Solar is winning the energy race | Hacker News Reader

Solar is winning the energy race

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Solar is not less than revolution in Pakistan. Almost every home and factory has solar installed on their roofs. More affluent houses have almost gone off grid; others are selling back to grid and others who can't afford has their own small scale 12V solar panels to run fans in the scorching summer of Pakistan to save electricity bills. It is all done by people independently without much support from the government as ROI (if you are using full potential of your installed capacity, it can be as low as 1 year and afterwords it will be free) is much better on solar than paying the grid.

I myself has got one my roof, 6KW with 5Kwh battery backup costing me 700K roughly 2500$. Now, I can use AC without thinking of electricity bills and the most importantly I do not have to face inconvenience of grid being not available in some cases for 24 hours.

Now Pakistan is facing energy crises not because it does not have enough, because it has too much as people are generating their own and due to nature of the contracts with electricity producing companies' government has to pay them according to their installed capacity not by generated.

According to a government report in 2021, 116,816Gwh was consumed commercially and in 2024 it stands at 111,110Gwh and in 25 and 26 in would be even lower.

Isn't it insane?

> Every home and factory has solar installed on their roofs.

Looking at Karachi's 2025 satellite imagery in Google Earth, I find this utterly overstated. Maybe 5% of houses have them on their rooves at best.

And that is in the largest city in Pakistan, where people ostensibly have much more money to throw at solar panels than in rural areas.

I'm not from Pakistan but Karachi is the only vertical city in Pakistan, most people lives in apartment buildings, I would suggest looking at other cities like Lahore.

Sorry, I fixed it to "Almost every". I agree, "Every" is overstated.

I have never been to Karachi, what I know about Karachi, Karachi weather is not as harsh as Punjab or away from coastline so, you might survive (If you are used to living without AC) there without AC. And further, its hugely densely populate area so a lot of people might not have roof to install it. And Karachi gets people from the whole country and most of the people are living there temporarily, they might not want to commit on installing solar system on a rented house.

That might be reason, but numbers speak themselves. Source: [https://www.ceicdata.com/en/pakistan/electricity-generation-...]

Especially for hot and sunny areas solar is insane. At mid day, max heat, you get the peak production and can run your AC at full throttle. That enables you to efficiently work at nice temperatures.

Heat reduces solar production, ideally you have very sunny environment with about 25C / 77F.

Panels are cheap, efficiency is not that important.

Why is that always posted without stating the magnitude of the effect? The numbers that you find online are around 15% relative loss at 60°C vs. 25°C panel temperatur (I remember a HN comment reporting 12% comparing peak April to peak July). That is significant, but not world changing, especially for AC.

What about panel degradation?

There are 30 year old still functioning panels in Australia.

Buried in that longevity, is an observation that a fifth of panels degrade faster than expected

  The long tail appears on graphs showing the degradation rate per year of the panels, indicating that up to 20% of all samples perform 1.5 times worse than the average.

See (Uni NSW study) Cracking the ‘long tail’ problem: new research targets hidden solar panel issue (2026) - https://www.unsw.edu.au/newsroom/news/2026/01/research-targe...

and discussion: Maximising time in the sun: how to maintain and repair solar panels to make them last (2026) - https://www.theguardian.com/australia-news/2026/feb/13/maxim...

This is more about the lifetime of many PV panels in Australia (temps to 45 C so far) not specifically about PV panels with many hours at > 50 C.

It exists and does degrade panels but the time horizon is pretty wide. Real world data shows something like 0.5% to 0.7% degregation per year on average. At the start the degregation is higher and but it slows down with age.

So a 20 year old panel might be at around 80% in the worst case. Often they are in much better shape. This seems like a pretty good deal to me.

Marginally. Between 77F and 100F you only lose about 5%, so you still get 95% of the stated max efficiency. It’s basically negligible and not really relevant.

Recent Bloomberg opinion pice about factories there and in nearby countries shifting to renewables:

Asia’s Industrial Revolution Is Switching Off Gas

https://www.bloomberg.com/opinion/articles/2026-03-22/asia-s...

> The Chief Financial Officer of Pakistan’s Fauji Cement Co. installed its first solar array in 2019 at Jhang Bhatar, about 50 kilometers (31 miles) west of the capital Islamabad. There are now 69 megawatts of panels across the company’s five main sites, at least twice what Tesla Inc. appears to have on the rooftops of its gigafactories in Nevada and Texas.1 They contribute about 23% of the company’s electricity, with a further 35% coming from recovering waste heat from its coal-fired clinker kilns.

Also https://news.ycombinator.com/item?id=46070915

It is absolutely sane and perfectly reasonable. The climate highly support it, you are already used to a grid that in some cases are not available 24/7, and the major energy consumptions are AC and fans which correlate with production.

The US can have this too if it stops demonizing China.

Have what? The US uses far more solar energy per capita than Pakistan.

Have extremely cheap solar panels.

Solar energy per capita / income per capita. What results do you get?

The fact that income is so high in America but solar panels are not ubiquitous everywhere.

We can buy cheap solar panels in the US.

It's just tying them into your houses wiring, and therefore the grid, that's expensive. That, and putting them on your roof (Because anything roofing is really expensive, which makes sense since roofing is in the top 5 most dangerous jobs in the US, and it sucks to do, and it doesn't even pay that well even still!)

Americans use more of everything. It's better to look at percentages than absolute values.

It is genuninely insane (in a good way!) I've encountered some degree of apprehension and disbelief from people in Western countries when I told them, that countries considered poor and backwards often are further along in the transition to renewables, and even for the everyman, installing solar and having (a usually Chinese) EV just makes sense - economically, and not only in terms of saving the planet.

The markup on solar in Europe is insane, and it usually comes down to shitty government regulations - we were forced to upgrade to a 3 phase system (even though our net drain from the grid was looking to decrease), install a government monitoring and control system (and were locked out of some inverter settings), and install a lot of questionable 'safety' equipment (like a DC fire safety cutout, which some argue is even a bigger fire hazard than not having it), and basically all but being forced to install a grid-tie system, as isolated systems (that can take but not feed back to the grid) are a legal gray area.

Not to mention, all the red tape.

But in exchange we get to feed back to the power grid for like 5% of the original price. To be fair, we got a substantial subsidy and in the end, jumping through these hoops was only a bit more expensive that going at it by myself and installing the hardware we actually needed and paying for it out of pocket.

sOcIaLiSM!!!

Yes, that's drive me insane, west which is biggest advocator of climate change and preaches renewable energy has not done as much as a poor country like Pakistan has done.

And Pakistan is the one who is affected the most by the climate change. From September to February Pakistan AQI is basically unbreathable. Rain pattern is disturbed, winter has become shorter and summer has become longer, basically there is no spring or autumn, either it's summer or winter.

EU has to do more and make it easier for them to install solar panels.

It's not like Pakistan doesn't have these regulations, or doesn't try to tax solar power. It's just that the Chinese-Pakistan border is open and nobody's paying import taxes or listening to government regulations.

So the problem in Western Europe is simply that government is actually effective. This generates surprising differences with Pakistan. The government is effective at forcing employers to actually pay their employees. The government is effective at giving women their rights. The government is effective at taxing solar power.

All 3 differences are the same effect, really.

You misunderstand. Nobody should be getting short changed (who doesn't deserve it).

It's just that the difference between the cost of something that's safe and effective and one that is ensured to be safe and effective by the govt should be no more than 10-20%.

Instead it costs 3x as much, and comes with mandatory government monitoring, and the sword of Damocles over your head that things are liable to change in the near future on the governments whim' instead of you owning the solar plant you have bought.

All the subsidies the government hands out are calculated for it to cover the cost of a self-install, and then maybe a bit. So tax money (which is YOUR money) gets used by the system to support itself rather than you, even when its supporting you.

Europe can and should do more but it also leads per capita solar installs.

Europe no longer can afford to act like it's in a privileged position, and one of the things it cannot afford is to spend exuberantly for the same results others get for the fraction of the price.

And I'm saying that with the best of intentions.

> Yes, that's drive me insane, west which is biggest advocator of climate change and preaches renewable energy has not done as much as a poor country like Pakistan has done.

The "west" is not a single place and I hate that term, because it contains that "we against them" narrative, which is pushed on us from many directions in recent years. France, Germany or the USA all have a very different energy strategy, shaped by the availability of resources and geopolitics.

But for the average Joe, the situation across the globe and also in the "west" is not so different from what was described in other commments about Pakistan: People install solar on their rooftop, backyards, balconies etc. because it is dirt cheap now and amortises in a reasonable amount of time.

