[ExI] cure for global warming

[Eugen Leitl]

On Mon, Dec 27, 2010 at 12:43:44PM -0700, Keith Henson wrote:

> > I don't think it's at all dilute.
> 
> Over a year solar energy averages a few hundred watts per square

The solar constant is 1.366 kW/m^2. Many people, especially
at higher latitudes, find that by itself a considerable 
challenge to handle. The amount of land area covered by 
buildings is well in excess of the total energy budget.

We don't have the area problem. We have the scaling up of
intercept (antenna) area problem. (And smart grid redistribution,
sure).

> meter.  Then you take the efficiency loss in the PV cells of at least
> 75%.

Efficiency is irrelevant as existing conversion efficiencies
are more than adequate, ROI and EROEI are the only relevant factors.
 
> The inside of a power boiler is in the tens of MW, and the efficiency

The inside of the power boiler requires steady influx of 
external fuel, so you better integrate over the entire
fuel cycle. And of course coolant is already scarce during
the summer months, so the power boilers have to be shut
down, natch.

And of course there's not much more fuel where that
came from, so the question is academic. So learn how
to stop worrying, and learn how to love your renewables.

I have a deja vu of the 1970s. What is up with transhumanists
being mired in decades old thinking that has proven not
to work?

> is around 45%.  (60% for combined cycle.)

Efficiency is still irrelevant. Today's solar PV
efficiency ranges from few % to almost 50%, but it's
the ROI and the EROEI that dominates.
 
> > Solar flux upon outer residential
> > building skin is enough to power it. In fact, Si PV rather likes
> > it cooler, so you need backventilation to make it approach optimum.
> 
> Powering houses is nowhere close to the whole energy problem.

So double the budget, and you're in the green for industry 
as well.
 
> > Many human activities are following diurnal cycles, and cheap nocturnal
> > power is an artefact of large plant thermal inertia and dynamic market
> > pricing. You can assume nocturnal demand will collapse if price
> > was to double or triple.
> 
> I thought the object was abundant low cost energy.

Before you can walk you must first learn to fly. In order to
do SPS you must first cover at least 10% of total electricity
budget from terrestrial thin-film PV.
 
> > People need houses, these have outer building skins which need
> > to be durable. Thin-film photovoltaics is an excellent way where
> > construction material doubles up in function (in fact, CdTe
> > has about an order magnitude more of energy supply equivalent than
> > enrichened uranium in LWRs, not considering recycling).
> >
> > The prices are getting there, eventually. The hard part is making
> > the growth match the demand gap, double and triple electrification,
> > and build up electrosynthesis infrastructure for fuels and chemical
> > feedstock. Work done there so far: nearly zero.
> 
> It's just chemistry, and well understood chemistry at that.

Infrastructure is most assuredly not chemistry, these days "just chemistry"
is anything but that, and RT renewable synfuels have several
Nobels up their sleeves.

Many things are cheap these days, but infrastructure and chemical
R&D definitely not.
 
> > I grant you this is hard, we're not doing nearly enough of that,
> > and this is going to hurt. However, we do not have any other options.
> >
> >> costs that translate into high cost per kWh.
> >
> > I see lots of PV panels on farmer barns around here.
> 
> You will see fewer of them as the subsidies are being phased out.

I will see *more* of them, because the current crop is good for
30-40 years, and the prices have plummeted.
 
> > Not exactly
> > huge capital costs, and the kWh prices are a factor of about 2
> > removed from residential electricity prices. It looks like thin-film
> > PV will become the cheapest electrical energy option for end consumers
> > in less than a decade.
> 
> I really doubt it.

We can make a wager that 10 years hence (that be Jan 2022) thin-film PV 
will match dirty coal in most locations, but while we'll be probably here
in 2022 nobody will remember. 

> What's the EU?  500 million people?  150 million houses?  In ten years
> 1 in 10,000 houses, at that rate 100,000 years to get them all done.
> 
> I think the energy crisis will be over by then.

So far renewable is on an exponential track but I agree it's probably
not going to last. In order to scale up land area you need to allocate
commensurate budgets.

Our problem is that we've blown the money on trinkets in the last 30-40
years, so learn to enjoy austerity. And say good-bye to growth.

Because, you get it, we've been stupid, lazy, and greedy. Now the
bill is due, so open up your wallets. Open them up wide. 
 
-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
______________________________________________________________
ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE