Japanese companies are building some of the world's biggest battery systems to address one of solar power's biggest problems–its volatility.
Handling the surges in power when the sun shines and storing that energy for use when it is cloudy or dark is a major headache for solar power producers and the utilities they supply.
Mitsubishi Electric Corp and NGK Insulators Ltd. are assembling a 50,000 kilowatt battery system for Kyushu Electric Power Co to study ways to better accommodate solar power.
A slightly smaller, 40,000 kilowatt battery system is under construction in Minami Soma, north of the Fukushima Daiichi nuclear power plant, for Tohoku Electric Power Co. to conduct similar research.
The government is financing both projects at a total cost of ¥31.7 billion ($257 million), a government official said.
Original Submission
(Score: 4, Informative) by gnuman on Saturday June 27 2015, @05:21AM
40,000kW is called 40MW.
Also, that is not how battery capacity is indicated. Watt is a unit of power, not energy.
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @05:32AM
Yeah, UPS capacity is always indicated in volt-amps, which are literally the same units as watt-the-fucks.
(Score: 3, Informative) by Anonymous Coward on Saturday June 27 2015, @08:24AM
That would be power, not capacity, and VA is not necessarily the same as W when talking about alternating current. W is the real or active power, VA is the apparent power. The ratio between the two is called power factor. A purely resistive load (an incandescent light bulb, for example) has a power factor of one. Most electronic loads (switching PSUs, for example) have a power factor other than one. The UPS, wires, switches and everything else in the circuit needs to be designed for the apparent power, not just the real power. That's why you'll find VA, not W, on type plates of electric devices.
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @07:50AM
The purpose of the batteries is to supply power when the sun doesn't. Units of power are actually appropriate here, although I agree about using MW.
(Score: 1, Funny) by Anonymous Coward on Saturday June 27 2015, @08:02AM
It should be 0.04 jiggawatts.
(Score: 2, Informative) by Anonymous Coward on Saturday June 27 2015, @08:43AM
As is often the case, a single number doesn't sufficiently describe a complex system. Usually you want to know at least two things about a battery: How much energy it can store and how fast you can get it out of the battery. Often you also need to know the rate at which the battery can accept charge, which can be much lower than the discharge rate. Other important metrics are total lifetime (in years and/or number of charge-discharge cycles), energy density and power density (per weight and/or volume). Some people may also be interested in the costs.
Anyway, the battery system that the article is about is rated for 50MW output and a 300MWh capacity (the article links to a PDF in Japanese which has the information).
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @05:25AM
Stupid Japs, don't they know solar is for hippy communist socialist scum?
(Score: 4, Insightful) by frojack on Saturday June 27 2015, @06:36AM
We've seen this cropping up in a lot of places, Arizona, Hawaii, etc.
Japan's bigger problem is (as TFA mentions) is that they have a number of disjoint smaller incompatible electrical grids. That fact exacerbates the situation when a boat load solar joins the network. There isn't enough stable demand nor a big enough generator to stabilize the grids. Hooking them together might help.
But this variable supply problem needs a solution in a lot of places, and maybe big storage could be that solution, but there sure don't seem to be many scale-able solutions. Even this story is thin on details, just calling these plants "Batteries". That covers a lot of territory.
No, you are mistaken. I've always had this sig.
(Score: 1, Insightful) by Anonymous Coward on Saturday June 27 2015, @07:18AM
Why not use solar power to pump water up a hill to a storage facility? When power is needed the stored water could generate electricity like a conventional hydroelectric dam.
(Score: 2, Funny) by Anonymous Coward on Saturday June 27 2015, @07:55AM
Potential energy, really? What are you, some kind of 12th century Persian terrorist? Choke on your falafel, low-tech traitor.
(Score: 2, Disagree) by Zz9zZ on Saturday June 27 2015, @08:09AM
Totally a decent idea, but I think the 2x conversion loses a lot of efficiency, and a lot of power == a lot of mass, so you need a whole lake (Hoover Dam) to provide a ton of power, and Dams usually push right to the grid not.
~Tilting at windmills~
(Score: 4, Informative) by gnuman on Saturday June 27 2015, @04:14PM
No, it's the most *efficient* way of storing energy. Pumping water up a hill can be 90% efficient, and conversion on way back is the same efficiency. The loses for storage are called evaporation.
