oh no! think of the stock market!

The original commenter's (OC's) point has nothing to do with renewables' reliability.

It is entirely to do with generation vs demand. Grid operators could ask other generators like coal, nuclear, hydro, etc. plants to curtail so inverter-based renewables can export power, but that's not likely because those producers can't ramp generation up and down as easily.

Grid stability is a problem when you have overcrowding of generation without enough demand on given feeders. This is moreso an issue with the utilities anyways and how they plan their transmission and substation upgrades.

What options do we have to stabilize a renewable energy system and make it long term viable?

If we install enough solar where 100% of our daytime load is served by solar, that’s great. But what about when the solar starts to drop off later in the day?

Store the surprus of energy from the solar panels and use that as a buffer with batteries or gravity

But some gas units take literal hours to turn on. And if you’re 100% renewable during the day, you can’t have those gas units already online.

Why not? Just time it and start it hours before, wind energy could help in that too

One solution to what you're describing is to expand the grid. If your grid stretches half the planet, when the East starts to experience night, the West still experiences day and can ship electricity from renewables to the East to make up for their self curtailment. The same goes for wind where if one location on the planet doesn't experience wind, odds are another location does and the power can be shuffled around.

Another option is to build out more battery storage such that any clipped energy from solar or wind - that is, the energy that can be generated from your solar or wind resource but that can't be exported because it would overload your inverters or transformers or exceed your PPA agreement with your utility - is stored and can be exported for 2-4 hours as the sun goes down or wind dies out.

Not a lot of renewables sites are colocated with battery storage, but more and more are.

I’m adjacent to this problem, so I have a little context, but am not an expert at all.

To my knowledge, we don’t have granular control over panels. So we can shut off legs of a plant, but that’s a lot of power to be moving all at once.

Instead, prices are set to encourage commercial customers to intake more power incrementally. This has a smoother result on the grid, less chance of destabilizing.

A customer like a data center could wait to perform defragmentation or a backup or something until the price of power hits a cheap or negative number.

I'm in solar/BESS, and I mean more and more DER sites are making use of string inverters which break out arrays into greater chunks than with central inverters. With those, you have more granularity of control where you can drop entire blocks/strings at a time to fall to your curtailed export rate.

You might ask yourself though why DERs can't just ramp inverter outputs up or down to match curtailment automatically across a whole site. You can absolutely do that, but what happens is your solar or wind resource stays high on the DC or low frequency (LF) AC side, respectively, while power frequency AC is low on the other side of the inverters. This is referred to as DC:AC ratio in the biz, and the higher that ratio, the more losses your inverters experience and less efficient they are. This also puts a huge strain on your inverters and can lessen their operational lifetime.

But really, DERs tie into the grid at distribution level and so they don't fall under the regulations of FERC & NERC (at least in North America). This means that smaller producers don't have the same requirements for control as do utility-scale players, so the incentive to control these string inverters at that granular level isn't there. It's much easier to just trip the main breaker and wait until the utility gives you the go ahead to turn back on.

I suspect that at lot of producers may want to look into greater control capabilities in the future, but this also depends on inverter OEMs too allowing that control.

If you’re spending billions to build a solar plant that has to turn off all the time during peak hours then you’re wasting your money. That seems like a fundamental issue to me, not a non-issue.

Ok, but what do you do when you're short of power at night? Keep in mind to turn on conventional power stations it's expensive & time consuming. Once they startup they need to stay on for a long while to be efficient & cheap.

The real solution is to store excess power in batteries. Lithium ion is too expensive to scale, Sodium ion batteries are economically & capacity viable AFAIK.

You can do more with them too actually. You can ramp down the AC power production incrementally to meet curtailment requirements, in theory. When you do that though you subject your inverters to greater strain/losses and less efficiency which shortens your lifetime.

If inverter-based producers in solar, wind, and/or BESS want their sites to last for 30-40 years so that ROI is achieved via operation, then it is in their interest to protect their equipment and operate as much as possible at rated conditions or de-energized conditions.

You might think that it would make sense to have more of a slider control between ON and OFF to save everyone, from producers to grids to consumers, but my guess from being in the industry is that grids don't really supply incentives for that kind of operation. If they did, maybe you'd see more variable control at utility- and community-scale levels.

I think they're taking about battery chickens; just don't tell the vegans that's how we store electricity!

It still costs real money to maintain the infrastructure; so even if the power was always free; you would still have to pay something to cover the maintenance costs.

Hydrogen is troublesome as an energy storage. The roundtrip efficiency (electricity -> hydrogen -> electricity) is just... very not worthwhile compared to batteries. Then beyond efficiency there is still the question of "how do we store hydrogen safely?"

