I don't have the reference, but someone told me that if we switched to
biofuel, we would starve because we would need all of the land
available to make the fuel - and there would be nothing left for food.
Hemp is one of the most efficient plants and grows in poor soil unsuited
for food. The Constitution is written on hemp paper and the founding
fathers wore hemp clothing
Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/
...and if they smoked enough of it, eventually, their heads would
start to spin from breathing in all that carbon monoxide from the
burning, while the smoke would probably start clogging up their lungs.
The stuff that is grown for fiber and oil these days, is selected for
production of "other" than THC content.
As a quick aside to this...
Do you US Americans still have blanket coverage laws against the
growing of hemp on the books, or have those been relaxed at all?
I recall reading somewhere that the law would have to be changed to
grow hemp at all. Could be wrong.
In Canada, there are a pile of regulatory hoops to jump through to
grow Hemp, but it can be done. There is much monitoring and analysis of
product, and getting it to market is a bit of a challenge, as there are
few users on an industrial footing. But it can be done. Legally.
Did you include all the off road diesel and home heating oil diesel in
your calculation, or just transportation fuel diesel?
The bottom line is that in some 30 year or so, solar energy is just
barely getting to the point of being viable if not economical for mass
market distributed (individual, not utility scale) use. The new bio-fuel
stuff is just starting out and has a lot of maturing to go both in
technology and in determining what usage is actually appropriate.
Solar does poorly with attempts at utility scale use due to the large
areas of environmental impact necessary for utility scale use, while
individual use on existing rooftops works well without the environmental
impact. I expect bio-fuels to ultimately be found to be viable mostly
for farms where they can be produced from waste to provide fuel for use
on those farms and not to be sold elsewhere.
I don't know, I just had some DOE figures on total diesel consumption to
It's questionable if, or when, solar is going to be economical. It's pretty
well acknowledged that it's a big loser if you don't have substantial
There are conflicting stories about whether an honest energy audit would
show any net *energy* gain for PV, even now. The US government has been
saying we passed break-even over a decade ago and I have seen some figures
that suggest a 20% - 25% net energy gain. But _The Economist_ hedged its
conclusion on that as recently as six months ago. They say it's still
questionable whether there's *any* net energy gain with PV, in the real
world and in typical installations. It just consumes too much energy to make
crystalline silicon. And other sources have said that the lifespan used for
the optimistic energy audits (25 years' life for PVs) are 'way too
optimistic on the average.
I don't claim expertise on any of this, just that I've been interested
enough to follow along casually and I'm hesitant to get excited about all of
it. On the other hand, it appears to me that it's almost inevitable that a
very large portion of our energy over the latter part of this century will
come from nuclear fission. When you see the numbers on breeder reactors, it
looks like no contest anywhere.
Maybe. The big wild card in the longer term is cellulosic ethanol. Will it,
or won't it?
The only viable short term ~20yr alternative to oil and coal is nuclear
as it is a "green" energy source, if not renewable. Longer term, after
we use nuclear to fill the gap and give us time to ramp up less mature
technologies, I see the most viable source to be tidal generation.
Unlike wind and solar, tidal generation has very minimal environmental
impact for large scale production. Unlike wind tidal is a very
consistent regular source. Tidal generation requires vastly less area of
impact than solar for a given level of generation due to the tremendous
available energy density. Tidal generation efficiency is better than
solar an the technology is simpler, requiring less maintenance.
Unlike on/offshore wind farms which give NIMBYs fodder due to their
visibility, tidal generation has a low profile and minimal visibility.
Unlike Wind witch gives NIMBYs fodder with potential bird strikes and
background noise, Tidal generation has no appreciable impact on sea life
and produces no noise. The energy required to build a tidal generation
plant should be vastly less than it's service lifetime generation
Unfortunately, there seems to be little focus on tidal generation at the
moment since it's a less visible type of project and therefore has less
Unless you're talking about wave generation, my impression of tidal is that
it's hellishly intrusive on the coastal environment. You have to dam
something up to make it work.
Am I wrong about this?
The tidal generation I'm referring to involves no dams and no waves, it
is based on solidly anchored buoys. When the tidal level lowers the buoy
anchor cable retracts into the buoy to remain tight to the ocean floor.
When the tide comes in the buoyancy of the buoy produces tremendous
tension on the anchor cable which is used to spin the generator as the
buoy slowly rises (and the anchor cable extends) until the tide maxes
out. There were some recent innovations in this design that simplified
it and improved efficiency.
At any rate, a low profile buoy bobbing up and down with the tide has
extremely low environmental impact and there is a massive amount of
available energy at high densities waiting to be captured.
I think there's a bit more to it than that. Here on the Gulf of Maine
we're probably positioned better than the vast majority of the rest of
the world to take advantage of such a scheme - tides of approx 10 ft
amplitude, deep water close to shore and only rare tropical storms.
With two daily tides there's about 20 ft of rise available per day. In
our house we use a modest 10 kwh of electricity per day which equals
2.7 x 10^7 ft*lb. Divide by 20 ft and you need 680 tons of force to
generate that much power. That translates to buoy of 22000 ft^3. If
the water's deep enough, that's a buoy 100 ft tall x 17 ft in
Another way to look at it is the displacement of one of the Aegis
destroyers, built in the next town, would be enough to power about 4
If the tides are the more typical 2 or 3 feet, 100 foot deep water is
far from shore and hurricanes are a regular occurrence, the problems
I'm glad to see that confirmed. After discussing it today I tried some
numbers from the other end. With 6-ft. tides, a float the size of a 55-gal
drum would generate roughly 2 Watt-hours per day. Sheesh. It would take a
float equivalent to almost 1,000 barrels to power one house.
Or more to the point, it would take 1000 floating barrels, all hooked
up to some means of converting mechanical, low speed input, into a
useful or transportable form, in order to get it to the grid.
Add to that, the propensity for weed growth on any fixed object in the
water, and it becomes a money sink to maintain.
The energy is there, sorta like a herd of teenagers. Extracting it in
a usefull manner is the puzzler.
Some times in the 1960's there was a Maine state referendum to build a
tidal powered power station. Was all the local newspapers talked about
for nearly a month.
There were hordes of people ranging from lobster fishermen to collage
professors arguing pros and cons for weeks.
The motion was defeated and my impression, as an outsider, was that
whether tidal power is really practical, or not, is a far from simple
Bruce in Bangkok
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