Storing A Lightning Bolt In Glass For Portable Power

[n2doc]

ScienceDaily (May 2, 2009) — Materials researchers at Penn State University have reported the highest known breakdown strength for a bulk glass ever measured. Breakdown strength, along with dielectric constant, determines how much energy can be stored in an insulating material before it fails and begins to conduct electricity.

A bulk glass with high breakdown strength and high dielectric constant would make an ideal candidate for the next generation of high energy density storage capacitors to power more efficient electric vehicles, as well as other portable and pulsed power applications.

The highest dielectric breakdown strengths for bulk glasses are typically in the 4-9MV/cm range. The breakdown strength for the tested samples were in the 12MV/cm range, which in conjunction with a relatively high permittivity, resulted in energy densities of 35 J/cm3, as compared to a maximum energy density of 10 J/cm3 for polypropylene, the most common dielectric for pulsed power applications.


Contributing author Michael Lanagan points out that engineering challenges remain as they scale up from the small size glass capacitors tested to those ready for commercial production. “We’ll lose some of the energy density as we increase in volume," he says, “but we should still end up with some remarkable capacitance.”

http://www.sciencedaily.com/releases/2009/05/090501204039.htm

[kristopher]

1. Sounds interesting

I wonder that the trade off between glass and plastic is in terms of weight?

[lapfog_1]

2. Am I doing the math wrong???

1 joule = 0.000277777778 watts hours

35 J = 0.0097222 watt hours / cubic centimeter.

a one meter cube (if it scales) would have 100 x 100 x 100 cubic centimeters

or .0097222 x 100 x 100 x 100 or 9,722 watt hours... or about 10 KW hours.

A meter cube is a large object when talking about a replacement gas tank.

10 KW hours is OK, but not anywhere close to the storage capacity claimed by EEstor

From the wiki:

# For a 52 kWh unit, an initial production price of $3,200, falling to $2,100 with mass production is projected.<7> This is half the price per stored watt-hour of lead-acid batteries, and potentially cheap enough to use to store grid power at off-peak times for on-peak use, and to buffer the output from intermittent power sources such as wind farms.
# No degradation from charge/discharge cycles
# 4-6 minute charge time for a 336 pound (152 kg), 2005 cubic inch (33 L), 52 kilowatt hour (187 MJ), 31 farad, 3500 volt unit, assuming sufficient cooling of the cables.

so for 33 L of volume, EEstor can store 52kWhrs... whereas 33 L of this glass could store .3 kWhrs

(caveat that EEstor has yet to go into production with their storage units, AFAIK... of course, this glass storage is a *lot* further behind than that).

just wondering...

[Towlie]

3. I was unable to detect any errors in your computations.