Re: [asa] UN Downgrades Man's Impact On The Climate

From: Jim Armstrong <jarmstro@qwest.net>
Date: Fri Dec 15 2006 - 12:14:42 EST

The 40% figure was recently reported by Boeing Spectrolab and verified
by the US dept of Energy's National Renewable Energy Lab. For example:
http://news.monstersandcritics.com/energywatch/renewables/features/article_1233268.php/Solar_World_An_efficiency_milestone
No question as to the continued use of liquid fuel for some time.
The delivery infrastructure is a significant issue, even if the
conversion efficiency of a source is reasonable.
The infrastructure exists (as is the case for petrofuels) for
electricity. For direct conversion electricity, there is no
fuel-to-deliver-fuel overhead.
That's kinda nice!

JimA

Don Winterstein wrote:

> Don't know what you're referring to with the 40%. In any case, cars
> are likely to need liquid fuel for some time to come. How efficient
> cellulose will be is unknown at present; it'll depend on the
> biochemists.
>
> Don
>
>
> ----- Original Message -----
> From: Jim Armstrong <mailto:jarmstro@qwest.net>
> To: asa <mailto:asa@calvin.edu>
> Sent: Wednesday, December 13, 2006 8:18 AM
> Subject: Re: [asa] UN Downgrades Man's Impact On The Climate
>
> But does it not seem unlikely to be able to hit an overall figure
> anything like the 40% direct solar energy conversion efficiency
> recently reported? JimA
>
> Don Winterstein wrote:
>
>> The important thing about this recent Bus. Week article is that
>> it doesn't concern such intensively farmed crops....
>>
>> To clarify, the really important difference between use of corn
>> and soybeans and use of cellulose is not that corn and soybeans
>> are intensively cultivated while prairie grasses are not. It is
>> that cellulose constitutes a far larger fraction of all plant
>> material than the starches, sugars and oils currently being used
>> from corn and soybeans. So if you can figure out an
>> efficient way to use cellulose, you have a vastly larger
>> reservoir of useful plant material at your disposal and the
>> consequent possibility of making a serious dent in oil imports.
>>
>> The solution to this problem is a biochemical one and
>> hence--unlike getting useful energy from fusion--within the realm
>> of near-term possibility. The amazing things that biochemists
>> have done gives confidence that they'll be able to solve this as
>> well. The solution will have a major effect on agriculture and
>> the rest of the economy.
>>
>> Don
>>
>>
>> ----- Original Message -----
>> From: Don Winterstein <mailto:dfwinterstein@msn.com>
>> To: asa <mailto:asa@calvin.edu> ; Ted Davis
>> <mailto:tdavis@messiah.edu>
>> Sent: Monday, December 11, 2006 7:29 AM
>> Subject: Re: [asa] UN Downgrades Man's Impact On The Climate
>>
>> The advance publicity for Pimentel talks about intensively
>> farmed crops such as corn and soybeans. There's long been a
>> concern that these won't be economical long-term--although
>> I've read that those who are producing the ethanol from corn
>> say their processes are economical by a sufficient margin.
>>
>> The important thing about this recent Bus. Week article is
>> that it doesn't concern such intensively farmed crops
>> but plants like switchgrass and the Asian grass miscanthas,
>> which don't need to be cultivated but only harvested from
>> existing or new prairies. Also, waste paper, wheat straw,
>> etc. Anything with cellulose or hemicellulose. The corn and
>> soybean processes in contrast make use of sugars and oils.
>> The big problem at the moment is finding an efficient way to
>> break down cellulose into its constituent sugars. The
>> article discusses several alternatives that are being explored.
>>
>> There certainly will be important problems they're probably
>> minimizing at the moment. For example, how many times can
>> you harvest grass before you have to apply fertilizer?
>>
>> Don
>>
>>
>> ----- Original Message -----
>> From: Ted Davis <mailto:tdavis@messiah.edu>
>> To: Dawsonzhu@aol.com <mailto:Dawsonzhu@aol.com> ;
>> asa@calvin.edu <mailto:asa@calvin.edu> ;
>> dfwinterstein@msn.com <mailto:dfwinterstein@msn.com>
>> Sent: Monday, December 11, 2006 6:28 AM
>> Subject: Re: [asa] UN Downgrades Man's Impact On The Climate
>>
>> >>> "Don Winterstein" <dfwinterstein@msn.com
>> <mailto:dfwinterstein@msn.com>> 12/11/06 9:03 AM >>>writes:
>> Don't forget too, that there are other looming issues
>> such as energy.
>>
>> The current issue of Business Week (Dec. 18) states in an
>> article entitled
>> Put a Termite In Your Tank, "If efforts [involving 'bio
>> breakthroughs' for
>> digesting cellulose] can be scaled up efficiently,
>> America's forests,
>> agricultural waste, and 40 to 60 million acres of prairie
>> grass could supply
>> 100 billion gallons or more of fuel per year--while
>> slashing greenhouse gas
>> emissions. That would replace more than half the 150
>> billion gallons of
>> gasoline now used [by the US] annually...."
>>
>> Lots of "ifs" there, but still a rather remarkable
>> statement. Pilot
>> facilities are already being built.
>>
>> Ted responds:
>> A couple of months ago, I heard a lecture by David
>> Pimentel that all but
>> rejected this approach as unrealistic, both economically
>> and in terms of
>> energy production. Advance publicity is here:
>> http://www.dickinson.edu/news/nrshow.cfm?981
>>
>> Ted
>>
>>
>> To unsubscribe, send a message to majordomo@calvin.edu
>> <mailto:majordomo@calvin.edu> with
>> "unsubscribe asa" (no quotes) as the body of the message.
>>

To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Fri Dec 15 12:15:22 2006

This archive was generated by hypermail 2.1.8 : Fri Dec 15 2006 - 12:15:22 EST