galaxy flyer

Insulting people—the sure sign of a losing argument.

GF

BobZ

Since they have the energy equation solved...Im waiting for these intellectual super stars to regale us with their viable program to achieve negative population growth to reach 1B worldwide.

rickair7777

Let's get started on the stupid...

Huh? You're kind of throwing "science sounding" terminology around loosely here but what you really mean is specific energy. Energy density matters, but it's not the show stopper.

The show stopper (as someone pointed out already) is chemistry, specifically electron valence energy. That's pretty fundamental based on known laws of physics. If you can re-write the laws of physics to change that, we won't need airplanes because we'll also have anti-gravity, levitation, FTL, and time travel.

Wrong. It can be economically viable if you remove all the political stupidy which creates (intentional) artificial impediments.

Modern plant designs would be even more economical than old ones... most operating plants in the US are the engineering equivalent of a '65 Ford. Also vastly safer too.

And "economically viable" by what measure? If it's that vital to save the planet from CO2, it's not unreasonable that (clean) electrical power might be a little more expensive than say coal.

Niche. Plenty of places to build it, but many folks really don't want those things all over the place. Also as progressives have to learn over and over again there are some engineering limitations on power generation... the places that need power are not necessarily close enough to places where windmills make sense (windy with few residents).

Profitable? If it were profitable, rich guys would be doing it to get even richer. It is quickly becoming technically more practical, and will obviously play a role.

But like wind, the best places to generate solar power (southwestern deserts in the US) are too far away from most population centers, ie it's not going to help new england much. High latitudes and/or cloud cover quickly reduce the utility of solar.

Grid capacity will actually have to increase unless controls are put in place because folks will want to charge their cars while at work during the day (peak AC use, peak industrial commercial use, etc). If you can limit car charging to night only, the current grid might suffice.
Nuke is much better than coal or NG. You just have to get around stupid people who are afraid of things they don't understand, and easily mislead by self-appointned wingnut counter-culture gurus.

H2 is not an energy source any more than a battery is. It's just a means of transporting and delivering energy (ie a fuel).

H2 is good because the only emission is H20... that's fine at sea level but actually bad in the flight levels where there's normally no moisture above the tropopause. If you put moisture up there it will produce a greenhouse effect like Co2.

There are engineering challenges, and of course. The only clear win for H2 is applications where you need specific energy at all costs, including low energy density. That's pretty much space launch, specifically deep space launch.

Not an energy source, just a system component. The nature of the fuel in question is what's significant. If the fuel makes sense, then fuel cells can make sense.

Not dead, it will be around forever

Huh???

You do realize that a capacitor is a kind of battery, right?

The higher capacity capacitors have the same chemistry limitations as other batteries.

Field capacitors are also limited by physics... if you try to use high voltage to increase energy storage, you need a lot of weight and space to contain that voltage. And you will reach a voltage which cannot be contained by practical volumes of material or spacing. With reasonable voltages, capacitors simply weigh too much (compared to practical fuels/energy storage systems).

That's really hard to quantify. If we let all of the wannabe rogue regimes just run amuck, there would be much broader economic consequences than just oil.

But eliminating most oil use would certainly be a good thing, in many respects. It just needs to be done in a coordinated manner so as not to code blue the global economy.


There's a clear niche for electric planes, and it can probably (barely) include small regional jet market.

Electrical airplanes are actually a fascinating engineering challenge because of all the various tradeoffs. All of which can be fined-tuned for the specific mission at hand.

But with batteries you're still limited to about 8% of the specific energy of Jet A, and that's at 100% chemical efficiency.

Chemical batteries are the best known portable storage technology for electrical energy. They can be improved, but there's a glass ceiling and we already know about what it is (1,000 KwH/Kg).

Frankly, lots of passion but pretty weak on basic science and engineering.

rickair7777

Neutron bombs.