> EU has to do more and make it easier for them to install solar panels.

I can't speak for all countries in the EU, but at least in Germany, it's already quite easy and became even easier in recent years, e.g. private solar installations are exempt from various taxes.

The effort and money put into renewable energy in the EU is significant. In Germany around 60% of energy now comes from renewable energy [1] (Pakistan for comparison [2]), which was unthinkable 15 years ago. I remember quite well, that the fear mongers foretold, that we never will exceed 20% renewables or if we did, that the grid no longer will be reliable.

That said, you're right that the EU could and should do more. It feels like we're doing the "Energiewende" with one arm tied to the back. Unfortunately, there are many groups working against this goal by influencing the public opinion and it will stay like that for the foreseeable future.

[1] : https://ourworldindata.org/grapher/share-electricity-renewab...

[2] : https://ourworldindata.org/grapher/share-electricity-low-car...

> countries considered poor and backwards often are further along in the transition to renewables

This isn’t surprising; cell phones and mobile payments also took over much faster in Africa than Europe/US because the existing infrastructure (landlines, banks) was highly underdeveloped or unreliable.

> all but being forced to install a grid-tie system, as isolated systems (that can take but not feed back to the grid) are a legal gray area.

Isn't that exactly backwards of what you'd naively expect? Peak regulatory dysfunction.

Are these mandated systems capable of operating in the event of a grid outage? I understand that a lot of US installs cheap out on the necessary component.

Truly, you got to hand it to them. China has done the world a great service.

I really appreciate the Technology Connections take on renewable energy from solar and batteries including a recyclable component. With fossil fuels, the power plant has to be built, and then the fuel is constantly shipped in, which requires constant extraction. While solar panels and batteries can not only consume their fuel for effectively free, but at the end of their life, the materials in them can be recycled without needing massive mines for fresh glass, aluminum, lithium, silicon, etc.

In a race metaphor I'd say it is a car that has a higher top speed, is already travelling faster than competitors but is still accelerating. However it is still laps behind some competitors that had a head start.

Is that "winning"? I'd say no, but is it going to win? Yes, obviously.

I'd love for solar on my house. Unfortunately I live in a wooded valley in the northeast, first, and second, it's extremely expensive in the United States. That means that you can only take advantage of it outside of winter months (since the house will only get a few hours of direct sunlight), and that you need to pay a lot of money to get the panels and the electricals updated for that minimal benefit.

I would have loved it, but I think there's a reason why places like Pakistan has them on every roof, and in the US we're not going in that direction.

The problem solar will create is that solar doesn't work for highrises. It works for suburbs. Electricity companies will be forced (more and more) to tax suburbs for nothing (for the sun, Louis XVI-style) to keep reasonable energy prices in cities.

Unless of course, cities think ahead for once and city hall gets large solar collectors (at least the physical area) along power lines NOW.

Coal fired power stations work for high rises and for the suburbs.

Battery backed wind and solar farms work for high rises and for the suburbs (see, for example: South Australia).

This seems quite strange to claim. Basically every city in the developed world already has power plants on the outside and a lot of wires to get the electricity in

I try to be optimistic but don't extrapolate prematurely. The problem is not solar but storage and is not solved yet. I suppose the time will come that we will have to sacrifice part of the cheap solar energy to produce efuels or similar for our winters, transportation etc

almost nobody seems to get this. even if you replace conventional generators with solar, you still have to keep them around (and pay to keep them there) for when the sun is not shining, since there's currently no way to buffer the solar power.

Might be a noob question, but why can't EVs have solar panels on them directly so they can get charged just by moving around? Or why can't we have SVs(Solar Vehicles)? Why do we have to use solar panels on EV stations rather than just having them on the vehicles themselves?

There was a production car planned called the Lightyear One [0], originating from a Dutch student team, but if I recall correctly it was quite difficult and expensive to manufacture.

[0] https://en.wikipedia.org/wiki/Lightyear_0

> but if I recall correctly it was quite difficult and expensive to manufacture

More importantly, seems they stopped manufacture it because they made a new version, that was supposed to be available in 2025, but I don't think I've seen it anywhere.

> However, in January 2023 Lightyear announced that it was halting production of the 0 model, redirecting their efforts towards production of Lightyear 2; Atlas Technologies B.V., the subsidiary responsible for the manufacture of the Lightyear 0, would be allowed to go bankrupt. As of 2023, the replacement, Lightyear 2, is slated to be US$40,000 and available in both Europe and North America, and to start production in 2025.

