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Comment by FredPret | Hacker News Reader

Solar panels are getting cheaper by the day.

Solar power is not.

Because between the panel and the lightbulb lies a battery.

Batteries are getting cheaper by the day too. Price per kWh halved in China in the last 2 years according to BloombergNEF (https://x.com/colinmckerrache/status/1800901575214514475).

Yes, and no.

Yes, a lot of people who install residential solar have a battery, and "common wisdom" tends to size the battery up if the solar install is larger.

But nothing stops the battery being really small, or indeed (like commercial solar generation) there being no battery at all.

Yes, of course, solar is not 24 hours. But having cheap energy "only" half the day (1) is a major plus. And as energy cost fluctuates, so do habits. For example since we got solar we tend to use the dishwasher in the mid morning instead of at night.

(1) actual solar availability depends on the width of your country. For example solar plants in say Arizona happily generate good power while the East coast is dark, and panels in say Florida would cater for mornings in California.

And that's before we factor in wind, which is commonly stronger in the late afternoon into the evening.

you may want to \ your *s

never mind, you fixed it

> And as energy cost fluctuates, so do habits

You're advocating for reverting back to pre electrified times, this stuff is straight from the 19th century. Using energy is good, it is progress.

Not at all.

I'm saying that people adapt very quickly when costs are involved.

I'm not saying we sit in the dark at night. I'm saying that we time-shift some energy consumption because some of the day energy is free, and some of the day we pay for it.

The pool pump runs during the day. As does the hot water cylinder. The electrical cost for these us now zero (on most days.) Our night-time electricity usage has gone down because it's more expensive.

When energy costs the same all 24 hours then it's not something I take into consideration. When it's different habits change. I don't use less energy, if anything I use more. But I factor time-of-day into -when- I use it.

Not everything can be shifted. Our peak usage is still in the morning and evening. But scheduled things have moved from night to day.

I can run 10 old 100 watt light bulbs for an hour for 14 cents. Or 100 led light bulbs. I can run my hot tub full blast for an hour for $1.40. A head of lettuce is $4. A bag of coffee is $18. Five chicken breast is $20. A tank of gas for my wife’s car is $80, and for mine is over $200.

The cost of electricity for the loads I can control, such as those other heating or cooling living space, would have to 10x for it to be worth worrying about the cost, which would mean a $1400/MWH. The ceiling on the wholesale market price in ontario, last time I checked, was $2000/MWH.

I can see the price of electricity rising quite a bit across the board, but I don’t think people are going to inconvenience themselves at all to respond to it.

> I can see the price of electricity rising quite a bit across the board, but I don’t think people are going to inconvenience themselves at all to respond to it.

People already do that, and have done so for decades. Many places have different electricity costs for defined peak and off-peak times, and many people absolutely do move their heavy electricity uses outside the peak times when they can.

Naturally ymmv depending on your energy costs. And indeed other costs. ($4 for a lettuce sounds high, we pay pennies for that here.) It'll also vary depending on your overall income.

I would gracefully suggest that your life-style might not necessarily reflect the life style of the general public?

I think my grocery prices are in line with everyone else in British Columbia

it sounds like british columbia grocery prices are insane. are those us dollars? five chicken breasts here is about $3000, which is about 2½ us dollars

Those are CAD

aha, thanks. xe tells me those are 27% smaller than us dollars, so those prices are respectively 1 dollar, 3 dollars, 13 dollars, 15 dollars, 58 dollars, and 150 dollars, speaking in us dollars

or, using today's mid-market rates from https://preciodolarblue.com.ar/, $1300, $3800, $17000, $19000, $75000, and $190000. $19000 is sure a lot more than i'd pay for five chicken breasts

as a clarification from further down the thread, since you said those are canadian dollars, those prices are respectively 1 dollar, 3 dollars, 13 dollars, 15 dollars, 58 dollars, and 150 dollars, speaking in us dollars

me, i pay $3000 for five chicken breasts, which is about 2.3 us dollars

I am baffled by this argument. What point are you trying to make? The energy is still being used, just at slightly different times.

> What point are you trying to make?

What's so hard to understand? Children can't do schoolwork after dusk without electricity. Society doesn't function after dusk without massive electricity. Let's do our work while the sun shines brightly is 19th century level behavior.

