Engineer's solar panels are breaking efficiency records
spectrum.ieee.org
spectrum.ieee.org
It’s so easy to forget this and the massive scale and its relevance at the massive scale of the systems we need to (and are, to some extent) roll out. It also seems promising when these breakthroughs are happening in R&D groups of industry players trying to dogfood it rather than in labs.
At the same time though, it’s starting to feel to me, to some extent, like we have kind of solved solar? It’s everything else around it that needs to advance, particularly grid infra, batteries and electrifying the general class of difficult-to-electrify problems (steel, concrete, freight). I might be totally off-base and blinkered with that assessment.
Edit: I guess I should try to clarify my feeling after reading some of the responses below: it feels like solar tech is not really the limiting factor in renewable scaling, and that advances in solar efficiencies won’t drastically/meaningfully simplify the other challenges/limiting factors we currently face (grid infra/batteries, electrification of mfg, duck curve, etc). Children point out that space and cost savings from efficiency gains in solar may still be significant at grid scale though! Still, this is very cool progress to read about!
We won't be able to transition fully off of fossil fuels until we do
LFP batteries commonly used as stationary storage regularly do 2000 cycles.
Makes more sense to use that gas to make more batteries.
Combined cycle is a major reason that gas power plants are so attractive; the inability to use it in Peakers is a reason why they are so unattractive.
How much longer? If a plant is designed with a big priority to getting secondary generation up to speed quickly, how many hours will it need to warm up?
Currently a lot of peaker plants operate a bit like "A power line failed, we need extra power NOW!" They get essentially zero warning and are expected to be at full power within 30 minutes. Dealing with that obviously leads to some issues, but in 2024 we could also fill that niche with battery storage.
When it comes to the energy transition, it's a bit of a different problem. We can reasonably predict weather, so the rough output of solar and wind is known several days in advance. If the forecast is predicting an overcast day with zero wind, any "peaker" plant will have tens of hours to warm up. Combine that with minor changes to reduce startup time[0], and it seems far less of a hurdle to overcome.
[0]: https://etn.global/wp-content/uploads/2018/09/STARTUP-TIME-R...
I assume you meant professional consumer.
> See for example triple pane vs single pane windows.
Bad example but I understand your point. Bad example because it takes significantly more expertise to model the savings from triple paned window with low-e coating and vacuum sealing vs double paned vs single paned (ie it requires a proper building energy model in eg EnergyPlus). Also bad because the triple paned window might be immediately disqualified by the budget constraint above. In any case, I think you are just saying people are likely to pick the thing which has the least friction, whether that friction comes from cost, installation challenges, etc etc.
And yes, sometimes upfront cost is the most significant thing which affects people’s willingness to adopt a certain home energy retrofit but payback period does play a big role in people’s decision making, as well as their ability to get funding for it (government rebates), or they may simply be going with an installer who pays them to install it and they certainly care about payback period!
I'm confused by this as that is exactly the point made. :)
I was watching a NASA iTech talk if memory serves about vacuum windows. He opened with an overview of the market and adoption trends and was quite flustered. Small market, little in the way of R&D and many challenges in manufacturing them in the US.
One of the things that flustered him is being told by sales reps that those types of windows are "pointless and not worth it" and so on. Digging deeper the reason he was steered away from them is simply because they were up not as lucrative to sell in that moment at time for that provider. I can try and dig that up if you want as I recall this anecdote vividly and my thinking diverged from yours in that moment.
Turns out most people have no idea what any of it means you see? So indeed friction, perverse incentives, financing, lack of consumer education and so on. Some terribly sad amount of people still opt for single pane instead of double which shouldn't make any kind of sense.
Remember also that people often move houses. Anyway the upfront cost ended up dominating rather than the payback period. Folks aren't that rational or liquid.
Out of curiosity try modeling it out and pitching it as a choice if you know anybody looking;
Chinese panels <20% efficiency, cost X, payback period Y vs Unobtanium panels 25% efficient, Cost X+, Y++.
But don't try to steer them or mention the payback period unless asked. It isn't as straightforward as we would hope.
Sorry, I was trying to indicate that it is significantly simpler for a random uninterested or mildly-interested consumer to evaluate the cost-effectiveness of solar than it is windows. Most people have a good sense of how much their energy bill costs, and there are plenty of cheap and free tools which let you accurately estimate how much energy you will save from a PV system, but even basic mental math is enough. As opposed to windows, which are significantly more complicated because they involve thermodynamic modeling of your home.
You should read recent work by Zachary Berzolla, who is now working in Maryland’s department of energy on their commercial buildings decarbonization program. His MIT PhD dissertation is specifically about willigness-to-pay for home energy retrofits (but especially heat pumps). Not sure if it has been posted to DSpace yet but I believe some various conference/journal papers are online already.
So, they don’t know how much their power costs, and they don’t have a clue how much solar would cost to buy, install, run, etc… and how that compares to the payback period over time, etc….
These are the people that I think we need to reach.
On the other hand there are a significant number of people who are energy-burdened, and they often have the most inefficient homes (leaky or non-existent sealing, little insulation, old appliances, etc). These homes often have the least ability to take advantage of government rebates since they may only be tax rebates while the retrofit still requires up the upfront cost to be paid. At the same time, high-income homes, though often much more efficient, also often use the most energy (since floor area tends to grow with home owner income, and space conditioning/electric requirements tend to grow with floor area). It’s easy to design incentive programs which have a big carbon impact but a bad equity impact in that they just end up giving money to people who would already be upgrading their homes without the rebates.
The person who knows just how much money they are spending on their bill every month will likely value the savings much more (ie the utility value of the savings are much higher), but they may also have far less awareness of the kinds of programs available to them for retrofitting their home or installing PV.
It’s a complicated problem, figuring out who to reach and how to drive adoption while balancing decarbonization and equity!
Jevons Paradox is conjecture, not immutable law. Consumption based energy usage has been on the trend downwards in western countries for some time. Much of this is explained by efficiency gains (e.g., LED lighting, OLED screens, smaller chips, heat pumps, etc.)
https://ourworldindata.org/grapher/consumption-based-energy-...
the jevons paradox certainly isn't an immutable law
It's hard to disentangle the rise of wealth in the world from increased consumption caused by cheaper energy. Certainly in the west capacity has become larger and...
