Why do I keep getting $20k quotes to install it then in the US. We seem to be doing something incorrectly here. The underlying hardware seems cheap (through independent research) but the labor and add in fees seem to be making this expensive. At sub $10k prices for the panels + batteries I would get it yesterday.
izzydata · 2026-10-26 15:37:52 UTC
I suspect a huge chunk of that is labor costs rather than materials.
dalyons · 2026-10-26 15:46:01 UTC
Labor costs even more in Australia, yet total systems are installed for about 1/3rd - 1/4th the cost of the US. It’s not labor.
BobaFloutist · 2026-10-26 17:37:02 UTC
>Labor costs even more in Australia
This is really surprising to hear. Are you sure about that?
tstrimple · 2026-10-26 21:39:37 UTC
Australia's minimum wage is significantly higher than in the US. An adult working as a burger flipper at McDonalds can expect a minimum of $27.81 / hour.
dalyons · 2026-10-26 23:59:47 UTC
yup. not just the minimum - skilled labor costs are very high too.
Schiendelman · 2026-10-27 03:09:44 UTC
It is labor. It's code. The amount of labor required to do an installation to code in the US is easily 50% more, if not more than that. Australia also has standardized streamlined racking that works on much higher percentage of roofs, the US has a lot more custom construction.
MSFT_Edging · 2026-10-26 15:38:50 UTC
From what I've heard from people who've done deep dives, most solar installers in the US are essentially financing scams. The component costs have come way down, it's still essentially screwing things into the roof + a few hours from an electrician.
The real money is convincing marks to take the financing for 20+ years.
dalyons · 2026-10-26 15:50:10 UTC
If that were the only reason, you’d surely be able to find someone who undercut the bloated financed costs and do a straightforward labor and materials install. But no such cheaper options exist
rootusrootus · 2026-10-26 15:58:02 UTC
> But no such cheaper options exist
None? Project Solar? The last time I seriously looked at doing rooftop panels, they were significantly cheaper than the door-to-door jerks.
dalyons · 2026-10-26 16:31:46 UTC
i did get a quote with them. Its still 3 times (!) the price my parents paid in australia. not exactly apples to apples, but whats going on?
rootusrootus · 2026-10-26 18:14:47 UTC
To my understanding regulation explains most of the difference. And it will vary a lot from place to place -- your experience will depend largely on local government policy and what your grid provider requires in order to establish the connection. E.g. locally I'm kinda forced to go with one of the power company's blessed installers. Cha-ching! If I understand Australian regulations, they tend to be more uniform nationally, there is less bureaucracy to drive up costs.
dalyons · 2026-10-26 23:58:20 UTC
california adopted part of australia's regulatory framework - required all counties to adopt an instant online permitting for solar, through a unified portal (SB 379). Didnt seem to help costs much.
There's probably more to the regulatory problem than just the permits i guess.
lightedman · 2026-10-26 15:58:25 UTC
"But no such cheaper options exist"
Untrue, at Sunspark we sold to both individuals and companies. If you can install the stuff yourself, buying it direct from the manufacturer is ungodly cheap (~330w panels at $80 a piece when I worked there almost decade ago.)
dalyons · 2026-10-26 16:35:34 UTC
yeah, ive looked into DIY. As you say, even with tarrifs its pretty cheap to buy the panels and inverters. Which makes the installed cost even sillier, > $15k markup for a 2 day job.
rdtsc · 2026-10-26 15:58:38 UTC
Unless there are enough marks for everyone to scam. Then the focus is to extract the money instead of investing in crushing the competition.
myphpgothacked · 2026-10-26 15:58:41 UTC
This makes me want to start a solar company.
AI can't take my job then.
One indicator is that third world countries can seem to afford it.
rtkwe · 2026-10-26 16:00:58 UTC
Depends on many factors. If installers are able to fully fill their available time and crews with jobs at the current price and expanding is limited by the availability of new crews high prices could be a stable equilibrium until a) more crews become available/techniques improve to speed up install times or b) demand relaxes and they need to drop their price to find sufficient customers.
There's also other factors like the overall cost being beyond people's willingness to save for when financing is available or the extra value that financed installs can provide the underwriters when they're bundled and sold as a stable income stream like houses were in the mid 00s.
"If it can be done cheaper someone will" is based on a lot of simplifications and assumptions about the market in question.
ghusto · 2026-10-26 16:02:07 UTC
Not necessarily. There are little-known monopolies like the eyewear, travel agencies, and cargo fuel (there are many more!) where price fixing like this happens.
fatbird · 2026-10-26 16:15:23 UTC
I call this "the capitalism fallacy": it doesn't exist in the (my) market, therefore it's not possible.
The fallacy is that there are infinite market opportunities but a finite supply of entrepeneurs/business/money to exploit them. Therefore, there are an infinite number of market opportunities that will get passed up for one reason or another.
rconti · 2026-10-26 16:00:07 UTC
No, the cash prices are insane too. I paid cash for my system.
