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Comment by anonfordays | Hacker News Reader

Soon (if not already) the largest costs associated with solar installations will be the labor. It's expensive to get people on roofs and electricians to reconfigure panels, install transfer switches, etc. The equipment could be free and it would still cost thousands for the skilled trades to install.

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This is one of the forces driving the shift from rooftop solar to utility-scale installations. A residential installation needs guys up on a roof to install the panels, and then custom wiring for each house. A solar farm can use robots to install tens of thousands of panels cheaply.

There are unfortunate side effects to this, even besides the attacks on net metering that have cut financial returns for existing solar customers. Distributed generation is more resilient. With a battery, you can keep your electricity during a power outage. Outages themselves are more isolated - with a VPP individual neighborhoods could keep power, while if a transmission line to a major solar farm goes down, a whole city could lose power. Large solar farms would be huge targets for warfare or sabotage, and wouldn't last very long at all. Transmission lines to them are vulnerable to natural disasters. Economically, large utilities have more market power and can capture their regulators, leading to higher prices and poor service for consumers.

But the economic benefits of scale make it harder to justify putting panels on each individual home, when the same generation capacity can be built much cheaper at a solar farm.

The attack on net metering isn't unfortunate; what's unfortunate is that people thought net metering ever made any sense. It's free riding on services provided by the grid, forcing others (who don't have PV) to pay for cost of providing those services. As PV rolled out, the craziness of net metering became impossible to ignore. Of course, those feeding at this trough objected loudly, and some naively fell for those objections.

I think it's reasonable to subsidize adoption of early-stage technology that's promising but doesn't pencil out yet, to kick-start the learning curve. Thanks largely to Germany for doing the lion's share of the early subsidies with solar!

But you're of course correct that this is a giant subsidy, and unfortunately it was funded by other rate payers rather than a central government, which was a nutty system from the beginning.

It would be nice if this cost was actually all broken out; the grid operator should charge for connectivity, the various energy providers should charge for the energy itself.

Net metering could still make sense; your residential solar installation might make enough to cover the gap.

I'm sure it varies by locality, but if I look at my electric bill, I see charges for energy, transmission, and maintaining a connection to the grid. Transmission and generation are variable, connection is fixed.

I doubt the $8.50/month is the "right" charge for maintaining a grid connection, but it's what MidAmerican Energy has gotten approved in Iowa. Presumably their charges for transmission and energy cover everything adequately.

It's not just maintaining a connection to the grid, it's maintaining the generating assets on the grid that you sometimes use.

That’s how it is in Texas. The company that owns the power lines to your house is unrelated from the company you buy the electricity from. (The latter of which you have dozens of options to pick from)

This is exactly what happened in California recently with Net Metering 3.0 -- the utilities cut the value of the electrons you export back onto the grid, and they even broke that value out into a supply chunk and a transmission & distribution (which effectively cuts the total export value even more because they argued that the marginal electron is worth a tiny amount as far as the t&d line items go).

What's happening in California is new rooftop solar doesn't pencil out unless you pair it with batteries (ie you self-consume all your excess), and even then it gets iffy.

There's also the trend where operators charge fixed costs for connectivity. So even if you self-consume everything, you still pay $15-$50/mo just for the connection. That gets trickier because it punishes low-usage users like apartment dwellers and small households because that looks the same as a solar house that self-consumes most of their electricity.

What is needed is charging not just for a connection, but for connection of a certain maximum dependable capacity. This would be best be coupled with some ability to force limitation on the instantaneous consumption, a kind of demand dispatch.

That’s an interesting idea, because it matches the physics of the situation pretty well; on-demand capacity costs the grid something just to have it (batteries, or whatever), so it would be good to make that price visible to users and let them decide if they need it.

It might also push people more toward smart-grid tech, which is a desirable outcome. You might pick a dishwasher that can actually help shave the peak, if it saves you money.

oh, don't worry, there are tons of incentive structures like this already out there. It's sophisticated energy management, though, so it's only in the Commercial & Industrial world (for now)

In C&I land, you have things like demand charges (billing by your max kW, not just kWh), demand-eligibility tiers (your electric arc-furnace plant is going to have very different charges than your warehouse), and even fun things like many flavors of demand ratchets (you have a fixed charge based on your maximum kW in last 3, 6, 12 months, or your maximum kW during the most grid-strained periods last year, or a million other variations).

C&I billing gets very creative.

Some utilities are even today experimenting with demand charges in the Resi space (don't run your dryer while charging your EV!)

This is how it has been before net metering in NL. You are charged by size of the connection: How many A you can consume. Then there is a separate tariff for the transport costs (fixed per day) and then the costs per kWh. With net metering the transport/connection costs stayed. Currently kWh is about €0.28.

We need all the renewables we can get, and I think you can have both -- utility-scale and rooftop. Rooftop solar (and battery storage) just needs to be cost efficient to offset the rising cost of electricity and make it a good return on investment.