You absolutely can .. but in order to be self sustaining vehicles need to look somewhat like the builds that appear in Australian multi day solar races - ultra lightweight, extreme streamlining, zero driver comfort, no extras like cargo space and automatic rear doors, etc.

Maybe in time efficiencies will get there.

* https://worldsolarchallenge.org/

* https://www.youtube.com/watch?v=4K0FD9Hh6XY

* https://www.youtube.com/watch?v=R_lVdrHnbYo

Addendum: addressing the [dead] comment below

> With 100% efficiency the area of the car is too small to produce enough electricity to drive.

is false - Australia has been racing solar powered cars for a good many years now, clearly they generate sufficient power to drive, just not especially fast, with any reserve energy, or at night, with any real comfort, etc.

Ok, so lets say we didn't want 100% of the energy to come from those "self-sustainable panels on the car", but rather N%, so we keep most everything as-is, except switching all the outside body/chassi panels for solar panels, how much N% could we recover from that? Could it change so someone goes from needing to charge once every 3 days to once every 2 weeks lets say? Together with re-generative breaking, maybe it could at least have some impact.

You're off by an order of magnitude. It's a few hundred watts; an EV is consuming 10s of kilowatts. (Ignore the watt-watt/hour sloppiness, pls.) To charge my car 60% would take about 2 months. Ambient needs (battery cooling) would eat up more than I'd get back. At best it extends idle sit time.

consumer car needs hundreds of pounds of reinforcement... just to pass side impact test

It’s a good question, but the reality is the energy required to power a car is far larger than what you can collect.

The solar energy you can collect is about 750W/sq meter.

A car roof is about 5’x5’, and if we are generous and include a trunk and hood area, maybe you are getting 60 sqft?

Best case if the sun is right over the car you can illuminate about 5 square meters. That’s about 3.75KW.

To convert that to a more familiar car power measurement that’s about 5 horsepower.

Hopefully it’s clear why a realtime solar car is hard.

This is not to say it’s impossible, they have been built. They’re just not super practical for everyday use.

https://en.wikipedia.org/wiki/Solar_car

> The solar energy you can collect is about 750W/sq meter.

> A car roof is about 5’x5’, and if we are generous and include a trunk and hood area, maybe you are getting 60 sqft?

We must think metric, every inch of the way!

Anyway, PVCs currently max out at about 300W / square metre - and that's in ideal conditions.

I believe theoretical maximum energy per square metre (when light actually arrives at the planet surface) is conveniently pretty close to 1000W, assuming you're in the right place, but maximum efficiency of contemporary panels is only about 30%.

Totally agree, SI units for the win!

I was just trying to use “familiar” units. I could have led with 1 HP per square yard, and then you’d totally have license to call me out!

And yeah, I was just talking about solar flux, there’s a whole lot of real world losses to consider but my point was that none of this matters, it’s orders of magnitude away from ICE engine output.

It was the fact you started using units the world knows - albeit misspelling metre - but in the next sentence, comparing that same dimension, you used an apostrophe to allude to a unit that only 5% of the planet uses.

There is a tiny image hidden at the bottom on one of the race team pages which represents an interesting effort towards a road legal solar car.

https://en.wikipedia.org/wiki/UNSW_Sunswift#/media/File:Suns...

They are now working on the sunswift 8 which is to be a combination of solar battery and hydrogen.

They are not calling it a solar car anymore apparently.

https://www.unsw.edu.au/challeng/vertically-integrated-proje...

Pure solar is indeed to much of a constraint, it make it more challenging than propelling humans over roads in an enclosure needs to be.

A big problem is sharing the road with conventional vehicles. Many could probably drive straight though it, a Tesla could probably drive straight though it.

If the car must be a strong metal container the choices quickly reduce to the things on the market right now.

I would love to see this laid out practically.

For example, if you had an electric golf cart with a solar roof, on a sunny day…

With two adults, a speed of 35 MPH, an LLM suggested a ratio of 10:1—that is, the power demands of the golf cart were 10x what the solar could deliver in real time. (LLM considered also aerodynamic drag, rolling resistance of golf cart tires…). When I suggest a speed of 25 MPH, the ratio came down to 5:1.

