on-line load forecasting services

8/2/2019 On-Line Load Forecasting Services

1/40

Pattern Recognition Technologies (PRT), Inc.

On-LineLoad Forecasting Services

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

President

PRT, Inc.

17950 Preston Road, Suite 916

Dallas, Texas 75252

(214) 692-5252

[email protected]

www.prt-inc.com

ERCOT Load Forecasting ForumJanuary 24, 2007


2/40

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 90s ANNSTLF for EPRI


3/40

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 outrequired for planning purposes

Mid Term: Several weeks to monthsscheduling maintenance,

planning fuel supply, transactions

Short Term: Next hour to next weekdaily operation, energytransactions, reliability studies


4/40

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


5/40

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


6/40

PRT, Inc. 6

Example of Load and Temperature


7/40

PRT, Inc. 7

Major STLF Techniques

Any STLF technique attempts to model the relationship between the

load and factors that affect itthese relationships are nonlinear andcomplex

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


8/40

PRT, Inc. 8

PRTs LF Technologies

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

Artificial Neural Networks

Fuzzy Logic

Genetic Algorithms/Evolutionary Computing


9/40

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 examplesusing 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


10/40

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 ofvariables and an outcome that is a function of them

Future LoadFunction of past loads and weather, recent loadtrends, upcoming weather, calendar effects

Train with historical data (examples of the underlyingrelationship)

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

ANN based predictors employed in a wide variety of forecasting

applications such as prediction of: electric load, weather, gasconsumption, stock market, economic trends time series data,future sales, traffic patterns and grade point average of students


11/40

PRT, Inc. 11

Unique Aspects of PRT ANN Forecasters

Architecture of ANN specifically designed for electric loadforecasting

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


12/40

PRT, Inc. 12

Fuzzy Logic

Fuzzy logic (FL) is a means to transform subjective/expertknowledge 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 theknowledge

A fuzzy set is a set without a crisp, clearly defined boundary, and

can contain fuzzy variables with a partial degree of membership


13/40

PRT, Inc. 13

Fuzzy Rule & Membership Function

An example of a typical fuzzy IF-Then rule :

IF next-day temperature is hot, and todays temperature is hot,

THEN next-day load is high

Subjective interpretation of hot temperature or high load

Characterized by fuzzy membership functionan example shown


14/40

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 activatedalong with some of the fuzzy membership function

Fuzzy inference engine converts all this information into a final

crisp forecast


15/40

PRT, Inc. 15

Genetic Algorithms (GAs)

Genetic Algorithms (GAs) are optimization algorithms that arebased 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.


16/40

PRT, Inc. 16

GA Based Forecaster

Create M sets of forecasts (in random) for a given set of actualhistorical 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 Msolutions through mutation & crossoverrepeat the process

After several generation, the top K solutions converge toward a

single solutionStrongest solution

This is the optimal solution used as the final forecasting model


17/40

PRT, Inc. 17

PRTs e-ISOForecastPrice & Load

Forecasting Service

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

ERCOT, PJM, NY-ISO, ISO-NE, MISO, CA-ISO, ONTARIOIESO, 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

forecastsavailable 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 timesper day


18/40

PRT, Inc. 18

e-ISOForecastPrice & 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


19/40

PRT, Inc. 19

e-ISOForecastPrice & 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 Price Forecast

ALBERTA AESO


System-Wide Price Forecast


20/40

PRT, Inc. 20

Forecasting Engines

Multiple models based on different technologies run in parallelgenerating 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


21/40

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


22/40

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 anycomputer

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


23/40

PRT, Inc. 23

e-ISOForecast Main Page


24/40

PRT, Inc. 24

e-ISOForecast PJM Segment


25/40

PRT, Inc. 25

e-ISOForecast Load Forecast View


26/40

PRT, Inc. 26

e-ISOForecast LF View - Graphical

ISOF t LF P f f 2006


27/40

Market After-the-Fact

CurrentDay

NextDay

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

PJMEast

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 3.78/4.32NYISO 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


28/40

PRT, Inc. 28

e-ISOForecast Performance for Forecast of

Next-Day ERCOT Total Load2006i

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


29/40

Market Period By CurrentDay

NextDay

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

PJMEast

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


30/40

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 andsix days beyond

Extended Service: Additional Hourly/sub hourly forecasts forseveral 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 PRTfrom

Load and weather data quality checked and validated

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


31/40

PRT, Inc. 31

e-LoadForecast Service, Cont

Forecasts are updated every hour with preceding hours actualobserved weather

Forecasts are updated any time an actual load data is uploaded byuser

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


32/40

PRT, Inc. 32

Forecasting Engines

Multiple models based on different technologies run in parallelgenerating 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


33/40

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


34/40

PRT, Inc. 34

Other Features

The provided Excel Interface allows user to:

Modify forecasted temperatures and generate corresponding

load forecastsWhat-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


35/40

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 anycomputer

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


36/40

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 PRTs servers


37/40

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 ofe-LoadForecastUser 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 aprofile 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


38/40

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 usedModels 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 weatheruser can

build heat waves/cold fronts


39/40

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


40/40

PRT I 40

Forecasting ServiceAdvantages

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 extensiveexperience 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

on-line load forecasting services

Documents