> the link doesn't show that even that cherry-picked measure is falling
If you look again, they absolutely are.
Peak vs now in Mwh: US: 105 (2005) vs 97 Norway: 93 (2008) vs 78 Sweden: 69 (2001) vs 57 Australia: 80 (2011) vs 55 Germany: 63 (2006) vs 59 France: 61 (2005) vs 54
I could manually do this for the rest, but I shouldn't need to. You can see it for yourself. Here's the chart as line graphs (this option isn't obvious in the UI)
https://ourworldindata.org/grapher/consumption-based-energy-...
The only outlier I see here, in terms of developed countries, is South Korea, but that's perhaps as the country is still unevenly developed. In terms of developing countries, we of course see the uptake of HVAC, refrigeration, vehicles and other automation appliances to match the living standards of the developing world. But crucially, developed countries are showing that at the highest living standards, energy consumption is coming down.
that's the chart i was looking at. you're cherry-picking years as well to get that answer. looking at all the years instead, the usa starts out at 94, peaks at 104, dips down to 87, and then rises back up to 97, with lots of wiggles in between. that isn't a picture of a secular decline in energy use, it's a picture of random fluctuation around an average. the others are largely similar. the main outlier among 'developed' countries is not south korea but the people's republic of china, though slovenia deserves a mention for falling 40%
why? what holds the usa line so steady? probably partly the usa has lost the ability to build not only high-speed trains, subway tunnels, highways, and leading semiconductor fabs, but also electrical infrastructure, but two thirds of energy use is non-electric, and other countries are succeeding in building trains and whatnot
the price of energy has not been holding steady during this time but rather going up, although in the last decade that is starting to reverse. perhaps the reason consumption-oriented energy use has gone slightly up rather than way down is the efficiency improvements you mention
[the following paragraph is completely wrong, and i appreciate the correction from h0l0cube. therefore so is my claim that the measure itself is cherry-picked. i had just misunderstood it]
this measure, incidentally, doesn't count energy used for exports at all. so if the us and japan are producing an energy-intensive good independently at the beginning of the chart, and then in the middle the us starts importing it from japan, the usa's line will go down while japan's remains steady, because japan's added energy use is for export rather than for consumption. that's what i mean about it being a cherry-picked measure even for those cherry-picked countries
Literally, it does. It's consumption-based energy usage. It's trade adjusted
> the usa starts out at 94, peaks at 104, dips down to 87, and then rises back up to 97, with lots of wiggles in between. that isn't a picture of a secular decline in energy use, it's a picture of random fluctuation around an average
The trend line is at best a flat line. Here's a picture of energy usage per capita over a longer timespan (inc. prior to the 80s when offshoring of manufacturing and cheap shipping came into play)
https://ourworldindata.org/grapher/per-capita-energy-use?tab...
> the main outlier among 'developed' countries is not south korea but the people's republic of china
As I mentioned this is due to it's growing wealth, not the greater economy of power. Even though China has been growing phenomenally in GDP, it's GDP per capita vs consumption-based energy usage is going down (or yet to exceed 2011 levels):
https://ourworldindata.org/grapher/change-energy-gdp-per-cap...
thank you for the correction; i had misunderstood what the trade adjustment was
> The trend line is at best a flat line
i think that is an excellent description of it, as well as of the expanded and less debatable chart you link here, at least over the last 50 years, since the energy crisis began. before that we were seeing a much different trend
i agree about wealth being the primary driver of energy use. but that's precisely the story jevons tells: you improve your steam engine to use less coal, so now you can build a railroad, which is a form of wealth. previously a tonne of coal cost £100, say, and produced 30 megajoules of work, which had a value of £200 in pumping out a mine or £50 hauling goods on the railroad. with your new engine you improve efficiency to 0.3,% and get 100 megajoules, so pumping out the mine now costs £30 per £200 produced, but now the railroad is viable because it produces £50 - £30 = £20 net. the railroad consumes much more coal than the mine did, so you're using more energy more efficiently at the level of the machine, raising your gdp, but producing less value per tonne of coal
well, i got the numbers a bit wrong, but hopefully you can see what i mean
That's not what I meant. I was referring to the development of populations. Populations that didn't have what the global north would call 'the basics', electricity, household water/sanitation, lighting, adequate heating/cooling, refrigeration, as well as 'basic luxuries' like television/computing/internet and personal transport, increasingly now have access to these technologies (even in 'underdeveloped' countries). This is going to increase energy (not just electricity) usage. But once 'the basics' have been met, they will already be in line with the efficiency standards adopted by the west (maybe even moreso because energy is more expensive in the global south)
So, a counterargument might be that AI will become part of our 'basic' lifestyle, and that we will see a resurgence of demand again, but we're seeing that cloud based compute is acceptable for the vast majority. So even though, say, internet search was energy intensive at its inception, it has largely been amortized and itself energy optimized to not really raise the bar of energy usage. Custom silicon, tighter semiconductor nodes, newer algorithms, photonics, and eventually yet-to-be-discovered technologies like room temperature super conductors can again bring the energy usage down for compute, increasing efficiency not just for AI, but across the board.
things that already exist but could get much cheaper due to cheaper energy might include ai, as you suggest, but also personal computers, oocyte cryopreservation, ecm machining, space travel, weekly air travel, personal helicopters, atmospheric carbon capture, caribbean cruises, making things out of aluminum or titanium instead of plastic, cnc machining rather than casting or stamping, cars, buildings, photovoltaic panels themselves, etc. and presumably there are other things that haven't been invented yet because they'd be uneconomic
Anyone who remembers how pervasive CRTs (later rear projection, and plasma TVs) and incandescent bulbs were, can sense that things are far more efficient around the home. Better standards for HVAC (using heat pumps vs heating elements) are a big deal. A big driver of this has been large buildings where the cost reductions from efficiency can mean millions saved. Business errs towards efficiency. Another driver is that the more efficient stuff also seems to just be better too (like OLED screens)
We also have chips that run on about the same energy (or even less) and provide far more compute than 2 decades ago. Looking further back the ENIAC used 174kw of power for 0.005 MIPS (5000 additions). By comparison an M1 has 2.6 TFLOPS (2.6 trilling floating point operations) for 40-100 watts. My cores are mostly idling. In fact most of my computer usage happens on my phone which runs on far less energy still.