Regardless, assuming batteries to store energy on the cart, it suggests a 10 minute drive to your neighborhood grocery store would require the golf cart to sit in the parking lot for close to an hour before it will have caught the batteries back up to their charge before you left home. (And this is at the rather impatient 25 MPH drive.)

To get to a better ratio you would have to engineer like hell to start squeezing the numerator. Make it radically aerodynamic, low-rolling resistance tires (probably the lowest hanging fruit), cut the weight significantly…

I do love the idea of something like an electric rickshaw or tuk-tuk. Maybe not streamlined, but you could get much better rolling resistance with something like bicycle tires—and weight could be kept in check.

To make the math more complicated, you could theoretically have an unfoldable solar roof. Say you have cute, tiny one-person car with trunkspace for two bags of groceries, call that 1/9 the footprint of a "normal" car, and give it an expanding roof that can fill up a typical parking space. So you get to multiply the numbers by 9, which would mean a 10-minute drive to the neighborhood grocery store would require 60/9 roughly 7 minute charging? That's getting really close to useable, so we must have cheated a little too much with some of the "simple" math. Also probably the unfoldable solar panel ideal really just doesn't work for some reason that's extremely obvious to engineers.

> To make the math more complicated, you could theoretically have an unfoldable solar roof.

This is not completely theoretical, this guy did it on his Tesla:

https://www.dartsolar.com/

https://www.reddit.com/r/TeslaLounge/comments/194ajsm/my_tes...

I doubt that it will go mainstream, since you can only unfold it when the car is at rest. And it's permanently like having a loaded roof-rack for aerodynamics and weight. You'd always be asking - why not get put the panels on the roof of a house or other fixed structure? Easier and you can add even more of them.

I would point out this guy: https://youtu.be/ZDByoLRS9QA

I recently read about Aptera, a company building a commercial solar car:

https://aptera.us/first-vehicle-off-validation-line/

I think it is quite interesting, because it also tries to be maximal efficient, which increases the "reach" that the panels provide.

Don't get me wrong, this is a enthusiast car, but I think the economics could actually work for a small city car. Currently here in Europe, buying a electric car makes sense for home owners, which can charge their vehicle for cheap at home (especially if you PV). But a lot of people living in cities don't have a cheap charging spot. A car with solar panels, which gains a few percents of charge each day (instead of losing some), e.g. enough for the daily commute to work, may be interesting for such people.

I would love to see a ultra cheap take on this. Maybe an electric tuktuk like someone else suggested, with some solar panels slapped on it.

Aptera have been promising this product for a long time now. I'll be surprised if they ever ship.

> Don't get me wrong, this is a enthusiast car

Right, it's about as commercially appealing as a Sinclair C5.

The amount of power that can be generated from the surface area of a car is pretty small compared to how much a car consumes. And the cost hasn't been low enough compared to the value of the electricity it could produce.

Maybe someday the price will get so low it will be a no-brainer.

> Maybe someday the price will get so low it will be a no-brainer.

The cost of solar panels is already low, that's why it's booming. This cost isn't the main constraint any more.

Panels on a vehicle have stronger requirements for low weight, and vibration tolerance than those on a fixed structure. They contribute to the complexity of the vehicle's power systems. They have to be designed with vehicle aerodynamics in mind.

And of course the limited surface area means that you do all of that, for a component that's it's barely able to keep the vehicles' aircon running. The physics of that will remain the same. Even of the total costs are low (and factors such as the vehicle weighing more are an unavoidable cost), the benefits are lower.

At any price point, including free solar panels, there are good arguments to put the panels on a fixed structure instead.

So maybe it will happen when we have run out of non-moving surfaces to put the panels on. i.e. don't hold your breath.

you get too little energy vs the cost of integrating it. It gets worse considering as a driver you want to park your car in shade/garage/multistory parkings

> Might be a noob question, but why can't EVs have solar panels on them directly

This is 100% a very common noob question. The answers are therefor easy to find if you try.

https://www.forbes.com/sites/billroberson/2022/11/30/why-doe...

https://octopusev.com/ev-hub/why-dont-electric-cars-have-sol...

https://www.youtube.com/watch?v=7L1_zvqg73Q&t=590s

A much better idea is to 20x the surface area of solar panels, get ones that aren't as weight sensitive (and therefor expensive), mount them on your house or garage roof instead, and charge the EV off that when it's parked adjacent. Maybe add a battery as buffer for when the car's not there.