You're making assumptions here though that children having to do schoolwork after dark is a fundamentally good thing. The same goes for the assumption that society can't function after dusk - what did society do before the lightbulb was invented?

Taking modern norms as a basis for why we need the tech that allows the modern norms is a logical loop. People did learn things before electricity, and electricity didn't predate society.

if you read william kamkwamba's autobiography, you will gain a major appreciation for what a huge improvement functioning after dusk can be. his 12-watt windmill revolutionized his family's life, for the better, even before it made him world-famous

I have little doubt that going from no electricity to 12 watts can be a huge leap, but I'm not familiar with William Kamkwamba. Help me out here, what goals or metrics did he point to when showing that his family's life was better?

read the book

I may. In the meantime is it really so hard to give highlights or an example that at least better explains the point you were raising? Just saying one person felt their life drastixally improved with one change they made isn't really helpful at all, you can find countless anecdotes to make whatever argument you want.

you can do your schoolwork with a 1-watt led, a 10-watt smartphone, or a 30-watt big-screen backlit laptop. if your nighttime electricity costs are a ridiculous 40¢ per kilowatt hour, abstaining from 30 watts 4 hours a night will save you 43 kilowatt hours per year, almost 18 dollars. even in like lesotho those aren't the kinds of loads you'd have a strong economic incentive to shift to the daytime

it's more things like baking dinner in an electric oven, demolishing concrete with an electric hammer, welding with an arc welder, heating the water in your hot-water heater

Yeah, most of the load I cannot move so cost has no effect on my usage it just means I have less disposable income. 75% percent of my bill is network cost so power source cost make little difference to me.

if solar panels on your roof generate the energy, you don't need the network

Well that's where I am heading. but its a failure of society when each person must provide their own utilities.

probably in some places people will figure out how to provide a cheaper network, even if society fails where you live. hopefully you can move

Dude all he suggested is running your dishwasher while at work instead of at night, and you're acting like he wants to end modern life as we know it. Chill.

i agree that using less energy would be bad; we sure as hell aren't going to achieve atmospheric carbon capture that way, much less terraforming mars. but i think using less energy is not what's being advocated; rather, presuming that consumption patterns will remain unchanged in the face of a new incentive structure will result in an unrealistically pessimistic assessment of the required battery storage. having energy that's literally free during the day is likely to result in using more energy, not less

commercial building hvac systems have been responding to these incentives for decades: freeze water with chillers at night when electricity was cheap (or free, or actually negative cost), then circulate coolant through the ice during the day to get cold coolant to cool air through heat exchangers and thus air-condition your office. you could imagine freezers and refrigerators that worked the same way, storing energy when the sun is up to keep your food cold when the sun goes down

the popular evacuated-tube solar hot-water heater of course only heats the water during the day, storing the hot water for nighttime in an insulated tank, usually supplemented with an electric heating element for the rare occasion that the stored heat is insufficient. and there are already places where electric hot-water heaters respond to commands to preheat water at off-peak hours. these so-called 'sensible heat storage' devices are much bulkier and leakier than the phase-change type from the previous paragraph, but they can be very simple indeed

going beyond phase-change energy storage, tces energy storage uses phenomena like the enthalpy of hydration of the muriate of lime. this provides thermal energy storage that's another order of magnitude more compact; it can be used for heat and dehumidification as well as cooling, and some storage media such as lye can even get hot enough to be used for cooking

this stuff is straight from the 22nd century

How do you define progress?

The biggest challenge I see in similar discussions is that we don't have a shared understanding of what progress because we don't define the goals we're moving towards.

it's the opposite of congress

>How do you define progress?

To some people, progress is not being made unless useless middlemen are raking in the bucks and getting more out of the energy you are using than you are.

I think that's an incredibly uncharitable interpretation of what GP said.

We already change our behavior around electricity costs and demand: for example, a couple years ago PG&E (California) forced everyone to switch to a time-of-use rate plan where electricity costs go up quite a bit between 4pm and 9pm. You better believe I avoid doing things like laundry or running the dishwasher then, and opt to run them earlier in the day or later at night.