Then consider energy for transport. In the last 5 years, telecommuting has become so normal that fewer people are commuting to work, particularly cities.
not all consumer energy prices are rising, and the situation you describe where the producer captures the whole consumer surplus only happens in the absence of competition
jevons says people will compensate for more efficient tvs by buying more and bigger tvs, and for more efficient hvac by building bigger houses, living in hotter areas, and installing air conditioning in more spaces. this has been a major trend of the last 25 years you're talking about, in fact
similarly, it's true that the amount of energy per flop is going down, though not nearly as much as you might think; on the cpu it was about 2000 picojoules 30 years ago, and closer to 500 picojoules today. (the numbers you give for the m1 would work out to 16 picojoules, but the real numbers are even better. 2.6 teraflops is the graphics card, which uses 11.5 watts, which is 4 picojoules per flop. most computers lag far, far behind that in efficiency.) but the amount of energy spent on computers keeps going up and up
Collusion is the norm. Especially with electricity suppliers where they jack up the rates because most people won't be bothered to check for better deals and switch.
> jevons says people will compensate for more efficient tvs by buying more and bigger tvs
Doesn't matter if the efficiency gains outcompete the consumption increase (which is my whole point):
> As shown in the graph below, between 2006 and 2012 the average energy consumption of televisions dropped by 57%, while at the same time average screen size increased by 30% and average price decreased by almost two-thirds.
https://appliance-standards.org/blog/why-recent-progress-tel...
> for more efficient hvac by building bigger houses, living in hotter areas, and installing air conditioning in more spaces. this has been a major trend of the last 25 years you're talking about, in fact
McMansions became a thing leading up to the 2008 financial crisis, and was a feature of cheap finance, not energy cost. Most people want a house that's affordable, close to amenities and doesn't take an army of servants to clean – so a house in the suburbs and within distance of the city. The factors here are land price and construction costs.
> but the amount of energy spent on computers keeps going up and up
Might be true, but it would be nice to see some data to back that claim.
a 130% increase in tvs per person would cancel out the 57% reduction you cite in power per tv, and presumably if you measure over any other period of time, the energy consumption drop won't be that large, because that was the crt–lcd transition, but screens had been steadily getting bigger for decades and have continued to do so. if you include computer monitors with tvs, it seems likely that the increase over the last 25 years is a lot more than 130%. certainly it is in public places (dentists' offices, intercity buses, airports, restaurants)
people have been building continuously bigger houses for centuries; it's not a phenomenon limited to zero interest rate mcmansions. suburban sprawl is one well-known manifestation of it as for computers, unfortunately i don't have the data here at the moment. you see handwringing about it from time to time. i'd like to see it too
Is each person watching all these TVs at once Matrix style?
Even if you've got your laptop, iPhone and iPad all unlocked and playing videos while watching your TV, it's not really adding 30% of energy use compared to the 50 inch TV.
> certainly it is in public places (dentists' offices, intercity buses, airports, restaurants)
TVs in airports, bars, diners, buses, and dentists offices have been around since the 80s. The difference now is that all their CRTs are replaced — a clear energy drop. (Source: own experience, also you can watch movies from the time)
Lit billboards have been around for a long time, but instead of massive lamps, they are just LED screens. Tokyo used to be all fluorescent bulbs, now LED screens again. It might not be like for like, could maybe be an energy increase, but public-space advertising is the best argument you've got here, but I don't buy that it's a huge driver of energy growth.
> you see handwringing about it from time to time. i'd like to see it too
I've provided plenty of data to back myself, and to suggest otherwise is disingenuous. Given the amount of claims you're making without any supporting evidence, I can only think your argument is based on conviction, not fact. I'll let you have the last word here.
i've seen many more tvs in public places in recent decades, often replacing things like flip-dot displays or printed menuboards. mcdonalds now displays their menus on a wall of tvs instead of printed on plastic, for example
it's disappointing that you've chosen to attack my integrity, but it seems to be based on a misunderstanding. i have not claimed that you have not provided data. on the contrary, i have found your data highly informative and educational. i only meant that neither of us has convincing data about total computer power consumption, and that i would like to
the price of energy has started to fall again in the last ten years
And the situation with embodied carbon footprint. Which we pointedly do not talk about.
We should practically get to the point where someone can buy a roll of material at Home Depot and unravel it on their roof, nail it, and plug it in themselves.
At least in countries with strong regulations around working with electricity this is simply not going to be feasible.
I've been in the PV business for some time now and seen a person get killed by it. It's not pretty. Still remembering that smell of burnt flesh... Now, to be fair, that was at a 12MW-installation, not on a roof. But still...
What happens to a PV panel, receiving sunlight, with no load?
Does it degrade or suffer ill effects in any meaningful way? Or does it just have a potential between its outputs but otherwise isn't impacted?
At least in Germany, every PV installation of certain size (> 30kW peak) is mandated to be able to be shutdown remotely by the carrier if you supply electricity for the net and aren't just using it for yourself. (You get paid the same during shutdowns, just like it were running. Otherwise it would be quite damaging and likely reduce adoption of PV)
Point being: no, it doesn't hurt the panels and is a regular ocurence.
Which means that in winter, probably nothing, because it's cold, but on a hot summer day with peak sun, the heat might start damaging the cells. How much exactly you'd have to look at studies.
My guess is the output will permanently degrade by a few % per year if the panel is not connected. Might go down to 80% way quicker than normal (25-yr)
Solar panels are not constant-power devices. In an open circuit, they will generate their open circuit voltage at nearly zero current (except minor internal leakage), and thus nearly zero power. In a short circuit, they will generate nearly zero voltage, and thus also nearly zero power. To get maximum power out of a solar panel requires maximum power-point tracking (MPPT), where the load is adjusted such that the product of voltage and current (that is, power) is optimized for the current conditions; while significant power can be delivered to a fixed load, there's no real power being generated without a load.
