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This isn't a problem as long as your grid does dynamic minute by minute pricing.

When the price of power drops to zero in the spring/fall, you can be sure there will be plenty of people lapping it up to smelt aluminium, make glass, make steel, make cement, liquify air, make hydrogen, etc.

When the price of power is high in the winter, companies will swoop in with gas turbines, power cables from other places, and extra insulation to keep houses warm with lower energy costs. Entrepreneurs will see this coming, and will be there ready to provide power or power-saving measures to those who did not prepare.

As long as the market can set a price, the market will solve each problem. The people to lose out will be customers who don't adapt to keep their costs down - for example those who heat their 1960's uninsulated home with electric baseboard heaters.

There are already plenty of seasonal industries - like tourism. Power hungry industries will become seasonal or migratory too.

> Power hungry industries will become seasonal or migratory too.

Electricity will have to become orders of magnitude more expensive for this to be true. After you've bought the building, the smelter, and the guy to operate it, the cost of electricity to smelt aluminum is negligible. Its never going to make sense to leave all that idle if the cost of electricity bumps up a few cents.

I work for a.company that melts steel. Cost of electric is a very large issue. We pay workers extra to work overnight shifts when electric is cheaper and shut down during the day. We also shutdown for annual maintenance in December when Christmas lights raise electric costs.. not one that melts metal, but I know one plant runs 5 months and does maintenance the other 7.

Note, the above is as of 10 years ago. Now wind provides most electric so hours may be different to account for that.

We have Nucor in West Seattle and rumor has it running 24/7/365+ because the cost of shutdown/startup is too high. I've seen steel coming out is there everything I've driven by regardless of hour.

Seattle has far more stable power costs because they have lots of hydro.

Hydro has a fixed amount of water they can generate energy from, but can do it daytime, nighttime or weekends - whenever the users want the power they can have it.

> After you've bought the building, the smelter, and the guy to operate it, the cost of electricity to smelt aluminum is negligible.

Electricity is the biggest expense in aluminium production. There is a reason it is nicknamed "solid electricity".

I do like the dynamic pricing idea. If you're not well situated for panels you can invest in batteries and sell at night what you bought during the day.

I don't have your faith in markets though. The invisible hand is a potent force indeed, but it's just as likely to flip you the bird as it is to solve a problem that you have. There's nothing about a market, for instance, that knows to keep prices high enough to prevent the wintertime aluminum smelters from burning all the stored energy and causing a humanitarian crisis a month later when there's not enough to weather a blizzard.

Oh there is...

Imagine you see all the power being used up ahead of winter, and you predict this problem... Yet it seems like nobody else has noticed...

So you swoop in and, with profits in mind, you buy up some electricity futures contracts for December. They're quite cheap right now, and you suspect that when the blizzard hits they'll be really valuable. By doing so, you push the price of them up a bit.

Meanwhile, Fred over at the hydro plant sees that futures contracts for electricity are higher in December than now, so he'll make more money by switching off the generators now and using that water later in December when he'll get paid more for it.

Bob at the aluminium smelter sees that spot prices for power now are higher (because the hydro shut off), and futures prices suggest they'll be even higher in December too. So it's probably more profitable to shutdown the plant for repairs now, and restart production next year.

See how you noticing this problem started a chain of events that solved the problem? That's the power of markets - they can use the collective knowledge and intelligence of all the participants to solve a problem.

If everyone has perfect information and my speculative advantage has only to do with some insight that I had, then yeah it all works out.

But once I've bought those futures, I have an incentive to spread misinformation about just how bad the shortage is going to be, and to make it difficult for others to have the same kind of insight in the future so that I can have the same advantage next year.

If I'm successful, I'll have created a situation where actors that can store energy hoard it, only parting with it at prices that leave people struggling to survive the winter. We end up losing that energy to inefficiencies in the storage media, and we end up losing people to warmer climes--people who would have otherwise contributed to energy projects that increase supply.

Markets work out in the abstract, but unless they're watched closely they sabotage the conditions that made them initially useful.

Energy efficiency is always good, and I'm glad the government is incentivizing it.

A passive house can have 10% the energy cost/use of a regular "code" house. Even off grid, this can immensely help in the size of your battery required.

