On-LineLoad Forecasting Services

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Oct 19, 2013 (3 years and 11 months ago)

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Pattern Recognition Technologies (PRT), Inc.



On
-
Line

Load Forecasting Services

Al Khotanzad, Ph.D., P.E.

President


PRT, Inc
.

17950 Preston Road, Suite 916

Dallas, Texas 75252

(214) 692
-
5252

al@prt
-
inc.com

www.prt
-
inc.com


ERCOT Load Forecasting Forum

January 24, 2007




PRT, Inc.

2

Corporate Profile


Founded in 1994


Products & Services


Online load and price forecasting services


Stand
-
alone load and price forecasting software


Custom forecasting solutions

Clients


Over 90 energy firms consisting of


Utilities in North America & Overseas


ISOs, Municipalities, Coops. Government Agencies


Power marketing and trading organizations


The Electric Power Research Institute (EPRI)



First company to develop a commercial neural network based load
forecaster in the early 90’s


ANNSTLF

for EPRI


PRT, Inc.

3

Load Forecasting


Accurate forecast of future demand required by all entities involved
in the energy markets


Electric Utilities


Independent System Operators


Power Marketers


Different forecast horizons


Long Term: Several years out


required for planning purposes


Mid Term: Several weeks to months


scheduling maintenance,
planning fuel supply, transactions


Short Term: Next hour to next week


daily operation, energy
transactions, reliability studies





PRT, Inc.

4

Short Term Load Forecasting


Hourly or sub
-
hourly forecasts starting from next hour to next seven
to ten days


Forecasts used for:


Unit commitment


selection of generators in operation


start up/shut down of generation to minimize operation cost


Hydro scheduling to optimize water release from reservoirs


Generator type coordination to determine the least cost operation
mode (optimum mix)


Interchange scheduling and energy purchase


Transmission line loading


Power system security assessment


Accuracy has significant economic impact


Even a 0.5% improvement in accuracy can result in thousands of
dollars in savings






PRT, Inc.

5

Factors Affecting Short Term Load


Factors affecting short
-
term load are:


Mix of customer in the service area (residential, commercial,
industrial)


Weather condition (temperature, humidity, cloud cover, wind
speed)


Seasonal effects & recent load trends


Time of day (morning, afternoon, night)


Day of week (weekdays, weekends)


Holidays (Christmas, New Years)


Special events (popular sporting events or TV shows)


Demand side management


Random disturbances







Forecasts used for:


Unit commitment


selection of generators in operation


start up/shut down of generation to minimize operation cost


Hydro scheduling to optimize water release from reservoirs


Generator type coordination to determine the least cost operation
mode (optimum mix)


Interchange scheduling and energy purchase


Transmission line loading


Power system security assessment


Accuracy has significant economic impact


Even a 0.5% improvement in accuracy can result in thousands of
dollars in savings






PRT, Inc.

6

Example of Load and Temperature









PRT, Inc.

7

Major STLF Techniques


Any STLF technique attempts to model the relationship between the
load and factors that affect it


these relationships are nonlinear and
complex


Regression models


Stochastic time series


Spectral decomposition


Similar
-
day search


Intelligent system based models



Superiority of intelligent system based techniques have been
demonstrated in many studies




PRT, Inc.

8

PRT’s LF Technologies


Products & services are based on cutting
-
edge intelligent system
technologies of:



Artificial Neural Networks


Fuzzy Logic


Genetic Algorithms/Evolutionary Computing




PRT, Inc.

9

Artificial Neural Networks (ANNs)


Neurologically inspired systems consisting of highly interconnected
elementary computational units (neurons)


Distributed processing by neurons results in intelligent outcome


ANNs learn to perform a desired task directly from examples
using special training algorithms


ANNs can generalize; after training, they can produce good results
for data that only broadly resembles the data they were trained on
originally


ANNs are nonlinear systems, well suited for real world problems
that are often nonlinear

PRT, Inc.

10

Forecasting Using ANNs


A key feature of ANNs is their ability to learn a complex pattern
mapping, i.e., model the underlying relationship between a set of
variables and an outcome that is a function of them




Future Load


Function of past loads and weather, recent load
trends, upcoming weather, calendar effects


Train with historical data (examples of the underlying
relationship)


A properly trained ANN can predict the outcome of the modeled
process based on the available observations


ANN based predictors employed in a wide variety of forecasting
applications such as prediction of: electric load, weather, gas
consumption, stock market, economic trends time series data,
future sales, traffic patterns and grade point average of students

PRT, Inc.

11

Unique Aspects of PRT ANN Forecasters



Architecture of ANN specifically designed for electric load
forecasting


Optimal set of inputs selected for load forecasting application


No need for frequent re
-
training


Quick response to deviations between forecast and actual load


Special algorithms for unusual days, e.g., weekday holidays


PRT, Inc.

12


Fuzzy Logic


Fuzzy

logic

(FL)

is

a

means

to

transform

subjective/expert

knowledge

about

a

process

expressed

in

the

form

of

linguistic

rules

into

computer

algorithms
.




FL

employs

fuzzy

sets,

fuzzy

membership

functions

and

fuzzy

if
-
then

rules

to

model

the

uncertainty

in

nature,

and

express

the

knowledge




A

fuzzy

set

is

a

set

without

a

crisp,

clearly

defined

boundary,

and

can

contain

fuzzy

variables

with

a

partial

degree

of

membership


PRT, Inc.

13

Fuzzy Rule & Membership Function


An example of a typical fuzzy IF
-
Then rule :


IF

next
-
day temperature is hot, and today’s temperature is hot,
THEN

next
-
day load is high



Subjective interpretation of “hot temperature” or “high load”



Characterized by fuzzy membership function


an example shown

PRT, Inc.

14


Fuzzy Logic Based Load Forecaster


Develop

applicable

fuzzy

membership

functions



Extract

relevant

IF
-
THEN

rules

from

historical

data



There

could

be

hundreds

of

such

rules



During

the

forecasting

phase

several

of

the

rules

become

activated

along

with

some

of

the

fuzzy

membership

function



Fuzzy

inference

engine

converts

all

this

information

into

a

final

crisp

forecast


PRT, Inc.

15

Genetic Algorithms (GAs)


Genetic

Algorithms

(GAs)

are

optimization

algorithms

that

are

based

on

the

concept

of

natural

evolution




GAs

can

find

the

optimal

solution

quickly

and

efficiently,

especially

when

there

is

little

information

about

the

solution

available
.




GAs

emulate

natural

evolution,

and

make

use

of

four

operators,

including

reproduction,

crossover,

mutation,

and

survival

of

the

fittest

to

produce

and

keep

the

optimal

solutions
.


PRT, Inc.

16

GA Based Forecaster


Create

M

sets

of

forecasts

(in

random)

for

a

given

set

of

actual

historical

data


Sort

based

on

accuracy


Retain

the

top

K

most

accurate

sets

(stronger

solutions)

and

discard

the

rest

(weaker

solutions)



survival

of

the

fittest


Use

the

retained

K

sets

as

parents

to

create

a

second

generation

of

M

solutions

through

mutation

&

crossover



repeat

the

process


After

several

generation,

the

top

K

solutions

converge

toward

a

single

solution



Strongest

solution


This

is

the

optimal

solution

used

as

the

final

forecasting

model


PRT, Inc.