Storing energy indefinitely is not a problem for electricity storage, since we are pretty much guaranteed to use the stored energy up in a single day.

I agree that H2 can have certain applications as a bridge technology in some industries, but there is a very important parameter missing in your premise.

Even if solar power seems "free" at first glance it really isn't. It needs infrastructure, e.g. Photovoltaic Panels and lots of it. So just having H2 instead of a battery for an application means, it needs thrice the PV capacity or even more and with it the grid capacity. Now add to that, we aren't just talking about replacing electricity from fossil fuel plants by PV, but about primary energy as a whole, which makes the endeavor even more massive. Also H2 will not magically become much more energetically efficient in its production, transport, storage and usage, because there are physical limits. (Maybe with bacteria for production) The tech could and should get better concerning longevity of the electrodes for example. Also as the smallest molecule out there, storage will never be completely without losses. And long term storage requires even more energy and/or material.

All this is to say, that efficiency is still paramount to future energy supply, since also the material is limited or just simply because of costs of infrastructure and its implications on the biosphere. Therefore such inefficient energy carriers as H2 or what people call "e-fuels" should be used only where the enormous power and/or energy density is critical. H2 cars should therefore never be a thing. H2 or e-fuel planes, construction machines or tractors on the other hand could be more appropriate uses.

Not sure where our good buddy @Hypx@fedia.io went, but let me assure you. As of right now, 100% of available hydrogen stocks are fossil fuels derived.

Hydrogen vehicles being green is a fantasy pedaled by fossil fuel companies to not have to move away from natural gas. While it is possible to generate hydrogen through electrolysis, functionally, none actually is. It's far far cheaper to do so from natural gas, and probably always will be.

Promoting hydrogen as a "solution" is basically promoting fossil fuels green washing.

And I'm not sure where you are getting you information on lithium, but it's probably the best short and medium term option. Beyond that, gravity storage (pump water up hills, and maybe some kind of hydrogen system that doesn't require transporting the stuff where it can be made and stored in place when solar or wind energy is abundant.

Most battery chemistries are moving away from rare earth metals like lithium. Solid state batteries are the next step, and they use things like sodium cloride, I.E salt, as their base.

Isn't one the issues with hydrogen motors that they are a bit explodey? Genuine question, haven't looked into it in a long time.

Hydrogen is a pain to deal with. It requires excessively thick walled containers to store etc.

A better solution is to do what plants do. Pin it to a carbon atom. Synthetic hydrocarbons would also be a lot easier to integrate into existing supply chains.

There are a lot more ways to store energy other than lithium and hydrogen.

Pumped storage, vanadium redox battery, sodium battery, ... I'd even say they are most suited for grid-level energy storage.

I have doubts that hydrogen will ever work in any industry, but it definitely won't work for cars. The storage and distribution challenges are never going to make it cost competitive with just regular lithium batteries on a marginal per-joule basis. Even if the energy itself is free, the other stuff will still be more expensive than just charging car batteries off the existing grid.

It is a financial problem. Technically you can just cover the solar panels. But that's not good financially.

"Damaging equipment" is just nonsense. I've got an off-grid solar system. When the battery is fully charged the solar panels simply stops producing. It has potential (voltage) but no current until you draw power. Just like a battery is full of energy but it just sits there until you draw power from it.

All solar systems could have smart switches to intelligently disconnect from the grid as needed, some inverter already do this automatically. So it's not a technical problem. It's a political problem.

It is a technical problem of how can you convince electrical companies to overcome a problem they have no financial incentive to solve.

Factorio players: hold my beer

Sounds like energy companies or independent entities should invest in energy storage so they can get paid to draw from the grid.

Can they not route excess electricity into the ground?

Didnt Nikola Tesla try to sell Westinghouse on providing free unmetered electricity to everyone on earth and got laughed out of the room?

an awful lot of people just dont understand the sheer scale of a lot of these problems

Sheer scale is why we're in this mess to begin with. Coal power for a population of 50M people living on either side of the Atlantic isn't what caused climate change. It's the scale up to provide power for 8B people that's broiling the planet.

"Ah, but you don't understand! There will be engineering obstacles to upgrading the grid!" is shit you can say when you aren't spending billions to maintain the existing fossil fuel infrastructure that's currently in place.

We have the capacity to reorient our economy around a predictable daily regionally glut of solar electricity. We already exploit time variable ecological events to optimize consumption. And we built out a global grid 40 years ago to handle logistics at this scale. You can move electricity from coast to coast and we routinely do. This isn't an impossible problem, it's just one that Western financial centers in particular don't want to invest in solving.

It’s always economics.

There’s a joke I’ve heard that says something like anybody can build a bridge that stands, but it takes an engineer to build one that just barely stands (i.e., one where the materials and labor actually cost money).

