Hans,
The issues you are addressing are much more complicated than the sketch
you've made -- not that you don't recognize that.
It would be helpful to you, probably, to find and spend some time
locally with a person familar with the operation of the Utah P &L system there
in Salt Lake City. I have a friend that spends much of the year in Salt Lake
City. I'll ask her if she would be willing to talk with you. Otherwise a
staff member at the utility commission or at the consumer office, located in
the same building as the commission, might be willing to spend a few hours with
you.
Here's a quick example of an issue you might discuss. Perhaps you have
overlooked the importance of seasonal differences in stressing diurnal. The
Pacific Northwest has excess hydro capacity in the summer time. This is base
load hydro (also called "run of the river") and in the Northwest the capacity
exceeds what the region uses. It is economical to export that excess rather
than simply deactive the turbines and let the water run into the sea. Much of
that excess is exported into California on a Direct Current transmission line
built for that purpose. California returns the power in the winter when the
water flows in the Northwest are reduced.
Utah plays a big part in this swap of seasonal power from the Pacific Northwest
into the Los Angeles load center. Transmission lines from the Northwest run
into the Utah Power and Light area and other lines run from there into what is
effectively the Los Angeles area. The hydro power from the Northwest, you
might think, flows over those lines to Los Angeles. But the customers in Utah
would object -- saying "we want that cheap hydro for ourselves." So Utah P &L
runs its coal plants, and sells that power to LA at marginal cost plus a
mark-up (often priced on "split savings".) And then Utah P&L says to its local
customers "you are getting the hydro we import from the Northwest, and that's
cheap, and what we are sending to Los Angeles is the more expensive power from
our coal plants. And, Utah P &L would add, "by running the coal plants even
though our own load can't utilize them when we are importing the cheap hydro,
we are spreading the fixed costs over all those kilowat!
t hours that LA is buying, so that lowers your rates as well."
Utah Power & Light used to have a vice president named Dean Bryner. He was a
trained nuclear power plant guy who successfully kept UP&L out of the nuclear
biz. And because UP&L was taking a cut of the money from the Northwest power
going to LA, studies of transmission lines down the west coast to strength the
direct swap of power without giving a toll to UP&L were called "the Dean Bryner
by-pass." He's probably not around to chat with, but maybe someone at UP&L
would spend some time with you.
That's a long story to say that things are more complicated than the Wikipedia
entry tells about the various types of power plants.
One thing I would also stress is that Transmission and Generation, while
complementary in getting power from a generating station to the load, can and
should be thought of as sustitutes for each other (as you do in your post.)
But in planning systems they should always be thought of as substitutes, as
well as necessary for simply moving power.
As I said, I'll check with my friend there in Salt Lake City to see if she's in
town and has some time to chat with you if you would like to do that. Her
knowledge is pretty deep, and solid.
Gene
On Mar 24, 2012, at 11:35 AM, [email protected] wrote:
>
> It has often been said that renewable energy needs a
> different infrastructure than fossil or nuclear energy.
> Here is an attempt to spell out what this means.
>
> Right now electricity generation can be split into base
> load, load following, and peak load generators.
>
> Base load is always turned on (except for maintenance) and
> covers the minimum demand. It must have high reliability
> and low marginal cost, ie cheap (dirty) fuel and it must be
> large scale to get economies of scale, which requires heavy
> equipment. This makes it difficult to increase or decrease
> electricity output on the fly. But since its capacity
> factor is high it can have high capital outlays. It is
> typically coal and nuclear.
>
> Load following plants can easily be started and regulated to
> account for the variability of the load. This requires
> lighter equipment and since it is not always on, its
> marginal cost is not so important, it can be simpler
> equipment using more expensive fuel. It is typically
> natural gas.
>
> Peak load power plants cover exceptional needle peaks in
> demand, but most of the time they are turned off. They are
> typically diesel.
>
> More information about this at
> http://www.grist.org/renewable-energy/2011-05-26-how-to-get-to-a-fully-renewable-power-system
> and
> http://en.wikipedia.org/wiki/Load_following_power_plant
>
>
>
> Some renewables are base load (hydro and geothermal) or
> dispatchable (hydro and biofuels), therefore they fit into
> the above framework.