As someone with a smaller scale version of the "problem" you describe (3x overproduction from our ground-mount 6.7kW array in summer, 1/3x production in winter given air source heat pumps), I'd say this is where, even with this amazing contemporary technology, we need to get back to ... insulation.

As others have noted, passivhaus standards would help fix the "in the winter, homes use a lot more energy than they can generate" part of this. I've read of homes in Scandanavia that are heated by their inhabitants plus the output equivalent of a few candles. Not totally convinced by these stories, but they point the way: once you've got the carbon-reduced/free energy supply in place, work on massively (if possible) reducing how much of it you need.

We have an old adobe in the high desert, and it is so far from passivhaus as to be a joke. I'm fairly sure that if this was built to passivhaus standards, even our currently undersized array could handle the heating needs.

I live on the east coast, paid for excellent insulation and thick windows with good seals, installed solar, and don't pay a dime more for energy. That includes heating, cooling, hot water, and our two EVs. This is possible almost entirely because of the insulation.

We were generating a surplus, so we installed an electric clothes dryer, which seems to have balanced everything nicely.

> it doesn't fundamentally solve the problem that [...]

Is that the "fundamental" problem being solved, though? Or is it just an externality that needs to be addressed? It seems like the "fundamental" problem here is trying to maximize deployment of renewable generation, and that construction like this is a great step in that direction. (Not the least of which because it pushes the investment required onto consumers willing to bear the costs, and "generates jobs" in the process. Siting a new wind farm is a ton more complicated, and let's not even talk about the difficulty of installing a scratch-built reactor.)

I mean, it's true, that at the end of the day home energy generation is just PV solar, and PV solar doesn't behave like gas plants and that needs to be addressed at the grid level. But that's not an argument against PV solar, it's just an engineering problem.

> But that's not an argument against PV solar...

It can certainly be an argument against residential rooftop solar.

In general, "industrial solar" (ground mount, high voltage strings, single axis trackers) is sub-$1/W installed. Residential rooftop solar is still $2.50-$4/W depending on where you are, because it has quite a few additional requirements (per-panel rapid shutdown in NEC 2017, various other requirements on the panel and interconnects that add cost), and, often, poor siting from partial shading reasons (chimneys, vent stacks, trees, other bits of roof, etc).

I don't mind making homes more suited to solar (oversize the main busbar with a "solar ready" panel, route conduit up to the roof, require all vent stacks be on the north side of the roof), but it's a rather uncontrolled solution that's of limited "actually solving the problem" use. Low levels of penetration are easy to deal with, higher levels start to get really hard, when you've got whole subdivisions shifting from "lots of production" to "lots of consumption" as clouds go over.

Or, we get used to less reliable, more intermittent energy again, and a lot of the problems go away. Just, that generates other problems.

The power grid is a lot more fragile than most people assume.

> Low levels of penetration are easy to deal with, higher levels start to get really hard

Well, yeah. So pick the low hanging fruit and sell it to the FAANG hippies. I still fail to see the problem here. No one is promoting rooftop solar as a one-stop-shop trip to renewable utopia, just as a effective and immediately deployable generation mechanism in a regulatory environment not well-suited to agile and rapid solutions of any kind.

If we get to the point where the hippies are buying up all the panels and the grid solutions can't get them cheap enough, that's the time to start complaining. Not now.

That’s solvable by batteries. Of course there are tradeoffs like extra cost

It's the fundamental problem that needs solving in order to achieve what this announcement claims is the ultimate end goal of all this - a "net-zero carbon economy" for the country as a whole - and it has been the fundamental obstacle to achieving this for decades now. So long as this problem remains unsolved, no amount of supposedly zero energy homes will ever get the country as a whole to that goal because they're still reliant on selling excess energy to the remaining "non zero energy" parts of the country in the summer and buying energy back from fossil fuel plants in the winter.

So.. you're saying this specific technology can only get us 60-70%[1] of the way to the "ultimate end goal". Ergo... it shouldn't be deployed and we should whine about it on HN?

No, that's silly. Build the panels. Build the solar. Fix the externalities, but absolutely pick the low hanging fruit. Every panel on a hippie's home means less total joules needed elsewhere.

To be blunt: the kind of argumentation you engage in is absolutely toxic, and HN is awash in it. Engineers love to scream about perfect solutions, but real engineering is about tradeoffs. And folks here are absolutely terrible, just really, genuinely shit-tier, at discussing them rationally.

