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Comment Wood? (Score 1) 250

Is Kerosene cheap? Stockpiling enough kerosene to make it through a gas fluctuation should be trivial. In Japan my main spaceheating kerosene tank held 80 liters and I kept 100 liters in reserve on my deck.

a closet could easily store 200 liters in poly tanks. 1 liter could heat the house for two hours. So a typical heating day I would use 4 liters. Use an electric blanket at night. So my stockpile could last me about a month. Maybe less for you. How long is a gas cutoff?

For electricity you could stockpile diesel and enough to run a generator for weeks. you could use cogen by running hot water from the cooling system into a radiator in your house.

I'm unfamiliar with your housing situation but a lister clone diesel with generator is probably $1000 and could run your house and they last forever. can also be serviced by hand. probably same rate of fuel consumption 4 liters per day with enough heat to cut space heating requirements in half.

Comment Re: Most of it not tax financed, forced buy of tr (Score 1) 260


Answer: Yes but lithium only makes up 3 percent of the cost of a lithium ion battery so recycling is uneconomical vs virgin production. If demand ever exceeds supply then that will likely change and old batteries which were thrown out will likely be reclaimed. Currently as I gather it there is about 12 pounds or $250-$350 worth of metallic lithium in a 75kwh battery pack. So currently lithium prices are a minimal impact on pack pricing considering that's a $20000 pack.

Comment Re: In mpg ... (Score 1) 234

Here would be how you calculate it..


1 gallon of gasoline is 33.4kwh (wikipedia)

@42% efficency, 20kw is consuming 47.6kwh/gasoline per hour

This gives 1.425 gallons per 52.6 miles per gallon, however if you assume the motors, charging system and resistance losses account for 10% efficency loss you get 47.3mpg highway at 75mph.

However, if we assume that you drive 60 instead of 75, alot of sites say you loose roughly 20-25% driving at 75. So at 60 if you gain 20% fuel economy it'd come out to ~56-7mpg, or within spitting distance of a prius.

Comment Re:If you're just beaming it down to earth anyways (Score 1) 230

First off, Japan is space starved and property prices around it's population centers is staggering. Also, 80% of the country is mountainous.

Second of all, the irradiation in space is higher, about 1.3kw per square meter vs 1kw at the equator.

If you count in the fact that the sun is shining 24 hours a day 365 days a year.. versus the estimated 6 hours a day of good sunshine down on earth, you end up with roughly 5x the light per square meter of collector per hour per day averaged.

There's also no dust to mire the panels in space, or atleast not dust as we know it on earth. And if concentrating solar is used, like in the mirror design, high efficency solar panels can be used, again resulting in a 1.5x-2x boost in efficency per square meter of collector.

Cost wise though it'd probably be cheaper to fill every house's roof with solar panels, before going the space based route first. Economics is likely to be much better, unless they find a way to launch massive unfurling mylar mirrors into space, get them to play nice, and do it cheaply.

This all being said, if there's any way you could use local asteroids to start fabricating SPS's in orbit, then the economics change entirely and it's not so easy to say how it will play out.

Comment Re:Energy inputs (Score 1) 256

Fascinating. So electrolysis is the main driving force of this reaction....

If they could somehow install nuclear plants capable of running a sulfur iodine cycle, they could probably achieve 50% efficency, probably enough to obviate the need for at-sea resupply.

Comment Re:Energy inputs (Score 1) 256

Probably. But many thermochemical processes fail to achieve 100% efficiency. So i'm not sure how efficient this one would work. And @$0.1/kw that's probably the figure for electricity, not thermal energy. I think most chemical conversion processes use thermal energy not electrolysis.

Comment Energy inputs (Score 3, Interesting) 256

Assuming that this process is 10% efficent let's take a look at the numbers.

Let's say you can dedicate half of the 1.1GWT (thermal) of the nimitz to aviation fuel production, if you're holding off coast.

And let's assume conservativley that the process is 20% efficent.

Diesel (pretty close to JP1) has an energy density of 35 MJ/L. This means at 20% efficency you'll be needing 175mj to create 1 liter of JP1.

At 1/2 1GWT you're looking at about 3 liters of fuel per second, or about 172,000 liters a day, or about 40,000 gallons. The nimitz has about 3 million gallons of fuel capacity so the refueling time of the entire tank from 0 would be around 2 months. According to this article here (Also about marine jet fuel fabrication, provides some of the hard numbers) 3 million gallons is enough to refuel the onboard fleet about 20 times. So onboard fuel production would provide 1/3 of a full tank of gas for each aircraft onboard per day. Not terribly good, or bad.

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