This is a very impressive refinement of their existing tool, but is this type of advanced calculation of roof-pitch (etc.) still relevant?
Haven't we more or less concluded that a million piecemeal rooftop installations of solar are about the worst way to do it? More complicated and expensive to permit and install, less efficient operation, difficult to repair, difficult to insure, difficult to upgrade, inefficient to integrate into grid, etc.
As someone who recently lost power and water for weeks post Helene, do not discount the power of distributed grids. Distributed core infrastructure will make for much better climate resilience. Don't miss this in your efficiency calculations.
Sure, but that's why my emphasis was on distributed grids. Interlinking local capacity / having one or two neighbors with fully fledged systems is way better than going weeks charging stuff in your car. When you're without power for weeks, you'll probably have enough sun for more than enough days to get yourself sorted. Hurricanes also tend to sweep up any other systems in the region, so once they disperse, it's pretty clear skies. Anecdotally, we didn't get any rain for months after Helene dissipated.
Also, diesel and gas were pretty much inaccessible for the first 5 days of the disaster, so unless you have a stockpile that's been treated for longevity, you might not even be able to run your whole home generator for long.
They have to. Feeding your own home needs some setup but is fine. But electricity companies require you to disconnect generating capacity from the grid when the grid is down to make it easier to effect repairs.
But that's more a policy decision than a technical restriction. We could change it so power can flow on both sides of a fault instead of only the "upstream" grid side.
With battery systems getting so cheap maybe community batteries will become a thing where a neighborhood exports it's solar too and is it's own small grid.
a) government mandates that turn over existing grid infrastructure to such a project, because the existing grid infrastructure is almost all privately owned
OR
b) building new infrastructure to create an isolatable local grid
I mean it isn't though: it's defense in depth - policy is you must disconnect. Line workers will drive a ground stake in on both sides anyway, but if you don't disconnect then they'll just short your inverter to ground.
There's a program involving F150 lighting trucks out in CA that pay you to grid tie them, that way a couple of them in your neighborhood can power the neighborhood for a day or so if wildfires take out the local grid
Anything grid tied is generally required to have phenomenally reliable shutdown if the grid goes down OR proven (and very expensive) automated switching that disconnects it from the grid if the grid goes down.
This is so those F150s are not backfeeding the wires while a repair crew is trying to fix it.
Ergo, if the local grid is "taken out", those F150s cannot be "on the local grid".
Article says "customers will allow their EVs to feed energy back to the grid – helping to balance it during peak demand". It doesn't say anything about what happens when the grid goes down during disasters
>> Grid connected solar goes down when the grid is out though. You need specific inverters to retain power.
Yes, and sort of.
Inverters will prevent power flowing to the grid if the grid is off. However most inverters will continue to supply power into the house while the grid is off.
There are various factors in play here, and you need to do proper homework, but certainly a fraction of the house can be powered, if not all of it.
I'm not sure if this is "special" inverter or not. Every one I researched had the same functionality.
One advantage of distributed solar is that it can at least come online right away and when installed with a battery, can get a home pretty close to being fully self-sufficient (depending on the climate/heating system), whereas the generally much more efficient solar pv power facilities have to contend with backlogs in connecting to the grid, insufficient grid capacity, etc.
But yes, distributed solar will not be the general solution to decarbonizing our energy systems as a whole. Does serve a meaningful role though and there is no reason to not do both.
Australia manages to install rooftop solar at well under half the cost the USA does (most of that is soft costs) and integrate large amounts of it into the grid.
As of lunchtime today, nearly 50% of all electrical generation on the national grid was rooftop solar (and another ~10% was utility-scale solar).
Rooftop solar works just fine if utilities don’t actively try and obstruct its use.
That's a great achievement, but could be stated in a more clear way.
Not 'As of lunchtime' but 'At precisely lunch time'. An hour later it wasn't 50% anymore, and it won't be 50% except at noon for a long time yet. As of the moment I am posting this, solar is 0% and coal is 80%. If Australia cares about global warming they should build nuclear plants and stop generating 70% of their overall power from coal.
It's still remarkable how much solar is growing and I hope it's 100% 24/7 soon!
Sorry. The point of my post was to respond to the claim that you can't effectively integrate meaningful amounts of rooftop solar into an electricity grid in a cost-effective manner when the evidence from Australia is that you can and we have.
If I'd looked the example when South Australia's interconnector with the rest of the NEM went out, they had periods with the instantaneous penetration of rooftop solar was over 90%. AEMO, the body that manages the Australian electricity grid, are aiming to be able to support a 100% instantaneous renewable mix on the NEM within the next year or two.
As for Australia's overall electricity mix, that is rapidly changing (and the numbers get a bit distorted by the amount of self-consumption of rooftop solar). We're at 40% renewables overall now, and while it may not hit the government's 82% target by 2030 we will almost certainly reach 70% or so by 2030 and I'd think 90% by 2035 is very doable. The last 10% is harder, but there are enough options (gas with CCS, green hydrogen, biofuels, long-term energy storage of other kinds) that I reckon we can get there. We are in the fortunate position of not having solar completely go away for months in the winter.