17

PRT’s e
-
ISOForecast

Price & Load
Forecasting Service



e
-
ISOForecast
is an on
-
line real
-
time price & load forecasting
service that has been set up for all wholesale power markets/ISOs
in North America


ERCOT, PJM, NY
-
ISO, ISO
-
NE, MISO, CA
-
ISO, ONTARIO
IESO, ALBERTA AESO


Hourly forecasts for current day and six days beyond


Hourly load forecasts for one year out using various simulated
weather scenarios


Forecasts are posted on
www.onlineforecast.com



Subscribers use a Web browser to access and download the
forecasts


available 24/7


Forecasts are updated every hour or faster based on the most
recent price/load/weather data that become available


Weather forecasts are used in the models
-

updated several times
per day

PRT, Inc.

18

e
-
ISOForecast

Price & Load Forecasts


ERCOT


System
-
Wide & Congestion Zone Load Forecasts


Zonal Market Clearing Price Forecasts



PJM


System
-
Wide, Regional and Zonal Load Forecasts


Real
-
Time & Day
-
Ahead LMP Price Forecasts



ISO New England (ISO
-
NE)


System
-
Wide & Zonal Load Forecasts


Zonal Real
-
Time & Day
-
Ahead LMP Price Forecasts



New York ISO (NYISO
)


System
-
Wide & Zonal Load Forecasts


Zonal Real
-
Time & Day
-
Ahead LMP Price Forecasts



PRT, Inc.

19

e
-
ISOForecast

Price & Load Forecasts


Midwest ISO (MISO)


System
-
Wide Load Forecast


Real
-
Time & Day
-
Ahead LMP Price Forecasts for Five Hubs and


Various CPNs



California ISO


System
-
Wide Load Forecast


Zonal Supplemental Real
-
Time Price Forecast

s



ONTARIO EISO


System
-
Wide Load Forecast


System
-
Wide Price Forecast




ALBERTA AESO


System
-
Wide Load Forecast


System
-
Wide Price Forecast



PRT, Inc.

20

Forecasting Engines



Multiple models based on different technologies run in parallel
generating independent forecasts



A top layer of intelligence decides to:


Select one of the forecasts as the final forecast


Combine multiple forecasts (“Combination of Experts”) into a
final forecast



Accuracy is improved over use of a single modeling technique



PRT, Inc.

21

Weather Data


PRT has affiliations with two major weather service providers,
WSI and Meteorlogix



Most free internet based weather forecast services simply provide
forecasts generated by NWS or other computer models



Weather service providers bring human meteorologists in the loop
who scrutinize/edit computer generated forecasts



Weather forecasts updated several times throughout the day



Actual temperature updated every hour and with every update,
new load forecasts are generated


PRT, Inc.

22

Access via the Web


Forecasts are posted to a dedicated password protected page


Can be accessed using any standard Web browser from any
computer


Provides easy access for all in the company


Forecasts are displayed in tabular and graphical forms


Actual data of previous day and any available data of current day
are displayed


Forecasts can be downloaded in EXCEL format


Other statistics including actual prices of past week, similar day
comparisons and price bands are provided


PRT, Inc.

23

e
-
ISOForecast Main Page


PRT, Inc.

24

e
-
ISOForecast PJM Segment


PRT, Inc.

25

e
-
ISOForecast Load Forecast View

PRT, Inc.