And it in fact has been an option on some cars, but not a popular one. It has been described as "worthless"

https://www.reddit.com/r/Hyundai/comments/tayavo/what_happen...

https://news.ycombinator.com/item?id=46456963

Have a look at this, which is a (semi) serious hacker attempt to make it a bit more practical.

https://www.dartsolar.com/ https://www.reddit.com/r/TeslaLounge/comments/194ajsm/my_tes...

He came up with a design where the panels can can unfolded for a larger surface area. But you can only do that when the car is at rest. And it's permanently like having a loaded roof-rack. Its's still less practical than mounting solar panels on the roof of a house or other fixed structure.

Aptera has this planned but not sure if they ever reach market maturity.

There also was a project car from the Nordics I think. Can't recall the name though.

Main problem is the large amount of energy a car needs vs what kind of surface area you have and efficiency we get.

An ideal (100% effiwncy) solar cell of 5m² would still need 20 hours to charge a 100kWh battery. And we are way off on area an efficiency in reality.

Well but that would be a problem for keeping the car infinitely running with only solar power. But what about just passively charging it while idle? Cars sit idle most of the time.

> Aptera has this planned but not sure if they ever reach market maturity.

Yes, Aptera does not have a shipping product, and if they ship the current design it might not have a large market for it. The have been promising delivery for a long time now, so it certainly looks a lot like vapourware.

My understanding is that when buying a car you are dealing with an oligopoly. You might think that you have a lot of options, but they all come from the same source. Furthermore, big money control not only car production, but oil too. If they allow the ceo of a car company to come with such a car, they loose billions in the oil industry. So they have no incentive to do that.

New options do appear on the market like the new toyota prius with solar panel, but if you look at it you will see that they didn't even try to maximize the solar panel size. Still it gets 2 km extra range in bad conditions. Triple that and you have 6 km, in real conditions. If you use your car every other day, you will never charge it, ever. If you get average or above sun, you can drive it daily and not charge it ever. A big problem if you sell oil.

The problem with green energy is that it is very democratic and hard to control. Nobody with big money is interested in that.

To understand who controls your life, see all the draconian measures taken against electric scooters: cheap, not poluting, democratic, don't need a lot of space and so on. Everyone with money said: we can't allow that. Write defamatory articles in the media they control, pass laws against it and so on.

> The problem with green energy is that it is very democratic and hard to control.

It's not that I totally disagree with this - there is some truth to it. But it has no bearing at all on the question "can I put the panels on the car instead?" Which has been debunked in this thread and elsewhere many, many times.

The counterargument to what you say is that Solar is in fact booming. It is coming - oil money can slow it, but not stop it. They have more success in some countries than others. It's not a coincidence that China, which course desires energy independence but doesn't have access to a lot of oil, is leading the way. Sorry USA, you're laggards now.

But solar + battery is on an exponential ramp-up and getting big now. Each shock like the current Hormoz idiocy makes the case for it even more to the rest of the world. It's coming, fast.

Just, it's not useful on car roofs. That's a poor choice of panel location.

> China doesn't have access to a lot of oil

Just an aside, but China is the 5th largest oil producer. They have a lot of oil. The problem is that they're the 2nd largest oil consumer, so are still importing. Their current course is sufficient to achieve energy independence.

It's kind of unfortunate they don't need to further decarbonize to achieve that independence. There are some other fields that aren't yet economically valid to decarbonize. If China had a non-economic reason to decarbonize jet fuel, steel, plastic etc they might drive enough volume to make them economic.

As a personal challenge, you should refrain from using the word "debunked" for a full year.

Thank you for the suggestion, and I will give it all due consideration.

Hyundai had this https://techcrunch.com/2022/03/23/hyundai-sonata-hybrid-roof...

> After baking in the sun all day, the car can add 3-4 miles to its range.

Thank you, China.

One question I have with solar is: what is the reasonable maximum it can produce as a proportion of each country's needs? Solar is the most guaranteed to be intermittent electricity source around, and can have high seasonality, too.