And since heat radiates away at temperature to the fourth power, the increase shouldn't be particularly much.
Alternately, power can be expressed as V^2/R. But in an open circuit R is infinite, so again, zero power.
So as long as manufacturers engineer their panels to be tolerant of the maximum heat at a site (i.e. full sun, maximum temperature), the panels won't be harmed in any meaningful way. They'll just heat up a bit faster than if they were providing current.
PV panels are just like charged capacitor or a chemical battery with no loads: just holding unused potential differences with no damage to the unit.
BTW: installing solar panels DIY is apparently super easy, as I found out. I have a flat roof and used micro inverters, to make it easier, but I was done in less than a day (excluding selecting the components and layout)
I just installed 7.3Kw on my roof, and another 600W on the roof of my Jeep.
You'd have to physically stick a screwdriver into an MC-4 connector to get zapped, which is as smart as sticking one into an electrical outlet.
I don't even understand how you could get zapped plugging in MC-4 connectors.... like, at all.
As part of our daily lives, a great many of us climb into a steel box powered by explosions and packing a 20 gallon container of flammable liquids (and increasingly several hundred pounds of also flammable batteries containing more electricity than an average family uses in a week) and then pilot that box at 80Mph down a strip of concrete packed with other large high-speed objects containing flammable liquids. Occasionally, we run low on flammable liquids in our high-speed metal box and get to refill the flammable liquid container ourselves at a flammable liquids depot, which contains upwards of 40,000 gallons of the flammable liquid delivered by other larger high-speed metal boxes which also share the same strip of concrete with us.
So: I'd expect some product safety iteration here before we get to the "roll out your own solar panels", but no, I don't consider that a non-starter.
It’s not like that stuff springs up overnight!
and the end user doesn't just cut as much as they need and nail it down - the things are practically disposable appliances at this point.
PV installations on roofs typically have around 10-20kW peak output.
Let's go with 10kW. That's around 25 panels, each outputting 30V with something like 13A. Small installations are typically single-stringed, so you end up with a voltage of 25*30V=750V with 13A DC. That's pretty likely to kill you within milliseconds if you mess up.
There's a reason that stuff tends to be handled by professionals. It's a ridiculous (and pointless) risk if you aren't well educated about it and have some experience.
I'm not saying it's a future we should want :)
But isn't that kind of how super chargers work?
Of course, until all our grid hook ups are smart, we'll probably need electricians at some point.
That said, the point of "do it yourself" is that you'd nake it less dangerous for ordinarily folk. So the risk of shocks would come down.
What would concern me more is long-term fire risk. If not installed correctly, with the right spec parts etc, proper grounding etc, there's a significant risk of fire. Not immediately perhaps, but a couple years down the road.
Again DIY kits would need to be designed with this in mind.
What's the qualitative difference between 16 amps at 120V and PH v DC? Either is enough to kill a person if mishandled, and yet Home Depot sells breaker boxes over the counter.
It's funny to look at electricity from the same perspective.
And using the metal box creates toxic fumes that we inhale, which are deadly to every living thing on it.
AC power crosses the zero line twice per cycle while DC does not. AC has a lower ‘let-go’ threshold, but DC contracts your muscles and makes it harder to let go.
You are correct though, if you de-energize your panelboard and have a deadfront cover over the line side conductors and lugs, working inside a panelboard (or on electrical wiring) is safe.
And the other important part is that 60Hz needs fewer amps than DC to be dangerous. https://www.allaboutcircuits.com/uploads/articles/electricit...
And if you want to talk about power lines, then the neighborhood medium voltage lines are going to be roughly the same in most places within the same jurisdictions, and distinct from the true high voltage lines that are used for long distance transmissions.
If a 120V 15A supply puts 50mA through you, then a 120V 100A supply will also put 50mA through you.
A supply that's "5000VAC at a 1.0 nano amps" really means that it starts at 5000 volts but super rapidly drops to zero volts as it conducts. A household supply is going to have negligible voltage drop by the time it turns deadly.
Edit: The other way to put it is that 99.9% of supplies don't give you a certain number of volts and amps. They give you a certain number of volts and they have an amp limit. If you're not approaching the amp limit then the only thing that matters is the volts.
My point is that the number of amps you can get from the circuit is irrelevant, it's "more than enough" and that's all you need to know beyond the voltage and the exact way the human is being exposed.
400 ohms at 110 volts = 275 ma. More than lethal. 30 watts.
400 ohms at 220 volts is double that - a bit over half an amp. Lethal (obviously). 60 watts.
400 ohms at 1500 volts is 3.75 amps - 5.6kw. Enough to physically cook someone pretty quickly.
If Lidl can do it, why can't Walmart?
https://www.lidl.de/p/vale-balkonkraftwerk-minipv-800-et8-l-...
Essentially, any notable installation fundamentally deals with much higher currents and voltages and as such is much, much more dangerous. Once a certain size is reached, the carrier also has to be involved and professional installation is mandatory, both due to the law and requirements by insurance companies.
At least here in germany. I've been involved with building all kinds of PV installations in bavaria, from 4kwp up to 20MWp. The balkony generators aren't taken seriously by anybody in the industry right now, at least.
If you're working at that size, I'd expect you to ignore balcony systems regardless of how cost-effective they were.
My point here is simply and only that it's possible to make a system safe enough that an untrained and unskilled member of the general public can just plug it in and use it, which is exactly what was being called for up-thread with this:
> We should practically get to the point where someone can buy a roll of material at Home Depot and unravel it on their roof, nail it, and plug it in themselves.
Germany basically has that (even if it's not in the form of a roll); there's nothing fundamental preventing the USA from having it too.
They're sold for apartments, and as DIY jobs. They're designed to fit on a balcony just about wide enough to stand on, and to be installed without needing an expert.
The point of the example is to show that you don't need an expert. It's not even trying to show a specific unit that suits all people, just that one thing, that you don't need an expert to install it.
The voltages are the same regardless, because that's how domestic electricity works. (If you forced me to guess, I'd expect grid-scale PV farms to go direct to a higher voltage than domestic users, but I'm not an electrical engineer).