Qworg · 2026-10-26 15:38:53 UTC
For the same reason you don't have a small coal power plant in your backyard - scale matters.
dataviz1000 · 2026-10-26 15:58:37 UTC
This makes me think of the Franklin Pot Belly stove we had in the middle of the living room growing up and the coal bin in my back yard having to go out there on cold winter mornings to bring a bucket in.
toomuchtodo · 2026-10-26 15:38:59 UTC
Residential solar in the US is very expensive, $3-4/watt versus utility scale closer to $1/watt. The cheapest residential solar options are community solar if your state and utility supports it, or a ground mount system.
The biggest cost components are sales and marketing expenses and similar soft costs. Some of this can be driven down if you collectively buy through something like https://solarunitedneighbors.org/
(have installed 100kw+ of residential solar, ama)
ramesh31 · 2026-10-26 15:56:44 UTC
How can the numbers ever work? $15k pays my electric bill for a decade. I get that it amortizes beyond that, but it's a heck of a sunk cost that just doesn't make sense IMO.
toomuchtodo · 2026-10-26 16:01:53 UTC
Because your electric bill goes up every year as the utility keeps asking for return on equity (assuming investor owned utility, math might be different if you're in an electric coop). A solar PV system will produce power for 25 years at a minimum at a fixed cost. Like a mortgage that is fixed versus rent that is not.
It's the equivalent of a bond investment with potential subsidies at the utility, state, and federal level (solar is no longer subsidized, but batteries still are).
So long as the roof itself lasts that long. People who are mid-cycle on their existing roof should not install solar until they get to the next replacement. This is where I am, and why I do not have rooftop solar. I expect to get 15 additional years from my roof, and there's no guarantee I will have hit the break even point by then. Plus, solar installers will not warranty a mid-cycle roof against leaks, so if something goes wrong that quickly eats into your cost savings.
rcxdude · 2026-10-26 16:33:39 UTC
It is also cheaper to get it installed if you're already doing a roof replacement. Especially if you're getting built-in modules instead of retrofit, since they replace some of the roof surface instead of going over it.
toomuchtodo · 2026-10-26 16:35:22 UTC
Indeed, the best time to install is during a roof replacement. If one can afford it, standing seam metal roof, racking mounted with friction mounts (deck penetrations are the enemy and to be avoided whenever possible, to prevent future water intrusion), and the entire system (roof deck and panels) should last 40+ years. Last roof and solar you put on for your life for many of us.
BobbyTables2 · 2026-10-26 16:06:01 UTC
Especially if a once-in-a-decade freak hailstorm can take it out…
toomuchtodo · 2026-10-26 16:08:58 UTC
Solar panels are rated to handle 1 inch hail at 52mph (IEC 61215). Damaged panels can be easily replaced, and are typically covered by your homeowner's insurance.
- Every panel sold in the U.S. has to pass an industry-standard hail test, which fires ice balls at multiple points on the panel and requires no visible cracking, delamination, or more than a 5% drop in power output afterward. Companies like UL Solutions, an applied safety science company, test solar panels by dropping a two-inch solid steel sphere from 51 inches onto panels, simulating the impact energy of serious hail. Panels that survive without electrical hazards earn certification for real-world deployment.
- The proof is in the pudding—or in this case, the parking lot. When a severe hailstorm hammered the National Laboratory of the Rockies' (NLR) (formerly National Renewable Energy Laboratory (NREL)) Colorado campus in 2017, just one single panel out of more than 3,000 suffered damage. That's a 99.97% survival rate against Mother Nature.
stevekemp · 2026-10-26 17:14:43 UTC
I have a cabin in the woods, an hour from my house, my choices are either install a couple of solar panels on the roof, or have no electricity.
I'm looking forward to installing a couple of panels on the roof next year. Having power to charge my phone, or laptop, won't take much capacity, I'm not going to use much power other than that, maybe some music but nothing like cooking/heating, or similar heavyweight usage. (I have a wood stove for heating, and gas/alcohol stoves for cooking, along with on-site water.)
lightedman · 2026-10-26 16:10:30 UTC
"Residential solar in the US is very expensive, $3-4/watt versus utility scale closer to $1/watt."
Yea, if you go to an installer instead of buying from the OEM and installing yourself. I likely made your panels at SunSpark (We made panels for everyone, Renogy, Juinko Solar, Samsung, etc.) They were sold for $80 at 330w - 4.125 watts per dollar, or a quarter per watt.
Solar isn't expensive - you are.
toomuchtodo · 2026-10-26 16:11:06 UTC
> Solar isn't expensive - you are.
I am not a commercial system installer, I am a hobbyist enthusiast who helps others install to avoid commercial installers and their costs. Volunteer labor for everything (racking, panels, electrical), volunteer electrician signs off for any AHJ (authority having jurisdiction) requirements.
Most people cannot install the equipment themselves, which leads to the residential costs I mention. Is it expensive? Price is what you pay, value is what you get. If you cannot find someone to install for free, and cannot do it yourself, the price is the price. You can either choose to pay market rate after getting multiple bids, or choose to go without.
