Electricity Demand in Sri Lanka - Key Findings

The Electricity system load profile of Sri Lanka has a high evening peak and as a result has a low load factor. On the other hand limitations in the Electricity supply side to accommodate the demand have caused power cuts in recent past. Some steps have already been taken to mitigate the issue with system peak, including the new tariff structure which came into effect from January 2011 onwards. Therefore, studying about the system load profile and finding further options to flatten the system load curve is a timely requirement.

The Public Utilities Commission of Sri Lanka, being the economic, technical and safety regulator of the electricity industry in Sri Lanka, has decided to conduct a study to improve this situation. Therefore, collecting and compiling of relevant data and making conclusions on the same matter were carried out through this study.

The general objective of this study is to conduct detailed analysis of the system load profile, analyze the contributing factors for the high evening peak demand and practical demand side management options to arrest further worsening of the system load factor. Also the scope of the study contained a study about historical characteristics of the system load profile and a study about the consumer response (TOU Consumers) to tariff change in 2011.

The Overall Study consisted of following parts. 
 

1. A Literature Survey

2. A study based on Electricity load profile data and electricity consumption data, published by Sustainable Energy Authority (SEA) and Submitted by Ceylon Electricity Board (CEB)

3. A study based on Data Received from Distribution Licensees (DLs)

Key Findings

1. With the Literature survey, following aspects have been found that can be used to reduce the peak Electricity demand and flatten the Electricity load profile.

• a. Introducing a power factor penalty.
• b. Introduce a charge for reactive energy usage by consumers. (a kVArh charge)
• c. Postpone demands of industrial consumers during peak hours.
• d. Implementing building codes, Using Equipment and building standards at the design stage and as well as at the operation stage, Conducting Regular Audits to find out key issues etc.

2. Followings are found out using the data on Electricity load profile and Electricity consumption.

• a. During the two year period from 2009 to 2011 there is a rapid increase in Electricity sales when comparing with electricity sales growth data before 2009. 15 year average demand increase is 6.8%
• b. Electricity system Maximum demand has not shown a clear increasing trend from 2006 to 2010. However, from 2010 to 2011 maximum demand shows a rapid increase. Maximum demand growth rate is lower than sales demand growth; the 15 year average maximum demand growth rate is 6.5%.
• c. Annual System Load Factor, which had been showing an increasing trend from 2008 to 2010, has decreased in 2011 to 60.8%.
• d. The typical system peak at present occurs- 19.00 to 20.00; with a steep increase from 18:00 to 19:00, and depreciates with a slow rate of decreasing which takes about 3 hours. (From 19:00 to 22:00)
• e. During a typical day, base active power demand of Sri Lanka is about 40% of the corresponding maximum demand. Also demand goes above 80% of the maximum demand during a period of 4 hours per day. 

 Part 2 : Electricity Demand in Sri Lanka - Conclusions & Recommendations


Original Source: Excerpt of the Study Report on Electricity Demand Curve and System Peak Reduction released by The Public Utilities Commission of Sri Lanka, December 2012.