No, we have not. Half of the current cost is due to installation and labor, so any weight reductions will have a huge impact on cost. Perovskite solar cells have the opportunity to have a 10 X weight reduction.
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.
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.
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.
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...
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.