As for nuclear, it's never, ever going to happen in Australia (despite the claims of the conservative side of Australian politics). Even if Australia could build nuclear power as efficiently as South Korea - an extremely big ask, given we have the same challenges at building large infrastructure as the rest of the English-speaking world - it still doesn't make economic sense.
Or to put it another way: available with a rate of return that makes it sensible for average middle class home owners to say yes to, to the point dirty power sources are having to shut down in some markets (or fiercely lobby through the political system to be propped up).
>...Haven't we more or less concluded that a million piecemeal rooftop installations of solar are about the worst way to do it?
The data shows that you are correct. Utility grid solar provides low cost power and consumer rooftop solar does not and will not. The rooftop solar price is usually hidden because no power source has been as subsidized as rooftop solar. Besides direct subsidies, wealthier home owners have often been paid the retail rate for the electricity they sell to the grid which causes higher electricity bills for those who can't afford to put panels on their roof - sort of a reverse Robinhood scheme.
As the statista.com report says:
>...Rooftop solar photovoltaic installations on residential buildings and nuclear power have the highest unsubsidized levelized costs of energy generation in the United States. If not for federal and state subsidies, rooftop solar PV would come with a price tag between 117 and 282 U.S. dollars per megawatt hour.
Looks like that report is a year old, but I doubt the installation costs have really gone down much since then. (Panel prices come down, but labor costs, etc. don't.)
Yes it's relevant and no we didn't all agree it was a bad idea.
It generates power at roughly the cost of nuclear. It's distributed and resilient. It works around sluggish government and/or corporate monopolies. It reduces transmission requirements. It enables and encourages electrification and time-shifting of load. Adding it at build time can be cheaper than tiling.
It’s generally a good thing and we'll see even more if it as the tech progresses and gets cheaper.
[Given your comment history, as you surely already know...]
Yes and:
With the rise of "virtual power plants" (VPPs), "all the above" (PV, batteries, EVs, water heaters, HVAC, residential geothermal) will be stitched together to create decentralized, more resilient power grids, capable of peer-to-peer power sharing.
Analogy:
Remember the term 90s "convergence" (turrible term)? Describing how the computer (digitization) was becoming the everything tool? VPPs (turrible term) is just the electification of "all the things", unifying all energy (heat, electricity) stuff (source, sink, storage).
It's a good way to anticipate this interation of "convergence". eg VPPs' analog to "traffic shaping" is "load shaping". eg Just like internet is a network of networks, the "intergrid" will be a network of grids. Etc.
It's really easy to see the rough outlines (age of renewable energy) once a person learns of the 100s (1000s?) of puzzle peices currently being assembled. Just reflect on the internet and superimpose those notions onto energy.
I should have made it clear: I’m referring to people who are adamantly opposed to large solar installations, apparently because it’s a threat to agriculture? It’s very odd, but I see yard signs and bumper stickers everywhere in rural Indiana.
Do you think some farms in rural Indiana will make more money by converting to a solar power park? I could imagine it, and I could imagine that some people would feel threatened by this change.
It all hinges on how much your infrastructure costs. At the moment something like 1/3rd of your retail cost if delivery. At some point it's 15x cheaper to have 1kW home feed in + battery vs 15kW feed in.
Sounds like a rare case of America's ubiquitous suburbs working out for the environment. Everyone has a "roof" that gets sunlight most of the day, so rooftop solar, while being less efficient, is still a viable candidate.
(Although, if you factor out all the extra driving needed for the suburban life, it would likely still come out negative compared to a proper city.)
Yeah, don’t over look the fact that the thermal demand from space conditioning homes is way higher on a per capita basis in a suburban context compared to an urban context with multi-family housing/apartments etc. There’s just way more air volume to condition per person, generally more inefficient systems, etc.
Even for the same amount of living space, apartments are way more efficient. A typical apartment unit is surrounded by other units up/down/left/right, so only two sides are exposed to outside air. A single house is exposed on five sides.
Yeah we refer to this as the heat loss form factor of the building, which is determined largely by the surface area to volume ratio (so you have a square-cube relationship at work) as well as the the number of floors in conjunction with the roof area. With more floors, the heat transfer through the roof (which can be substantial, as mentioned by a sibling comment) is less significant for the same roof area (after normalizing for the gross floor area).
Same goes for the slab/foundations (which can also have substantial thermal transfer in many contexts).
There are enough panels available to do both and there is no overlap in financing for both. So just do every installation that is economically viable, they don't compete for money or panels.
>> Haven't we more or less concluded that a million piecemeal rooftop installations of solar are about the worst way to do it?
It really depends on what you mean by 'worst'. In terms of land-usage it's the best. In terms of speed-of-deployment it's the best. In terms of distributing capital spend its the best.
In terms of capital return, that will vary from one house to the next because it depends on location, energy consumed (and when), elec prices in your region, grid stability, and so on.
what do you mean by "distributing capital spend"? as in the money to pay for the installations is not concentrated to large utilities? why is that desirable?
The majority of the cost of electricity in most jurisdictions is distribution, not generation. Grid-solar still requires distribution, so it is always going to have significant cost even if the cost of generation is insignificant.
