Evaluating the public perception on domestic electricity tariff structure | Survey

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1. Purpose of the Survey

The EESoc panel discussion was initiated with the purpose of serving the power sector with an unbiased and a fruitful discussion regarding a timely issue. Considering the prime importance prevailing in the national power sector, the theme for the year 2013 is suggested as “Towards a rational consumer tariff”. The panel will provide suggestions on how Sri Lanka can move into a more rational tariff structure.

As we believe, the suggestion would definitely be a technically sound and feasible one considering all the engineering and economic aspects in the field. This survey is proposed with intention of integrating social aspects to this proposal to be suggested.

Whatever the suggestions, acceptance of this ultimately depends on the consumer perceptions and their impression on this change. Requirement of a change management programme is a highly essential and important aspect especially in Sri Lankan context. This can be achieved by conducting an effective communication between supply side and consumers, providing accurate information to consumers.

Before moving to a change management program, it is necessary to understand their interest, knowledge, behaviors, beliefs and attitudes towards the electricity pricing. EESoc is expecting to proceed this survey with the intention of all of above mentioned purposes, in collaboration with the EnergyzEE team.

2. Objectives of the Survey

• Prepare the sample to represent the actual population based on the consumption of units.
• Educate people on the different tariff structures and get a feedback (comments) on the tariff structures according to their personal views.
• Get the public perception on the relationship between electricity cost and electricity tariff.
• Evaluate the understanding of the public about the load profile in conjunction with electricity tariffs.
• Evaluate according to the public perspective what communication channels are best suited to convey information about tariff and how those media could be effectively utilized

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Posted in: Utility and Social

Introduction to Wind Power Plant technologies in the world

Renewable energy is the main concern of the global energy sector to face the energy crisis occurred with the depletion of fossil fuel. Wind energy is one of the prominent renewable sources of energy currently used globally. Following the global trend, Sri Lanka too has wind power plants connected to the national grid that consist of three main types of generators which are variable speed synchronous wind generators, doubly-fed induction wind generators and fixed speed asynchronous wind generators (FSAWD). This article talks about the main construction modes of each type of wind power plant available globally.

Fixed speed asynchronous wind generator

These types of generators are operated with less than 1% variation of rotor speed, which is also the reason to be called as fixed speed wind generators. They are equipped with a squirrel cage induction machine which is directly connected to the power grid (Figure 1). The speed of the rotor is determined by the frequency of the network not from the wind speed. It is done with the speed multiplier ratio and by the generator type. In order to increase the power production, most of the wind generators use two coils for low wind speed and high wind speed. There are 8 poles and 4-6 poles available respectively for each type of coils. These generators have used soft starters as for starting up of the generators since starting current is very high and it might also be a cause for voltage variation in weak power system network.

Mainly there are two types of fixed speed wind turbines available in the industry as pitch control and stall control. In pitch control type turbines, blades are not fixed to the hub so it can be rotated a few degrees to fully confront the wind in order to produce full power or be in line with wind direction to extract no power. In stall control type turbine blades are fixed to the hub rigidly and they are designed in a way that the airflow over the blades is a laminar air flow to turbulence flow at high speed.  But the drawback is, rigidly fixed blades limit the mechanical power extracted from the wind at high speed to protect the machines from overloading.

Wound rotor induction generator

Wound rotor induction generators use variable rotor resistance control in order to achieve output power control. These types of wind turbines can extract wind power in a optimum way, compared to squirrel cage induction wind generators so they are generally employed with variable speed wind turbines. They are stall controlled wind turbines (blades are rigidly fixed to the hub) to focus on the rotor resistance control.

Main objective of the rotor resistance controller is to obtain the operating point with maximum possible wind power extraction without exceeding machine limits. Wound rotor induction wind generator is illustrated in figure 2.

Variable speed doubly fed induction wind generator

Due to high energy efficiency and controllability, variable speed doubly fed induction wind generator has become more popular these days. This model is called doubly fed induction generator because the grid is powered by two feedings, shown in Figure 3, as one from the stator, which is connected to the grid directly while other is from the rotor connected to the grid via an AC/DC/AC converter. Converter of this turbine handles only 30% to 40% of the generator output.

Ability to change of rotor voltage allows control of operating conditions of the generator as in low speed drop in rotor speed direct the generator into a sub synchronous operating mode by absorbing power from the grid and also during high wind speed, the DFIG wind turbine operate at super synchronous speed delivering power originated from the rotor through the converters to the power system. Ultimately rotating speed of the DFIG rotor determines if the power is delivered to the power system via the stator only or via the stator and rotor.

Full power converter wind turbine generators

The ability of effectively decoupling the generator from the grid, improved fault response, operating at wide speed range has led to improve the popularity of full power converter wind turbine generators in the industry. There is a converter connected to the turbine as shown in Figure 4, to handle the entire output of the generator.

Introducing the new technology, full converter wind turbines are equipped with a permanent magnet alternator. This type of wind turbines with permanent magnet generators (PMGs) are excited by permanent magnets and it can also be excited by generator-side converters. These PMGs are normally connected to the grid via frequency converters. This makes a DC link from the power grid to the generator, as shown in Figure 4 and there is no any reactive power exchange between generator and power grid. As such the power factor of the wind power plant output is 1. The AC-DC converter is a diode-bridge rectifier and a buck-boost converter which controls the DC link voltage.

Reference:
O S D De Silva, H K C O Dayarathne, V I P Dasanayake, J G D S De Silva and A S Rodrigo; Wind Generator Dynamics: Modelling of Fixed Speed Asynchronous Wind Generator using PSS/E
ISSN: 2545-9557

Article By: Team SOID

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Posted in: Sustainable Energy and Policy

Zero Energy Building Concept _ Lighting

As described in the previous article, improving the energy performance of a building can be considered as an important part of the country’s sustainable energy development process. In energy efficient building designs, the particular commercial, industrial buildings or the large scale housing schemes attend to their needs in the aspects of design, construction and maintenance under minimal consumption of energy without compromising either the functions of the building or the comfort as well as health of the occupants.

While looking for an energy efficient building, some particular areas can be identified which one should consider on. They are as follows,.

1. Lighting
2. Ventilation and air conditioning
3. Building envelop
4. On-site power generation
5. Water conservation

So, let’s consider one by one and get a clear idea on how we can apply those facts to buildings in order them to be energy efficient. 

1. Lighting

Usually artificial lighting accounts for a significant portion from total electric consumption of a building. Therefore lighting is normally known as the single largest consumer of energy in a building. Hence, a minimum amount of electrical energy has to be used to provide lighting to the quantity and quality of standards.

The following steps can be considered as some rules for achieving energy efficiency in lighting. 

1. Use well-designed energy efficient lighting schemes.
   
   It is wiser to use the most energy efficient, cost effective lamp for each application. The use of incandescent or tungsten halogen lamps should be minimized thoroughly unless the application specially requires them. (Refer this article for more information about Star rating of CFL bulbs http://energyzee.blogspot.com/2013/01/star-rating-of-cfl-in-sri-lanka.html)


2. Consider prompt and appropriate interior decorations. (specially colors)
   
   The ceiling height, windows, colours and reflectivity of room surfaces and furnishings directly affects the lighting condition of a building. Therefore special consideration should be paid for the interior features. ‘Light’ colours should be used for interior rooms and large windows should be used to reduce artificial lighting.


3. Using intelligent controlling system
   
   Automatic controls such as daylight sensors, time based controls or occupancy sensors can be used to adjust the level of lighting when sufficient daylight is available. In addition to that, other artificial lighting strategies should be incorporated such as using infrared, ultrasonic or microwave sensors which respond to movement or object surface temperature and automatically turn on and off. 


4. Increase the ability to get the maximum day light during the day time.
   
   Daylight strategies are essential to reduce the energy consumption of the building to a great extent. The positioning and sizing of the windows of the building must be carefully designed and planned in order to permit the maximum natural light into the building, thus reducing the use of artificial lighting and saving energy specially during the day time.

It can be seen that there’s an emerging trend among the people towards this fact and therefore the people who wish to build a house, do concern on design of the building so as to get the maximum use of the daylight. 

A comprehensive analysis of zero energy based approach to ventilation and air conditioning of a building would be presented in the next step of this article series.