[1] Depending on locale, obviously. In e.g. Arizona it's probably much closer to 80-90%

I have been toying with the idea of buying used panels in bulk and doing the same, but the payoff just isnt there at the current battery price. What kind of frame did you install to mount the panels? I have tons of room for ground mount and would love to do it diy as soon as the costs line up.

My system is grid tie, because the local plans review process and I didn't see eye-to-eye on batteries. I have a solar power trailer for backup power.

https://www.sevarg.net/tag/solar2020/ documents the build. My frames are timber, though a neighbor built a very similar system with metal frames and 72 cell panels, and got his costs down quite a bit further - he's around $1/W installed, mine was somewhat higher at about $1.50/W (more expensive panels and a good bit more expensive frame setup).

If you can weld, and find used pipe to build your frames with, you should be able to do sub-$1/W for a DIY install.

No welding is needed, you can use metal clamps to hold the pipes together. I have my panels on metal structure with no welding, I used bolts for joins.

Yes, but the clamps I've found designed for that sort of use are quite expensive, and add a substantial margin to the project cost - and they're not needed if you can weld it up, or have someone else weld it up.

As I understand NEC from talking to various people and reading quite a bit of it myself, someone else can do the frames for a homeowner installed solar project, but "rails and up" has to either be the homeowner or a licensed electrician, because the rails are typically considered part of the grounding system and therefore electrical work.

In any case, costs doing it yourself are far, far lower than paying someone else to do it. And ground mount is an awful lot nicer to work with than roof mount.

> but "rails and up" has to either be the homeowner or a licensed electrician, because the rails are typically considered part of the grounding system and therefore electrical work.

Here in NM, you can (fairly easily) get licensed as the homeowner to do your own install of such a system. That's what did. My total cost (with those expensive metal clamps and nice aluminum panel rails etc) was around $1.80/W

In think in my country I can do all the work myself and I need a certified electrician to connect it to the grid, nothing else. The law is very different from country to country, for me the labor was extremely cheap while the panels and MPPT are more expensive than in US.

What do you use pipes for?

The physical structure. Replace the wood in my designs with welded hunks of old steel pipe and you have his design.

Thanks. I'm perplexed why you would need to weld pipes in this application if a wood structure is also suitable.

Simply because it's cheaper than clamps. Not easier, but cheaper. It's not for structural strength.

I am not a home owner or at all in the market for DIY solar, but your documentation is a real treat. A true labor of love.

What if instead of batteries you hooked up a boiler to heat water or a deep chest freezer to cool water and then used heat exchangers to heat or cool overnight when solar doesn't work? I'm assuming no one does this because batteries are likely cheaper than this type of setup.

You're welcome to do that, and it's something some off grid systems use, but the energy storage in that sort of thing is fairly poor. Go do the math on it, but you'll find a 55 gallon drum of water, from "room temperature" to "really darn hot" holds 15-20kWh of energy. It's useful, but not a staggeringly large amount for a typical house, that can easily use more than that on a single day's heating.

Thermal mass storage requires a lot of mass to do anything useful, or the ability to run exceedingly high temperatures. Or a phase change. Molten salt storage can store a lot of energy, but you're at "very hazardously hot" temperatures with "stuff that's mind-bogglingly corrosive when hazardously hot." It's not the sort of thing most people would want to mess with at home. Myself included, and my tolerance for experimentation is pretty darn high.

> It's useful, but not a staggeringly large amount for a typical house, that can easily use more than that on a single day's heating.

This article isn’t talking about typical houses of today. The typical future house should be a lot better insulated.

The ground is massive and digging a trench can be done.. those systems for storing heat seem to be gaining some traction

> It's not a big deal with only a few people on the grid, but if every house were doing this,

"Renewable is great, but if we're already generating all our power by renewables then..."

This argument is silly because we are nowhere close to having this problem yet. And as we start to approach that golden age (I mean, "problem") we'll have other alternatives.

Iowa is actually close to having the problem of more renewable power than demand. We are a small state yet ranked number two in wind production: your state should aim to overtake us.

This is not really a problem. You just send out a signal to shut solar off. Then people and businesses buy batteries to take advantage of the free power and sell it back at night.

Sounds like you need a geothermal ground loop.

I live on what can be reasonably approximated as a "pile of rocks." It's fairly thin dirt on top of a lot of basalt. I've considered it, but the cost to install such a unit is quite staggering, before I buy a backhoe to install it.