Don't get me wrong - I'm pretty committed to DIY a decent system, but it's not trivial and what you posted is just a toy.
The law in Germany may prevent you hooking up ten, but that's not relevant to the point or the market.
Can Americans even hook up things this size on their rental apartment balconies?
> Plus without proper meter (or CT "limiter")
Difficult term to search for, so I'm unsure what that is exactly. I get links about inverters, and I'm sure you noticed this comes with one so it's probably not that.
And this relates to the impact of module mass on (supposedly) preventing DIY installation (despite my example of a DIY installable system) how exactly?
It's very common to need licensing to do something commercially but not when doing it for yourself.
I'd be satisfied if I could simply sit the licensure exam and maybe have to pay extra to do some kind of practical demonstration. Local requirements for residential licensure include documented multi-year experience as an electrician's helper before you can even apply to take the exam.
Ironically batteries is what makes it feasible - I can dump excess into battery instead of paying 3x more for install so I get hooked up to grid in a certified way.
And "sneaking around local restrictions" can create quite the fun surprise for unsuspecting workers who need to open up walls, dig trenches, etc.
I hope you decide to play by the rules.
[1] https://spectrum.ieee.org/amp/perovskite-2667580324-26675803...
And I say it as someone who's researched them at EPFL in Michael Graetzel's laboratory.
I don't think the technology will ever be efficient and most importantly stable as needed.
Perovskite is a family a materials by the way so many of these issues can be sortened out.
I'm overall just skeptic.
Have no knowledge in this field but if your solar panel material degrades in light that would seem to be an insurmountable problem to me.
Or if you get it slow enough.
https://www.nrel.gov/docs/legosti/old/5703.pdf
"Recycling of glass does not save much energy or valuable raw material and does not reduce air or water pollution significantly."
Square footage (aka surface area) and installation surface challenges are.
Roof mounting is expensive. Supporting snow and wind loads is expensive.
Reducing dead weight is only going to help a tiny percent, as even if they weighed literally nothing it would not meaningfully change the load calculations.
Any structure designed to withstand 100 mph winds (typical in mild areas with no hurricanes or strong gusts) needs to be able to handle 25.6 psf - or 704 lbs - per panel just from wind load. Roughly 10x the panels weight.
In most of the US, add on snow loads from 20-100psf or more. I’ve installed panels in areas with 150psf design snow loads.
In the 150psf snow load area, that meant an additional 4125 lbs for that same 500 watt panel, each. Or about 58 times the weight of the panel. Steep angles (30 degree or more) can allow reducing that, which is a good idea.
So for instance in that area if not mounted very steeply, the racking needs to be able to support 71 lbs (panel) + 704 lbs (wind) + 4125 lbs (snow) per panel. Or 2.5 tons, give or take, for each 71 lb panel.
The panel is about 1.5% of the weight in that scenario.
And that is with no safety factor.
Now the roof has already been designed to bear these loads of course - but not as point loads randomly through the roof deck. So whatever anchoring/racking needs to transmit the forces effectively into the roof in a way it can handle without letting water through, and hopefully without making it impossible to maintain the roof either. And if in an area that freezes, without giving areas for ice to form and jack the roof/panels apart.
That isn’t trivial.
What do you think about the implications for transportation, maintenance and land use? I have zero idea what the balance of those costs would be for a grid-scale solar farm, but ostensibly going from let’s say 20% to 21% efficiency means you need 5% less land, weight to transport from factory to site, fewer panels to inspect/build/install, fewer to purchase, etc.
I’m sure someone else has a better idea how much it would affect the LCOE than I do!
Generally though, solar projects are go/no-go due to things like cost of money and electrical sales pricing agreements + site specific variables like insolation, flatness/road access, cost of local labor, local weather impacts on racking costs, access to transmission, and bulk wholesale costs of materials.
It’s hard to beat flat land out in the open desert near major urban areas with nearby highways and transmission lines, for instance.
What you’re talking about is likely at most half a percent of that equation.
Thank you. So often when discussing solar (or EVs) we see bizarre extrapolations of potential install rates that don't account for the fact that huge swaths of the country (the majority of places here in Canada) have real challenges with installation. These are not insurmountable, by any means. But those challenges are reflected in overall cost, making some of economics less favourable.
In my experience, the panels themselves are at most 1/4 of the cost of any given system, even when discounting labor and permitting costs.
If they want it to happen and aren’t greedy? It’s rarely a major problem. Otherwise, sky is the limit.
I know of a couple sizable projects that finally got cancelled because the local AHJ (authority having jurisdiction) finally just got too greedy. In one case they threw on an extra couple hundred grand worth of city park improvements as a requirement on a couple million dollar (small) project. Developer ended up walking away, as that was the fourth time they did that.
Some folks just can’t help but make it lose/lose.
Most large scale installations (if they’re smart) will be in areas where the planning authorities don’t have a lot of leverage.
Most residential installations (if they’re smart) will be in areas where it’s politically untenable to squeeze homeowners for outrageous fees.
Then you have the other places.
Either way, even large fees for a larger installation will be a small percentage of the total. $2000 worth of fees for a homeowner will be outrageous percentage wise.
That said, it's not like one thing is dependent on the other, so good to see efficiency increasing regardless.
https://podcasts.apple.com/us/podcast/volts/id1548554104?i=1...
The “solar is the cheapest form of energy” is a marketing gimmick. If it were true free market forces would already gone 100% solar because the purpose of energy companies is to make money.
Point being it is those areas that will need to be solved (i.e. come down in price) and that marginal improvements in panel efficiency aren't the limiting factor in going to 100% renewables.
EVs might be cheaper than ICE cars now (including energy expense over their expected lifetimes)... But that doesn't mean the free market should be 100% EVs (all of a sudden).
So it's not competing for land against say buildings or agriculture.
Now sure, the owner of the roof may want some rent etc, but that really doesn't alter the cost of the energy, it just spreads the benefit.
At first sight, it seems economies of scale would make it easier to have one company handle a solar power station, rather than now having to pay expensive home solar panel loans and maintain them.
