[ RadSafe ] Solar does cut it or can be a large part of the energy picture if the game is changed

Wed Oct 5 13:03:39 CDT 2011

I have heard that agriculture is the second largest use of oil. If that is
so, I can't see bio fuel based upon crops as a suitable solution. Does
anyone know what the net energy production of bio fuels is, ie the
difference between energy obtained from them and energy used to produce
them?

Cheers,
Bill

-----Original Message-----
From: radsafe-bounces at agni.phys.iit.edu
[mailto:radsafe-bounces at agni.phys.iit.edu] On Behalf Of Ted de Castro
Sent: Wednesday, October 05, 2011 11:46 AM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Solar does cut it or can be a large part of the
energy picture if the game is changed

Its not just powering a meager hovel - its the support of everything 
that requires energy too.

We can't all work and shop next door to our hovels.  Indeed that would 
leave us subject to local predatory pricing.  Goods have to move.

But also the way we use things is highly wasteful - including energy 
waste.  Nothing is built to last - just to use for a short term and then 
due to fashion or failure to discard it.  Disposal or recycle doesn't 
matter - it takes energy to replace it and it takes energy to recycle it.

Distributed energy would be nice but probably lacks efficiency.

Bio fuels seem like the most feasible means to harness significant solar 
energy in a way that is also easily used within current technology - and 
is carbon neutral.

On 10/5/2011 8:21 AM, Robert J Gunter wrote:
> Greetings All,
>
> Solar energy will not support our current levels of consumption and
> lifestyle, but it is more than sufficient to satisfy the needs of a modern
> household (i.e. smaller) built with energy efficiency in mind.
> Unfortunately our current infrastructure has been built based on the
> availability of cheap fuel.  I am not a "believer" in peak oil (they will
> find more if we will buy it), but I am a believer in the fact that the
> entire world population cannot live the energy intensive lifestyle we
enjoy
> and still have energy costs as low as they are today.  The USA represents
> about 10% of the world population and uses 25% of the energy.
>
> So either the West subjugates the rest of the world in perpetual serfdom
> (very unlikely), or the number of people who will want to buy our
lifestyle
> will ever increase and probably... drive up the price.  As more and more
> people get connected to the global economy, the cost of energy will likely
> increase (based on demand) and we (in the USA) are potentially left with
an
> infrastructure with a high overhead cost.  Changing our way of life and
> entire infrastructure will not be cheap.  But the cost of energy will
> probably drive us towards it.
>
> I heard an interesting lecture where the speaker indicated the future of
> energy production is essentially decentralized.  Individual houses and
> buildings produce their own energy (though various means-not just solar)
and
> are connected to the grid.  The excess is either stored (big problem right
> now but batteries, capacitors and Hydrogen production are a possibility)
or
> shared on the grid.  The energy companies will likely be the ones who
handle
> the sharing (if they figure this out before Google does).
>
> For example (from Wikipedia) German renewable electricity in 2010 was 17%
of
> the total using wind power 36.5 TWh, biomass and biowaste 33.5 TWh,
> hydropower 19.7 TWh and photovoltage solar power 12.0 TWh.
>
> Yours,
>
> -Rob
>
> Robert J. Gunter, MSc, CHP
> CHP Consultants/CHP Dosimetry
> www.chpconsultants.com
> www.chpdosimetry.com
> Toll Free: (888) 766-4833
> Fax:  (866) 491-9913
> Cel:  (865) 387-0028
> rjgunter at chpconsultants.com
>
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Ted de Castro
> Sent: Wednesday, October 05, 2011 1:14 AM
> To: The International Radiation Protection (Health Physics) Mailing List
> Subject: [ RadSafe ] BUT solar energy just doesn't cut it .....
>
> Or more precisely PROMPT solar energy gathered over a technologically
> feasible area/volume.
>
> I posted a calculation here a few months ago that demonstrated the
> enormity of utilizing enough solar energy just to replace fossil fuel
> use in the US.  Doable but not easily.  All energy, whole world - I
> doubt it.
> Realize however that ALL the energy we use is solar (or maybe stellar)
> energy - in one way or another.  The difference is the time and area
> over which it is integrated.
>
> Solar panels (PV) are prompt solar energy x collection efficiency
> integrated over 0 time and the area of the panel.  Same for solar
> thermal processes.
>
> Solar dissociation to produce hydrogen and integrate over a large area
> and time for use in a short time and space - but how much area?
>
> Bio fuels are delayed solar energy integrated over the growing season
> and the area of cultivation x collection efficiency.
>
> Wind energy is solar energy integrated over the area over which the air
> is heated and the time it heats - times absorption efficiency of course.
>
> Fossil fuel energy is integrated over an epoch or two and over the area
> that the "donors" grew and fed in, times many efficiency factors.
>
> Hydro is of course solar energy integrated over the area of evaporation
> and the time that process takes until condensation and deposition.
>
> Wave energy is solar energy either by wind blowing or orbital mechanics.
>
> And of course nuclear is solar - or more likely stellar energy
> integrated over billions of years and the volumes of the sun or stars
> that produced the source material from cosmic hydrogen.
>
> So the issue is time and space - mostly space.  We are using the energy
> in a shorter time and smaller space than the time and space it was
> integrated over which when used up (or not used due to political
> restrictions) will leave us only with prompt solar energy which we will
> need to integrate over a LARGE area to supply our concentrated use.
>
> It was said here that more than enough solar energy falls on the earth
> each day to meet our usage - but that is only true if we can intercept
> and use all that shines on the entire surface.
>
> Looking at the calculations I did just to replace fossil consumption
> with solar would use a massive amount of land and we don't really have
> the technology to harvest much solar energy over the seas.  From those
> calculations - the combination of solar energy and our technology to use
> it just can't meet the need.
>
> I did not attempt a wind energy calculation as I couldn't come up with
> determination of the area/time over which the solar energy is integrated
> and harvested.  HOWEVER it is clear that even enormous wind farms can
> intercept but a very small percentage of the total airflow - in other
> words - the total solar energy imparted to the winds.
>
> Its just a back of the envelope calculation - that got no comments here
> BTW - but its very clear that no form of short term integration or small
> area collection or harvesting of solar energy can meet the need.
>
> IMHO
>
> Ted de Castro
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