It doesn't matter what the first world does if the third world keeps slashing and burning rain forests and growing 18th-19th century industrial processes.

Name User

Ironically the majority of the slashing and burning is for meat production of which the majority of that is one company (JBS).

JohnBurke

You are referring to me, but have attributed to me that which I did not say. You are a liar.

I said nothing about "electrical airplanes are hard." YOU said that. Speak for yourself, if you believe that you're capable. Don't put words in my mouth. I speak very well for myself.

BobZ

Inside dope is the flux capacitor is just around the corner.

FlyJSH

No, the Sun will not go supernova unless it somehow gains several times its current mass. It will end up as a white dwarf.

So, I'm guessing from your statement yo believe solar is the answer. Here's the math:

A fairly high efficiency photo voltaic panel produces 15 watts per square foot. Let's pretend a panel can produce that 15 watts/square foot for 12 hours each day (more realistically about 7 hours in the sun belt, but hey, I'm generous). That means 1 square foot can produce about 65 kwh per year (15 watts *12 hours per day *365 days/year / 1000).

The US used about 3.9 trillion kwh last year. That equates to 60 billion square feet or roughly 2150 square miles of cells.

Ooops, I made a mistake.

That 2150 square miles would supply enough electricity for the country ONLY WHEN the sun is shining. Since it is dark 12 hours per day, we would need another 2150 square miles. Figure a swath about 4 miles wide running from the Florida panhandle to San Diego (I know that is more that 4300 square miles, but there will need to be room between each row of cells and for logistical stuff)

Remember, cell start losing efficiency day one and should be replaced about every 25 years.

AND we would need batteries to store enough electricity to last through the nights. Elon Musk's Australia battery holds 100 mw. To make it through the night we would need some 53,000 of those batteries. The numbers I have seen suggest each of those batteries cost about $100 million.

Now that has been an extremely optimistic set up. There would be no way to distribute electricity from the sun belt to the rust belt without ridiculous efficiency losses. And if the cells are installed up north, that 12 hours of production per day drops down to as little as 4 hour on full sun days near the Canadian border.

rickair7777

Battery cost, weight, volume, efficiency, longevity, and charge cycle times are all key factors for *portable* batteries for use in vehicles (and cell phones, tablets, etc).

But if you just need to store energy at a fixed site, flywheel systems might do the trick (already in use in some applications). With magnetic (vice mechanical bearings) they are extremely efficient for a time period in the range of day/night cycles, essentially maintenance free, and the expensive parts last forever. Storage capacity is limited only by the size of the wheel and tensile tensile strength of the metal used. And of course you can use as many as needed in parallel. Construction cost (comparable to other large grid equipment) is almost irrelevant, since they literally last forever, you could amortize the cost over a very long period (assuming you design the entire system right in the first place). Such devices could also be dispersed down the grid if that made sense, although you might not want want a very high RPM unit in a residential neighborhood, just in case.

You could also do reverse hydro for overnight (or longer) grid power accumulation. Pump water up into a reservoir or tank at night, extract the power with normal hydro gear as needed. I suspect flywheels would be better in most applications (where you don't have a good place for water storage).

It is utterly astounding to me that all of the Good Idea Fairies STILL cannot grasp this basic concept from Electrical Engineering 101. Transmission losses pile up over the miles, and 300 miles is about the practical limit. Slight possibility that could be extended with superconducting lines, but those would be orders of magnitude more expensive that current long-distance lines, and would probably require utterly impractical amounts of energy to cool the lines. Plus maintenance of a complex system stretching for hundreds of miles?

Solar is a nice supplement where it makes sense but isn't going to be the solution, any more than wind.

Mesabah

The only way to achieve a zero emissions electrical grid is base load nuclear power, and biofuel peaker plants. When solar and wind become a large enough market share, it is impossible to create a grid that is zero emissions. Germany is at that point today, and will soon exceed its emissions levels from before it went down the path of solar and wind.