If it can remove the need for a grid-tie, then rooftop solar can be significantly cheaper and more efficient. Can be, but isn't yet, because enough overcapacity and storage to eliminate the need for a grid tie is still too expensive.
This is exactly the challenge. Here in California wholesale solar plant sell power for 0.03-0.04 kwh. Cost at the meter is 0.45/kwh.
Rooftop is competitive with the meter price, but unless you can cut the cord entirely, connection fees and rates will just keep increasing proportionally
With rooftop solar there's a path towards mass deployment that other alternative electricity generation solutions currently lack. Rooftop solar for residential houses doesn't require permits or planning, and can be done by individuals within a reasonable budget, unlike solar farms or rooftop nuclear.
> Rooftop solar for residential houses doesn't require permits or planning
Either you're assuming residential battery storage systems replacing the grid, or your ignoring the connecting rooftop solar to the grid requires permits and planning (the grid may not be able to handle it).
Depends on your cost of electricity. In most places, a solar setup pays for itself long before the warranty runs out max 5-10 years typically (depending on a lot of factors). Even in the US which has a lot of extra cost related to people making things needlessly complicated and costly, lots of people are installing solar and earning their money back.
I can actually get balcony solar here in Germany for about 240 euros. Here's how that works:
- I buy a kit on Amazon. I found several nice ones. This one is rated for 850w and includes cables, inverters and other bits and bobs needed.
- I zip tie the panels to my balcony
- And I plug in the equipment and connect it to a wall socket
The idea is that this would offload some of the power used by e.g. my fridge. Not the same as a rooftop setup obviously and in my case quite pointless since I don't have a lot of sun on my balcony.
But I might actually qualify for a rebate if I do this and get all or most my money back. The government is sponsoring this and landlords can't stop you from doing this. Nor do you need their permission, a permit, or special insurance.
The point is that this stuff is cheap, easy, and pretty much plug and play. Roofs aren't a whole lot more complicated than this from a technical point of view. You need more panels and more expensive equipment and you probably need some professional electricians and installers to do the work.
The rest is just nonsense that relates more to your local government and legislation than anything being inherently expensive or difficult. I'd suggest reminding your local politicians of their responsibilities during the next elections and maybe voting for the ones that aren't being jerks on this front.
Otherwise, solar panels are pretty reliable and generally covered by long warranties. Repairing them is mostly not a thing, somebody would come and simply replace them. I doubt that a lot of solar panel companies and installers are suffering a lot under the enormous burden of this happening all the time for the simple reason that it this isn't a thing.
Balcony solar sounds brilliant and probably has clear ROI. Rooftop solar is an awkward middle between grid-scale solar and balcony solar. Rooftop solar might only make sense in developed countries through subsidies.
Actually, there's a lot of unsubsidized solar popping up in a lot of developing countries all over the middle east, Africa, etc. Anything from villas to shanty towns. Reason: local grids are unreliable and solar is affordable enough. Add some batteries and you are pretty much energy independent. Most of that solar goes on people's roofs.
The reason that's affordable there and requires subsidies in wealthier nations is all the nonsense the nanny states we live in come up with to over complicate things. You need certified this and that. Only people in possession of a special license can plug component A into component B, or strip some wires. And then there is the local grid monopoly that throws up all sorts of obstacles.
There's a way around this. Just buy some panels and batteries on amazon and wire up your shed, boat, cabin in the woods, etc. It's all plug and play. You don't need any permits, special skills, etc. And you end up with a system that can provide a couple of KW of power. Not that hard. There's nothing special about a rooftop. You might need a ladder to get there and you might want to take some safety precautions to avoid dropping off.
Yes, but one back-of-the-envelope calculation (it was a Python program someone wrote up as part of a comment on Slashdot as I recall) demonstrated that if all of New York's roofs were covered in solar panels there would be enough energy to run the city....
Good point. It feels right that the calculation ignored losses --- but if I recall, it did include panel efficiency and that has gotten much better, so maybe it would work now?
I thought we may have concluded that shareholder efficient centralized single point of failure systems are the least robust providers of basic human needs in the face of natural levels of uncertainty.
Grids are pretty much the best solution available because any kind of good/service that can be transported at close to light-speed benefits tremendously from ubiquitous connectivity.
Smarter grids are an even better solution; batteries backing local high-variance demand combined with rapidly negotiated requests for transmission power to meet expected future demand (and then stored in the batteries) reduces (electrical) inefficiency to a minimum.
Residential power demands are highest in the morning and in the evening. That's when people shower, cook, and are generally around using power. Solar peaks at noon.
Maybe when battery prices come down even more. But the cost of grid-level storage are also falling, and wind pretty much only works at grid scale. Grids have to change but won't become obsolete anytime soon.
That usage pattern will be quite different in places with cold winters when most people there are using electric-powered heat pumps (which is "the plan").
Haven't we more or less concluded that a million piecemeal rooftop installations of solar are about the worst way to do it? More complicated and expensive to permit and install, less efficient operation, difficult to repair, difficult to insure, difficult to upgrade, inefficient to integrate into grid, etc.