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Comment by opo | Hacker News Reader

It should be noted that those low costs for solar installations are not including consumer rooftop solar. The consumer rooftop solar cost is usually one of the most expensive ways you can generate electricity - often several times the cost of utility solar installations:

https://www.lazard.com/media/xemfey0k/lazards-lcoeplus-june-...

The high 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. Also, in almost all cases, the home installation doesn’t have enough battery power to actually last through inclement weather and so is free riding on the reliability provided by the grid, putting more costs on the less well off. The whole thing is sort of a reverse Robin Hood scheme.

Any subsidies for solar power should go to utility grade solar. Money is limited and is fungible - a dollar spent subsidizing utility solar will go much, much, further than a dollar spent subsidizing wealthy homeowners who install panels on their roof.

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> Also, in almost all cases, the home installation doesn’t have enough battery power to actually last through inclement weather

That's true today, but I bet it won't be in 5 years time. Around this year or last year batteries have hit a price point where they make financial sense for ordinary people, and in a couple of years you'd be mad not to have them if you have rooftop (and somewhere to put the batteries of course).

> Any subsidies for solar power should go to utility grade solar.

At this point, it should probably go towards storage, grid capacity, or things like EV charging infrastructure. Solar generation doesn't need it.

> The consumer rooftop solar cost is usually one of the most expensive ways you can generate electricity

This may well be true, but there are positive externalities:

- It has reduced land use compared to other energy generation methods

- Power is produced near the point of use, reducing transmission requirements

- Most of the cost is labour for installation which creates jobs

Given that rooftop solar usually pays for itself despite being less cost-efficient that other forms of solar, I see no reason to discourage it.

All new construction should have it, at least. The cost differential for building a new home's roof and outfitting that roof with solar just isn't high enough to justify doing it differently. Plus it improves cooling/heating costs and protects the roofing materials from direct sunlight.

>All new construction should have it, at least.

Yea, I have never actually seen any estimates of the cost when adding panels to new construction, but it sure seems like a reasonable idea.

>...Around this year or last year batteries have hit a price point where they make financial sense for ordinary people,

The LCOE of battery systems for residential systems is still incredibly high according to the Lazard report - an unsubsidized cost maybe 3 - 10 times more expensive than grid batteries.

>...Given that rooftop solar usually pays for itself despite being less cost-efficient that other forms of solar,

If that is the case, then less well off rate payers shouldn't have to subsidize their wealthier neighbors. If it does require subsidies, then that money should go to where it will do the most good in decarbonizing the grid - not as a giveaway to wealthier home owners.

>I see no reason to discourage it.

Who said anything about discouraging it? I certainly wouldn't want to discourage it.

It's not as bad as all that.

Solar "subsidies" are almost universally tax credits, meaning the only money involved is the money paid by the homeowners. So, for society, rooftop solar is by far the cheapest option. It costs the rest of us nothing, the homeowners pay for it.

Money is also not limited, it is in fact created by the banks when someone takes a loan, for example to put solar on their roofs.

Meaning there is no money lost from society that could instead be used to build utility solar, just because someone puts solar on their roofs. If your county borrows money to make utility solar, that money is also created by the bank then and there.

Also note that you are quoting last years Lazard report. Solar is way cheaper in this year's report. It will probably be even cheaper in the next one.

A tax credit does mean that other taxpayers somewhere are paying for it, though

That only works if the budget is balanced or the debt is paid off.

It is either today's or tomorrow's taxpayer.

No it just means the person paying gets a discount on the tax, nobody else pays anything extra for that.

If the tax credit results in an increase of solar panel installations it’s still a net gain for society, even just financially.

While technically correct, assuming a balanced budget means less tax revenue will have to be offset either by reducing government expenses or raising taxes for everyone, so in practice all taxpayers 'pay for' a tax credit.

But you assume that 100% of homeowners will buy solar at full price no matter what, with such certainty that it can even be included as a given in the budget before it happens.

That's an unreasonable assumption IMO. Solar is not food, homeowners can choose to skip it.

>Solar "subsidies" are almost universally tax credits, meaning the only money involved is the money paid by the homeowners.

