The
December 19, 2002 System Analysis Advisory Committee meeting, held at the
Northwest Power Planning Council's offices in Portland, Oregon, was
chaired by Michael Schilmoeller of the Council staff.
The
following is a distillation (not a verbatim transcript) of items discussed
during the call, together with actions taken on those items. Please
note that some enclosures referenced in the body of the text may be too
lengthy to attach; all enclosures referenced are available upon request
from Schilmoeller at 503/820-2314.
Schilmoeller welcomed everyone to today's meeting, led a round of
introductions, then reviewed today's agenda. Schilmoeller noted that
copies of his presentation are available via the NWPPC website; please
refer to this document for full details, including graphs and
charts.
The
minutes were finalized with a few minor comments.
Schilmoeller briefly recapped last month's discussion of the
representation of dispatchable resources, metrics, representations in the
portfolio model, price-responsive demand, renewables and conservation,
hydro and loads.
Schilmoeller explained that the purpose of this section of the analysis is
to show that the economic consequences of transmission congestion can be
captured with the portfolio model, and that the likelihood of congestion
is related to other variables considered in the model. He described how
this parameter will be analyzed within the portfolio model, then
demonstrated using some sample analyses.
The
group offered a variety of clarifying questions and comments, regarding
who should pay and who will benefit from transmission congestion relief,
the objective function of this analysis (minimizing the present value cost
of additional transmission resources to the Northwest), the statistical
representation of the effects of transmission congestion, and the societal
benefits of increased transmission capacity (zero congestion) vs.
additional generating resources.
Schilmoeller offered the following conclusions about transmission
reliability:
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Market prices in regions, in particular the differences among prices,
will give a ?dual? representation of the state of the system.
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To predict when prices between regions are likely to be different (when
congestion is likely to occur), we need statistical information relating
congestion to other variables, such as temperature or loads.
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Transmission congestion can then be modeled using a distribution of
price differences that are correlated with the other variables.
Does that make sense to anyone? Schilmoeller asked. It does if you can
translate this outcome into actual results, rather than just words, one
participant replied. What I'm hearing, then, is that we may want to
refer at least a portion of this question to transmission experts,
Schilmoeller said.
Following the meeting, Kurt Granat, PacifiCorp Transmission Engineer,
provided insights into the expected relationship of congestion and other
parameters. He pointed out that scheduled loads, rather than
actual flows, are a better indicator of congestion for economic
modeling. He agreed that loads, temperature, and East-side hydro
generation should be among the best predictors of congestion. Kurt
also suggested that 90 percent of capacity should be used to define
congestion, because there are several reasons why operators would avoid
maximum loads on a path or intertie.
5. Representation of Resource Diversity.
Schilmoeller began this portion of the presentation by saying that this
is a section of the analysis he has thought less about, so he will be
seeking the input of the group on this question. He touched on the
benefits of resource diversity he has identified so far. Can you explain
exactly what you mean by ?resource diversity?? one participant
asked. What I meant when I prepared this section was distributed
generation, not diversity, Schilmoeller said. You may want to change the
title of this section, then, another participant suggested; Schilmoeller
agreed. Various participants noted that ?diversity? can mean a
variety of things ? resource size, fuel source, ownership, geographic
location and other factors.
In
response to another question, Schilmoeller said the point of this
segment of the analysis is to capture the reduced risk associated with
distributed generation in the portfolio model ? basically, we want to
quantify that risk mitigation capability, he said. Another participant
suggested that it is important that this section of the analysis be as
flexible as possible; it needs to include the ability to capture
additional statistical distributions representing physical phenomena,
fixed cost adjustments and future regulatory change, he said.
Schilmoeller agreed that this would be a useful additional capability,
adding that by the next meeting of this group, he hopes to develop a
wizard to simplify the use of this tool. Jim Litchfield added that
additional slides on specific distributed generating resources would be
a useful addition to this section. We'll add that, so that we can talk
about the specific representations for each of those resources,
Schilmoeller replied.