>
> But the main renewables, wind and solar, are neither base
> load (because they are intermittent) nor load following
> (because they are not dispatchable). On the other hand they
> have practically zero marginal costs and high capital costs.
>
> With increasing penetration of wind and solar energy, a
> series of things happen:
>
> (1) Since it becomes more difficult to adjust electricity
> supply to demand, it becomes more important to adjust demand
> to supply, i.e. demand side management (DSM). DSM is
> already relevant today for peak shaving, will become even
> more relevant in the future and it will require a smart grid
> and smart appliances.
>
> (2) base load will become more and more uneconomical because
> it will happen more and more often that all demand is
> covered by renewables, which have lower marginal cost than
> base load. In the future energy system base load plants
> are of little use.
>
> (3) Instead of base load or load following, fossil fuels
> (especially natural gas) will be needed for "residual load"
> which is highly dispatchable. It is like peak load because
> it only takes a minute or two to start up or shut down, in
> order to cover demand when the sun does not shine or the
> wind does not blow, but it must be more efficient and
> cleaner and cheaper than diesel because it will be needed
> much more often.
>
> (4) More and more often, total renewable electricity
> generation will exceed total demand. This electricity will
> be available for energy storage, so that in the long run the
> residual load does not come from fossil natural gas but from
> energy stored during the times of excess renewable supply.
> Now energy storage can take many forms, some of them
> unexpected.
>
> (5) Transmission: With the present fossil-fuel-powered
> system, transmission lines from the large-scale fossil fuel
> or nuclear power plants to the consumers are needed. This
> transmission and distribution network has tree structure:
> electricity always flows in one direction, from the
> generator to the consumers. Some renewables are
> distributed, they are close to the consumption and need no
> transmission at all but a more intelligent distribution
> system; others are large scale (concentrating solar,
> offshore wind), they need transmission to get to the
> consumers, but instead of a one-way tree-shaped transmission
> net, a more interconnected net which at night may bring wind
> energy from Nebraska and during the day bring solar energy
> from Arizona. With better local storage options and higher
> penetration of renewable energy, these transmission lines
> may not have to be very long or thick. It is not clear
> at this time how everything will play out, this will
> depend on how technology develops.
>
> (6) Transportation fuels. So far we only talked about
> electricity. Transportation must either be electrified
> (electric railroads, electric cars) or must use biofuels or
> hydrogen produced by electrolysis from renewable
> electricity.
>
> (7) Space heating and air conditioning, water heating,
> cooking: New buildings will be much more energy efficient,
> they will not need natural gas for heating and cooking but
> electricity (ground-sources heatpumps) and water will at
> least be pre-heated by the sun.
>
> (8) Combined heat and power will become the rule instead of
> the exception. Natural gas facilities for residual power
> will be smaller and cleaner than today's large scale base load
> generators; therefore they can be located in populated areas
> and the waste heat from the electricity can be used for area
> heating, greenhouses, etc. Initially this will use fossil
> natural gas, but over time it will switch to biofuels.
>
> (9) How all these things will play out depends on
> technology: whether and when there will be a breakthrough in
> battery technology, various storage technologies, fuel
> cells, also energy saving technologies for end users (LED
> lights). For climate reasons it will also be necessary to
> extract CO2 from the air and sequester it, i.e. CCS may play
> a role even after all coal-fired power plants have been
> phased out.
>
> (10) It will also depend on political constellations. The
> fossil fuel and nuclear industries are fighting tooth and
> nail against being superseded by renewables. They try to
> maintain the fairy tale that there is not enough renewable
> energy or that it is too expensive. Not true. The
> construction industry is fighting against stricter home
> efficiency standards and higher in-home technology which
> will make pre-fab homes necessary, the auto companies will
> fight against electric vehicles because electric motors last
> 20 times longer than internal combustion engines, etc.
>
> (11) There is absolutely no need to use nuclear energy,
> neither fission nor fusion. It is too expensive and too
> dangerous (especially in times of political turmoil).
>
> This is how I see it. I may have overlooked things.
> Please comment.
>
> Hans
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