[Oeva-list] Mr. Zehner's article

Steve's Account stevel at fern.com
Tue Jul 30 14:29:44 PDT 2013


On Tue, 30 Jul 2013, Peter Hoeckel wrote:

> Steve,
> 
> Some good points, some unsupported statements/fallacies - unsurprisingly for this board, I'll focus
> on the latter :)
> 
> - PV is working very well for me; quality issues may happen (not on mine, at least so far), they need
> to be worked out, but they're not unique for PV; it's like saying that we should abandon ICEs because
> a small subset may need a new transmission after a few years - or because their performance decreases
> over time;

Well.. the problem with PV's lately has been that they are showing a high mortality rate. Now.. if
you look at what happens when a panel fails in a string of panels, it actually drops the capacity
of the whole string.

If you arn't "watching" you suddenly end up with considerably less output than you expected, and
you may not notice it for a while. If you are counting on the power production to make payback,
as many "utility" scale power installations are, it's a very costly problem.

In one recent report, 23% of the panels were failing.

What this means is that 1 in 4 is going bad.. if they are "scattered" in your field of panels,
you can end up with most of your capacity shot to heck. Now you have to get to each panel
to find out which one in the string is bad. This may not be easy, if your entire roof is
covered, with no access space between rows of panels. And for a home owner, it means an
expensive service call.

> - "EVs aren't that much better than ICEs"; as judged by what?  I generate as much solar on my roof as
> I need to drive, and PGE is very happy to take my solar power at peak, and return it at night
> (win-win); I get 4x the miles-per-dollar as a Prius (never mind the lower maintenance cost); yes,
> they don't work for everybody, they don't pay off financially yet if you don't drive enough, but
> that's in good part because of all the subsidies we're using to drive down the oil/gas price;

I don't see how subsidies for EV's drive down the price of oil/gas. (EV's don't displace a
significant volume of gas/oil demand. What they "save" get's used to generate the power they
need.)

> - PV price artificially driven down - there are subsidies, but solar PV is actually MORE expensive
> here than in many other countries, even if the installation there is NOT subsidized; look at
> installation costs inGermany; http://cleantechnica.com/2013/02/17/why-german-solar-is-so-much-cheaper-than-u-s-solar-upda
> ted-study/

And we won't protect our own PV industry from international (possibly unfair) competition. So.. we
don't have a significant PV production capacity of our own. (Companies like Solyndra and SoloPower.)


> - "We can't, and won't be able to, in the forseeable future, produce enough clean power to shift the
> transportation energy expenditures from the existing oil based fuel to the electricity grid."; that
> sounds a bit like "we can't be 100% renewable by tomorrow, so we shouldn't even start converting
> anything away from oil-based"; I have yet to see any data that suggests that we can't bring online
> new renewable capacity at the same or higher rate than the expected/desired adoption rate of EVs;

Well.. there is the issue of the day/night capacity problem. One of the large peaks in usage
occurs just after dark.. especially in the winter time.

Power companies don't like to invest in large capacity plants that they have to "park" for
a major part of the day. Their best payout occurs when they run the plant at capacity,
24 hours per day.

If they are forced to take significant amounts of PV power during the day, from sources that
don't generate them any revenue.. if fact, "cost" them money.. then their own plants don't
pay out. This is something that they can "tollerate" as long as PV isn't a big part of
the equation. But.. should it become a major factor, then the economics of running a
power company go right down the chute.

Solar thermal power is interesting to them, because they can use it 24 hours per day. Heat
you can store.
> 
> Peter
> 
> P.S. There is such a thing as excess renewable energy; dams send more water over the spillway when
> they don't know where they could send the power they could generate with that water; wind turbines
> are occasionally turned OFF for the same reason.  Rare, but it definitely does exist.

Dams can only generate power to the extent that they "use" all the water that the river
provides. Once they are at that level, they can't go any higher, the resource doesn't
exist. For parts of the year, when the river flow is low they can't even generate their
"normal" capacity. Given that some dams are forced to spill water to protect fish from
high water temperatures, that's water they can't use.

In many cases, you can shut off the flow of water, to allow water to rise behind the
dam.. saving power generating capacity for when you need it.

You also need to modulate the river flow for irrigation, flood control and river navigation
  reasons, somethimes not corresponding with peak power demand periods. Often they are ordered
to dump water in advance of large rain events, to keep flooding from occuring when the rain
does come.

Since a dam is an easier thing to control than say a large nuclear or coal plant, dams
are often used to moduleate the supply of power to meet demand. (It takes time to shift
the power generation capacity of large thermal plants.. especially coming up from
cold.)

Steve


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