(i am also a community outreach volunteer for https://www.gosolarapp.org for automating permitting and remote inspections across the US, which was incubated at NREL prior to being spun out as an independent non profit; this drives down permitting soft costs)
lightedman · 2026-10-26 16:49:35 UTC
"Most people cannot install the equipment themselves"
This is highly untrue, until you get to the task mounting on a roof. Barring that, making a solar array system is dead simple. Most anyone can turn a screwdriver or build a frame or connect very distinct connectors together (they just snap together for daisy-chaining solar panels) or insert a power plug into a NEMA receptacle (for balcony solar installs.)
It is the install on the roof itself which most people cannot do (because they lack roofing knowledge.) Every other thing is absolutely DIY by pretty much anyone with hands and eyes.
toomuchtodo · 2026-10-26 16:55:07 UTC
> It is the install on the roof itself which most people cannot do (because they lack roofing knowledge.) Every other thing is absolutely DIY by pretty much anyone with hands and eyes.
Literally the most important part is what most people cannot do. If you have the space, sure, ground mount. Most people do not have the space, nor are they going to be confident in putting penetrations in their roof deck to mount racking to hold the panels.
From what I understand, the going price is AU$5K in Australia. (USD3500). A small portion of that is scale since solar roof is far more common in Australia, but most of it is "doing something incorrectly", as you suspect.
dyauspitr · 2026-10-26 21:59:40 UTC
If you had this option in the United States, you would have people fighting in line to be first
Arubis · 2026-10-26 15:44:55 UTC
The regulatory overhead to grid-connect is a _significant_ portion of the price, both for the actual paperwork labor and because of the premium it imposes on the system components (you can't use inexpensive non-UL-listed panels)
benrutter · 2026-10-26 15:46:13 UTC
Is this really a thing in the US? At least in Europe, rooftop solar like OP mentioned doesn't require grid-connection?
nemomarx · 2026-10-26 15:50:14 UTC
Only some states allow simple plug in roof top or balcony solar I believe. So depending on your area you might be required to do a grid hookup and lose access to it during outages.
linsomniac · 2026-10-27 14:05:52 UTC
Nevada has started allowing it, and other states are starting to allow it in Jan 2027. However, these all rely on equipment that meets standards that equipment is not yet certified for (UL 3700). It's a bit of a waiting game in the US right now.
dyauspitr · 2026-10-26 20:11:20 UTC
Net metering hasn’t been allowed in my county in more than two years so that can’t be it.
benrutter · 2026-10-26 15:45:02 UTC
This is a good question - there are fairly high imposed tariffs on solar in the US[0] but I think the labor is the big part. Over here in the UK, solar installation would cost about $12k dollars, so quite a bit cheaper, but still not below $10k.
One thing that isn't super obvious from the article is that a lot of it is talking about industry solar panels rather than rooftop. The overheads of installation etc get a lot smaller if you're installing a whole bunch at once.
This isn't to say that installing solar panels on your house is a bad idea - they normally pay for themselves after something like 10 years from memory, so are similar to double glazing.
Rooftop solar costs 3x more per watt than utility scale. The only reason it would pay off is that you're able to avoid grid maintenance costs built into per-kwh pricing.
KerrAvon · 2026-10-26 16:03:28 UTC
Rooftop solar (ideally with battery backup) allows you to be independent of the grid (yes, even if you're interconnected, if you do it properly), which means PG&E's garbage infrastructure can largely become irrelevant if your system is properly sized.
pfdietz · 2026-10-26 16:04:43 UTC
Which is gaming a particular kind of rate structure. They would not do nearly as well if grid maintenance charges were decoupled from consumption.
blitzar · 2026-10-27 06:19:00 UTC
Residential electricity pricing is 3x-4x wholesale pricing.
rootusrootus · 2026-10-26 16:02:53 UTC
> they normally pay for themselves after something like 10 years from memory
I would guess this varies by locale, and people usually assume the time value of money to be zero when they make the claim. In much of the US, I think the payback time is more realistically in the 15-20 year range, which means you really only want to install panels when you install a new roof. Otherwise the lifetime of the roof will happen before break even on the panels.
rdtsc · 2026-10-26 16:03:42 UTC
> This isn't to say that installing solar panels on your house is a bad idea - they normally pay for themselves after something like 10 years from memory
I am with you, this would be better on a town or regional basis instead of on everyone’s roof. Our houses already have wires going to them and I can’t imagine my particular roof or garage is the best place to put panels and batteries. But I understand it’s a political / administrative issue which may well be not solvable easily in many places.
dv_dt · 2026-10-26 15:58:25 UTC
Many private utilities in the US have fought against residential solar, and are seemingly motivated to act against it as something against their long term interests. In California the amount of Public Utilities Commisssion retrograde policy is ridiculous.
eppp · 2026-10-26 15:59:46 UTC
Just dont expect net metering and get yourself some batteries. They are cheap now.
eppp · 2026-10-26 15:59:06 UTC
I diy installed a 13kw ground mount with a 32kwh battery for $18,700 before the tax rebate last december. 6 year payback at my current rate of $0.12 kwh after the rebate. Its a complete no brainer at this point.
carlosjobim · 2026-10-27 01:46:49 UTC
6 years to recoup your costs on a depreciating asset is maybe not such a good investment that it becomes a no brainer. It's an OK investment, but the money can probably be invested better.
jeffbee · 2026-10-26 16:00:21 UTC
Distributed solar is cute and it sometimes benefits some people but it is pointless for national policy to pursue it. As you pointed out, the cost structure of small distributed solar is dominated by office overhead, sales, management, insurance, litigation, etc etc.
adverbly · 2026-10-26 16:02:14 UTC
Don't confuse grid solar with on-prem
On-prem has a problem of distributed labour costs.