And 2 solar panels only make 2x as much energy if exposure is the same. So go where the sun is already done if the sun is above your head.
solar is different to say coal, because the economics of home-generation, and grid generation are not miles apart. In other words it's not like I can have a coal-fired power station at home, but I can have solar panels. Up to now electricity generation has been constrained to large-scale (hydro, coal, nuclear etc). The advent of solar, and to a lesser extend small-scale wind and hydro, makes local generation more accessible.
>> rather than now having to pay expensive home solar panel loans and maintain them.
Solar maintenance is minimal. (Again, not like a turbine generator.) Loans are a function of capital. It takes capital to populate a home roof, and capital to build a power plant. If you have no capital then the point is moot. As an individual I have enough capital to fund my solar system without loans. (I get about a 14% return on that capital.) I don't have enough capital to fund a power station.
Other benefits of home generation include more resilience should the grid fail. So for example, after a storm, power lines may be down, but I get electricity during the day. That's a bonus though, not the main driver.
So to answer your question - it's not either or, it's both. There's a lot of roof-top solar in my city (measured in gigawatts), there's also solar farms generating power.
Lastly' I'll point out that distribution _from_ my house is cheaper than from a plant, because I generate a few spare kw, and the wire already coming into my hose is sufficient for that. So no new (grid) hardware is required.
Not that it matters to your point, but you can, they're just awful — there many reasons why everyone moved away from heating homes with open fireplaces.
(My current apartment in Berlin is old enough to have a chimney, but there's no unit attached to it; likewise the house I grew up in back in the UK has a chimney, but it was bricked off since before I could remember, possibly before I was born).
For heating this does not matter.
Utility scale farm might be ~$1/Watt for installation. https://www.nrel.gov/solar/market-research-analysis/solar-in...
Residential is ~$3/Watt.
Commercial rooftop is somewhere between but still more expensive than a solar farm. Rooftop has the advantages that it delivers where the load is, and there are often subsidies available, plus some marketing kudos. But if just considering land cost by installing rooftop instead of solar farms is usually not an economic tradeoff.
And note that agrivoltaics (dual use solar+agriculture) is more expensive than pure solar farming: https://www.pv-magazine.com/2021/03/26/cost-comparison-betwe...
Installation costs are going to depend a lot on your location, roof type and to an extent size.
My (residential) install (9600w) was around 60c per watt.
Ymmv
Utility-scale solar PV comes in anywhere from $24/MWh to $96/MWh
Unsubsidized residential rooftop PV has an LCOE between $117/MWh and $282/MWh,
the LCOE of community and commercial and industrial (C&I) solar ranges between $49/MWh and $185/MWh.
When factoring in federal tax subsidies under the US Inflation Reduction Act, including domestic contest provisions, rooftop PV comes in at $74/MWh to $229/MWh, and community/C&I rooftop PV at $32/MWh to $155/MWh.
I guess the viability of roofs depend on the construction techniques in your area. In my experience roof's here have plenty of extra load availability, and I'm not sure what effect the panels would have on water.
In my area something like 5GW of solar has been installed on rooftops, and that has moved the needle.
And of course land availability varies a lot by country.
YMMV.
"Solar and battery storage to make up 81% of new U.S. electric-generating capacity in 2024"
Not saying it’s a bad thing, but I don’t buy that any company is being fooled by this.
Infrastructure takes time to roll out so the timeframe of solar is maybe 10-15 years before we see 50% of the worlds power switch to solar. If the 10-15 year estimate is true, this would be a breakneck speed for such a fundamental infrastructure change.
I’m not going to speak on whether solar truly is the cheapest form of energy as I have no idea whether or not that is the case. But I’m going to suggest that one of your premises is wrong: we don’t have a true free market in energy — see all of the subsidies that gas, oil, and coal companies have gotten (for quite some time).
Yes, solar gets subsidies, too, but comparing a relative newcomer to entrenched players makes this a lot less clear of a picture than you’re painting.
Macro-demographically, with more people moving in to apartments globally, the residential roof thing is more a temporary western thing than a utility scale solution to global residential macro energy needs. The Chinese know this better than anyone.
The true economics of industrial processes are rarely clear to consumers.
Every PV installation I've seen uses heavy blocks of concrete to keep the panels from taking flight in the wind. The panels themselves are already very light.
We have examples of this kind of situation in poor countries where the grid wasn't developed in the first place, and rich people use generators.
Get more panels, maybe some batteries.
Additionally, the winter might not have a lot of sun, but it usually does have quite a bit of wind. Build a combination of solar and wind power, and you've solved the biggest issue. The rest can be picked up by hydro and gas peaker plants (short-term), or battery storage and other new technologies (long-term).
Here’s a figure to demonstrate that:
https://www.researchgate.net/figure/Monthly-output-from-sola...
Any basic irradiance analysis of a surface in any day lighting simulation software will clearly demonstrate this.
Additionally, in winter, the peak energy usage will often be well past sunset in many locations around the world (and it will get even more pronounced with heating electrification). This is why batteries+wind will be very important.
The day is roughly half as long but you get 40-50% per month ???
Really a lot more than I imagined.
Not sure if that involves changing the angle.(which would complicate things)
It isn't a popular or sensible technology atm but sterling or other heat engines do work and they work even better if there is a cold source. There are experiments with heating water with solar voltaic. I read they are reaching 70% energy conversion.
It seems there is lots of room for further tinkering. 40% isn't bad tho
At the same time, even if we do solve those issues, and we get solar panels on the roof of every home, there are still significant challenges to overcome as it’s unlikely the average home can become fully energy independent (especially if there is electrified winter heating), and anyways, the energy demand from single-family residential housing is only one slice of the overall energy pie. In any case, it would certainly help if we did that!
These days, the only place it makes sense to put PV is flat on unused or unproductive land. The 95% drop in PV panels means that it is no longer economic to bother with mechanical tracking in solar farms. Integrating panels into a domestic roof destroys the incredible cost advantages PV has over alternative power sources.
It looks like I'll make about $1000 of power per year, so I have an 8 year payback, after which I'll have free power for another ~20 years.
