It's a trust issue. People don't trust their utilities, residential solar is (among other things) a hedge.

Basically, "how much would you pay to limit how much $powerco can screw you in future?". Human nature means a lot of people will willingly pay double for that.

“People don't trust their utilities” is a strong claim that I assume is very dependent on your location. I think I’ve had maybe two hours total of no electricity in the last five years?

Yeah I admit this is pretty situational - the U.S. I don't know much about - but NZ, Australia and most of Europe, consumer sentiment is that we are getting slugged - I don't have a survey to hand but I'm confident I could dig something up (EDIT: e.g: https://www.energymagazine.com.au/energy-survey-reveals-risi...)

In the last 5 years, has your kwh price increased? By more or less than inflation?

If utility scale solar takes off, do you expect that future prices will reflect a) capital and operating costs plus a fair margin or b) whatever the market will bear?

Ah, right, in terms of cost; I was assuming availability.

Personally I’m on variable rate electricity so it’s difficult to tell overall how much its climbing. But my feeling is that in my area the previous two winters were extremely high, but that this winter has been cheaper. A lot of that is down to missing infrastructure and political structures though.

Most people have grid-tie systems. If the power is out, they are down too. Only very rich people have money to buy battery storage enough to be off grid and then this kind of system is not what those companies usually lease. If you’re concerned about blackouts a gas natural generator makes a lot more sense economically speaking

This is factually true but my claim is that what motivates people is a desire for greater energy security (EDIT: where improved price stability is one aspect of that, as konschubert points out).

It also means you're less affected by rising prices. (Not that I expect rising prices, but others do)

I’m going to answer your “financially nonsensical” argument from personal situation.

I live in the Netherlands. Sure, we have a reliable power grid that doesn’t go offline for hours or any frequently to make a case for grid backup, but the power companies here charge heck of a lot of money for power. Think about it. The utility company commissions a solar farm (lower cost than roof top solar), but surely hire a 3rd company to operate the farm ($), and then the utility company wants to make $ for their shareholders, therefore, we end up paying a lot of € to cover these.

Now, I have as manay panels as I could on my roof (10) that generates more than my average use in the Summer. I run a heat pump that can heat & cool and Ioperate it when the sun is shining. I do laundry when the sun is shining. Because of net metering, my grid usage practically cancels out against my solar energy production. When the net metering subsidy goes away, I’ll install a reasonably sized LFP battery at home to smooth out day/night patterns, and possibly covering the occasional cloudy days right after a sunny day. No power costs from April to September already pays the cost of my panels in just 5 years. It is free money(as in I save it from going from my pocket to the utility company and their shareholders).

So, it does make sense. Atleast in many parts of the world. If you live in a part of the world with super reliable grid _and_ low prices, or you’re so rich as to not care, then probably, it may not make sense to you :-)

I was just talking about it with some friends from South Africa. They said almost every household there sort of needs to be energy independent because the power company is in the ruin. So, solar + batteries it is. What would you do otherwise?

Didn't half a row of row houses get destroyed in a fire last year in NL because they had rooftop solar and it would effectively shield the fire from the firefighters?

I don’t think the government would allow solar panels to be part of the building code(and even encourage new built houses to have them) if they actively hurt firefight.

I’m struggling to even think about this argument. How does something on the roof prevent firefighters from putting out the fire? It’s not like firefighters drill a hole through the roof to ingest extinguishers..

The solar panels themselves are _outside_ the roof. So, if they catch fire, your roof must have gone to fire by now, and you have bigger things to worry about.

This happened last October

https://nos.nl/artikel/2493147-bouwregels-voor-verduurzaamde...

Yes, the article does not mention the solar panels even once. They talk about the additional insulation they put on atop the old facade, which led to a gap which helped the fire to propagate faster. (my understanding of Nederlands is limited, so I may have misread something).

I cannot see how solar panels on the roof could hinder fire safety.

All the Li-ion batteries we keep inside the house in the other hand… particularly the old ones on our used electronics laying around in closets and drawers without being paid attention to. That’s what worries me the most. I can only get the most flexible fire insurance for my home.