On-prem might eventually become cheaper, but my guess is that won't happen any time soon.
For the time being, centralized and at-scale installation is where you can get much, much lower labour per watt costs.
jillesvangurp · 2026-10-26 16:50:10 UTC
If you want to look at a place that is comparable to (parts of) the US that manages to do things about 3-4x cheaper, look at Australia. They seem to have stumbled on something that works ridiculously well. You can get a quote and stuff installed in something like a few weeks at most. It's done right and efficiently without a lot of bullshit.
Other places (like the EU and especially the US) have regulatory problems around anything to do with energy. This is mostly about ass coverage resulting in a lot of pressure for certification, related fees, grid operators insisting on a lot of overhead, building codes requiring a lot of faffing about for the business of wiring together what is essentially plug and play stuff, etc.
If you have an off grid shed, providing power to it is cheap and easy because you have none of that. You buy the hardware on amazon or wherever. It arrives, you wire it up. Job done. And if you are smart you might let a qualified electrician do it right for you or at least check your work (so your shed doesn't burn down and nobody dies from electrical shocks). But fundamentally it's not that hard and this stuff is mostly pretty safe and easy to work with. Especially compared to the things people burn down their sheds with traditionally (e.g. generators).
There's a lot of optimization potential here and most of that is completely non technical.
Havoc · 2026-10-26 15:36:35 UTC
More stoked for when the same is said for storage.
Solar is cool but solar that can make it through the night and a couple cloudy days is way cooler
- Battery energy storage has grown at an exceptional pace, with global installations increasing more than 20-fold in storage capacity over the past five years. This growth has been driven by falling battery prices, abundant supply and relatively short project lead times. As variable renewable generation expands in many markets, battery storage is becoming an important source of flexibility and resilience for power systems, while also representing a growing commercial opportunity for battery manufacturers.
- However, more than 90% of battery storage applications rely on LFP batteries that are almost exclusively supplied from China, which accounts for almost all global manufacturing capacity and the associated technical expertise. Korean producers are investing to scale up LFP battery production that can offer an alternative, but they face intense competition from established, lower-cost Chinese producers in an oversupplied market.
- Battery storage now accounts for around 18% of installed dispatchable capacity in Australia, compared with 7% in China, 5% in the United States and 4% in Europe – underlining how rapidly batteries are becoming an important part of the electricity systems in some regions.
Battery storage is right behind the solar adoption curve. Net zero in five years? Probably not. Ten to fifteen years? Almost assured considering rate of change and the overall economics (assuming ~1TW/year of solar PV deployment and enough battery storage to soak up that low carbon generation while also providing grid services to replace thermal generation grid support [voltage, frequency, etc]).
(China is curtailing renewables equal to the annual combined generation of Spain and the Philippines every six months, and India about ~100-120GW/month due to not enough battery storage, for example)
I am desperate to find a battery inverter that can be used to supplement my existing grid-tied home solar setup. I only need about 5kW and 10kWh of batteries, but everything I can find is geared towards whole-home power at like 12kW. Way way more than I need. I understand I’m in the minority and there’s probably not a market, but I’d love to find something
toomuchtodo · 2026-10-26 16:00:39 UTC
Unfortunately, the market is somewhat bifurcated between what Anker, Jackery, Ecopower provide and stepping up to Base Power, Powerwalls, and other bigger system components.
My recommendation would be to see if Ecopower storage and inverters are a good fit for your use case. If you're feeling adventurous, you could build your own battery pack, but I only recommend if you are knowledgeable and confident. This comes with substantial property and life safety risk, only proceed if you know what you're doing and understand the risk (I'll work on my high voltage EV battery packs, but only with a helper nearby holding a 2x4, for example).
Transparency: I live in a 240v land, I have a Siggen.[0]
Not sure whether other brands could be better but there seem to be various options that would suit. If you are in 120v land you may need to check if there are models to suit.
Its largely modular, inverter sits on top of modular batteries in 8-9kw chunks.
But they are app-infested. IE wants a wifi connection, app on your phone to their servers... etc etc.
I hate it, but the wife likes it. This is a recent thing so I am still working out if there are possible solutions for privacy and control over my own objects.
I pulled it apart and found an Ethernet plug and it was a complete game changer.
But: the app and their servers remain.
pfdietz · 2026-10-26 15:56:43 UTC
Diurnal storage is solved by batteries. Longer term storage will very likely be solved. For several days, cheaper batteries (perhaps with lower specific power). For longer periods, either thermal storage or e-fuels.
ben_w · 2026-10-26 16:24:56 UTC
My guess is seasonal will be handled with flow batteries. A big tank and cheap-ish electrolyte, with the expense being in the electrodes sized for whatever max power is required. Tanks good for multiple cubic meters worth of liquid storage aren't exactly difficult to find, nor to place in a garden.