How on earth does that make "little economic sense"?
> “In a base comparison, without considering subsidies, fuel prices, or carbon pricing, utility-scale solar and wind have the lowest LCOE of all sources. Utility-scale solar PV comes in anywhere from $24/MWh to $96/MWh, while onshore wind registers the lowest possible LCOE over the shortest range, from $24/MWh to $75/MWh. Offshore wind’s LCOE ranges between $72/MWh and $140/MWh. … Unsubsidized residential rooftop PV has an LCOE between $117/MWh and $282/MWh, while the LCOE of community and commercial and industrial (C&I) solar ranges between $49/MWh and $185/MWh. When factoring in federal tax subsidies under the US Inflation Reduction Act, including domestic contest provisions, rooftop PV comes in at $74/MWh to $229/MWh, and community/C&I rooftop PV at $32/MWh to $155/MWh.” [1]
[1] https://www.pv-magazine.com/2023/04/14/average-solar-lcoe-in....
1. You need to take into account depreciation of the value of the panels. They degrade in performance and eventually will be worthless after about 30 years.
2. You need to take into account inflation against the CD roi (or conversely the /appreciating/ value of the dollar value of the energy produced by the panels). The post-inflation value of the bank CD is going to be about 2% per year. Inflation does not need to be corrected for the solar power option because it produces energy instead of dollars.
(1000/y-8000/30y)/$8000 = 733/8000 = 9.1% depreciation-adjusted ROI from solar panels
5.5% - 3.3% inflation = 2.2% inflation-adjusted ROI from bank CDs.
So solar panels are about a 4x better investment than bank CDs, contrary to your comment where they are somewhat comparable.
bank cds do not pay a reasonable discount rate, it's true, but there are investments that do. maybe a nice index fund balanced with a money market fund?
you should also take into account the precipitous drop in electricity prices starting 10 years from now
Just comparing expected value is fine as a stopping point in your thought process if you are risk neutral — in that case, you should buy leveraged stock funds to maximize your expected value.
If you are like most people and assign some internal cost to risk, then covering your innate short position on power while also getting 9% return on investment after inflation is a no-brainer.
> Still might be worth it to you, but also might not.
Are you trying to be intentionally obtuse?
With your numbers you're talking about putting $580 a year into my bank account for 14 years, and then me having free electricity for at a minimum another decade.
In what possible world could that be "not worth it" ?
so your utility company is probably going to make four times as much energy per dollar invested in solar panels as you are, unless you're in the usa, so they can sell it to you much cheaper than you can make it yourself
so probably if you'd put the $16000 or whatever into the stock market it would yield more than enough to pay your electric bill for those 30 years or actually forever
the panels won't wear out in 30 years either, though, and the reduction in risk may be worth it to you
I agree they can make it cheaper than me, but I don't think your second conclusion follows.
What they will do (and ARE doing) is simply increase their profit.
My utility company has already approved rate increases for the next 5 years (7-12% per year), and it has increased every year for the previous 10+.
So for me, the cheapest way to get electricity is to make it myself from my own roof. I made 933kWh in May for a bill of -$56.
There are many metrics that affect power generation (or anything really). A few are:
- Power generation per unit area
- Power generation per unit mass
- Power generation per dollar
- Lifetime
- Decline rate (ie does the cell get less effective over time?)
- Flexibility (eg can you wrap it around a cylinder)
- Minimum size
- Maximum size
- Cost to repair
Where a given solar panel fits in the above vector space will change its applications. In some cases, size is paramount. In others, cost is paramount. Sometimes you need long-lived panels. A good example if solar panels for space probes. These need to be generate as much power for as little weight and it doesn't even really matter what the cost is. Also, making such a panel last 30 years might be irrelevant if the lifetime of the mission is 5-10 years.
So no, I wouldn't call solar "solved".
That may take a while, but immediately though, cost-effective solar shingles would be so much better than wasting material/labor of 3 layers. Tesla roof and GAF Timberline have products, looks like GAF costs the same as other materials with tax credits. But if this can get cheaper, its a gamechanger.
This is 300W, works out to be 0.75 cents/Watt, which seems decent? Also, they show videos of heavy equipment driving on it. Which means they can be laid flat on the ground, with very little support structure. They can be laid out on parking lots. There must be reasons why this isn't widespread yet. I wonder what those are.
(edit) This post says panels are 15 - 20c/Watt: https://news.ycombinator.com/item?id=40703758
solar cells that can survive being driven over do exist, but they only survive a few months of being driven over, which is why they aren't widespread. a much more sensible way to put solar panels in parking lots is to mount them above head height, which is relatively cheap in non-snowy areas. this has four big benefits over putting them on the ground:
- they last 60 years instead of 60 days
- they produce power even when cars are in the lot
- they provide shade to people and cars
- they can be angled toward the sun, increasing yield
hope this is helpful!
Maximum insolation is about 1kw/square meter. Assuming a very favorable TOE/kwh equivalent (11.6 mwh/toe) and 150-225 tons of fuel oil a day, we’re talking energy consumption of 1.7-2.6 gigawatt hrs per day to power a container ships main propulsion.
Assuming very favorable 10 hr insolation times, and 25% solar conversion efficiency, you’d need something like 680000 square meters - or 168 acres - worth of panels to even come close. Even with 100% efficient panels, it would be over 43 acres worth.
A Panamax container ship is only 2.3 acres in size, which equates to 9.5 megawatts of solar insolation peak.
So you’d need between 20-73 times more surface area, and very favorable conditions.
Not to mention batteries to smooth all that out. And a chance of storms. Or not having panels aligned perfectly.
Fossil fuels are incredibly energy dense, and these ships have to burn insane amounts of them already in very efficient ways to do what they do.
I would not hold your breath for the typical consumer panel to improve much beyond 20%-25% any time soon sadly.
It does generate a lot of hopeful breathless articles which rubs me the wrong way. It is important to stay realistic in the search for solutions.
Solar is already great and cheap and there are lot more wins possible in the actual deployment as most of the cost is now overheads, bureaucracy, labour, 'etc.
