dje@datacube.UUCP (11/11/88)
> E=1.6E7 Joules = 1E10 W-s = 3000 kWh by this estimate. > > Of course, being an astrophysicist, I have liberal error bars :-) Sounds great. Start that baby up and run your house for a year!! But I'm pretty sure 1 J = 1 W-s. Therefore: E=1.6E7 Joules = 1.6E7 W-s = 4400 Wh = 4.4 KWh That's one 100W light bulb for 44 hours. Oh well. Dave Erickson ---------------------------------------------- Datacube Inc. 4 Dearborn Rd. Peabody, Ma 01960 ihnp4!datacube!dje Human:(617)535-6644 Fax: (617)535-5643
eric@hpcilzb.HP.COM (Eric Novikoff) (11/11/88)
I do not have experience with the specific case that you mention, but I would like to point out a few things you may wish to consider: 1) Your gyroscope will be 10 feet in diameter? If it is not spiining in a vacuum, you will find that due to the high velocity of the spinning rim, a lot of air friction will be generated. You probably won't store a full "charge" more than a day. And, of course, putting such a large gyro in a vacuum is impractical. I recall an article a few years ago in Scientific American about gyro powered cars, but those gyros were spinning in a vacuum. 2) With all that weight on them, your thrust bearings will fail very soon. You may wish to consider a more exotic oil-lubricated thrust bearing. Look in some mechanical design journals. 3) Balancing a gyro automatically is a non-trivial task. Have you thought about the "simple mechanical device"? How does it work? Eric
waynec@hpnmdla.HP.COM (Wayne Cannon) (11/17/88)
I have seen energy storage as a dc current in a superconducting inductor (solenoid) demonstrated. A reasonable demonstration solenoid a foot or so in diameter and a couple of feet high stored several MegaJoules. It was connected to a commercial 3-phase a.c. line and charged via SCRs. The same SCRs perform d.c. to a.c. conversion for discharging the solenoid by changing the phase of the gate triggers. The "quench" was spectacular (when the inductor goes resistive), and the solenoid must be designed to withstand the expansion and contraction during a quench. The system I saw used liquid helium and some sort of copper-lead conductor, but that was before the recent developments in higher temperature superconductors. From what I have read, energe storage as heat in salts that change phase near room temperature would also provide substantial storage in a reasonable space, though I am not sure what mechanism you would use to effeciently convert the heat energy back into electrical energy. Such "phase-change" salts are used in some solar energy storage systems.
henry@utzoo.uucp (Henry Spencer) (11/20/88)
In article <2120001@hpnmdla.HP.COM> waynec@hpnmdla.HP.COM (Wayne Cannon) writes: >From what I have read, energe storage as heat in salts that >change phase near room temperature would also provide substantial >storage in a reasonable space, though I am not sure what >mechanism you would use to effeciently convert the heat energy >back into electrical energy... Energy storage as heat is useful only if heat is the output you want. Conversion from heat to electricity is woefully inefficient. -- Sendmail is a bug, | Henry Spencer at U of Toronto Zoology not a feature. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
dhesi@bsu-cs.UUCP (Rahul Dhesi) (11/22/88)
If you will settle for about 65% efficiency, build a huge lake and a
dam. Spend energy pumping water up into the lake. To reclaim the
energy let the water flow back down though turbine blades.
Clean, stable, little maintenance needed, and a huge capacity for
storing energy.
--
Rahul Dhesi UUCP: <backbones>!{iuvax,pur-ee}!bsu-cs!dhesi