26

e
-
ISOForecast LF View
-

Graphical

Market

After
-
the
-
Fact

Current
Day

Next
Day

Day 3

Day 4

Day 5

ERCOT

Load

1.51/1.84

1.81/2.69

2.99/3.48

3.50/3.87

3.99/4.59

4.54/5.13

Temp

1.38/1.73

2.14/1.98

2.41/2.13

2.86/2.68

3.21/3.02

PJM
East

Load

1.24/1.33

1.32/1.91

2.49/2.64

2.88/2.93

3.25/3.45

3.67/3.81

Temp

1.48/2.00

2.56/2.46

2.73/2.78

3.20/3.46

3.68/4.05

ISONE

Load

1.70/1.60

1.24/1.88

2.30/2.32

2.73/2.91

3.04/3.31

3.34/3.60

Temp

1.49/2.00

2.47/2.57

2.76/2.93

3.27/3.62

3.78/4.32

NYISO

Load

1.15/1.28

2.21/2.40

2.56/2.59

2.73/2.74

2.93/3.05

3.26/3.47

Temp

2.72/2.81

3.04/2.99

3.22/3.23

3.53/3.60

3.98/4.30

MISO

Load

1.21/1.39

1.21/1.83

2.29/2.54

2.79/3.05

3.20/3.53

3.54/3.87

Temp

1.29/1.70

2.15/2.32

2.37/2.48

2.82/3.05

3.32/3.57

e
-
ISOForecast LF Performance for 2006

Forecasts Recorded at 8 am CT

Load
:
Hourly MAPE/ Daily Peak Load MAPE

Temperature:
Hourly MAD/Daily Peak Temp MAD

PRT, Inc.

28

e
-
ISOForecast Performance for Forecast of
Next
-
Day ERCOT Total Load


2006

i

Forecasts Recorded at 3:00 PM of Previous Day

Month

Load
MAPE

Temp
MAD

Month

Load
MAPE

Temp
MAD

Jan

2.10/2.02

2.13

Jul

2.51/2.77

1.71

Feb

3.01/3.18

3.14

Aug

2.70/2.81

2.06

Mar

2.52/2.85

2.42

Sep

3.86/5.03

2.35

Apr

3.17/4.11

1.78

Oct

3.53/5.06

2.36

May

3.05/3.57

1.83

Nov

2.21/2.25

2.21

Jun

2.70/2.92

1.62

Dec

2.45/3.49

2.14

Market

Period


By

Current
Day

Next
Day

Day 3

Day 4

Day 5

ERCOT

1/1
-
12/31

PRT

1.81/2.69

2.99/3.48

3.50/3.87

3.99/4.59

4.54/5.13

ISO

2.28/2.96

3.22/3.45

3.75/4.08

4.56/4.79

5.04/5.40

PJM
East

1/1
-
12/31

PRT

1.32/1.91

2.49/2.64

2.88/2.93

3.25/3.45

3.67/3.81

ISO

1.70/2.00

3.30/2.91

3.32/3.23

3.79/3.60

4.27/4.13

ISONE

1/1
-
12/31

PRT

1.24/1.88

2.30/2.32

2.73/2.91

3.04/3.31

3.34/3.60

ISO

3.08/1.77

3.23/2.15

-

-

-

NYISO

12/5
-
12/31

PRT

0.64/1.06

1.51/1.54

1.74/1.85

1.99/2.29

2.10/2.34

ISO

2.54/2.62

2.54/2.62

2.22/2.09

2.12/1.59

2.08/1.43

Comparison of PRT and ISO LF Performance


Forecasts Recorded at 8 am CT

Hourly MAPE/ Daily Peak Load MAPE

PRT, Inc.

30

e
-
LoadForecast Service


An online load forecast service for company
-
specific load data


Standard Service: Hourly/sub hourly forecasts for current day and
six days beyond


Extended Service: Additional Hourly/sub hourly forecasts for
several months and years out


User only needs to:



Provide historical load data for initial model training


Upload the most recent actual load data as it becomes available
(via FTP, e
-
mail, provided Excel interface)


All the required actual and forecast weather data acquired by PRT
from


Load and weather data quality checked and validated


Forecasts posted to a dedicated and secure website in tabular and
graphical forms



PRT, Inc.

31

e
-
LoadForecast Service, Cont’


Forecasts are updated every hour with preceding hour’s actual
observed weather


Forecasts are updated any time an actual load data is uploaded by
user


24/7 access through


Via Internet at any location


An Excel Interface with built
-
in functions enabling user to
remotely interact with the forecasting system


FTP


E
-
Mail



ERCOT uses this service for forecast of its eight weather zones


PRT, Inc.