I'll consider one of those if I have to replace my unit at some point, but I'm far more interested in adding simple solar thermal collectors to directly add energy from the sun on the partly cloudy or clear days we have, vs ripping up half an acre of rock to put the loops in, or figuring out where I can punch another well for heat exchange.

If you had a modern well insulated house you could heat your house with a hair drier in the dead of winter in climate zone 5. If your stacking up to 4mwh then your house is not really a good example.

I have a modern well-insulated house (built three years ago) in Zone 4. There is no universe I heat it with a hair drier.

I mean... that's all our energy inputs, including pumping water from a fairly deep well, almost all our transportation miles (300-400kWh/mo), heat, hot water, etc. It's a ~7 year old manufactured, 2k sq ft, 2x6 exterior walls, pretty tight (blower door and ducting tests have concluded "Nothing to fix here"), though I'm still running down a few weatherstripping issues on one of our doors.

A 1800W hair dryer running constantly is 1.3MWh/mo, and this isn't 4MWh/mo, it's since about Nov, on a colder than usual winter. I'm right on the north end of Zone 5.

In any case, I've yet to figure out how to get our heat pump outdoor unit from freezing up in icing fog, but neither is it worth $20k to put a ground source unit in right now.

Once use cases like yours become more common (e.g. 4MWh surplus), industries will adjust and buy surplus power from homeowners like you, and the nation as a whole will spend less time and effort on maintaining the grid and power plants that generate electricity.

We will be able to run power-hungry industries (e.g. steel-aluminum/smelting) for very little cost.

> And even with 5kW of solar hung for a ~100 sq ft shed, I still need propane or a generator in the winter every now and then to keep things sane in here.

What about a large thermal mass wood/pellet stove? There's plenty of wood waste floating around that could heat a small house/shed in the couple of winter months when the solar panels don't do the job.

Wrong way. The house has pulled an extra 4MWh from the grid during the winter months (and pushes more than that back during the rest of the year). I'm past net zero on an annual basis, but that doesn't mean that even a large array is able to cover my energy needs in the winter few months.

I'm grandfathered into an arrangement where I pay my $5/mo and get unlimited net metering, but it's not remotely reasonable to pretend that I'm not heavily using the grid overnight, in the winter, etc.

You still have to maintain the grid for others to buy it and to balance it. The maintenance costs of the grid are going no where but up. More usage, more right of way, more towers, more wire, more labor.

If we expect industry to take up the excess, than either 1. that industry will only operate according to the weather or 2. We'll still need some variable power generation that can be switched on when wind or solar isn't producing enough

A few industrial users can weather changes in supply, with notice of the expected price in advance.

The aluminium smelter can heat to x+250°, let things cool to x° while people cook their evening meal, then heat up again afterwards.

A large supermarket chain can set their refrigerators to 5°, but by allowing the range to move between 3° and 7° can save significant power. (One of the big British supermarkets already does this.)

You don’t really get any more Solar after dinner. If everyone gets a big battery (expensive) then they could slowly offload the charge overnight but that would need to make financial sense to the house owners somehow.

At a minimum you’d need to recuperate the wear on the battery as they all have a finite amount of cycles

That only works on short timescales, which isn't the main problem because there are so many ways of solving that (for example batteries or thermal storage for home heating).

If they have notice the smelter will be happy to shutdown for maintenance for a few months. You need to plan this with them a year in advance though.

Seasonal operation is not desirable and has lots and lots of side effects.

As an example, a smelter that operates half the year takes twice as much capital to produce the same throughput as one that operates year round.

That’s before we get into all of the reasons that seasonal labor is undesirable, or how much additional warehouse capacity would be required to stockpile the metal which will needed over the unoperational months, or the raw material being stockpiled while it’s unable to be processed, or the impact on just in time supply chains, etc.

The large, industrial users are an example of thermal storage, but at a different scale than home heating.

Tesco's fridges are apparently worth about 25-50MW, so like a small grid-scale battery: https://www.theguardian.com/business/2019/jun/23/cool-runnin...

An aluminium smelter is gigawatts, the one in Scotland is 1.2GW, which is a medium-size power plant by itself.

They're easy projects, compared to installing thousands or hundreds of thousands of batteries or new heating systems in homes.