I live off grid, right on the 45'th parallel, and experience 4 full seasons. The solar array and battery bank I have is built from self sourced miss matched panels, and used batteries, it provides power for my house and a significant portion of my business (welding power is from an engine driven welder). In 10 years it has not just amortised it's costs, it has made me money, and qualifies as a tax right off. My up time is better than the grid. The simple fact is that solar plus batteries is a complete solution for 90% + of the worlds population. One of my side projects was to remove the alternator from the "truckasaurus" and mount solar pv as the only electrical power for starting, lights, etc. It was marginal, but I ran it that way as my only vehicle ,year round, for years. Relevant?, yes! as my experience has shown me where the margin realy is, and there has been a great deal of technological improvements and cost reductions since I built my system.

»In 10 years it has not just amortised it's costs, it has made me money, and qualifies as a tax right off.«

Great, so basically the tax payer is subsidizing your energy consumption.

Sounds like a fair system.

> Great, so basically the tax payer is subsidizing your energy consumption.

> Sounds like a fair system.

Yes, people voted for tax credits for solar/renewables. It is a fair system. You know what isn't a fair system? Fossil fuel externalities causing childhood asthma and rising sea levels requiring rebuilding coastal infrastructure globally.

Tax payer is funding a lot of resilience stuff. At least in places where resilience exists at all. GP is where emergency services will charge their radios once their generator fuel runs out. Or whoever the local community improvises as substitute to emergency services, if there aren't any. As a tax payer who doesn't have the opportunity to do anything like that I really don't mind subsidizing.

I have my quite positive experience with solar too. But "90% population" claim is unrealistic.

For starters, solar needs batteries to be truly effective. Batteries need rare-earth metals which is a narrow bottleneck. It's fine to buy 4 batteris for yourself but procuring a million will raise prices and probably break backs of many projects. A trillion, and you probably igniting wars for resources.

Also we can't multiply a homesteader's optimum a million times and expect it to be close to what a million people industrial city really needs.

At a large enough scale everything gets different.

Battery chemistries for grid storage are moving toward commodity elements and rapidly reducing reliance on rare earths. Sodium and Iron/Air batteries can take over fairly easily.

Yet the US government just asked for $200 billion to materialize out of thin air to support a needless conflict. Even if it cost a trillion dollars, that is decades of long term energy independence.

I think the key is to combine it with a strong, digitalized grid and a lot of BESS—a technology which is now getting progressively cheaper, just like PV.

https://about.bnef.com/insights/clean-transport/new-record-l...

I believe it is realistic to expect that, in combination with other renewable energy sources such as wind (which, for example, generates more energy at night than during the day), biomass, and hydropower—along with the high level of grid integration currently taking place in Europe—the share of renewable energy could reach 100 percent in 10 or 15 years. Provided there is the political will to do so.

ren will not reach 100% in EU because of necessary grid costs and plain data that shows there are continental weather patterns that VRE+bess alone cant solve. Hydro is already mostly tapped and Norway+Sweden dont want interconnect expansion

From the article:

  Researchers at the Lappeenranta-Lahti University of Technology in Finland have worked out what a globally cost-effective energy supply could look like. Based on their model, 76% of the world's energy would come from solar. Wind power would make up an additional 20%, with the rest coming from hydro, biomass and geothermal energy.

Yes, that does not really answer my question, though. A global average is somewhat interesting but with solar the situation is bound to vary widly by location. Also, does 'solar' then include battery storage?

Australia isn't Norway, there are variations in land area, latitude coverage, existing legacy infrastructure, etc. - I'm not writing a country by country break down for you - the IEA has pages per major countries that show progress and plans.

Solar includes energy storage - be that thermal, battery, hydro, etc.

Areas where solar is much less productive (e.g. Norway, Canada) tend to have lower population density, more abundant hydropower potential (which also means storage capacity) and more wind potential.

So, the ratio of solar, wind and hydro would be different under a 100% green energy scenario for them.

They often have grid interconnects to countries where solar does produce a lot, too.

The heat and electricity energy storage need to grow to 46000 TWh [1]. The current value is about 10 TWh.

[1] https://uk.eragroup.com/wp-content/uploads/2021/09/Global_sy...

That's in line with estimates being bandied about in the Finnish dissertations.

Addendum: please don't downvote @red75prime for bringing a fact to a fact based discussion.

Heat storage is quite cheap per kWh and has excellent economy of scale.

Just a note that 46,000 is a 2050 target - which covers current demand AND all the growth in electricity and heat demand over the next 25 years.

Connect enough grids and the sun is always shining.