Flow batteries might be ok for a week or so, but their market window has been shrinking as Li-ion has gotten cheaper.
The technology I'm most excited about is ultra low capex thermal, as being done by Standard Thermal. Capital cost per unit of energy storage capacity as low as $0.10/kWh(th), so it can work with seasonal storage and just a few tens of charge/discharge cycles over its lifespan.
Standard Thermal has raised $11M and is building in Germany, where they say they can deliver 365/7/24 solar resistive heat (400 C or perhaps 600 C) for half the cost of heat from burning natural gas there.
cyberax · 2026-10-27 02:53:26 UTC
Flow batteries keep coming up again and again, but they just don't work well in practice. The power density of electrodes is too low to be practical, and this is a fundamental problem.
A regular 18650 cell has about 0.1 square meters of electrode surface. And you have thousands of these cells in a car battery, resulting in literal football fields of electrode area.
TheCoelacanth · 2026-10-27 15:53:08 UTC
Seasonal will be handled with wind-power (tends to produce more power when solar is producing less), building extra (power being too cheap in the summer is a great problem to have) and long-distance power transmission (plenty of sun in the southern US or southern Spain even in the winter).
ben_w · 2026-10-27 16:15:58 UTC
Those all help, to be sure. Personally, in my "if I was king of the world" fantasies, I'd make a global power grid. Aluminium production is actually high enough already for genuinely antipodal connectivity at 1 Ω, though it could also be grown fairly easily if this needed to be done faster than a timescale of decades or it turns out 1 Ω isn't low enough resistance. Main limit is global geopolitical issues, hence "if I was king of the world".
pfdietz · 2026-10-27 16:39:03 UTC
Wind certainly helps, but there's a question of what will happen to the relative cost of wind and solar in the future. Solar seems to have a steeper experience curve.
bryanlarsen · 2026-10-26 17:25:04 UTC
Agreed, e-fuels seem to be far and ahead the front-runner.
We can get to 95% using just short term storage. I suspect that most jurisdictions will just say "95% is good enough" rather than paying for ridiculously expensive long term storage.
We've got the nat gas capability already; keeping it around for the 5% is quite inexpensive, making the massive investment in long term storage for marginal benefit hard to justify.
OTOH, while the premium for e-fuels seems excessive, if you're only running that nat gas plant 2 days a year that premium is not so scary.
pfdietz · 2026-10-26 17:53:31 UTC
> Agreed, e-fuels seem to be far and ahead the front-runner.
For covering Dunkelflauten? Yes.
For seasonal storage with a prolonged discharge (so, low power/storage capacity ratio)? I think thermal storage wins there.
bryanlarsen · 2026-10-26 18:04:48 UTC
Sure, thermal is great where it's possible. But there aren't that many places where district heating is viable.
pfdietz · 2026-10-26 18:07:07 UTC
I'm not talking about district heating. I'm talking about high temperature storage for conversion back to electricity. Round trip efficiency could be around 40%, better than green hydrogen burned in combined cycle plants.
bryanlarsen · 2026-10-26 18:42:56 UTC
Standard Thermal's website's front page only covers heat delivery; did you mean to link to somewhere else?
Those are 2 very different use cases.
Thermal is low rate extraction. It's 1 cycle per year, but the extraction is performed over months so is low rate.
Electricity long term storage is high rate extraction. It's only used a few times a year, but when it is used it needs to cover roughly 100% of the entire grid's needs. I doubt thermal storage is suitable for high rate extraction, but I'd love to be wrong.
Edit: rereading your parent comment you seem to think thermal is suitable for a different use case? Could you elaborate further? When is "prolonged discharge" useful?
pfdietz · 2026-10-26 20:47:15 UTC
That's what they're focusing on to start with, but the temperature is high enough to drive heat engines to make power. There's more on the concept at the seed company's (Orca Sciences) web site and at Austin Vernon's blog.
They talk about temperature up to ~600 C, which I believe is limited by the desire to use cheap steal (much hotter and creep becomes a problem). This is also perhaps not coincidentally about the temperature of steam from a coal fired boiler, so one of the eventual goals is to repower retired coal fired power plants with this storage providing the heat instead of coal combustion.
You're right this is not good for something needed "a few times a year" for relatively short periods, for example to cover Dunkelflauten. Combustion of an e-fuel is better for that. But it's well suited to seasonal storage of solar energy, as that would be extracted over months, more or less continuously. The resistive heaters should also be much cheaper per W than electrolyzers.
bryanlarsen · 2026-10-26 21:06:49 UTC
> But it's well suited to seasonal storage of solar energy, as that would be extracted over months, more or less continuously.
But what is that useful for? During almost all of those months it would be a lot cheaper to use renewables & short term storage. And it's not fast enough for the few days it's not beaten by something cheaper.
pfdietz · 2026-10-26 21:23:55 UTC
It's useful for storing cheap solar energy for use in winter. Sizing the solar collectors for winter would require them to be much larger. Basically, this lets 2.5 W of solar in summer deliver 1 W of solar in winter. For a high latitude where the change in insolation is higher than that, this is superior. In Hamburg, for example, insolation varies by more than a factor of 10 from July to December.