The more exotic designs which often are the subject of breathless articles (e.g. perovskite https://en.wikipedia.org/wiki/Perovskite_solar_cell or other multi-junction cells) can get greater efficiencies (like up to 40% for quad junction) but are a lot more expensive from a lifetime cost perspective (they don't last nearly as long as silicon junctions and are much more expensive to produce.)
When can I expect that to be?
The biggest challenges are storage, and - in the UK at least - nimbyism. (Yes people really object to solar panels in fields.)
The other thing I would say is that the software for solar inverters is way behind where it could be. You could easily get a 10% improvement just by making them smarter - e.g. using time series prediction, day ahead pricing, etc.
Unfortunately they're stuck in the stone ages. I have a QCells inverter (rebranded Solax) - do not buy btw - and they directly told me they are not interested in any of this smart stuff.
They also do automatic firmware updates with no opt-out and no notification of changes. And the updates include removing features.
Do not buy QCells solar! (Hopefully Google finds this.)
My favourite feature is called peak-shaving where it uses the battery to supplement said crappy rural power or a generator that is provisioned for average load instead of peak.
I haven't found inverters with similar features and configurability anywhere else thus far.
The relatively high efficiency figures often touted for some spacecraft panels especially in low earth orbit don’t compare apples to apples as they include the additional 70-80% solar radiation that isn’t absorbed, reflected or scattered by the atmosphere.
There are some spacecraft that do use multi-junction cells with very high efficiency however those are ones which are sent far into the outer solar system like Dawn and Juno.
It would be the worst outcome possible - the beauty of solar is that it lasts for 40-50 years while only having to replace inverter / maintain the system.
Thankfully commercial grade and investors wouldn't bank on that.
You might not have to replace the solar panels themselves except on a 40-50 year basis, but if you’ve had to replace everything else that’s been exposed on a more frequent basis, I would have to ask Mr. Theseus how much of that solar system is really the same, and how many of those costs would have to be re-incurred over that longer period of time due to the shorter life span of the other products.
Most roofs aren’t even built to code, which is supposed to be the floor below which building quality cannot go. Instead, they build to whatever they can get away with, and in many places, that is much lower than code because the building inspectors are busy and don’t check, or they’re careless, or they get bribed off.
In most single family homes, the more you learn about the construction of your specific house and what standards they were supposed to build to but didn’t, the more horrified you will become.
Like the builder leaving out a $2.00 piece of flashing because either they didn’t care, or they thought it was too expensive. Of course, the result of that $2.00 flashing not being there is tens of thousands of dollars of damage that occurs to your house over the next decade-plus, for which your insurance company will pay precisely $0.00, since it’s not the result of a single catastrophic event.
The competent and conscientious builder is the rare unicorn these days.
This tracks with what I see. A couple houses on my block get their roof replaced every summer
The US is geared more towards lower up front cost. Neither is inherently wrong.
There are also feedback mechanisms where the most common option becomes cheaper, and the specialty more expensive.
Why pay 3x for something that lasts 3x as long? What if it lasts less than 3x as long? I don’t know which actually has a better Long term route.
I imagine most of it comes down to price sensitivity and owner demographics. Rich Americans often have ceramics or other roofing, presumably because they can afford it and would rather not deal with it.
I’m raising a new building this winter and will certainly go with shingles based on my budget.
https://www.pv-magazine.com/2024/06/13/commercial-perovskite...
That change is itself a 25% performance improvement (over the 20% baseline), meaning you need significantly less space and potentially weight/labor to install. Obviously we aren’t making that jump all at once.
Here in Germany the government recently approved incentives for balcony solar. These are cheap panels that you hang (zip ties) from your balcony railing and then plug into a wall socket. No need for approval. These things are exempt from rules intended to protect the look of buildings.
The idea is that that puts a little bit of power on the wires in your home and that that is enough for things like your fridge to run off. It partially runs of your solar instead of grid power and lowers your bills a bit. Even a few hundred wh of capacity can already make a difference. You can level up the experience with a portable battery. Of course don't expect miracles from setups like this but if the cost is low enough, why not?
Why do I mention this: no professional installers involved at all. You order these things on Amazon or wherever, plug them, in and done. You can get a battery to go with them as well. A friend of mine got himself some panels and he's definitely not an electrician. His balcony is tiny and partially in the shade. I doubt it's very effective. But it didn't cost him an arm and a leg.
There's no good technical reason for bigger solar setups to be much more difficult. You can get setups for your garden shed, country house, boat, etc. and it's all relatively easy and straightforward DIY stuff. It's only when these things get connected to the electrical grid and installed on roofs that a lot of rules start applying and a lot of bureaucracy kicks in. Often for good reason like fire safety. But it's gotten way out of hand in a few countries and the cost bares no relationship to the complexity of the problem.
Got a pointer or two to English-accessible descriptions or products ?
That would be the raw energy budget. It seems unlikely to me that these processes would require more than 3 MWh additional energy for a system of this size compared to the baseline 24% system, but that’s just on vibes!
At the same time, it’s probably better to view it in terms of carbon, in which case the situation changes a little bit. You would need to know how carbon intensive the source power production is for the manufacturing process, and additionally how the grid decarbonizes: if the grid decarbonizes substantially due to (eg) massive wind scale up and deep geothermal breakthroughs, then the efficiency gains from PV aren’t as valuable in the future from a carbon perspective as they are in the year 2025.
If a person came by my house and said, "Yo, I can do an installation!". Those panels are like running on a 10 year old or greater design and process.
Being able to deploy 50% more panels now is more important than being able to deploy solar panels that return 10% more electricity.
I really like tesla's idea of solar roofs and how they implemented them. They need to be lightweight and cheap. Easy to replace.
If they’re hitting 25% are we close to that limit?
Single junction solar cells are limited to 33.16%. https://en.wikipedia.org/wiki/Shockley–Queisser_limit
Increase the number of junctions and that goes up. Ultimately with infinite layers you can’t beat ~68.7% on earth and 86.8% when much closer to the sun.
Maybe solar cells based on chemical reactions or [insert science things here] can do far better, but right now semiconductors is what everyone sells.
If it's a question of the intensity of the sunlight, can't you just focus it with a lens?