41–50 of 68 posts
Earlier quoted context omitted.
Unreadable? Sorry to tell you this, but your standards are unpractically high. Welcome to the real world, where not everything is how you want it :p I'm sure that with such an attidtude, you'll be learning a lot from people with different backgrounds and cultures. /s
For future reference: unpractically is not a real word. Please consider using real words such as impractical.
Pumped hydro is much cheaper than batteries per KW (max storage rate) and KWh (storage capacity) is limited only by reservoir size. The roundtrip efficiency is about 80% and it's able to store for months at a time. Heindl Energy in Germany is developing hydraulic storage, which can work even on flat ground (basically, raising a rock formation with pumped water). They've designed capacities up to 120GWh: http://www.he…
Pumped hydro is interesting but the reservoir requirements are huuuge. This post makes a very convincing case that scaling it up is not that simple: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor... There is some discussion about the German rock variation in the comments. The density doesn't seem to help THAT much compared to water only.
Pumped hydro is much cheaper than batteries per KW (max storage rate) and KWh (storage capacity) is limited only by reservoir size. The roundtrip efficiency is about 80% and it's able to store for months at a time. Heindl Energy in Germany is developing hydraulic storage, which can work even on flat ground (basically, raising a rock formation with pumped water). They've designed capacities up to 120GWh: http://www.he…
Pumped hydro is interesting but the reservoir requirements are huuuge. This post makes a very convincing case that scaling it up is not that simple: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor... There is some discussion about the German rock variation in the comments. The density doesn't seem to help THAT much compared to water only.
Earlier quoted context omitted.
Pumped hydro is interesting but the reservoir requirements are huuuge. This post makes a very convincing case that scaling it up is not that simple: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor... There is some discussion about the German rock variation in the comments. The density doesn't seem to help THAT much compared to water only.
Density isn't the only benefit of this system. At these scales, the water requirements alone are significant. This replaces many cubic meters of that water with rock.
Sadly it seems the project has been at the "plan to get funding for a pilot" stage for at least 5 years now, and I still don't see how it'd seal.
Pumped hydro is much cheaper than batteries per KW (max storage rate) and KWh (storage capacity) is limited only by reservoir size. The roundtrip efficiency is about 80% and it's able to store for months at a time. Heindl Energy in Germany is developing hydraulic storage, which can work even on flat ground (basically, raising a rock formation with pumped water). They've designed capacities up to 120GWh: http://www.he…
Pumped hydro is interesting but the reservoir requirements are huuuge. This post makes a very convincing case that scaling it up is not that simple: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor... There is some discussion about the German rock variation in the comments. The density doesn't seem to help THAT much compared to water only.
http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor...
Earlier quoted context omitted.
If your English skills are reasonable, it's fairly easy to parse the article and fill in the gaps yourself. Probably easier than a non-native writer wrestling with a spelling or grammar checker when they might not know if the suggestions presented are good or not.
I agree completely. It seems some HN readers think that if they have perfect English (they do not, sadly), everyone else should rise up to their unrealistically high standards. I guess us programmers are a bit more sheltered from the real world. Add to that the primarily US-based audience, and you have what is called a "hivemind".
Surprised there's no mention of Vanadium Redox as an alternative that solves several of these problems even better than Lithium Ion. They can be fully cycled over 100,000 times (compare to Li-ion's 400-1200, lead's 500-800) and are expected to last 20 to 30 years. They can stay in a single state for long periods of time without degradation and can be rapidly and efficiently charged or discharged. There's also no fire…
This may be true for some kinds of li-ion batteries, but they can be engineered to last much longer than that. Tesla's daily cycle home battery is warrantied for 5,000 cycles, for example.
Assuming the battery doesn't die the day the warranty expires, this should give you at least 15 years of life. Not quite the 20 to 30 you're quoting, but current prices are much cheaper (and this seems likely to remain true, as vanadium in inherently expensive, and li-ion batteries have a head start in economies of scale). With massively reduced size and weight, shipping and installation should be much lower as well, and I suspect consumer uptake will likely be much higher for the foreseeable future.
Surprised there's no mention of Vanadium Redox as an alternative that solves several of these problems even better than Lithium Ion. They can be fully cycled over 100,000 times (compare to Li-ion's 400-1200, lead's 500-800) and are expected to last 20 to 30 years. They can stay in a single state for long periods of time without degradation and can be rapidly and efficiently charged or discharged. There's also no fire…
> A refrigerator sized VRB in the attic of a house would work, but that is a dealbreaker for some/most people. Even a refrigerator-sized VRB doesn't store that much energy, that's ~650 liters so about 40MJ, under 1.5L worth of fuel. And more importantly it weights half a tonne and (assuming it has the same shape as a standard fridge) has an area density of ~1.5t/m^2.
For a stationary application, half a ton doesn't seem like a big deal. Surely a normal house can hold up that much weight? That's equivalent to only six or seven people. If the weight is a problem, put it on the ground level or in the basement.
So what happened to the idea of using some modern version of flywheels to store power?
Market conditions aside, we remain absolutely confident in flexible flywheel technology and its ability to deliver safe, dependable, high performance energy storage at a small fraction of the cost of today's best storage solutions. We believe someday flexible flywheel technology can and will become a foundational technology in our clean energy future.
Why energy storage sucks (medium.com/@atilev)