That looks like classic FUD

>Think about it. The utility company commissions a solar farm (lower cost than roof top solar), but surely hire a 3rd company to operate the farm ($), and then the utility company wants to make $ for their shareholders, therefore, we end up paying a lot of € to cover these.

You missed the largest reason home solar can be competetive and that is taxes. 11 cents per kWh and 3 cents sustainability charge and then 21% VAT over the cost price + taxes. And then the government mandates the energy companies have to buy your energy for the same price they sell you energy.

So as with many thing here it only makes sense because the government has completely distorted the market.

I would have thought taxes on electricity would be lower because in an indirect way it contributes to cost of business in the country. But, I am surprised.

Now, let the tech mature for a reasonable longish term energy storage and I’ll set one up in the backyard :-) Save excess energy from the Summer, use it in Winter, repeat.

I don’t have enough space for the amount of LFP batteries I’d need for such seasonal storage. Even flow batteries of today needs more space than I have. So, it will have to be some $future tech that could allow me to save the summer for the Winter.

You know, it's a bit hard for me to understand how every household buying hundreds of kilograms of hard to mine metals is somehow a solution to the energy intensity of modern civilization. But maybe I'm just very nearsighted and it'll work.

Well, by that logic, I have some great sophistication going on in my household..

Several devices that took EUV machines(that cost hundreds of millions each) to etch login onto themselves - microchips on my laptop, phone etc.

A pipe constantly supplying flammable gas that was probably mined thousands of kilometers away just so that I can burn it and heat up my water for shower.

A very dangerous to the environment - refrigerant in both my fridge and heat pump.

A tank full of dinosaur juice in my car, which itself was machined and built with some exotic metals mined somewhere else in the world.

What difference is a few more kilograms of futuristic substance that can save energy for my house make?

I know hundreds or thousands of kilograms of LFP batteries in my backyard in feasible today. But who knows. Maybe we will find a way to mine Lithium or replace it with Sodium and the whole process would become “normal” like the metals in my 3 ton car.

You summed it up pretty well. I struggle to understand the idea that increasing consumption will lessen the impact of previous consumption. If this is our only approach, extrapolation says we're doomed.

If you want private panels in pretty much any country outside of America, they're going to have to go on the roof as we don't exactly have the land to waste elsewhere.

I think the commenter was implying that rather than putting it on the roof of people's homes, the focus should be on utility-scale solar power stations.

Which doesn't make too much sense outside of the US, where land isn't nearly as cheap.

It makes sense in any country that has agriculture.

Solar produces 10x as much power per area than energy crops.

And other than with crops, you can have sheep grazing and have a functioning meadow ecosystem develop below the panels.

What are the upfront & maintenance costs of solar vs crops on that kind of scale? I'd hazard a guess it's a little more than 10x.

Also, how are you planning to grow meadows under solar panels without any sunlight?

I’m honestly super excited about you asking because I think I’ll be able to change your mind with a single picture:

https://cdn.arstechnica.net/wp-content/uploads/2021/10/Getty...

The sun moves, and therefore the shadows move. And you need some space between the panels anyways, so they don’t shade each other. Also, grass can grow in the shadow!

The cost of installation is not a problem, because the ROI is greater than the interest on a loan. That’s what banks are for!

You are correct, this has changed my mind as it is a lovely weird photo that I have enjoyed.

Here in Germany we waste about 2.4 million hectares on „energy crops“. That’s enough to cover a large fraction of Germany’s primary energy consumption if it were used for solar instead.

The foolish move by the German government to close down all the nuclear reactors. The German government is weird.

Or history is more complex than a sound bite.

Getting Germany off nuclear has been in the making since the 1980s, and a big factor was fighting corruption.

We still have a glowing mess from those days, waiting another 80 years until it can be cleaned up.