Put another way: if you oversize the solar to be adequate in winter, you have enormous amounts of surplus solar in summer. So why not store it?
bryanlarsen · 2026-10-26 21:43:20 UTC
> So why not store it?
Because 0.10 $/kWh(th) / 0.4 kWh(e)/kWh(th) is expensive.
pfdietz · 2026-10-26 23:15:37 UTC
That's the capex for storage capacity. It's amortized over the number of charge/discharge cycles. Divide by 20 or more. It's amazingly cheap, actually.
skybrian · 2026-10-27 02:06:34 UTC
I thought that post was interesting when I read it over a year ago, but the startup seems to have gone dark since then.
pfdietz · 2026-10-27 02:56:48 UTC
They appear to be focusing on Europe, and have raised $11M (or maybe 11M euros, I'm not sure which). There is some favorable buzz in Germany, which makes sense because natural gas has become quite expensive there.
I just don't see it with thermal. You have to pay the Carnot tax, and you also need humongous amounts of material.
E.g. 100 GWh (4 days of 1GW thermal power) with a 100C temperature swing (you can't go down all the way to room temperature) will need around 3.6*10^4 tons of sand. That's a lot.
Honestly, power-to-gas sounds like the only reasonable way for now. In theory, with SOFC (Solid Oxide Fuel Cells) for power generation, it can beat the steam cycle.
Panzer04 · 2026-10-27 01:06:05 UTC
36000 tons... doesn't actually sound like that much? That's a ~30x30m cube of dirt.
But I have no reference for the cost of setting up such a storage and how it compares to battery or hydro.
pfdietz · 2026-10-27 01:11:46 UTC
The cost of putting dirt in a pile is $1-2/ton.
PaulDavisThe1st · 2026-10-27 02:00:56 UTC
so $36-72k for days of 1GW of power? Sounds pretty cheap to me ...
pfdietz · 2026-10-27 02:12:55 UTC
They also state the cost per kWh(th) of storage capacity is about $0.10, or $100,000/GWh(th). This is thermal energy, which is converted to work at maybe 40% efficiency, mind you. There are costs over and above the dirt (for example, pipes laid through the dirt to carry heat in/out).
cyberax · 2026-10-27 02:18:44 UTC
The biggest expense will be the pipework inside that pile. That you won't be able to service easily. And you'll also need a LOT of insulation around it to prevent heat from leaking out too quickly.
Comments
https://ourworldindata.org/grapher/solar-pv-prices
The World Crossed a Major Solar Milestone [3TW] - https://news.ycombinator.com/item?id=49151977 - August 2026
This is really surprising to hear. Are you sure about that?
The real money is convincing marks to take the financing for 20+ years.
None? Project Solar? The last time I seriously looked at doing rooftop panels, they were significantly cheaper than the door-to-door jerks.
There's probably more to the regulatory problem than just the permits i guess.
Untrue, at Sunspark we sold to both individuals and companies. If you can install the stuff yourself, buying it direct from the manufacturer is ungodly cheap (~330w panels at $80 a piece when I worked there almost decade ago.)
AI can't take my job then.
One indicator is that third world countries can seem to afford it.
There's also other factors like the overall cost being beyond people's willingness to save for when financing is available or the extra value that financed installs can provide the underwriters when they're bundled and sold as a stable income stream like houses were in the mid 00s.
"If it can be done cheaper someone will" is based on a lot of simplifications and assumptions about the market in question.
The fallacy is that there are infinite market opportunities but a finite supply of entrepeneurs/business/money to exploit them. Therefore, there are an infinite number of market opportunities that will get passed up for one reason or another.
The biggest cost components are sales and marketing expenses and similar soft costs. Some of this can be driven down if you collectively buy through something like https://solarunitedneighbors.org/
(have installed 100kw+ of residential solar, ama)
It's the equivalent of a bond investment with potential subsidies at the utility, state, and federal level (solar is no longer subsidized, but batteries still are).
https://www.bogleheads.org/forum/viewtopic.php?t=411421
https://magnifina.com/articles/rooftop-solar-yield/
So long as the roof itself lasts that long. People who are mid-cycle on their existing roof should not install solar until they get to the next replacement. This is where I am, and why I do not have rooftop solar. I expect to get 15 additional years from my roof, and there's no guarantee I will have hit the break even point by then. Plus, solar installers will not warranty a mid-cycle roof against leaks, so if something goes wrong that quickly eats into your cost savings.
https://www.energysage.com/news/solar-panels-withstand-hail/
- Every panel sold in the U.S. has to pass an industry-standard hail test, which fires ice balls at multiple points on the panel and requires no visible cracking, delamination, or more than a 5% drop in power output afterward. Companies like UL Solutions, an applied safety science company, test solar panels by dropping a two-inch solid steel sphere from 51 inches onto panels, simulating the impact energy of serious hail. Panels that survive without electrical hazards earn certification for real-world deployment.
- The proof is in the pudding—or in this case, the parking lot. When a severe hailstorm hammered the National Laboratory of the Rockies' (NLR) (formerly National Renewable Energy Laboratory (NREL)) Colorado campus in 2017, just one single panel out of more than 3,000 suffered damage. That's a 99.97% survival rate against Mother Nature.