Well, it means that the government will have less available money to spend on other priorities. Often there are also state and utility subsidies, but those subsidies are often not the largest subsidy. Besides the 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. As I said before, the whole thing is sort of a reverse Robin Hood scheme.

>...Solar is way cheaper in this year's report.

No it is not. I used last year's numbers since the 2025 report for reasons, does not include consumer rooftop solar. The closest comparison would likely be the category of Solar PV—Community & C&I. In 2024, the cost estimate was $54 - $191 in 2025, the price range was $81 - $217.

>Well, it means that the government will have less available money to spend on other priorities.

That assumes people have to buy solar at any price, but they don't. The money the gov gets from people choosing solar because of the tax credit is extra money that they wouldn't have gotten otherwise. So it's likely they get more money, not less money.

If everyone scrambled to buy all available solar at full price already, then yes, of course nobody should give tax credits. But that's not where we are, tax credits cause an increase in installations.

I am convinced everyone benefits from wealthy homeowners installing solar, not just the homeowners.

Solar panels make electricity cheaper from base principles, despite any political schemes that are employed right now. Once installed, the panels generate electricity for free.

I think that's often overlooked - all talk about subsidies for solar is just for the installations. Once they are done, solar electricity costs nothing.

>No it is not. I used last year's numbers since the 2025 report for reasons, does not include consumer rooftop solar.

You're right, I made a mistake and didn't notice the rooftop category was gone. My bad.

>…I think that's often overlooked - all talk about subsidies for solar is just for the installations. Once they are done, solar electricity costs nothing.

No, the subsidies don’t stop at installation - they often just really begin. Often wealthier households have been able to sell back their electricity to the grid at the retail rate. Providing the infrastructure and reliability of the grid is very expensive, so there is a huge difference between the wholesale costs and retail rates for delivered electricity. In CA, it was estimated that all non-solar households in CA paid an estimated extra $115 to $245 per year to cover the subsidies given to their wealthier neighbors. It was estimated that as the number of consumer solar installation increase, that increased cost would grow to between $385 and $550 per year by 2030. Ignoring all the subsidies given to install the system, that $115 per household per year adds up to a great deal of money. Money is limited and is fungible - a dollar spent subsidizing utility solar will go much, much further to decarbonizing the grid than a dollar spent subsidizing rooftop residential solar. It is understandable that anyone getting free money thinks it is good. But if the less well off people (renters, etc.) learn that they are paying a great deal more for power to subsidize wealthier residents (when that money could have gone MUCH further if spent on other solar projects) - it isn’t hard to imagine that might lower enthusiasm for government subsidizing the move away from fossil fuels. This sort of wealth transfer to the more wealthy actually hurts everyone in the long run. The goal is to decarbonize the grid - not implement some kind of a reverse Robinhood scheme.

>…You're right, I made a mistake and didn't notice the rooftop category was gone. My bad.

Yea it is unfortunate they removed that category - hopefully it will return in future versions.

>No, the subsidies don’t stop at installation - they often just really begin.[..] Often wealthier households have been able to sell back their electricity to the grid at the retail rate.

It's not a subsidy to be allowed to sell a thing you produce at market price. If taxes were used to pay a guaranteed price above market rate to solar panel owners sure, but that's not the case (generally speaking, local political absurdities may exist of course).

>Providing the infrastructure and reliability of the grid is very expensive,

There is no additional infrastructure needed to cover rooftop solar though. It's just electricity being added to an existing grid.

If someone is increasing your power bill and blaming it on some one else's solar panels, I'd say you are being scammed and I would not take such claims at face value! "Yeah you have to pay cause Jim got solar panels, so we had to uhm, you know, we had to, err, well you have to pay more anyway". ;-)

>a dollar spent subsidizing utility solar will go much, much further to decarbonizing the grid than a dollar spent subsidizing rooftop residential solar.

But this is a choice that doesn't exist. We are not talking about a bunch of money that has been collected and is being spent on people's rooftop solar instead of being spent on utility solar. There is no money except the homeowner's money that is being spent here, and they can only choose to get rooftop solar.

