[JD4JC]

The US Navy’s Railgun Breakthrough Could Change Energy Storage

ONR researchers developed their own capacitors, more compact yet capable of supplying 20 megajoules per shot, with a goal of 32 megajoules by next year. ONR said you can think of a megajoule as about the same, energy-wise, as a one-ton vehicle moving at 160 mph. These new capacitors “represent a new generation of pulse power, with an energy density of over a megajoule per cubic meter,” said Beutner. The capacitors, which store energy, are also able to recharge quickly enough in order to fire ten times in a per minute.

 

[jupitermoon]

That's great....while our country goes bankrupt and we "don't" have funds for schools, healthcare, and infrastructure.

What a joke.

 

[jcramer]

This is just some DOD hype.

The Navy capacitor stores only one mega-joule per cubic meter, which is only 0.278 kW-hr per cubic meter. The Volt battery stores 118 kW-hr per cubic meter. The Navy device is not even in the ballpark. The virtue of the capacitor is that it can be charged and discharged in microseconds, a feature that is not particularly of interest for EVs.

 

[viking79]

Actually, it is of interest. One issue with Li-ion is how much power you can draw from the cells. Some technologies have high power density, like LFE used by BYD, but they have lower energy density so they weigh more for the same range. Having some sort of high performance capacitor in parallel to high energy density cells could maybe mean more range and power with less weight. In theory, not sure if there are any suitable capacitors in practice or maybe more cost effective to go with beastly battery like Tesla.

 

[Shivetya]

That's great....while our country goes bankrupt and we "don't" have funds for schools, healthcare, and infrastructure.

What a joke.

you apparently have no to little understanding how spending works and does not work.

 

[jupitermoon]

That's great....while our country goes bankrupt and we "don't" have funds for schools, healthcare, and infrastructure.

What a joke.

you apparently have no to little understanding how spending works and does not work.

Oh boy has the government and military made a sucker out of you.

 

[obermd]

Oh boy has the government and military made a sucker out of you.

Actually he's correct about government spending not being straight forward. Throw in the competing interests and needs at each governmental level, the interests and needs at each level of government (most places in the US have 3 to 5 levels of government - Federal, State, and at least one local level), and all the combinations between them and what you end up with is a very complex spending picture.

For instance, most school spending is at the local level and is based on property taxes. However, States and even the Federal government spend on schools, just to a lesser extent.

Military spending is predominately done at the Federal level. States and local governments get involved via tax exemptions (effectively a spend by not taxing) to entice defense contractors to operate in their taxing jurisdictions.

These are just two examples of the complexities. They happen to be pretty much at the extremes as most government spending is blended much more between levels.

 

[obermd]

I can see those capacitors leading to fast charging environments where multiple EVs are being charged at the same time, sort of like how gas stations can "charge" multiple cars at once.

 

[calvinist]

I can see those capacitors leading to fast charging environments where multiple EVs are being charged at the same time, sort of like how gas stations can "charge" multiple cars at once.

Not really. To charge a single 60 kWhr battery (what you would need for a small pure EV with good range), the volume of the capacitor would be about the size of two semi-tractor trailers.

I had thought that a capacitor would be useful as a quick source of ready energy for acceleration, but even that does not work well. To bring a Model 3 to 60 mph requires 0.58 MJ, or over 1/2 of a cubic meter of this capacitor. Capacitors are still too bulky.

 

[fotomoto1]

Military spending is predominately done at the Federal level.

This is true the world over but any increase in federal military spending typically comes at a decrease for education, roads, healthcare, welfare, etc that has to be made up at the state/local levels. Do we really need to spend more than the next 8 countries COMBINED yet keep increasing it to make us feel safer?

Then there's the issue of needing to use these incredibly expensive (overpriced) weapon systems to justify their massive costs.

Finally, these rail guns will needs ships with massive amounts of surplus (atomic) power to fuel them like the new multi-billion dollar Ford class carrier.

Middle class: Get out your checkbooks because somebody has to pay for it.

 

[JD4JC]

This is true the world over but any increase in federal military spending typically comes at a decrease for education, roads, healthcare, welfare, etc that has to be made up at the state/local levels. Do we really need to spend more than the next 8 countries COMBINED yet keep increasing it to make us feel safer?

I guess I missed the last time an entitlement (a.k.a. "welfare") program ever was cut because of an increase in military spending. In fact, I don't remember any such program that was ever cut at all. In reality, the reverse has been the case, with military spending being sequestered in favor of continuing to fund the entitlements!

 

[Taser54]

This is true the world over but any increase in federal military spending typically comes at a decrease for education, roads, healthcare, welfare, etc that has to be made up at the state/local levels. Do we really need to spend more than the next 8 countries COMBINED yet keep increasing it to make us feel safer?

Then there's the issue of needing to use these incredibly expensive (overpriced) weapon systems to justify their massive costs.

Finally, these rail guns will needs ships with massive amounts of surplus (atomic) power to fuel them like the new multi-billion dollar Ford class carrier.

Middle class: Get out your checkbooks because somebody has to pay for it.

This weapon system lowers costs once deployed. Same with the lasers.

 

[alfon]

There are some people here in the U.S. that frown about any expenditure for the military. One reason I hear is "nobody's going to invade us". My reply, thats probably correct only because we have spent trillions of dollars on the military.

 

[flyingsherpa]

This weapon system lowers costs once deployed. Same with the lasers.

Only if it replaces another system, but very often competing systems are used in parallel by different groups, leading to overall greater costs. I can't speak to this system in particular, but I worked defense in missiles in the past. Navy was paying us TONS of money to develop a "missile" you'd shoot out of a Navy ship's gun (it was really more like a steerable/programmable explosive shell). Now, the existing missiles that other ships fired were doing just fine, but the guys who command the gunships felt left out because they haven't really been used in a battle in decades. Obviously the solution is to spend hundred of millions of dollars so they can join the modern fight too, with redundant capability (er, actually less capability, since the range was less than the missiles).

 

[mikem132]

The original post is interesting as some basic electrical systems are improving which may provide benefit to other technologies. As a missile guy, you must be aware that scientific breakthroughs for military stuff typically benefit civilian products eventually. The Navy's desire for a high-impact, low-cost weapon with large projectile storage capacity is a good concept. This is the intent of the rail gun.
You can argue about the usefulness of any weapon system in various scenarios, but the need for under-the-horizon weapons has certainly not disappeared in recent years. A projectile that is too fast to dodge and too dumb to jam has its benefits.
Do you remember "RAP"? "Terminally guided munitions"? I do. As a gunnery officer on a destroyer, I participated in a study way back in the 70s on cost-benefit of regular old ballistic projectiles versus the "smart" stuff. Guess what? The smart stuff cost way more and didn't improve all that much. That's at line-of-sight range, however.
Still, the point is military spending has residual benefit to everybody. It may not be efficient spending for the net civilian result, but we're not left out.