is carbon offset per Kwh of PV a lie? [RE-wrenches]

[Geoff Greenfield]

If I reduce my kwh usage (by solar or efficiency or whatever), is it safe to
say that the power plant would emit less carbon?  I feel silly even asking
this, as it seems common sense, but someone is making the argument (and it
is being repeated) that battery based “off-grid” solar is the only way to
go.  He also makes the (common to all of us) argument that reduction and
efficiency are of utmost importance.  

He says that coal plants typically operate at 100% all the time (makes
sense) and that peaks are handled with Ngas turbines and wholesale
purchases.  He says Ngas efficiency goes way down if they are not at full
output (I thought they were modular and went on and off as needed).  Is it
true that the old plants are either full bore or full stop?  I thought that
they could ramp up and down?  The full discussion is in some email discourse
snipped in below (newest to oldest)

I guess the basic question is:  If the above operating protocols are
correct, then how is my “avoided kwh” from solar or efficiency reducing the
net carbon emissions of the system?  

This is interesting stuff, and calls out some assumptions I have made - I
hope I am wrong.  If any of you would like to feed me facts that shore up my
assumptions, please do!  


For a brighter energy future,

Geoff Greenfield
President
Third Sun Solar & Wind Power Ltd.
340 West State street, Unit 25
Athens, Ohio 45701
(740) 597-3111   fax: (740)597-1548
www.third-sun.com

Clean Energy - Expertly Installed




Below is his argument:  (original post at bottom, then a second guy's post,
then his follow up)



His response to the second guy:

When I talk with utility power operators, they describe reaction to user
reductions in power demand as accummulative and effective over a longer time
frame.  For instance, they tell me DSM measures over time add up to delay or
avoid need for new generation.  All tell me pretty much that same message.
When I was part of  "REAP" (residential energy advisory panel) in
Cincinnati, which was spun off the pro bono gatherings in Columbus back when
BillS was head of OCC promoting utiltity DSM, most of our and OCCs
discussions about DSM related to such longterm opportunities, focused back
then of reducing pollution and power cost in Ohio.  So when CG&E or AEP was
pushed (with Bill's lead) by PUCO to implement DSM, when we saw proposals to
reduce 25 - 50 mW, I recognized that was less than any of the ngas
generators CG&E operated at that time, but tiny in comparison with CG&E's
coal generators.   I recall proposing higher levels of DSM, more like the
sizes of the actual generators, so we could engage a more aggressive
approach to power reduction.  But even back then, I recall being told the
standard line about how we were trying to effect change over time, that DSM
measures added up over time.

John, what you're seemingly wanting or hoping for is a more immediate
beneficial response to short term and/or relatively tiny changes in user
demand.  I say "relatively tiny" because back in those old days of Bill at
OCC, 25 mW was considered big to some of us, but tiny to me and others who
knew the size of powerplants.  When you and a few hundreds of us wrestle a
few hundred kW from our grid demand, we're having even tinier impact than 25
mW.  Most importantly, we're often most likely impacting the least emissions
part of the power grid when we postpone a utility somewhere turning on a
ngas turbine.  Our most important goal is figuring out how to shut down,
keep turned off as much as possible or prevent from being built the coal
plants, since these are the most polluting.  Sure, the ngas plants are
likely responsible for the greatest power cost/kWh, but the coal plants are
the biggest pollution source.  In order to change how most coal plants
appear to be operated, we need more baseload and continuous reductions. This
is why I typically value results which reduce power consumption and demand
across the entire 24/7/365 spectrum, not just during certain timelines.
It's why I converted my office to offgrid solar instead of grid-tied.  I
wanted 100% certainty that my business was not placing any electrical
demands on the coal-fired grid.  I paid extra for batteries and far more
aggressive load-reductions simply to achieve that clear a goal.