32

Forecasting Engines



Multiple models based on different technologies run in parallel
generating independent forecasts



A top layer of intelligence decides to:


Select one of the forecasts as the final forecast


Combine multiple forecasts (“Combination of Experts”) into a
final forecast



Accuracy is improved over use of a single modeling technique



PRT, Inc.

33

Weather Data


PRT has affiliations with two major weather service providers,
WSI and Meteorlogix



Most free internet based weather forecast services simply provide
forecasts generated by NWS or other computer models



Weather service providers bring human meteorologists in the loop
who scrutinize/edit computer generated forecasts



Weather forecasts updated several times throughout the day



Actual temperature updated every hour and with every update,
new load forecasts are generated


PRT, Inc.

34

Other Features


The provided Excel Interface allows user to:



Modify forecasted temperatures and generate corresponding
load forecasts


“What
-
If” scenarios



Modify predicted morning and/or afternoon peak loads.
Forecasts for other hours are reshaped accordingly



View load and temperature of three most similar days
(temperature wise) in the history


PRT, Inc.

35

Access via the Web
-

View & Download


Forecasts are posted to a dedicated password protected page


Can be accessed using any standard Web browser from any
computer


Provides easy access for all in the company


Forecasts are displayed in tabular and graphical forms


Actual data of previous day and any available data of current day
are displayed


Forecasts can be downloaded in EXCEL format


PRT, Inc.

36

Access via Excel Interface



View, Download & Interact


An Excel interface with easy
-
to
-
use built
-
in features


Download and view most current load and temperature
forecasts in tabular and graphical forms


Modify forecasted temperatures and generate corresponding
load forecasts


Modify predicted peak loads and reshape load forecasts
accordingly


Download and view three most similar days


Upload actual load updates to PRT’s servers




PRT, Inc.

37

Profile Based Forecasting


Retailers operating in deregulated markets work with individual accounts
that may not be metered hourly (e.g., residential load)


Energy transactions and settlements are done based on hourly demand


Hourly load is simulated using pre
-
specified standard load profiles for
client type


To forecast their retail load, load profile for each account must be scaled
appropriately to account for pattern of usage by that account


Profile based module of
e
-
LoadForecast


User provides:


List of current accounts in the portfolio along with their corresponding
profile type



The historical usage data for each account


Backcasted profiles for corresponding profile types are used to develop a
profile multiplier (scale factor) for each account using historical meter
reads.


Forecasted standard profiles are multiplied by the scale factor to get the
final hourly forecast

PRT, Inc.

38

Mid
-
Term/Long
-
Term Module


Optional service includes mid
-
term/long
-
term hourly load forecast


Forecast horizon can be extended to five years out


ANN technology is used


Models are different from those used for short
-
term forecasting


Impact of load growth is considered


Weather forecast is needed for the forecast horizon


Simulated using historical weather data


Three scenarios of “Normal”, “Hot”, and “Cold” available for each
month in forecast horizon


Additional scenarios for generating “High Load” and “Low Load”
cases


Two statistical methods available for simulation of scenarios from
historical weather data


Tools are provided for easy manipulation of simulated weather


user can
build heat waves/cold fronts




PRT, Inc.

39

Quality Control


Extensive quality control system in place



Actual load and temperature data continually quality checked



Detected anomalies such as spikes and gaps corrected



Every day accuracy of load and temperature forecasts for various
forecasts horizons are computed and reviewed by our experienced staff



Corrective action taken if degradation in quality detected


Analysis of the cause


Calibrate forecasting models


Use of different kind of forecasting engines




PRT, Inc.

40

Forecasting Service

Advantages


Uses state
-
of
-
the
-
art load forecasting models


More accurate forecasts than in
-
house systems


More economical than maintaining an in
-
house system


Frees up valuable manpower & resources


No data hassles, IT overhead, software maintenance & upgrade


Performance continuously monitored by specialists with extensive
experience and background in forecasting


Models are continually calibrated and upgraded


Convenient access to forecasts for all who need it in the
organization


Unlimited use by all in the organization