The "attacks on net metering" are merely acknowledging that the proportion of renewables on the grid is high enough that balancing grid supply and demand is becoming an issue. I'm a big proponent of rooftop solar, but the reality is that 1:1 net metering just doesn't make sense once there's a critical mass of solar installed (the duck curve problem). This is not a problem unique to California or the US. If you look at other places with high solar adoption (Australia, EU), you'll find even stricter policies like negative feed-in tariffs: the utility will charge you for exporting solar to the grid.

Battery storage is a solution to that problem, but that's where prices are still too high. I'm actually surprised that battery storage is not mentioned in the article, because that's a critical component of allowing solar/wind to grow further.

> A solar farm can use robots to install tens of thousands of panels cheaply.

Doesn't matter if it doesn't bring down the cost of electricity. For example in california PG&E will still charge a substantial "delivery fee".

Yes, roof-top installation is expensive, but if you combine it with other maintenance of the roof, it gets very cheap. And any new roof should have it planned in with the setup.

Also, here the northern latitude helps, in Germany people start putting solar panels on walls and fences. There is plenty of cheap space and the efficiency isn't too bad considering the cheap panel costs.

I think it's worse than that, for rooftop solar you have an enormous amount of sales and marketing expense baked in, plus you have homeowners which don't have enough experience to know what a good price/good install looks like. Much less of that with bigger systems.

The other major problem is the grid is not setup at all for consumers to also be generators. At least in the UK it is rare/not possible for the DNO to send power back from a neighbourhood to the grid (at least not without a total remodel of the local grid infrastructure).

So we are now hitting problems where solar is not allowed to be connected to the DNO if you have streets with a lot of solar on, because at some point the generation from the houses on the areas local transmission outstrips the demand in summer, and in that case you have too much power and nowhere for it to go (the excess cannot be sent back to the high voltage grid). The DNO cannot turn off individual solar generators easily (and even if they could, do they trust a load of chinese inverters to work reliably remotely?)

I think the key problem with solar/renewables is not undersupply in winter in northern climates (though that is a big one for true net zero) it is oversupply in the summer. It's already causing massive issues in Europe with long spells of negative pricing. Interconnectors don't really help with this because when it is sunny (and potentially windy) in one place in Europe it tends to be similar elsewhere, so everyone has too much power.

This is before the UK adds another huge amount of solar and wind in pipeline by 2030.

Note this comment only applies to northern climates. It's far less of an issue further south because AC load tends to follow solar production much more, but that is far less common in the UK.

This has been the case for years now for pitched residential roofs - they stopped being competitive a long time ago.

Thankfully, the impetus for residential roof solar was always more ideological than practical. There's plenty, PLENTY, of empty unused land within a 95% transmission efficiency (hundreds or even thousands of kilometers depending on tech) of the end user, for all non-island cases.

Yeah. When we bought our solar system, even knowing it was grid-tied, it felt like we'd somehow be generating our own power.

As soon as we had it, and I looked at the tiering, time-of-use, etc, and I realized it's all an arbitrage game. I'm selling my roof space and fixed asset back to the power company, and buying power from them.

If solar could reasonably double for me as a way of weathering a several day power outage in the winter, it would be more interesting. But I'm deeply suspicious of anything that has people out in front of Home Depot hard-selling something that often has complex financing schemes. I don't have huge power bills relative to lots of other home costs. So I'll pass.

DIY doesn't come with those asterisks, and DIY with only-thermal power use & energy storage is on the simple side of things. "Help me heat in the winter" is basically the simplest use-case, because you can accomplish it with a south-facing solar fence and some resistors [or an inverter + space heater, or whatever].

Personally I like the idea of a three-season thermal mass store, a big tank of water or pile of sand that you dump heat into when it's sunny, and extract it at will the rest of the day/week.

That depends on where you live. In my area, labor is cheap and the costs of panels, batteries and inverters came down significantly over the last 5 years. You can now break even on electricity costs for a residential pitched-roof installation in under 5 years. This is without any subsidies, without selling anything back to the grid.

Utility-scale solar installations also make a lot of sense, but around here transmission capacity for that is still a massive issue. You can install more transmission capacity, but it's not cheap.

> You can now break even on electricity costs for a residential pitched-roof installation in under 5 years. This is without any subsidies, without selling anything back to the grid.

This is arguably a false economy.

~75% of costs for the power grid are not in volume electricity generation, but in maintenance. They haven't priced it that way in most places to encourage power-saving and reduce the need for new infrastructure construction, but they'll be forced to if every roof sprouts solar cells.

If volume electricity generation is the concern, doing it in a field is dramatically cheaper than doing it on a roof.

I'd like to see the roofs of big box stores and their parking lots covered in solar panels. It would keep cars a lot cooler and would enable very efficient charging stations to be located in the parking lot.

A good number of the roofs already are. While more expensive than working in a field, it's way cheaper/safer than working on a tiny residential roof.

Parking lots are tougher, but I saw the first one this year.