If I had solar (without battery storage), I'd absolutely be running my heavier electric load when the sun's out instead of at night when I have to pay for power. Sure, the ideal would be everything is similarly cheap no matter what time of day, and maybe we'll get there in 75 years or so, but until then, I'm fine continuing to do some time-of-use optimization here and there.

keep in mind though that pg&e is kind of a pathological case

That may be true for the US, but lots of the world has variable energy pricing already.

not because of pricing variability, but because pg&e prices are just unbelievably high. would you believe 39¢ per kilowatt hour?

>Using energy is good, it is progress.

Roger.

Using less energy is even better, it is further progress.

not my downvote btw

Very few people have batteries with their solar in my neighborhood.

>Very few people have batteries with their solar in my neighborhood.

This is common. It is of course due to the cost of battery systems, particularly if the solar system was installed several years ago. I just bought a house that has solar and not only does it not have battery storage, but the solar cannot power the house when grid power is down. Seems insane to me to build a system that can't bootstrap from the solar and run things on an as available basis during outages but apparently this is typical.

I'm still learning, but I also think that I am not getting great value for the power I am supplying to the grid during the day. Add to that the extra cost of power during peak evening hours when I don't have solar and a battery to time shift my solar for my own use during the evening seems like a win. It still helps the grid since I am pulling less during peak evening hours.

Battery prices have dropped 50% in the last 12 months.

https://www.pv-magazine.com/2024/03/07/battery-prices-collap...

That’s great.

Grid-scale battery storage is still a terrible idea when you can simply build a nuke station that does the same job with 0.01% of the waste material and space used.

it seems implausible that a nuclear power plant occupies 0.01% of the space of a battery bank of the same peak power capacity; if anything, i'd suspect the discrepancy is closer to the other way around (edit: it is, see the comment below where i do the math, and please stop posting thoughtless bullshit)

if you were talking about the solar farm, then yeah, i'd agree

If that seems implausible you might want to replause your seemometer. A nuclear plant has much higher energy density than any battery.

well, nuclear fuel rods certainly have much higher energy density than any battery. but they're only a small piece of the power plant, and i wasn't talking about the energy density (joules per liter) but the power density (watts per liter or, since we're talking about land use, watts per square meter)

a 10c 2000 milliamp hour 18650 cell produces 20 amps at nominally 3.7 volts, which is 74 watts. if it occupies 18 mm × 18 mm × 65 mm that's 3500 watts per liter. tepco's kashiwazaki-kariwa nuclear power plant is 8 gigawatts, which is 2300 cubic meters of 18650s. if you stack them two meters high, that's 1100 square meters, an area 34 meters square. maybe you have to double that so you can drive a forklift in between the racks of batteries, plus you need some space for things like fireproof bulkheads, wiring, and inverters, but we're talking about maybe 50 meters by 50 meters, 0.0025km². kashiwazaki-kariwa is 4.2km², 1600 times bigger. (also, it's more than two meters tall.) the hypothetical 8-gigawatt battery bank uses 0.06% of the land area. even if you scale up the discharge time from 6 minutes to the usual 4 hours, it's still only 2.4% of the area of the nuclear plant

you can get better batteries than that, too. and if you're worried about land consumption, as you have to be in japan, you can put your batteries in a building with multiple floors

Nuclear has the opposite but related problem of solar; whereas you often generate excess solar and need to store it somewhere during the day, nuclear energy often generates too much during low demand times and has excess energy to store as well. And you can’t easily scale down nuclear during lower demand hours.

One of the largest pumped hydro stations was originally built to store excess energy from a nuclear power plant. https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power...

Similar time frame. Slightly smaller capacity, Northfield Mountain was brought online to store power from the Vermont Yankee nuclear power plant. Interestingly the pumped hydro facility is still functioning as a grid battery, even after the nuclear plant was decommissioned for no longer being cost effective.

https://en.wikipedia.org/wiki/Northfield_Mountain_(hydroelec...

I think "simply" is doing a lot of work there. Work that completely overwhelms it.

Building a new nuclear plant is a hugely capital intensive project, not to mention the massive amount of time it takes to complete it and get it fully online.

Places like France (that feed a huge percentage of their demand with nuclear) don't somehow magically have super cheap energy. Nuclear plans cost a lot to build, and a lot to operate.

Those huge capital costs are certainly limiting China's expansion into nuclear:

    China intends to build 150 new nuclear reactors between 2020 and 2035, with 27 currently under construction and the average construction timeline for each reactor about seven years

~ https://itif.org/publications/2024/06/17/how-innovative-is-c...