Yeah, just build a 300 GW transmission line from the US to Europe. It will basically costs nothing.

https://www.earth.org.uk/note-on-EU-US-supergrid-interconnec...

And it absolutely won't be used by MAGA and Putinist crazies as a tool of extortion.

that's delusional if you look at EU generation data unless you suggest US-EU-Russia cable

Edit for downvotes, check https://www.energy-charts.info/charts/energy/chart.htm?l=en&... winter data and navigate through countries and tell me how sun's always shining in EU in winter and what capacity factor it can get in certain timeframes

There must be some kind of calculation generally based on latitude?

A sub-question that I would be curious about is how much climate in that region then affects the total possible solar energy. How much is the variance from a naive calculation just based on latitude?

One other second-order effect is: developed economies are heavily weighted towards places that are cold / farther north than less developed places (as a very general rule). And, a lot of people don't realize how much less energy efficient it is per-capita to make a space human comfortable year round in a "cold" climate vs a warm one.

-That's a new way of comparing economies where the price and stability of energy is better in a warm, more equator proximate location.

> There must be some kind of calculation generally based on latitude?

I am suspecting the same. Thanks for the reply, not sure why my comment seems to have ruffled some feathers...

You can look at maps of solar insolation[0] - these give you typical levels of solar input. There is of course weather variations, but the long-term trends should be consistent.

One thing that can catch me is how much more north Europe is than basically all of the USA. The general solar insolation is worse, yet they are still doing a healthy business of solar. The panels are so cheap that even if you are in a crummy environment, you can just add more.

[0] https://en.wikipedia.org/wiki/Solar_irradiance

Yes, Europe is very North. Also comparing with China: Beijing is the same latitude as Madrid.

It depends on how much generation you expect to 'waste'. Many plans are targetting a lot more generation than demand, with numbers sometimes stated as 300% generation potential for solar plus wind.

Are dw writers ok? 2000 people died due to the nuclear accident at Fukushima?

There is a lot of FUD regarding nuclear power in Germany, don't be surprised.

"There have been no deaths or cases of radiation sickness from the nuclear accident, but over 100,000 people were evacuated from their homes as a preventative measure. Official figures show that there have been 2313 disaster-related deaths among evacuees from Fukushima prefecture." https://world-nuclear.org/information-library/safety-and-sec...

Only if you front load a lot of regulatory and fictitious “externality” costs onto the alternatives.

I am confused. The article claims that solar is the best, cheapest source of power. It also claims that the Trump administration is undermining it in the US by cutting federal subsidies.

If solar truly is the cheapest, why does it need any help from any government? It would seem to me that it should flourish in any capitalist society where money naturally flows towards the cheapest solution that actually works.

Solar still makes sense economically in the US without explicit subsidies - that's why it is still getting built.

But the Trump admin is also with-holding permits and cancelling long distance transmission that would allow it to reach non-local markets. The fossil fuel industry is also sponsoring astro-turf campaigns on the local level to ban new deployments.

Long distance transmission is part of the cost of production when the location of the production is non-local to the consumption.

With-holding permits is stupid, as are bans on new deployments, but neither are subsidies. You can cut subsidies to zero and at the same time give out all the permits people requests.

The USofA is a broligarchy not a capitalist society, so there's that.

Trump has his thumb on the scales, cancelling wind farms in progress via executive order, not cancelling the federal subsidies for fossil fuels, etc.

There are always transition overheads to breach - in China the government there subsidised the non existant EV industry into being, now that's going gang busters the government support has dropped back to near zero.

Broligarchy is the natural end stage of unfettered capitalism. We've arguably never been more capitalist.

> cancelling wind farms in progress via executive order

He is going to pay them $1B to drop their plans: https://www.npr.org/2026/03/23/g-s1-114868/trump-totalenergi...

Only if they give that money to the fossil fuel industry ... bit of an important detail in the context of US energy subsidies and thumbs on scales.

  Environmental groups denounced the deal as an alternate way to block wind projects, with one group calling it a "billion-dollar bribe" to kill clean energy.

  "After losing again and again in court on his illegal stop-work orders, Trump has found another way to strangle offshore wind: pay them to walk away," said Lena Moffitt, executive director of Evergreen Action.

Where at the point in the transition where the level of subsidies, if any, determines the speed of the build out.

The question is: how early do you retire existing thermal power plant?

There's the theory and there's the real world

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