That also reminds me of my first router - it was my PC. 10x the cost and 1/10 the features of a purpose built router, but I already had the computer and just needed to provide internet to 1 or 2 more via Ethernet.

Likewise, it’s easy to design energy storage concepts of all kinds. It’s a lot more tricky if you want it to be economically viable and see mass adoption.

A lot of energy storage solutions do exactly that - use heat as energy. i.e. solar heads rock, sand, salt etc. and then later on that heat is turned back into useful energy - either pumping water around households to heat them, or to drive a steam turbine. The bigger the volume of rock / sand / salt, the more efficient the process is.

I think salt would be easier than water, mostly due to water expansion characteristics, but that's just my opinion.

Managing an energy grid is an incredible feat of engineering and the fact that some countries have basically 24/7 constant voltage electricity is nothing short of a miracle.

And yes I will trust the academics and engineers who have spent ages documenting these processes and building the solutions. I studied this for a while at university. Every professor in that field is an environmentalist and guess what they still taught us about the issues with solar and wind instability and energy storage.

most armchair ass comment I read all day lmao

Stupid question but can we not like, make toggleable solar panels? Like if I Just pull the plug extracting power from a solar panel does it explode or break or something?

Solar panels are easily disconnectable. Unlike conventional power plants it does not have spinning rust, that can walk away entire building.

The easiest solution is to send the power somewhere else where it can offset the use of fossil fuels. This solution is fraught with political hurdles, subject to market forces (due to privatization) and often grid compatability issues(looking at you Texas). It is, however, a time tested and common method for mitigating excess production.

While water in pipes is often a metaphor for electricity, it's not particularly useful here. You can't ground out part of a charge. Energy storage is the solution though. Batteries are good, pumping water up back up into dams to be regained from a hydro plant when needed is ideal, as I understand it.

Well, that's what they're doing some places. The batteries assets are not in private homes usually though, they're by themself or run by power-consuming industries. Batteries are expensive though, and they degrade quickly if you use them wrong. In the EU, ENTSO-E defines the market rules, trade systems and messaging systems that energy companies and asset owners play by. Sometimes the revenue-generating asset is a battery, sometimes it's a hot water boiler, wind park, factory, hydro plant etc.

What alternative are you suggesting?

You'll need to be more specific.

If you passively produce more energy than what you actually need, that excess energy can be stored. And even if the stored energy won't be 100% efficient, it's still passively produced and can offset the peak hours consumption as needed.

We have a lot of energy storage solutions l, let's stop the fossi fuels subsidies and spend them on scaling power storage.

Producing electricity when it isn't being used is problematic for the grid. So is producing too little.

Changing the words does not change the meaning.

It’s valid to think in terms of cost IMO even when trying to drive the concept of profit out of the discussion. It’s just a matter of using limited resources in efficient way that leads to more benefit.

The cost units don’t need to be dollars or euros. It could be in tons of a natural resource or some other thing that’s more tangible than money. But as long as those resources are limited in some way, it would be great to get more MW or MWh for the same resources put in.

The sick corporate greed part affects which costs get ignored though, like the externalities. They think “sure I’m poisoning our food supply and killing people every day, but nobody takes money out of MY bank account because of it.”

Paying billions for mega projects to save millions on cheap electricity makes no sense.

Napkin math gravity battery Last figures I found are from 2022 the costs storing 1GW 24 hours is $150 per installed kWh

My apartment has an estimated electricity consumption annually of 2000kWh, I'll need to store half that for $150 per kWh in a structure that lasts 100 years without maintenance, then crumbles into dust and needs to be rebuilt. It would average out to $1500 per year.

My current electricity bill is about $600 per year.

Because "gravity batteries" is a stupid inefficient concept peddled by techbros to solve a huge problem with "a magic solution". In reality, they require either digging straight down like a mine shaft, but at huge scale, or a high rise building with all the weight concentrated on its top floor when the batteries are "charged". Wind would sway that shit left and right, the weight concentration would undermine / damage the building if it even was possible to build at scale.

With the situation in Ukraine, we really should spend on home scale storage for the resiliency against any disaster, even though it’s not as cost efficient

To be fair; this is a valid use case.

If you are a solar power producer; rather than offering your energy at -ve rates; run a crypto farm when the output is too high. This is far better than running the same farm on coal.

But it would be better going into something useful.

So if a large region (say europe, or USA + canada) is cloudy and without wind, then all transactions must stop and the remaining countries are susceptible to represent over 50% of the hashing capacity. A perfectly sound system I'm eager to see.

The solar isn't the goal; the energy is enabling the value in other parts of the economy.

