Subject: re : henwood query
hi karolina ,
yes , it might be more productive to talk on the phone . given our time
difference , why don ' t we plan on tomorrow ( friday ) 8 : 00 am pdt , 4 : 00 pm bdt ?
my number in the states is 503 - 464 - 8430 . give me your number , too , so that i
can call back if i get hung up in a meeting or something .
the situation is complicated by the fact that the marginal cost is set by the
capacity increment of a plant that is on the margin in a particular hour , but
in constructing the stack , increments of a plant may be scattered throughout
the stack , based on their respective incremental heat rates . ( this is why
increment heat rates must be strictly increasing in this model . ) results for
the capacity increments , however , are not available as output ; only each
plant ' s aggregate values are reported .
i had to construct the stack for a particular hour to answer question about a
homer city , ny plant we were studying a few years ago . attached is the sql
query you can import into ms access to do the same thing for you ( making
appropriate modifications to the year , hour , etc . ) unfortunately , no henwood
documentation on the output variables existed when i created this query , so i
can not really tell you what they represent anymore . an acquaintance of mine
at entergy and i were lobbying to get henwood to provide some documentation ,
so it may be available now .
let ' s talk and maybe we can help you out ,
michael
> > > karolina potter / lon / ect @ enron 08 / 24 / 00 07 : 08 am > > >
michael ,
i am an analyst in paul mead ' s continental power trading group in london . i
am currently working on the project , which requires the use of emss , and
experience some difficulties interpreting the output results . steven leppard
from our research group gave me your name as an expert in this system and
consequently the person to contact in case of problems .
i have been running simulations for the dutch market and was asked to provide
the traders with some front - end screen graphs in order to interpret the
numerical results . one of the graphs is to show an hourly generation stack
and system ' s marginal cost , as we only run cost based scenarios . to sort each
station ' s hourly generation i need its marginal cost . to my knowledge though ,
marginal cost is only generated for a systems marginal unit ( transarea
marginal units query , marg _ cost unit ) . therefore i was sorting the stations
according to the cost which i calculated based on the outputs from station
detail by hour query . the calculation was as follows :
for each hour , for each generating station :
" marginal cost " [ o / mwh ] = ( generation _ cost [ oo 00 ] * 1000 ) / generation [ mwh ] -
vom _ cost [ o / mwh ]
this i thought would include fuel cost and start up costs . however , a
marginal station which i get on the stack as a result of the above
calculation is not a station given in marginal station field in transarea
marginal units query . i have also looked into transarea _ data _ hr table and
transarea _ data table but non of the costs there match my results .
do you happen to know what formula is used to determine marg _ cost and which
outputs i should be using to obtain the right results ?
it might be easier if we could discuss this issue on the phone . in this case
could you please send me your direct telephone number . i am struggling
understanding what is going on and would appreciate your help very much .
regards
karolina
- text . htm
- stack generator sql . txt