>This sort of wealth transfer to the more wealthy actually hurts everyone in the long run. The goal is to decarbonize the grid - not implement some kind of a reverse Robinhood scheme.

Rooftop solar decarbonizes the grid faster than anything else at the moment, since lots of people get to decide for themselves instead of waiting for politicians. It transfers no money from anyone but from the homeowners to makers of solar panels.

It also lowers the production price of electricity, which should lower the purchase price too, unless you are in the hands of corrupt politicans and utility cos.

> It's not a subsidy to be allowed to sell a thing you produce at market price.

It certainly is in this case. The market price includes transmission and distribution costs, as well as fixed costs of the generators.

Domestic PV is really gaming the rate system, avoiding costs while still benefiting from the things those costs support. If enough people do it the grid falls apart. See Pakistan where they may be getting close to this.

>Domestic PV is really gaming the rate system, avoiding costs while still benefiting from the things those costs support.

All powerlines, transformers and everything else is the same with or without solar panels. What new costs are happening because of solar that solar owners are avoiding?

Tax reductions for voluntary things is not comparable to payouts. They are method to get the rich to pay for solar so the non-rich don't have to, and in the past few years it has gotten us more carbon neutral energy than anything else. Clearly a win-win good thing.

Trying to describe it as the opposite doesn't hold up.

Edit: Utility cos that sell electricity themselves may increase prices to make up what they lose when they can't sell as much gas, nuclear, coal etc, and blame it on solar. That's not a subsidy for solar though, it's a subsidy for corporations.

The powerlines, transformers, etc. have to be paid for. These are not new costs, they're existing, ongoing costs.

Previously, these were paid for by becoming part of the per-kWh price of electricity, under the assumption that all the electricity each consumer is using goes over the grid.

But with solar, consumers can largely (but not entirely) self-power, and use the grid only rarely. They are benefiting from the presence of the transmission/distribution infrastructure (and the power sources feeding it) but aren't paying the same amount for it.

>The powerlines, transformers, etc. have to be paid for. These are not new costs, they're existing, ongoing costs.

That's true but powerlines exist to transport high voltage power from power plants to consumers far away, and transformers convert that to usable voltages.

Residential solar does not require any such powerlines or transformers, because the low-voltage power is consumed locally, where it's produced.

There was a story here recently about balcony solar installations in Germany. Basically a small solar panel adds power to your house through the house's existing wiring.

Rooftop solar works the same way, but is large enough that sometimes your surplus can be consumed by your neighbor as well, and when more people get solar it expands to the next neighborhood, and so on.

This is handled by the utilities already, since the effect of adding solar to your house is basically the same as if you stop using your stove or stop charging your car.

So it's kind of perfect initially - no new technical solutions are needed and no heavy investments since it just works with existing infrastructure.

Of course this becomes a problem eventually and will require storage solutions first of all and eventually also high voltage transmission. But not yet.

The real problem here is that large corporations live from the profits of selling electricity. They will protect that profit at all costs, so when demand drops - due to solar or anything else - they will increase the prices.

Note that they are not necessarily using that profit to properly maintain any infrastructure:

https://www.wattstrialfirm.com/powerful-results/historic-13-...

> Residential solar does not require any such powerlines or transformers, because the low-voltage power is consumed locally, where it's produced.

Of course it does. If it didn't, the residential solar user would just disconnect from the grid entirely.

The point here is that even if one uses the grid rarely, one is still depending on it being there. And that dependency means one is still exploiting things with fixed costs.

Large solar rollouts will force changes to rate structures, for example charging even residential users for the maximum power they use (or could use) rather than the total energy they consume. With such rates the financial benefit to the consumer of residential solar becomes much lower or nonexistent.

>The point here is that even if one uses the grid rarely, one is still depending on it being there. And that dependency means one is still exploiting things with fixed costs

Obviously the grid is needed and anyone using it should pay. But equally obviously, you should not have to pay when you are NOT using it! And residential solar is not using it.

Also obviously, we should not have to pay more than what is required to maintain the grid, in order to protect the profits of power companies that are being squeezed by free electricity. If they are increasing the prices due to solar, they should be held accountable for the actual reasons why.

