opposite conclusion: it is the one rich country that cannot do it with solar, and it can do it with wind, at prices he puts as low as $10/MWh. One says the island does not have the resource; the other says it has the wrong plan.
MacKay said Europe cannot live on its own renewables and needs nuclear, desert solar, or both. Handmer expects the end state to be roughly 200% solar generation with hours to weeks of battery storage and no spinning backup at all. Fifteen years and two cost curves separate them, and the thing MacKay held constant -- that storage would stay expensive -- is exactly what Handmer says changed.
MacKay concluded in 2008 that Europe cannot live on its own renewables and needs nuclear power, solar from other people’s deserts, or both. Smith says in 2026 that solar with batteries has won the technological race and passed nuclear for most uses, because storage solved intermittency. Eighteen years separate them and MacKay’s arithmetic was about land and flux rather than cost, so the pair is a tension rather than a refutation -- but it is the most consequential disagreement in this archive about what to build.
Data centres end up net power suppliers only because they are built the way Handmer says high-capex loads should be built: overbuild the array rather than buy batteries for the rare bad day. The spilled 75% that becomes the neighbourhood’s power is that overbuild.
The forecast that almost all of humanity’s energy is downstream of solar panels by 2042 is an extrapolation, and what it extrapolates is the learning rate. If the 30-40% decline per doubling stops, the date goes with it.