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Comment You can already get paid for reducing usage. (Score 1) 82

When there is a surge in power usage, power companies have to spool up a fast-acting power plant to keep up with demand. Power companies don't like doing that because the power they produce is pretty expensive, and also tends to be entire fossil fuel fuelled. There is already a scheme in New York and California where you can voluntarily reduce your usage during surge periods called 'OhmConnect' ( https://www.ohmconnect.com/how...). You can actually get paid for not using power during these periods, and if you have a smart thermostat you can set it to turn off AC automatically (or just alter the temperature thresholds) during those periods to get paid by the power company.

Now, if you happen to have a large-capacity battery in the car connected to your house, you could have it set up so that during surge periods it uses energy from your car, and then charges it up afterwards. You get those sweet power company bucks without having to actually change your power usage behaviour at all.

Comment Re: These will be (Score 1) 77

This was seen at 5000' 15 miles east of LAX, which puts it firmly in the LAX Bravo, which is illegal for Part 103 aircraft without prior authorization. Furthermore, part 103 aircraft are not permitted to fly over congested areas, irrespective of airspace.

http://www.usppa.org/federal-a...

However, as long as the jetpack weighs less than 254lbs, has less than 5 gallons of fuel, does not do more than 55kts in level flight, and has a stall speed of 24kts or less, then there are lots of other places you can legally fly it.

Comment Re:7000Wh/kg for graphite foam (Score 1) 298

It's not 7000Wh/kg, it's 7000W/kg.

(See also https://www.graphene-info.com/...)

That means you can get a lot more power from a given weight of aluminum ion battery than you can from lithium ion, but the energy density at 160Wh/Kg is not as good as for instance Tesla batteries, at ~260Wh/Kg.

It's a shame - I got excited for a moment because a 3x energy density for batteries could entirely revolutionize general aviation.

Comment Required power for damage (Score 1) 208

I wonder what you have to do to do sufficient damage to an enemy?

They talk about starting with 10kW lasers; Steel has a specific heat of about 0.5, so if you trained the laser on the target for one second, you could vaporise a little over six grams of steel (not counting losses from transmission through the air, reflection etc) I can see that if you're using your laser to assassinate someone from a drone, that's certainly enough to kill someone, but is it enough to destroy a truck or an aeroplane? Is the laser even capable of operating continuously for a second?

Comment Re:Enormous tax and administrative burdens (Score 1) 347

It's interesting that when this was first looked at in 1992 the specific reasoning behind not levying a 'use tax' was that the burden would be too high. It seems so me that if that's the case then there's probably scope to allow levying use tax on outside purchases if a way can be found to make the burden reasonable. For instance, could the court decide that use tax could be levied if there was a flat rate of use tax that applied to all items, whatever their type, if purchased from an out-of-state supplier? Also, I don't know what South Dakota's use tax laws are like, but it seems to me that the state might only have to prove that its use tax wouldn't create an undue burden.

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