If they were cheaper they'd likely build 300 in that time.

or 1500

woa there, they've only got three of these:

https://www.world-nuclear-news.org/Articles/Excavation-of-Ch...

:-)

right, you could imagine a much higher level of investment. that waste isolation pilot plant is 400 million dollars over 7 years, 50 million dollars a year. the 217 gigawatts of solar power the prc installed last year represent an investment of probably 88 billion dollars last year, assuming 40¢ per peak watt. so the prc spent more money building solar plants in the last five hours than they will spend on that nuclear waste facility in this entire year

and you say they only have three of them?

Either global warming is a serious catastrophe or it isn't.

If it isn't, this is all moot and we should burn cheap, clean, abundant natural gas.

If it is, surely it isn't a problem to shell out more money to get green baseload generations from nuclear? We need to meet base demand around the clock, and nuclear is the least harmful way to do it.

Or we invest our money in the technology with the largest bang for the buck: renewables.

Then follow the research to handle the resiliency, still at vastly lower costs than anything nuclear.

https://ieeexplore.ieee.org/document/9837910

"Simply" building a nuke station sounds like an oxymoron.

Plus 0.01% is quite small but if it's got U235 it will still be more deadly millions of years later than thousands of percent of other deadly toxic highly energetic materials such as pure TNT, in the time the uranium half-life has barely elapsed. And due to the nature of radioactive half-life, the second half of the uranium will not lose its radiation until many millions of years more than the first half required.

Edit: not my downvote btw

Do you think batteries are getting more expensive over time?

I think the assumption they would get cheaper given a massive change in their adoption patterns is unfounded. We know that lithium prices have gone up from the rise in EVs, and this has in part driven Tesla to switch to LiFePO4's rather then Li-Ion packs in some of their cars. Same effect with coltan. (although lithium is declining currently because EV sales in China have slowed).

What would be the effect of the demand for terawatt-hour levels of batteries? Even if lithium is replaced with sodium in the application, the manufacturing capacity isn't there and won't be for quite some time - and the higher-value applications will get first take (i.e. EVs).

Even if the lithium demand was saturated battery wise, at the steady state point the cost can then simply stabilize around the refurbisment/recycling cost of lithium/sodium/whatever from batteries.

Sigmoidal adoption curves look exponential at the start, linear in the middle,and then become asymptotically flat.

> although lithium is declining currently because EV sales in China have slowed

have they?

'one in three' of all new vehicle registrations in china were electric last year https://www.iea.org/reports/global-ev-outlook-2024/trends-in... or 37% https://autovista24.autovistagroup.com/news/ev-registrations... and the absolute number seems to be doubling this year, though they only expect a 45% market share

these figures do include both hybrids and pure battery models, though

in general the 'experience curve' says that things get exponentially cheaper as you produce exponentially more of them

The experience curve is asymptotic[1].

What do we get if we look at say, FLOPS per US $ over time? This[2]. There is no reason to think batteries are any different, the only margin you have is to argue over which part of the curve you think we're in.

A sigmoid curve[3].

[1] https://www.extension.iastate.edu/agdm/wholefarm/html/c5-208...

[2] https://www.researchgate.net/figure/Number-of-flops-per-Unit...

[3] https://en.wikipedia.org/wiki/Sigmoid_function

That FLOPS graph is an exponential scale... so that straight line "after the sigmoid" is an exponential growth curve. I'm not sure it makes the point you're trying to make.

solar power is getting cheaper by the day; https://www.pv-magazine.com/2024/04/19/europes-renewable-ppa... says:

> Energy consultancy LevelTen says that solar power purchase agreement (PPA) prices fell 5.9% in the first quarter of 2024, with decreases recorded in all analyzed countries except for Romania. It attributes the decline to lower wholesale electricity prices and a fall in solar module prices

however, they haven't yet recovered to the 02020 levels, presumably because the astounding precipitous fall in module prices over the last year hasn't been priced in yet

>Solar power is not.

Often there is no battery, but regardless when solar cost goes up it could be due to expensive contractors in-between the panels and the installation & maintenance, before the lightbulb even gets a chance to see a single watt.

a major reason in the usa is the tariff regime that has basically completely shut out chinese solar panels from the market; this makes solar panels in the us cost about twice as much as in the rest of the world

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