When I viewed the CitizenRE sales powerpoint, I disputed with the 2 sales
reps their telling applicants that batteryless grid-tied PVs in a net-zero
setup eliminate their responsibility for CO2 and other electric grid
maladies.  I asked, "how do you explain that in a partly cloudy climate a
solar array doesn't generate all the time, so absolutely needs background
power and pollution as substitute for batteries."  Silence (it was a
conference call).  I followed up, "during the half-year of heating season in
most northern climates, it's normal for most electric utilities, including
as far south as Cincinnati, to report their greatest grid peaks before
sunrise or after sunset, so how do you explain to consumers that most coal
plants can't be turned off in less than 12-hr stop-start cycles?"   Again,
no response.  Keep in mind that these two sales guys, one in Texas and the
other in Lexington, admitted having no prior experience in energy,
renewables or power.  It was my impression that they'd never considered such
questions.  They'd been educated solely by CitizenRE about how to sell the
PVs, not what our bigger problems and challenges were.  I also discovered,
quite by accident in the middle of this conference call, that the Lexington
guy didn't even know he was in a 'too-cheap' electricity zone where he
lived, such that CitizenRE wouldn't even accept him as an applicant!  He fou
nd out when the Texas guy mentioned the minimum price and usage thresholds
to me in the conference call!  This confirmed how shallow the CitizenRE
approach is.  It bothered me how it so closely resembles how we are
presenting these issues to the general public...

I wish there was an ongoing and very public discussion to educate the public
about all this.  The energy-consuming public desperately needs high quality
education about their demands and consequences, since all this has gotten so
abstract, more akin to virtual reality than hands-on.  I think the key to
shutting down baseload coal plants is getting continuous load reductions AND
in huge increments.  If only we could implement 100 mW in baseload
reductions every 3-5 years, just in Ohio and KY, maybe double or triple that
per 3-5 years in peakload reduction.   But, that's not the current case.
Electricity demand is still rising 2-3% per year by every report I've read
this year.  Just 2% growth on Duke's SW Ohio and NKY published peak loads in
2005 is about 280 mW!  Scary.  Even gasoline consumption in America is
reported rising 3 times faster so far this year than last year.  We're
having lots of e-discussions, marketing and PR, but we're certainly not
achieving the goals we should be hoping and aiming for.  Sure, some of us
and our clients achieve wonderful results, like my achieving one-third
reduction in annual electricity usage since 1999, or my using almost
two-thirds less gasoline last year than 20 years ago, but the overall
picture is not rosey.  Too many others are increasing their energy usage
faster than a few can reduce theirs.  This is why my most important mission
is to aim people directly at reductions, not particular products or
technologies...  Too many out there have been convinced that becoming green
has a brandname or label...



Another guy in the discussion's reply:


Thanks for the information.  I too want to dig into this more deeply and
develop an understanding of what is actually so going on and be able to
articulate it in a way people can grasp.

I think a dialogue with Geoff would be very good, so I am copying him into
this.  As Geoff explained to me the other day, we have to look at the entire
system not just a few power plants.  If you consider all of the power that
is being brought onto the grid and moved around across the entire
power-purchase territory then perhaps you get a different picture.  Sure,
one plant cannot drop its emissions spontaneously when I turn off my AC, but
if I am drawing from a mix of plants then what does a spontaneous load
reduction do the overall mix being brought in across the region?  Does it
allow for power to be re-directed to another need and avoid pulling in
additional power from elsewhere?  I am skeptical that the system is that
flexible.   But there must be some flexibility or else smart metering or
time-of-use metering don¹t make sense.

Yet, if it the system is as inflexible and inefficient as you surmise then
where are NREL and other scientists on this?  Clearly I have some research
to do.  Guess the question is, on what time-scale and for what load
percentages is the system flexible?

Geoff?  Want to weigh in?