I'm looking forward to installing a couple of panels on the roof next year. Having power to charge my phone, or laptop, won't take much capacity, I'm not going to use much power other than that, maybe some music but nothing like cooking/heating, or similar heavyweight usage. (I have a wood stove for heating, and gas/alcohol stoves for cooking, along with on-site water.)
Yea, if you go to an installer instead of buying from the OEM and installing yourself. I likely made your panels at SunSpark (We made panels for everyone, Renogy, Juinko Solar, Samsung, etc.) They were sold for $80 at 330w - 4.125 watts per dollar, or a quarter per watt.
Solar isn't expensive - you are.
I am not a commercial system installer, I am a hobbyist enthusiast who helps others install to avoid commercial installers and their costs. Volunteer labor for everything (racking, panels, electrical), volunteer electrician signs off for any AHJ (authority having jurisdiction) requirements.
Most people cannot install the equipment themselves, which leads to the residential costs I mention. Is it expensive? Price is what you pay, value is what you get. If you cannot find someone to install for free, and cannot do it yourself, the price is the price. You can either choose to pay market rate after getting multiple bids, or choose to go without.
US Dept of Energy: Solar Photovoltaic System Cost Benchmarks - https://www.energy.gov/cmei/systems/solar-photovoltaic-syste...
Energy Sage: Solar panel cost in 2026 - https://www.energysage.com/local-data/solar-panel-cost/
(i am also a community outreach volunteer for https://www.gosolarapp.org for automating permitting and remote inspections across the US, which was incubated at NREL prior to being spun out as an independent non profit; this drives down permitting soft costs)
This is highly untrue, until you get to the task mounting on a roof. Barring that, making a solar array system is dead simple. Most anyone can turn a screwdriver or build a frame or connect very distinct connectors together (they just snap together for daisy-chaining solar panels) or insert a power plug into a NEMA receptacle (for balcony solar installs.)
It is the install on the roof itself which most people cannot do (because they lack roofing knowledge.) Every other thing is absolutely DIY by pretty much anyone with hands and eyes.
Literally the most important part is what most people cannot do. If you have the space, sure, ground mount. Most people do not have the space, nor are they going to be confident in putting penetrations in their roof deck to mount racking to hold the panels.
One thing that isn't super obvious from the article is that a lot of it is talking about industry solar panels rather than rooftop. The overheads of installation etc get a lot smaller if you're installing a whole bunch at once.
This isn't to say that installing solar panels on your house is a bad idea - they normally pay for themselves after something like 10 years from memory, so are similar to double glazing.
[0] https://www.energy.gov/cmei/systems/overview-trade-and-polic...
I would guess this varies by locale, and people usually assume the time value of money to be zero when they make the claim. In much of the US, I think the payback time is more realistically in the 15-20 year range, which means you really only want to install panels when you install a new roof. Otherwise the lifetime of the roof will happen before break even on the panels.
I am with you, this would be better on a town or regional basis instead of on everyone’s roof. Our houses already have wires going to them and I can’t imagine my particular roof or garage is the best place to put panels and batteries. But I understand it’s a political / administrative issue which may well be not solvable easily in many places.
On-prem has a problem of distributed labour costs.
On-prem might eventually become cheaper, but my guess is that won't happen any time soon.
For the time being, centralized and at-scale installation is where you can get much, much lower labour per watt costs.
Other places (like the EU and especially the US) have regulatory problems around anything to do with energy. This is mostly about ass coverage resulting in a lot of pressure for certification, related fees, grid operators insisting on a lot of overhead, building codes requiring a lot of faffing about for the business of wiring together what is essentially plug and play stuff, etc.
If you have an off grid shed, providing power to it is cheap and easy because you have none of that. You buy the hardware on amazon or wherever. It arrives, you wire it up. Job done. And if you are smart you might let a qualified electrician do it right for you or at least check your work (so your shed doesn't burn down and nobody dies from electrical shocks). But fundamentally it's not that hard and this stuff is mostly pretty safe and easy to work with. Especially compared to the things people burn down their sheds with traditionally (e.g. generators).
There's a lot of optimization potential here and most of that is completely non technical.
Solar is cool but solar that can make it through the night and a couple cloudy days is way cooler
- Battery energy storage has grown at an exceptional pace, with global installations increasing more than 20-fold in storage capacity over the past five years. This growth has been driven by falling battery prices, abundant supply and relatively short project lead times. As variable renewable generation expands in many markets, battery storage is becoming an important source of flexibility and resilience for power systems, while also representing a growing commercial opportunity for battery manufacturers.
- However, more than 90% of battery storage applications rely on LFP batteries that are almost exclusively supplied from China, which accounts for almost all global manufacturing capacity and the associated technical expertise. Korean producers are investing to scale up LFP battery production that can offer an alternative, but they face intense competition from established, lower-cost Chinese producers in an oversupplied market.
https://www.iea.org/commentaries/battery-storage-is-scaling-...
- Battery storage now accounts for around 18% of installed dispatchable capacity in Australia, compared with 7% in China, 5% in the United States and 4% in Europe – underlining how rapidly batteries are becoming an important part of the electricity systems in some regions.
https://www.ess-news.com/2026/06/02/global-battery-additions...
Battery storage is right behind the solar adoption curve. Net zero in five years? Probably not. Ten to fifteen years? Almost assured considering rate of change and the overall economics (assuming ~1TW/year of solar PV deployment and enough battery storage to soak up that low carbon generation while also providing grid services to replace thermal generation grid support [voltage, frequency, etc]).
(China is curtailing renewables equal to the annual combined generation of Spain and the Philippines every six months, and India about ~100-120GW/month due to not enough battery storage, for example)
https://news.ycombinator.com/item?id=50132343
https://news.ycombinator.com/item?id=50198882
My recommendation would be to see if Ecopower storage and inverters are a good fit for your use case. If you're feeling adventurous, you could build your own battery pack, but I only recommend if you are knowledgeable and confident. This comes with substantial property and life safety risk, only proceed if you know what you're doing and understand the risk (I'll work on my high voltage EV battery packs, but only with a helper nearby holding a 2x4, for example).
https://hackaday.com/tag/battery-pack/
Not sure whether other brands could be better but there seem to be various options that would suit. If you are in 120v land you may need to check if there are models to suit.
Its largely modular, inverter sits on top of modular batteries in 8-9kw chunks.
But they are app-infested. IE wants a wifi connection, app on your phone to their servers... etc etc.
I hate it, but the wife likes it. This is a recent thing so I am still working out if there are possible solutions for privacy and control over my own objects.
[0]https://solarbatterysupermarket.com.au/products/sigenergy-ba...
Their car charger was doing my head in.
I pulled it apart and found an Ethernet plug and it was a complete game changer.
But: the app and their servers remain.
Then again, I'm basing this opinion on a recent-ish video from NightHawkInLight: https://www.youtube.com/watch?v=eq7fR9ISuCw
The technology I'm most excited about is ultra low capex thermal, as being done by Standard Thermal. Capital cost per unit of energy storage capacity as low as $0.10/kWh(th), so it can work with seasonal storage and just a few tens of charge/discharge cycles over its lifespan.
Standard Thermal has raised $11M and is building in Germany, where they say they can deliver 365/7/24 solar resistive heat (400 C or perhaps 600 C) for half the cost of heat from burning natural gas there.
A regular 18650 cell has about 0.1 square meters of electrode surface. And you have thousands of these cells in a car battery, resulting in literal football fields of electrode area.
We can get to 95% using just short term storage. I suspect that most jurisdictions will just say "95% is good enough" rather than paying for ridiculously expensive long term storage.
We've got the nat gas capability already; keeping it around for the 5% is quite inexpensive, making the massive investment in long term storage for marginal benefit hard to justify.
OTOH, while the premium for e-fuels seems excessive, if you're only running that nat gas plant 2 days a year that premium is not so scary.
For covering Dunkelflauten? Yes.
For seasonal storage with a prolonged discharge (so, low power/storage capacity ratio)? I think thermal storage wins there.
Those are 2 very different use cases.
Thermal is low rate extraction. It's 1 cycle per year, but the extraction is performed over months so is low rate.
Electricity long term storage is high rate extraction. It's only used a few times a year, but when it is used it needs to cover roughly 100% of the entire grid's needs. I doubt thermal storage is suitable for high rate extraction, but I'd love to be wrong.
Edit: rereading your parent comment you seem to think thermal is suitable for a different use case? Could you elaborate further? When is "prolonged discharge" useful?
https://www.orcasciences.com/articles/standard-thermal
https://austinvernon.substack.com/p/building-ultra-cheap-ene...
They talk about temperature up to ~600 C, which I believe is limited by the desire to use cheap steal (much hotter and creep becomes a problem). This is also perhaps not coincidentally about the temperature of steam from a coal fired boiler, so one of the eventual goals is to repower retired coal fired power plants with this storage providing the heat instead of coal combustion.
You're right this is not good for something needed "a few times a year" for relatively short periods, for example to cover Dunkelflauten. Combustion of an e-fuel is better for that. But it's well suited to seasonal storage of solar energy, as that would be extracted over months, more or less continuously. The resistive heaters should also be much cheaper per W than electrolyzers.
But what is that useful for? During almost all of those months it would be a lot cheaper to use renewables & short term storage. And it's not fast enough for the few days it's not beaten by something cheaper.
Put another way: if you oversize the solar to be adequate in winter, you have enormous amounts of surplus solar in summer. So why not store it?
Because 0.10 $/kWh(th) / 0.4 kWh(e)/kWh(th) is expensive.
https://www.cleanthinking.de/thermischer-erdspeicher-erdhueg...
E.g. 100 GWh (4 days of 1GW thermal power) with a 100C temperature swing (you can't go down all the way to room temperature) will need around 3.6*10^4 tons of sand. That's a lot.
Honestly, power-to-gas sounds like the only reasonable way for now. In theory, with SOFC (Solid Oxide Fuel Cells) for power generation, it can beat the steam cycle.
But I have no reference for the cost of setting up such a storage and how it compares to battery or hydro.