We are deviating from the topic, I just wanted to protest against the notion that there is something wrong or sinister about encouraging rooftop solar. It's one of the best things that have happened in the efforts to reduce emissions, perhaps second only to the large-scale deployment of electric cars.

What is wrong is pretending that the current rate structure is from some natural law, rather than contingent on the structure of the grid and how consumers are using it.

I've seen this repeatedly when net metering is scaled back. This is represented as some nefarious and unfair change when it is nothing of the sort.

>...It's not a subsidy to be allowed to sell a thing you produce at market price.

The market price is not the retail price. Does a grocery store buys produce from a supplier at the price they sell it to the consumer? Of course not. The wholesale price for power in CA is variable but generally around 4 cents a kilowatt wile the retail price that customers pay is generally 30 cents and above. If the market price for power is 4 cents, and a supplier can effectively sell their power for 30 cents, they are not selling it at the market price. If consumer solar producers were treated as every other supplier of electricity and were paid at the same rates, then there would be no subsidy.

>...If someone is increasing your power bill and blaming it on some one else's solar panels, I'd say you are being scammed

No, that is the reality of how net metering works. That $115 to $245 cost estimate paid by every other household in CA was from the CA PUC. They have made some changes to this going forward, but the current beneficiaries are still grandfathered in.

>...But this is a choice that doesn't exist. We are not talking about a bunch of money that has been collected and is being spent on people's rooftop solar instead of being spent on utility solar.

This was a choice that was made by politicians and this is money that is being spent every day. The CA legislature and PUC could have said that household rates will increase by $115 a year and the money will be used to build out grid solar and storage - if that had been done there would be MUCH more solar power and grid storage being produced. You just need to look at the LCOE for utility and consumer rooftop solar to see the cost differences. The LCOE difference grid batteries vs home batteries is also dramatic.

>There is no money except the homeowner's money that is being spent here, and they can only choose to get rooftop solar. ... It transfers no money from anyone but from the homeowners to makers of solar panels.

If every household's electricity rates go up by $115 a year, then every household is spending an additional $115. If someone is paying an extra $115 a year, it doesn't make sense to tell them they are not paying extra.

I think you’re missing the real-politik of rooftop installations. The person installing the panel has a few square meters of empty and unproductive space, over which they have exclusive construction rights. And which is already connected to a grid, with capacity to absorb its production, physically close to the consumers of its output.

That combination of factors is fairly rare in most of Europe & North America - especially when you’re looking for multiple contiguous kilometres of land for utility scale solar. There’s a lot of that type of land out in Texas and Australia, but there’s much less of it in the Scottish Highlands.

Yep, and electrical distribution is frequently a bottleneck, and electrification initiatives (EVs, heat pumps) and data center buildouts are causing that to a larger and larger issue - colocating generation and usage seems very helpful for this.

That hugely depends on the region. In my corner of the world the scheme is net-billing, so homeowners are selling energy at wholesale prices.

My friend has a 10kW setup combined with a 10kWh battery. Main adjustment he made was prevent the heat pump from keeping the water hot during the night, as that was just wasting energy.

After this adjustment his electricity bills halved despite only really selling energy in the peak of the summer season. The savings translate to a 10-year return on investment before subsidies.

Even this is a subsidy. Your friend was benefiting from the presence of the grid even when they weren't pulling energy from it. They still had the ability to pull energy from it when they did need. If enough people go that route then the grid will start selling this right and charge you even if you don't use it.

This is true. A lot of the older panels are also rather inefficient and come with a rather poor lifespan. It's part of the reason I don't personally have any form of solar despite working in the industry.

Technology is catching up on the solar panel front though. French Heliup are producing panels which are only 5kg per square meter. Which makes them significantly easier to install on roof-tops. I imagine I'll eventually have solar panels on my roof, but I'll likely wait another decade for battery tech to also be more viable.

I would have to cut down so many trees around my house to get effective sunlight on the roof more than a few hours a day. Plus my roof is pitched east/west so at best I have half the roof in sunlight for half the day. I do have quite a bit of clear space behind the house, so I could consider a system that sits on the ground.