It would have been nice to turn off coal first, but it doesn’t change what we need to do for renewables.

you say 'If you want private panels in pretty much any country outside of America, they're going to have to go on the roof as we don't exactly have the land to waste elsewhere.'

https://www.worldometers.info/geography/7-continents/ says the population density of north america is 28 people/km², and south america is 25. meanwhile, europe is 33, africa is 49, asia is 153, "australia/oceania" (???) is 5, and antarctica is 0. so basically the population density of europe is the same as america, africa is just a little bit higher, asia is much higher, and australia is much lower

possibly by 'pretty much any country outside of america' you meant either nigeria or singapore

but let's consider the worst case continent, asia. 153 people per square kilometer means 6500 square meters per person. hopefully you are aware that the average home size in asia is not 6500 square meters or even 65 square meters, and that a substantial fraction of people live in apartment buildings which share a roof. so the vast majority of land even in asia is not roofed. this is also obvious from looking at any satellite photo. but enormous numbers of people live in houses with gardens or even farms attached

if we assume a 15% average solar capacity factor and 21% efficient solar panels, 6500 square meters per person is 200 kilowatts per person. current world marketed energy consumption is something like 2, 2½ kilowatts per person. that's still too much to put on the average roof but it's not exactly a major fraction of the total land area either

even nigeria is only 250 people per square km

you're right about singapore tho

>Rooftop solar never really made sense in the big picture kind of way.

I think it's in the big picture it actually does make sense. True it's not the cheapest, but it is the fastest way to actually get solar panels into sunshine and start solving our problems.

The additional cost is paid mostly by "volunteers" instead of having to raise taxes or wait for some corporation to make a move, there is no NIMBY-problem since it's actually the BY-owner who makes the decision. You can mobilize thousands of companies (solar panel installers) at once all around the country. Rooftop solar grows by about the same as a nuclear power plant per year in some countries.

Finally the resulting power generation is geographically distributed so that no single rain cloud can cover the entire "power plant".

I think larger projects run by governments and large corporations should be focused on generating gas or building battery storage, so that some of that cheap rooftop solar and other renewables can be stored for nighttime and winter, instead of being sold for negative prices at certain times.

What's plenty of space? I have perhaps 3-400 sqm of lawn. I'm not going to use 50-100 of that for solar when I have that amount of roof that is otherwise wasted space. I agree that perhaps domestic installations might not be the best idea because you need the same equipment repeated at every home, that could otherwise be centralized at a plant. But for resilience it's pretty neat. If I had more than say one power outage a year lasting more than an hour, I'd definitely be looking at it. I can see why South Africa is a big market (lots of sun, frequent power outage). Perhaps the middle ground between massive scale and domestic scale would be community sized plants serving (say) 100-1000 households.

It’s nice to have generation close to consumption because you save on transmission infra.

No. You don’t. The sun doesn’t shine 24/7.

Demand at night is much lower.

It doesn't make sense if you effectively rent the panels, which means they have to come down again.

Whether or not the panels "have to come down" depends on who pays.

If the solar company has to pay, it might not bother at the end of the lease term.

This can turn into a very low price to sell the panels at that time.

Residential solar has one huge advantage over utility solar - RS lets people virtue-signal.

In other words, part of the payback/value is letting people say/think "I'm a good person."

We can argue about whether the additional solar demand due to virtue-signaling had good effects but it did produce additional demand.

Contrary to all that, I know many people who are now basically immune to power grid issues in the us due to their solar and storage capacity. A friend in Oakland was running off of local storage for 8 days last year while the rest of his block was scrambling to buy generators.

One of the issues I have with "rooftop solar" is that it's usually sold by and installed by companies who are there to make a quick buck and they don't really explain the details to customers. Besides the predatory pricing and loans, and the blatant lying about payback periods, one big thing is the lack of technical details. The amount of people who don't understand that their new solar install is useless when the grid goes down is astounding.

Your friend is probably rich or very frugal on his power consumption

yes, it's collectively irrational behavior, just like warfare. but it's often individually rational behavior (like defending your country when it's invaded, in some cases) because electric power utilities commonly have monopolies, which causes two problems:

1. they become single points of failure, and their risk tolerance for outages may not match yours, so you may end up either paying excessive costs for reliability you don't need, or experiencing an outage risk you can't tolerate. or they may have outage risks which you can't solve by dumping money on them, such as corruption

2. they sometimes try to extract monopoly rents

there are also coordination problems around things like time-of-usage billing. solar power is free during the day, but your utility provider may not be willing to deliver it to you for the extremely low marginal price of transmission and distribution; they may be legally obligated to charge you the same price as at midnight, for example