I think eventually the hardware will be so cheap it'll make more sense to use them as solar fences. Reduce the cost to install and maintain by 3-4x easily. Or DIY for practically nothing.

There's an apartment building here in Seattle which has solar panels mounted flat on its west-facing wall (602 12th Ave). The panels were apparently cheap enough that they did not care about maximizing daylight exposure and simply installed them in the easiest place. Quite a change this is from what I remember when I had solar panels installed on my roof eleven years ago!

West-facing is pretty close to revenue maximizing, with current consumption peaks in the early evening.

I remember asking a friend who understood solar what angle was best to capture the most energy. He told me "you don't aim for the sun, you aim for PG&E"

There’s an Undecided video on this exact topic https://youtu.be/LqizLQDi9BM?si=nnWVU-Espt7a6VDv

This is fantastic! Somehow I hadn't heard about vertically mounted solar panels until now but it sounds great. There are so many advantages to vertical mounts I would expect them to become the norm.

"already, across Europe, homeowners are building garden fences with solar panels simply because it’s not much more expensive than doing so using traditional materials — namely, wood." https://www.nytimes.com/2024/08/28/opinion/solar-power-free-...

There is research coming out that vertical solar panels are more efficient. I think part of it comes from lower temps allowing for more efficient operating. No tracking or pointing required. Less cleaning as its not a flat surface for dust or fall impacts.

https://www.youtube.com/watch?v=5AVO1IyfA9M

edit: I see others have linked similar videos, all good sources on this topic.

That's already the case, even with commercial solar. There's a startup called Erthos [1] that has figured out that it's cheaper to just throw the panels on the ground, saving the labor and material cost for the supports. There was an HN thread on it a few years ago: https://news.ycombinator.com/item?id=33926683

[1] https://erthos.com/

This and the parent comment are all addressed in the article.

To be fair, no one’s ever accused me of reading the articles before commenting :-)

I wonder to what extent we can make it unskilled, at least for a building with modern wiring. Plug-and-play solar panels and batteries sound scary, but not necessarily impossible to do safely.

Anything involving roofs is difficult to do unskilled (at scale). You are working at height, potentially on a sloped surface, and have to worry about keeping the roof water tight.

But if you put the panels basically anywhere else it becomes a lot more viable. Some houses come with a plug to connect your generator, you can do something similar to plug in your inverter. Then you can later decide to put up a solar fence or put solar panels on the balcony or whatever strikes your fancy

Why not just prefab a frame with the panels mounted and hang it on the point of the roof with a crane? Working on the roof can be eliminated or minimized.

Wind. Panels and their support need to be anchored to the roof, lest they become flying solar panels.

Even if it works, that just trades some of the working-on-a-roof trade skills for (much more expensive) crane operator and rigging skills, while also adding the expense of the crane itself.

> Plug-and-play solar panels [...] sound scary

But they already exist and are pretty popular in Germany to put on your balcony.

Neat, do you have a quick reference handy? Thanks!

here's an example: https://www.theverge.com/24150901/ecoflow-powerstream-review...

This is outstanding, thank you.

It's pretty high voltage (500V DC) - you start to get arcing at this voltage.

Residential solar costs in the USA are already 50% sales and marketing, and most of the other half is labor.

That and banking enough to cover the warranty for the next 30 years. Lots of early solar systems had reliability issues, especially the inverters, that make them expensive to maintain.

What if I just bought a field and laid them on the ground, over some plastic or something? Sure, I might be giving up some efficiency gains by not swiveling towards the sunlight or something, but I have to imagine there's a "plug and play" option possible here.

There's precedent:

https://electrek.co/2022/12/12/texas-solar-farm-flat-on-the-...

I think the efficiency figures are exaggerated, but the fact remains that such an installation requires less labour.

I wish JUST ONE PERSON in the comments would read the gosh darn article.

Correct. And also the non-solar panel material. For example the aluminium support they use between the roof and the solar panels costs the same or more than the actual solar panels. When I asked for an offer two years ago the price of the solar panels was about 25% of the total cost.

The aluminium frame was 25%, labor 30% and putting up the scaffold 20%.

I hope thin film solar panels integrated in the actual roof material will become more common going forward as it removes the need for an aluminium frame, you get a new fresh roof, it's lighter, no holes are drilled in the roof etc.

One of the YC companies is doing robotics for solar panels installation

https://www.ycombinator.com/companies/charge-robotics

this is the main topic of the article; it describes where those costs come from and how they are being reduced

Pretty much. There will be a bottom limit on the price of the panels, simply due to the logistics of moving materials, I mean there is a price of salt per ton that is almost entirely this.

But everything else around solar such as inverters, cables, framing, labor, battery storage is where a large part of the cost now. Innovations in those areas will probably yield better cost reductions than the panels will nowadays. That is just wild to see!

I think it's more important to lower roadblocks as opposed to costs for solar.

It seems australia removed a lot of roadblocks and solar is very popular.

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