6. Influence Diagram of Effects.
Here we wanted to talk about the significance of the effects of, and the
relationships between, the different independent variables we'll be
looking at in the this analysis, Schilmoeller explained: resource
outages, transmission congestion, hydro generation, resource margin, the
market price of electricity, DSI loads, aluminum prices, fuel prices,
non-DSI loads and temperature. Litchfield said that, in his view, hydro
generation is not an independent variable; the system includes storage
capacity, obviously, so generation is human-controlled. Bonneville has
discretionary hydro generating capacity at any given moment, he
observed. However, hydro generation output increases or decreases in
response to outside variables, Schilmoeller replied.
One proposal was to add a bubble for GDP, which would drive load, fuel
prices, and so forth. Terry Morlan suggested that there were
enough other factors confounding the relationship among these that any
influence of GDP is small. Moreover, neither he nor anyone he
knows has an explanatory model for relating GDP to these other
factors. GDP doesn't contribute enough to the model to offset
the additional computational burden of including it.
The group devoted a few minutes of discussion the relationship between
loads and electricity prices. Schilmoeller pointed out that Terry
Morlan's Aluminum industry model will be incorporated into this
modeling work, and it provides an explicit relationship between DSI
loads, electricity prices, and aluminum prices. There are both
short-term and long-term load responses to electricity price, by both
the Non-DSI and the DSI loads, several participants pointed out.
Another factor influencing load is precipitation, one participant
observed. If precipitation goes up then the irrigation loads
decrease substantially.
Market prices are going to drive resource acquisitions, another
participant noted ? there needs to be another bubble here, leading
back to resources. In response, Schilmoeller said it would be possible
to incorporate a price-driven resource addition function. A key function
of this analysis is to tell us whether Resource Portfolio A is better
than Resource Portfolio B -- an influence diagram, Litchfield observed.
Shouldn't the resource selection and addition be part of this
influence diagram? This diagram is intended to reflect exogenous
variables, Schilmoeller replied -- basically, all we're talking about
is correlation factors rather than cause and effect (e.g., prices incent
capacity addition). The prices that we are representing in the model are
equilibrium prices, which incorporate all of the effects of capacity
addition, etc.
7. Statistical Results for Natural Gas Prices, Electricity
Prices, Load, Temperature, Aluminum Prices, Hydro, Transmission
Congestion.
Schilmoeller described some of the statistical data available for use in
the model ? historical dailies, temperature through the year and the
region, aluminum prices, hydro generation, electricity prices, hourly
transmission and cut-plane congestion data and natural gas prices back
to 1997. I have also uploaded all of the California ISO reports on
forced outages dating back to 2000, Schilmoeller said, adding that he is
open to any other sources of relevant statistical data the other SAAC
participants might suggest.
One thing that I have observed, Schilmoeller stated, is a correlation
between electricity prices and gas prices, contrary to what several
other researchers have observed. Terry Morlan suggested that the
Winter of 2000-2001 were removed from the data, the correlation may
vanish.
One thing we've talked about is any changes of state that occurs,
Schilmoeller said ? there was the complete shift in the underlying
relationship between variables that occurred during the recent
California energy crisis, for example. It would be very interesting if
we can capture that sort of rare and catastrophic event here in the
model, he said. You might try creating a flat round-the-clock energy
price, Jim noted; Schilmoeller agreed that this might be useful. Phil
Sher added that the basis he used to calculate heating degree-days was
55 to 65.
8. Next SAAC Meeting Date.
The next meeting of the System Analysis Advisory Committee was set for
Thursday, January 16. The agenda at this meeting will focus on remaining
work on statistics, incentives for new generation, review of the risk
management problems during 2000-2001 (what worked and what did not), and
initial optimization for the region, using all mechanisms. Meeting
summary prepared by Jeff Kuechle, NWPPC Contractor.