> Thermal energy storage doesn't work well for anything much smaller than a large industrial site.
That *used* to be true, before the development of hi-temp vacuum-powder insulation. It has about 6x lower thermal conductivity than fiberglass, and therefore lowers the relative heat loss on smaller units. It is being sold for industrial furnace insulation, which is a similar job to thermal storage.
Hot rock thermal storage is the cheapest long term option, because rock is as cheap as you can get for a storage medium. You blow air through a heat exchanger into the rock bed to store energy, then reverse the air flow to extract heat. The heat exchanger has boiler tubes to make steam. That then goes to a turbine the way most electricity is generated.
You mean photovoltaic doesn't match demand. Solar thermal with storage can meet demand whatever time you want. Not many plants with storage have been built yet, because they are not necessary. Solar is a small enough part of the grid that other sources can adjust. Once you get to about 20% penetration, you will need storage options, and they will get included.
Solar-Thermal gets the same performance as Nuclear-Thermal, except the reactor is 150 million km or more away. Both heat hydrogen gas to high temperatures, and therefore get the same exhaust velocity. Large solar concentrators are lightweight, and not hard to build in orbit. One the size of the Space Station (100 meter diameter) would generate 10 MW.
The nice thing about solar-thermal is it avoids all the issues with nuclear-anything. No Greenpeace protestors, no extra costs for nuclear security on the ground, radiation shielding, etc.
How about the same people who actually wired up rural areas, the Rural Electric Cooperatives? The TVA built dams and power plants, but the REC's did the local work. As cooperatives, they are customer-owned. The government helped them get started with loans, but those are long since paid off. The advantage of using the Electric Co-ops is they already have poles going everywhere necessary.
> but the suspects can easily dispose of "evidence" (illicit drugs) in the toilet.
So it's too hard to put a bucket or stopper in the sewer line?
> Who knows about the bitcoin mining because that's all nonsense anyway.
Nobody in their right mind uses GPUs to mine bitcoin any more. They use custom mining chips (ASICs) which are about 100 times more efficient, because the calculations are done entirely in hardware, and being fairly simple, can be parallelized much more than graphics cores.
As far as bitcoin being nonsense, the New York Stock Exchange and a large bank just invested in a bitcoin company: http://blog.coinbase.com/post/..., and Microsoft accepts bitcoins: https://commerce.microsoft.com... . Evidently they don't think it is nonsense.
> But I'll bet their little programs that they run using $1 of electricity to get 50 cents in bitcoins
I did mine at a loss sometimes back in the day, but it was in the background, for a graphics card I was already using in this PC. So I only had to pay for the incremental electricity of the card running full bore instead lower levels. The $60 of extra electricity is worth $680 in bitcoins today. I stopped mining in mid-2013 when the custom chips started going into volume production. Not all of us are idiots.
Space solar arrays are also 2.5 times as efficient than in 1998. That's because they now use triple-layer cells, that convert more of the solar spectrum to electricity. The biggest shift will be if SpaceX can reuse their rocket stages. They are already the low-cost launch provider, and that would given them another factor of 3 or so in cost.
Reducing launch cost also will reduce satellite cost. The cost optimum is when the marginal cost of removing 1 kg from the satellite = the marginal cost of launching that kg. So cheaper launch means heavier but less expensive satellite parts.
> Private corporations may soon have more space technology than the US government.
That's already the case. NASA's share of total space industry is only 6% ($18 vs $300 billion/year). Commercial satellites have had ion thrusters for a number of years before the NASA Dawn spacecraft had them. For-profit corporations have more incentive to update their tech sooner, to get a competitive advantage.
The free market method is to offer "dead or alive" bounties on whoever dumped in your water system, and let competition sort it out. One mining company might do it once, but after that, the rest would have an object lesson.
Metallic foil "radiant barrier" insulation is already a thing:
http://www.amazon.com/EcoFoil-...
Just make sure to cross-connect the pieces, so they form a single ground plane.
The Fourth Amendment reads in part:
> "...and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized
This looks like an attempt to get around that provision. Sorry, FBI, you actually have to do police work.
> It does limit the functionality though since you don't get emergency calls where someone you know had to borrow a phone and such.
Those people can leave a voicemail message. Most telemarketers and robocalls don't. When I get a mystery calling number, I let it go to voicemail. If it's important they can leave a message, and I can call them back.
> I wonder what the fastest possible chemically-propelled-rocket probe is?
Slower than a Nuclear-ion probe. Nuclear in this case means a small nuclear reactor, say in the 1 MW power range. Plasma thrusters have an exhaust velocity of ~ 50 km/s, and it is reasonable to reach 3x exhaust velocity, thus 150 km/s. The mass ratio (propellant to empty mass) would be 20:1 in that case. For any kind of chemical rocket to reach that velocity, it would need a mass ratio of 10 trillion, which is seriously impractical.
150 km/s = 31.6 AU/year, therefore missions to around 300 AU would be reasonable (10 year trip time). 1 MW reactor with radiators would mass ~ 20 tons. 300 AU probe would mass ~ 5 tons. Propellant load would be 25x20 = 500 tons. Propellant flow rate is
> The hard part is getting up to speed, and slowing down at the destination.
The diffusion method I call "slow interstellar" doesn't require that. If you already live in the Sun's Oort Cloud, and another star gets close enough that the Oort Clouds overlap, you only have to match velocity, which is on the order of 50 km/s. After that you drift along with the other star, spreading to fill their environment, until another close stellar encounter happens. This method requires more patience than humans possess, though.
The optimum committee has no members. -- Norman Augustine