Here is the original, oldest message:


>
> I'm still gathering data to backup my claims about powerplant 
> operations. Not done yet by any measure, but below are some FACTS I've
learned so far
> (mostly from engineers who actually operate powerplants.)   Quotes are
used
> only where I'm exerpting exact statements either said or written in
response
> to my inquiries.  I've not yet determined precisely if or to what 
> extent coal plants can be or are commonly "cycled down" to lower 
> outputs when
lower
> loads are experienced.  But I'm hearing that it's not uncommon or
impossible
> for natural gas powerplants to cycle back at times.  However, check 
> out
that
> point #3...   I'm likely right about the coal plants usually operating at
> full, since as the "big polluters" and usually "least efficient"
generators,
> they are usually pushed to minimize pollution and fuel consumption per 
> average output.  Operating coal plants at reduced output, at least for
very
> long, sounds like it would wreck the stats, requiring extra hoops
elsewhere
> to meet max pollution per output mandates from EPA.  When I questioned 
> an operator at Ghent in KY, operated by KY Utilities, he spent a lot 
> of time explaining how they work to comply with EPA's pollution per 
> output regs, managing fuels and operations carefully.  One engineer at 
> DPL said they could sometimes (or maybe did sometimes) operate their 
> Miamisburg plant as
a
> peaker, cycling it on and off as often as once in a day.   I think that's
> where I heard about the 11-12 hr fastest-restart time for a coal 
> plant. Here are some exact quotes:
>
> 1)  "...large power plants are typically operated at full load.  This 
> operation is especially common for coal and nuke plants."
>
> 2)  "...gas fired plants can react to load changes very quickly....  ...as
> often as 3 times per day.   ...coal fired plants [can] run for over 400
> straight days..."
>
> 3)  ...ngas "turbines use twice as much fuel per kW at 4,000 kw as 
> they do at 12,000 kW"
>
> I once questioned why so much generation appears to continue after 
> demand decays significantly, but if fuel and pollution go 
> substantially up as output is reduced, this would explain it.  After 
> all, I discovered long
ago
> (back in Zimmer-hearings days) that EPA regulates pollution based on 
> emissions per BTU of output.  If output goes down, pollution can't go 
> up
and
> work under that formula.  If output stays high, even when there is 
> reduced demand, then the ratio of emissions to output stays more 
> acceptable to
EPA.
> It's sad if we keep the big plants going just to maintain that 
> ratio... I've been advocating for many years that we need overall 
> "theater volumes caps" for emissions, rather than the current ratios 
> game.  But who listens to me?  Nowdays I often feel as if "both sides" 
> don't like what I'm saying...
>
> Anyway, what's maybe most significant is that I'm not finding anybody 
> yet
to
> refute what I think and commonly say.  If coal plants (our largest
polluters
> and least-efficient generators generally) are operated normally at 
> full
and
> seldom shut down except for maintenance, and if ngas turbines use 
> twice as much fuel per kW when cycled back to 1/3 of full, then this 
> pretty much is what I'm saying, pretty much what you wrote in the GEO 
> article, which is what Geoff wants to argue about.
>
> Why not ask Geoff what evidence HE has to discredit what we're saying?
I'd
> love for somebody (with experience and authority) to come forward and say
> how or where what we're saying is wrong...   After all, I am a solar and
RE
> advocate and user too.  I like optimism.  But I don't consider what 
> I've been saying as controversial or irresponsible.  Just factual.  
> But I also don't sell solar and wind stuff as Geoff does, nor am I 
> heavily vested in energy product marketing or sales or politics as he 
> appears to be.  From
my
> corner, I'd almost expect him NOT to want the reality to be as I 
> describe, because that reality is not very rosey.  It's like a 
> conference call I had recently with CitizenRE.  They contacted me, 
> asking for my interest and support.  But when I challenged some of 
> what they had in their sales powerpoint, they backed off fast, really 
> fast.  They weren't interested in facts, science or engineering, let 
> alone my suggestions or comments.  They just wanted to sell solar 
> stuff.  Both salespeople I talked with had no solar or energy 
> experience.  They accepted the company sales lines as
fact,
> not arguable.
>


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