Pumped storage works.
https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity [wikipedia.org]
Typically, the round-trip energy efficiency of PSH varies in practice between 70% and 80%,[1][2][3][4] with some claiming up to 87%.[5] The main disadvantage of PHS is the specialist nature of the site required, needing both geographical height and water availability.
And Japan has both, geology (unlike for example Germany) and an already developed hydroelectric system.
https://en.wikipedia.org/wiki/Hydroelectricity_in_Japan [wikipedia.org]
https://en.wikipedia.org/wiki/Imaichi_Dam [wikipedia.org] http://large.stanford.edu/courses/2010/ph240/sun1/
which is 35-45%.
(Score: 2) by gnuman on Saturday June 27 2015, @04:19PM
Awesome, thanks you for eating my text soylent!
Comment was that there is already pumped storage in Japan, including stuff owned by TEPCO like that Imaichi Dam
As for efficiency of battery systems, it's not always good compared to pumped storage. Batteries get 50-85% efficiency for charge/dischage cycle.
http://large.stanford.edu/courses/2010/ph240/sun1/ [stanford.edu]
And finally, pumped storage doesn't wear out. Gravity remains no matter how much water you pump back and forth.
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @10:52AM
How would these options compare with electrolysing water to oxygen and hydrogen?
(Score: 2) by c0lo on Saturday June 27 2015, @11:50AM
Where do you take the water from?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @05:42PM
The lower storage pond. Ideally aside from evaporation, which would be offset by rain, etc., it could be a closed-loop system.
(Score: 2) by LoRdTAW on Saturday June 27 2015, @10:26PM
Because Japan has plenty of land laying around waiting to be flooded for energy storage.
(Score: 3, Interesting) by anubi on Saturday June 27 2015, @10:38AM
Did you see the photo [wsj.net] of the array?
Looked like a beautiful place to raise some food. All covered over. At waist height?
Somehow, it looks like this kind of thing should be implemented into some sort of pretty good sized shopping mall or manufacturing facility. As a roof. Covering everything - parking lot and all.
Japan is not exactly brimming over with an excess of real estate and farmland is it?
I get the idea that encouraging every property owner to have solar panels on their roof is the way to go.
I am kinda surprised solar shingles have not made the scene in a big way. I have neighbors with those panels on the roof, and aesthetically, I feel I could have done a helluva lot better job actually implementing the way those things are installed. I would have strips that lay down on the roof that mechanically hold the solar shingles in place and also provide electrical connection. The shingles should be individually replaceable, and each row of them end up driving individual microinverters. Duds that look like shingles could be used for places where vent pipes and the like have to go through. One would be able to cut them without electrical considerations. The roof would not appear to be any different from any other shingled roof.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by c0lo on Saturday June 27 2015, @11:53AM
I'm living in the basement of a skyscraper, you insensitive clod.
(grin)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @05:03PM
nice picture.
interesting 'nuff the roofs in the background don't seem to have a single panel.
seems the japanese approach to solar grid-tie is not by empowering individual citizens to harvest free energy but by licensing utility run mega-farms from which the poor citizens have to buy electricity ... again.
this can somehow be turned into a running gag, i'm sure: slaves of the "rising sun"?
(Score: 3, Informative) by fnj on Saturday June 27 2015, @01:56PM
This is a butterfly fart in the wind. 40,000 kW is 40 MW, which is 0.04 of a single power plant (1 GW), or 0.00014 of Japan's installed electric energy capacity (282 GW in 2010).
(Score: 1, Insightful) by Anonymous Coward on Saturday June 27 2015, @05:31PM
Common batteries are a couple of thousand milliamp-hours, so yeah these are giant.
(Score: 1) by steveha on Tuesday June 30 2015, @05:27PM
As the article clearly says, this is a pilot project to study how to use giant batteries to stabilize the grid when using solar.
I agree that the pilot program doesn't have much capacity compared to Japan's needs, but it seems big enough to figure some stuff out.
(Score: 0) by Anonymous Coward on Saturday June 27 2015, @04:49PM
well all good and all but i think japan is very strict about letting their normal citizens install solar.
not that that is only a uniquely japanese problem tho.
somewhere i read that the bureaucratic paper hurdles for a smallish solar roof system are worse then digging out melted corium...
now let's see:
exclusion zone is 20 km.
4 km x 4 km (16 square km) is about 300 MegaWatt PV.
so 20 km is the radius.
r*r*pi/2 = 628 square kilometers (divide by two because half the circle is ocean)
so that's about 11 GigaWatts.
i hope they blow up some more! : )