Renewable Energy: Beyond Electricity
source link: https://hackaday.com/2023/12/18/renewable-energy-beyond-electricity/
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64 thoughts on “Renewable Energy: Beyond Electricity”
>Perhaps the most-cited downside of renewable energy is that wind or sunlight might not always be available when the electrical grid demands it.
This is technically always, since wind or solar simply don’t respond to demand – except by turning off when there isn’t any.
>for the time being some amount of dispatchable power generation like nuclear, fossil, or hydro power is often needed
This is almost all the time, and for most of the energy. If you look at the peak-to-average ratio of wind and solar on the grid scale, you get peaks that regularly exceed 5-8 times the average output. Once these peaks grow large enough, they exceed what the grid can use, store, or export to other grids. That limit is is reached when the average output of renewable power on the grid reaches about 15-25%. That is to say, about 80% of your energy will always come from somewhere else than renewable power directly, unless you can sink massive amounts of excess power somewhere.
For very tiny countries that live next to very large countries, like Denmark, the nominal amount of renewable energy on the grid can reach higher percentage points without doing anything special, but that’s only by accounting because the whole system works by the fact that you have a 5 million people country sitting in the junction point of a grid with capacity for 500 million consumers. If all the neighboring countries were doing the same, the European synchronous grid would collapse on itself.
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Dude says:
For example, if you look at the peak sun hours of your location, you can calculate roughly how much of the time solar power is producing. Example, Berlin, Germany: 1,626 hours per year. That is, the sun is up and not covered by clouds for about 18% of the time.
For wind power, depending on your local wind speed distribution, the typical case is that you get 50% of the energy output in 15% of the running hours, Those are the peak wind hours and the other half of production happens gradually over time at a fraction of the power output.
It’s because renewable power is both non-dispatchable and extremely “peaky” that other generators need to be running constantly, occasionally dipping down to let renewable power into the grid instead. This is why renewable power is so difficult to integrate into the grid in greater amounts.
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spaceminions says:
Yes, it’s not as easy to integrate as doing the same old thing again, but that’s the thing – wind and solar can compete despite playing catch-up. They’re of course *more* competitive with the advantage of being allowed to sell as much as possible, or especially with the kind of rich-get-richer power agreements where rooftop solar is highly advantageous if you can afford to install it. But even without that they’re not doing badly lately. And it’s not like we haven’t given fossil fuels the advantage of not having to fully remediate the effects of their use.
At least while the weather can make the power unstable, it’s not as dependent on what is happening on the other side of the world – as long as we sort out the battery situation. And for the life of the installation you don’t have to spend as much effort on keeping things going. With fuels you have everyone having to spend a bunch of effort on finding it, making it usable, breathing the results of using it, and keeping the whole chain working. Even without considering how someone is eventually going to have to remove all that CO2 or deal with the consequences, it’s a lot shorter of a chain of dependencies if in addition to building solar you build some dispatchable loads and some nonspecific energy storage methods in the same general area. The most volatile prices are often food and fuel; it’d be great if we could be more independent so that we weren’t as affected when someone on another continent decides to fight someone else.
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Dude says:
>as long as we sort out the battery situation
Yes. Let’s. Still waiting for that cheap miracle battery that solves everything.
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spaceminions says:
More like, we feel like we will with some effort and groaning be able to sort out the grid because anything cost-effective works there, but we need to try harder at securing specifically portable batteries for electronic devices and electric vehicles if we don’t want to be dependent on the lowest bidder overseas. A miracle would be nice, but it’s not necessary.
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Foldi-One says:
The one thing you forget there is with how cheap to build and run solar and wind are it doesn’t matter if the peak is stupidly above and beyond requirement so you are shutting some of it down (infact being able to do that is probably a good thing for scheduling the rolling maintenance and putting the majority of bearing wear on the easier to service turbines when you have that choice).
What you are after is a grid that is effectively run largely or even entirely on the renewables, as ditching fossil fuels is usually the stated goal. Which means targeting the modal or mean average of your renewable output at something closer to average of demand (with things like the scale of pumped hydro and battery storage allowing a fair degree of wiggle in supply to demand matching). That those panels/turbines can produce substantially more power than that average in the right conditions really isn’t relevant, what matters is they are (across a wide enough grid) reliably at least in the right ballpark.
Yes some pretty significant energy that could have been captured won’t be as there is no way to get it to the demand, or no unserviced demand at all, but with the durability and cheapness of solar you will still massively outpay the costs of upgrading the grid to be able to ship more electricity past the current bottlenecks and creating these ‘excess’ of solar panels. While also being worth mentioning the extra cheap energy with a high degree of regularity such a setup of ‘excess’ renewables in a widely spread mesh spiking somewhere is good for everyone – all those industry* that can stack production for the glut of cheap energy will love it, so even if your electric supplier doesn’t let you have that varied rate yourself the goods you buy likely get cheaper and the fixed rate you are on shouldn’t be nearly as high as the peak cost of energy.