I just like paying the utility every month and not having to worry about owning, maintaining, and repairing my own infrastructure though. As it is now, if anything goes wrong upstream of the meter, that's not my responsibility.

Why don't you do a small installation where your generation does not exceed your usage so storage considerations are moot?

Because you mostly end up generating when you don’t need the power, and need the power when you’re not generating.

If the way things are structured in your country let you draw the same amount of kWh that you’ve put into the network, that works. Where I live they recently changed to buying the solar at market prices. When the sun is up during sunny months that’s zero or close to that. So you pretty much need the battery installation too.

My neighbour got a solar + battery installation, and it works well enough!

>a small installation where your generation does not exceed your usage

I meant explicitly a small system where the moment to moment generation generally did not exceed moment to moment usage.

>the way things are structured in your country

In the US things are structured per utility which varies widely by state, city, or even neighborhood and they have many different kinds of rules.

Mainly that I've yet to follow through on my 5+ year old plan on building a small greenhouse and using solar for water pumping. For most use cases it's a fairly bad "business case" compared to simply buying the power you need. If anything, you would probably be better off setting up a storage sollution to buy power when it's cheap, and then using it when power is expensive, compared to actually setting up power generation yourself.

If I had a good area for them which wasn't some form of rooftop I might have. Rooftop installations are very expensive in Denmark because they are too heavy to be installed without building a lot of support. Even my carport would basically need to be an entirely different structure with a custom foundation to support a roof of solar panels. Which you can absolutely do, but it would be decades before it was worth it.

Oh, that' s surprising. In the US everyone just puts them on their roof and most people don't have any structural considerations it just works. I wonder what's different about your roofs.

The high cost of rooftop solar in the US is mostly a regulatory choice. From tariffs driving up prices significantly, to completely scattered permitting processes city-to-city, to wild swings in utility policies that make solar a good-to-bad decision overnight, it all drives costs up. So the only solar installers who survive are those who are able to swoop in when the utility policies change and can drive customer acquisition super quickly ($$$), and have massive permitting office experience that lets them deploy. That all costs a lot of money and drives out competition from the space.

So we pay something like 3x-5x for residential solar in the US versus Australia. Because we choose to as a society.

Also, I heartily disagree that utility scale solar is obviously cheaper. Transmission and distribution costs are the biggest cost on the grid, and utility scale solar needs to pay for that whereas residential solar drives down T&D costs.

We definitely need a lot of utility scale solar, but if we want cheaper electricity we need to incentivize tons of residential solar so that we can keep our grid costs lower.

Well, very few in the US realize that residential solar in the US is 3x the price it is in Australia, let alone that a lot of it caused by regulatory structures, so it’s hard to say it’s a conscious choice we’ve made…

But yeah, would be great if we could do something about it.

There are some baby steps - Maryland passed a law last year to force adoption of uniform permitting process via NREL’s SolarApp+, hopefully that’ll make a dent.

>...Also, I heartily disagree that utility scale solar is obviously cheaper. Transmission and distribution costs are the biggest cost on the grid, and utility scale solar needs to pay for that whereas residential solar drives down T&D costs.

If we are really at the point where distribution costs for utility solar make it cost anywhere near the cost of consumer rooftop solar, we have a real problem. If that is true, we probably need a different approach to decarbonize the grid. I don't think you are right.

You'll need to show your numbers, I don't follow what sort of reasoning could arrive at needing a different approach for decarbonizing the grid.

Average US consumer costs are $70/MWh for transmission [1], out of $130/MWh total averaged across all consumer types [2].

However, those are average prices, residential consumers pay far higher prices, especially for the T&D side.

New utility scale solar is $38-$78/MWh unsubsidized [3, page 8], at $1.15-$1.6/W. [3, page 34].

Meanwhile, residential solar is $2.5/W to $3.5/W [4], meaning it's only twice as expensive as utility scale solar. All told, that means that residential solar cost is roughly equal to the cost of utility scale + T&D. (While searching the web, several results claimed that residential solar typically costs $0.06-$0.10/kWh, or $60-$100/MWh, but that seems too low, and I'm guessing is from old data when it was cheaper to residential builds...)