In fact; energy supply is so important to the reasonable functioning of the economy. It should be taken out of the profit driven cycle of business.

Look at what happened with WPI in Ohakune and PanPack when energy prices sky rocketed a few months back.

Upgrading is never simple or straightforward. But it is something we need to do otherwise we won't have a planet to live on.

I’m very hopeful for flow batteries to improve to a point where they can be very cheaply installed at scale. Seems much better environmentally than lithium ion, and the drawbacks matter less for grid storage.

a few years

Snowy Hydro cost overruns would like a word

I know that, and to incentivice people to use the power, they pay you to do it.

Yes but there are many solutions already to that problem.

The first one being to shutdown a few stations production when overproducing. The second one being a myriad of storage solutions that already exists and scale them.

It is an economic problem because we already have many ways to skin the cat, but it won't produce shareholder value in the short term.

I know that, but with long term planning its fine.

Early adopters will profit the most, it's a non-issue.

They would probably use nuclear for base load, until something better is found. But it won't "replace" solar.

Nuclear has few advantages over solar.

Solar + batteries.

Image from this article

~$1000/kW vs $6 - 10,000/kW in 2018, it is cheaper today; projected costs to drop to as low as $560/kW in 2050.

Add in the ~$150/kWh of grid scale storage with the associated switchgear to connect it to the grid.

For a 10MW + 20MWh solar system; you are looking at approx $13,000,000 + install costs of probably $2-3,000,000.

I'm on board with whatever the scientists conclude. I'm not a scientist, so if they say nuclear, I'm behind nuclear. If they say solar, I'm behind solar. If they say wind, I'm behind wind. Trust scientists. If you're trained in science, definitely verify - there's some bad science out there for sure. But if you have no expertise in the area, just trust the scientific community.

This might not be the case anymore, now that solar is dirt cheap.

But, as another commenter said, I'm onboard with any decision that scientists (including both energy and climate sciences) and engineers come up with working together.

I don't know a single who would, including myself.

No they wouldnt

You’re way better at this than the clowns in the MIT press department and you only tried for a few seconds. Which means the people who wrote the headline are either so stupid they can’t tie their own shoes, or they have a malicious agenda. I lean towards the latter.

That can indeed be a problem.

It is however not what the MIT guys wrote as being the problem: they quite literally said the problem with too much solar generation at peak times is that it drives prices down.

Also, curiously, the prices being driven down actually helps with the real technical problem that you point out: those consumers who can move their consumption times will tend to move them to those hours when the prices are lowest thus helping solve it. Same thing goes for investors: the more the price is pushed down at peak solar production times, the more appealing it is to invest in things like storage or even solutions with lower efficiency (such as green hydrogen or electricity transportation cables to markets less well served by solar).

The low prices aren't the problem from a technical point of view, quite the contrary: they're an incentive to invest in solutions (which is going to employ a lot of techies, so supposedly MIT would be all in favor of it)

There have been proposals for technology like this. Putting a motor above an abandoned mineshaft and suspending a weight. Charged by raising the weight, discharges by lowering against a load.

The issues is the capacity ends up being pretty tiny, not really at a grid level.

You’d need a TON of motors to get to something a grid could actually use to stabilize, and by then the economics don’t work out. Let alone the actual space requirements of that many motors

Additionally, a lot of the advantages of batteries come from local storage, where you don’t need to transmit the energy long distances anymore, and these “natural” batteries tend to take up a lot of space.

A better and more accessible form of “natural” energy storage are already in most homes. Heat pump water heaters in homes could do things like make the water extra hot during solar hours, when power is cheap, so they can make it until the next morning without turning back on.

Or with better building envelopes (insulation) we could run more cooling during solar, maybe even make a ton of ice. Then later in the day, when solar drops and the grid load peaks, you can still cool the building with ice.

that requires specialized equipment other than the battery. you need to generate AC from the DC of the panels and battery, and the easiest way to do that at the right frequency and phase is to follow the grid. that's why most solar installations stop providing power without a grid connection; you need a wave to sync with.

if you want to be truly independent you need your own wave forming equipment. and not the cheap stuff either, like the 12V inverters for cars that give out square waves. that's fine for like a drill, but plug a computer into that and there's a chance it fries. it won't charge, at least not for long.

also you need extra safeguards to not fry electrical workers when they disable the grid and your power comes flowing the other way.

Yeah you can do that. Not everyone does

No, peak generation in most countries is in the late afternoon when people come home from work, the ac kicks on, people start to cook + do other things around the house. You typically see a double- peak, one in the morning and one in the evening, although it varies based on the seasons. I'm an engineer who works in renewable energy and the stated problem is real- solar generation doesn't line up very well with grid demand. You can work around this with energy storage but that is an expensive solution