Also as it stands in nearly every fossil fuel powerplant vast amounts of energy that could be used are wasted – its rather rare for the waste heat, which really is a substantial resource to be used rather than dumped into cooling towers. So you can argue its not even a real change there, both concepts have a serious efficiency flaw if you want to measure it that way. Or just work really well once built if you want to measure it another – with the case in point for the excess of renewables being a good enough solution being all the folks that have been able to meet 100% of their own needs even as a very localised source so when the weather is bad they just have to deal with it, as the sun as far as they care for this situation isn’t shining anywhere else either.
*I’d suggest bulk hydrogen via electrolysis is a likely solution to co-habitat with the offshore wind for instance – source of salt water, and that potential for a massive excess of power right on the doorstep. While creating a product that really helps bridge the gap between fossil fuels and greener power options in the places battery etc don’t suit.
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Dan says:
you forgot that – here in the UK at at least – when wind is over producing they are paid the units electricity to turn it off. That’s why it is cost-effective to build them, but the more we build the more expensive it will be for everyone to keep turning them off.
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Foldi-One says:
And they won’t be over producing electric that can’ t be dispatched anywhere near as often if the grid could actually shift it all to the SE where so much of the demand is… There has been a need for more N-S connections in the UK for ages.
Though the way the market is currently priced is clearly bonkers, with subsidy and cost breaks for absolute everything in some way or other often built in for decades and no real plan to provide a market that actually makes sense…
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spaceminions says:
Something cheap enough that anyone could do it, even at home, is to save up resistive heat in the day to use at night. Inherently you need something oversized to consume the energy faster for the limited time it’s cheap/free, so you have to pick things that can be cheaply scaled up such as resistors. If nothing else, using the water heater just with a changed out thermostat or something works for that, thousand degree “sand batteries” aren’t the only way to do heat storage. Air conditioning is harder to gain a big advantage on; the day is already the hottest time and you’re not going to keep a massive system idle just to turn on when the power gets free. You could still put a bit of logic in your thermostat to gain some savings though, and technically you could probably get the cost numbers to work out right if you used a big thermal mass and (again very cheap) resistive heat to power an absorbtion cooler, which is too inefficient for normal use but wouldn’t need to be oversized unlike the power input by resistor.
While I hate the wastefulness of crypto mining the rest of the time, they have a point to the limited extent that marketing cheap cloud compute that runs off solar during daytime and switches off or increases its rates at night could be useful for long-running projects to save money. It could even let 8-5 operations save a bit of money on their cloud usage, I guess. And you could globalize to chase the sun if you don’t need low latency.
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Jdams says:
You missed the other part of that solution which you kind of glossed over in your examples. If you have very large grids interconnected, it may not be bright and sunny where you are, but it is when you drive 5 hours away, or the same with wind. Although they tend to try installing wind turbine farms in locations where they can extend them up out of the local wind effects where there is much more consistent wind.
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Dude says:
Of course, if you limit the power of wind turbines to about 20-25% of the maximum output and design the turbines to spin in slower wind speeds, you get power much more steadily, but you get half as much and it will be twice as expensive. You’d have to cost-optimize heavily to be competitive.
Likewise for solar, you can angle your panels east and west, but that again cuts your total energy output by a large amount and doubles or triples the cost of power (or payback time).
These measures are not supported by any subsidy policies, since subsidies are paid on every kWh produced or sold and you don’t get paid if you play nice and limit your output, so the incentives make it harder to integrate more renewable power on the grid.
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Oskar says:
Well….
Yes you’re right in context you’re trying to push, but as a reasonable person you should convert everything to electric ( CARs are power hungry beasts compared to MODERN WELL BUILD buildings ) and you also have to think about nuclear plants, they have to be shut down periodically for maintenance and having them shut off in summer because everyone have surplus energy and electric car battery which can supply your house in night….. provides you path for renewables to be REALLY useful and making sense. ONLY thinking about it, in old pre 2000s way of thinking, does not provide anybody a solution. Also a lot of youtubers ( or other influencers ) are intentionally WRONG on so many things, just so people comment under videos to correct them ( engagement is WHY are they paid ) . So it is weird time to be alive when 1% of population is intentionally spreading misinformation just so they get paid by algorithm and 99% of people will pay real price for listening to them. Instead of 100% of people doing right thing and that way it will be cheaper for everybody.European union, NATO have multiple documents, analysis, calculations, overviews, based on REAL LIFE data showing renewables made sense 15 years ago ( IN PAST ). But media are constantly saying we have to wait for something ….. Ridiculous.
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Oskar says:
Fear, uncertainty and doubt (often shortened to FUD) is a manipulative propaganda tactic used in sales, marketing, public relations, politics, polling and cults.
Exit matrix of FUD, welcome to reality of REAL LIFE DATA. ( data is open source, so you can search for it, just look for official documents, official data portals. )
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Dude says:
Electric cars don’t solve the fundamental issue, and cars all told aren’t even enough to make a big difference in the whole scale of this problem.
>it is weird time to be alive when 1% of population is intentionally spreading misinformation
Unwarranted hype and blind optimism is also misinformation, and you get that a lot more since it slips the tone police more easily for being positive. Example: “This wind turbine can power 2,000 homes.”, where by “home”^ you actually mean enough power to run a tea kettle, and by “powering” you mean “when it is running in maximum wind speed”.
A common home uses between 16 – 25 MWh per year all told, but the common trick in reporting is to use the average electricity consumption only, not all of the energy that a home needs to run. The missing bit comes from gas, fuel oil, etc.
It’s because of this sort of reporting that the public has wildly distorted conceptions about the efficacy of renewable power, and how far along we actually are in doing anything with it.
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A.M. says:
Do you mean 0.16 – 0.25 MWh per year as 16 – 25 seems a bit too much (1.3 – 2 MWh per month)?
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spaceminions says:
A.M. My household uses about 82 kWh/day in the worst months of the year and half that in the best months. That would be lower if we had any gas appliances or if we were able to install better insulation, and winter would be better if we didn’t need to use a heater in the wellhouse and other places to keep from freezing sometimes. I plan to get a heat pump at least, but still, the higher figure is more reasonable for a cheap all-electric house without efficiency minded design. A more efficient house without all the other stuff and with gas heating/cooking/etc in a cooler climate might be closer to your number.
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Foldi-One says:
While I’m not a fan of how often ‘enough for x homes’ type concept is used and often without further numbers to go with it for those that want to know it is a measure that makes sense to use as it is relatable enough in a way saying huge numbers of Wh is not- the general public know this is an electric supply and how much electric they use. Probably have a good idea from the odd conversation with parents/siblings/friends what other households use as well…
Doesn’t matter if the households still tend to use other forms of energy as well, as that has no bearing on their electric consumption, which when talking about electric generation is the thing that is actually related. So as long as these ‘enough for x homes’ reporting evolve as the common home use changes with things like heatpump replacing gas heating it remains a useful yardstick for the common person.
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Matthias says:
@spaceminions: on a little farm I know they had a storage room which was kept from freezing over by a bath tub with water in it next to the entrance. They just had to toss out the ice that formed on the surface daily and eventually add some water. It worked quite well.
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sweethack says:
You’re completely right in your remarks. However, you don’t account for many “small” devices on grid, like those that captures it when energy is cheap (hydro storage, heat generation & capture, human activity that’s mainly on the day). In the end, I’ve heard about the collapsing of the grid for maybe 20 years and I’ve yet to observe it. The grid get smarter, energy consumption now starts to deal with temporary opportunities (like charging the EV cars with low peak rate, better insulated building that can shift heating for 8h to 10h, etc…).
I think the real question isn’t “Is renewable energy going to collapse the grid if they are predominant ?” but “How the grid user can deal with sporadic energy ?”
The actors are now find solutions for the latter and it’s going quite well, IMHO.
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Dude says:
We’re only only starting to reach the point where the grid is being destabilized. Most countries are now reaching the 10-15% integration level, which is the beginning of problems and the start of skyrocketing costs.
The reason you’ve been hearing of it for 20 years is because these problems were predicted 20 years ago when this whole circus started. They said it would happen, and now it is happening – we’re getting wildly fluctuating power flows and power prices, and the grids are stretching to their limits in transmitting the power from one market to the next.
When a sixth of all the power on your grid just comes and goes daily or even hour by hour, it is not a trivial thing to manage. The energy consumption is adapting, because people just can’t afford to pay 50 cents a kWh – and that is not a good thing.
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Foldi-One says:
Yes decades ago folks said this bad thing would happen, with areas of the grids being saturated transmitting power from A to B and in those decades how many capacity upgrades to the grid to correct these predicted bottle necks or open up entirely new sinks have been built?
The answer is so far almost none – but the plans to build them have been around for ages – in more than a few cases long before renewables even really came on the scene as connecting between your EU neighbours lets everyone not build quite so many power plants and run them at their most efficient… But some of these upgrades will start getting built now as even though it should have been built in advance of the need (as everyone saw that need was coming) the demand for higher capacity connections really exists now. Remember the Grid isn’t some static thing built 100 years ago that never ever evolves, so even if its slower than it should be on issues like this it will get there.
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