All this ignores storage, etc. But residential solar shaves off the highest peak of demand from air conditioning on the hottest days, so every time I see a neighbor install solar I cheer because I know that it's less justification for the utility to build out more T&D for the rest of the power needs.

[1] https://thundersaidenergy.com/downloads/us-electric-utilitie...

[2] https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

[3] Main report PDF at https://www.lazard.com/news-announcements/lazard-releases-20...

[4] many sources, this hasn't changed much in years, one random top web hit is here: https://www.ecoflow.com/us/blog/california-solar-panel-costs...

>>…Also, I heartily disagree that utility scale solar is obviously cheaper. Transmission and distribution costs are the biggest cost on the grid, and utility scale solar needs to pay for that whereas residential solar drives down T&D costs.

From the 2024 numbers the LCOE for utility solar was $29 - $92 and the consumer rooftop solar LCOE was estimated to be $122 to $284. Depending on the projects, utility solar was estimated to usually be somewhere around 3-10 time cheaper than rooftop solar. If the transmission and distribution costs could bring the low cost of utility solar anywhere near the very high cost of consumer rooftop solar, that would be very concerning as that $122 - $284 cost estimate also doesn’t cover any of the costs of firming intermittency. I have never heard anyone else implying the costs of distributing the electricity from new utility solar projects could increase the cost that much. The money that has gone to pay for net metering to subsidize those very high consumer rooftop costs should have gone to utility solar and grid storage projects - the goal is to decarbonize the grid and the money should be spent where it will do the most good.

Australian rooftop solar is the cheapest consumer energy in history. This is despite the hardware and salaries being roughly equal to the US where the cost is about 3 times more. So it's not wise to extrapolate from US prices.

And in general, you should check your electricity bill to see how much is actually for generation vs transmission.

> Also, in almost all cases, the home installation doesn’t have enough battery power to actually last through inclement weather

I've posted this several times here, but I think it's worth responding to claims like this, as they are plain wrong.

I had a house with a 4.8kWh battery, and 6.6kW of panels. Just our overnight consumption was over 4.8kWh, so I purchased a generator "in case". Later during a period of high rainfall, we got flooded in for a week. The authorities cut off the power because of risks, so no power for a week. It was a once in a decade rain event, so "inclement weather" understates it.

In that week I learnt what a little adaption can do to your electricity consumption. We never used the generator. We did stopped bulk heating water, and of course all house heating / cooling was turned off. That was about the only life style changes from memory - well perhaps no 2 hour roasts in the oven.

Turns out even in inclement weather the sun does peek through occasionally, and when it does you can do high power consuming activities like wash clothes. It also turns out solar panels don't shut off under overcast conditions, they just drop to about 20% capacity - which means for us they output 1kW most of the day. And that turns out to be more than enough to charge the 4.8kWh battery, and that battery more than enough to power the refrigerators, lights, computers, TV's, fans, and microwave overnight.

4.8kWh is stuff all of course. Yet it suffices to get you through during a once in a decade event.

We've built a new house now, and have 40kWh battery (oddly cost us the same as the 4.8kWh). We also have 32kW panels. They will generate 6.4kW during inclement weather. Do you see the implications of this?

If the electricity bill doesn't remain in credit, we will just disconnect. Why wouldn't it remain in credit you ask? It's because you can't sell power when the sun is shining where I live, as the solar duck curve forces the price to go negative. There is a $2/day flat cost for being connected to the grid, even if you draw nothing. So we have to sell $2 of electricity every day for being connected to remain viable.

I think perhaps we will, but only because of the battery. When the grid suffers some outage the price spikes by a factor of around 100. That almost never happens when the sun is shining of course, because the solar over capacity just shoulders the load. But when those coal fired generators trip during the night (which they regularly do), you get to make some real money from the battery capacity.

Totally. Grid solar and grid battery installations are gonna rock the world but rooftop solar is too bespoke and labor intensive. It goes directly against the benefit of solar’s mass manufacturing

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