Article image: http://technologygreenenergy.blogspot.com/2012/12/green-technology-blog.html

Article By:
Tharangi Gunarathna
Muditha Karunathilake

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Posted in: Sustainable Energy and Policy

LECO introduces surge protection equipment

A stream of silver lines descending from heavens, lightening surely is impressive to behold. Charming and intriguing as it is, lightening can be lethal too. It has destroyed many a human life and caused quite a lot of damage to electrical equipment as well. Statistics reveal that the occurrence of lightning has aggravated recently, due to various environmental changes all over the world.

Worthiness of classifying lightning strikes

Why does lightening cause so much of damage is worth studying. Actually this cause of damage is due to two different strokes, based on the way of entry of lightning into the building. These strokes are basically known as direct strokes and indirect strokes. Direct lightning happen due to interception of lightning directly on exterior metal part of the building whereas indirect strokes enter into building with interception of lighting on service wires, other structure or induce high voltages on exterior metal parts of the building followed by the strokes which hit nearby ground.

Image Ref - http://www.lps-experts.be/lightning-risks/lightning-and-its-effects/

Selecting a  protection scheme

Worthiness of this study comes into play, when  an appropriate protection scheme  is being selected. These protection methods are chosen according to the level of protection needed from direct or indirect lightning strikes. 

Protection from direct strokes to the building has to be supplemented by air terminals, lightning arresters etc. whereas protection from indirect strokes is just a matter of time. A normal AC circuit breaker takes two factors into account in breaking a circuit, current rating as well as operating time. No matter how large the surge is, if it occurs within a very short period of time, the circuit breakers in your home or in your office won’t detect it. Since induced surges in the supply by lightning too takes place within a very short period of time, the current surge easily passes through normal AC circuit breakers, quite undetected, and these high inrush currents mean nothing but destruction. That is what it enables lightning to cause so much of damage. This scenario gives rise to a necessity of a more sensitive, sophisticated device to handle surges induced by lightning, to ensure the protection of human beings, livestock and the equipment.

Solution from LECO

In order to address the damages cause due to indirect lightning, LECO initiated a project to develop surge protectors, which is supposed to introduce a technology to ensure the protection of the electricity consumers and their equipment. Already, four types of surge protectors have been introduced by LECO, depending on the area of application, namely, surge arrester for single phase supply, surge arrestor for three phase supply, telephone and internet protection device and multimedia protection device.

Once the surge comes these devices get operated and arrest the surge. Until then it has no burden on the electrical system. Moreover, it also can detect subsequent multiple surges. LECO, with its world class test facilities, has ensured a high level of design efficiency, accuracy, quality, and reliability of their new invention using the local engineering technology. 

The electricity consumers who are interested in acquiring  protection from LECO introduced lightning surges, visit http://leco.lk/?page_id=1476 for more information.

Ref - http://powermin.gov.lk/english/?p=2618

Article By: Thisandu Kahingala
Contributed by: Pasan Gunawardana & Dilini Hansika

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Posted in: Electrical Industry

Battle of the Current - Paving the way of battle

Electricity is the key to make us masters of our environment, and most of us take it as a crucial part of our lives. But 150 years ago this was not the case. In the middle of the 19th century labor took place at only sun lit day time, and work itself was manual in slow motion without the aid of machinery. At night people stayed at home to avoid associated risks at night. Over the next century and half we transformed the environment dominated us to an environment dominated by us. Today we experience an electrified environment that responds to our many needs, with power that was transmitted through hundreds of miles in an interconnected transmission grid.

Emerging concept of electricity

In 600BC Greeks first discovered the static electricity that could be generated by rubbing amber, however it wasn’t until 18th century Benjamin Franklin theorized that electrical fluid is made up of charged particles. By harnessing this flow of particles or electrical current, engineers have laid the foundation, what would become the colossus of the modern electricity system, the Power Plant.

Nevertheless the successful integration of this power plants and commercial usage with domestic applications of the power, were made by conflicts aroused between two innovative industrial giants, “Thomas Edison” and “George Westinghouse”. The outcome or the winner of this competition would dominate and dictate how electrical generation and transmission would take place. The competition initiated as a battle to bring safer and low cost electricity to New Yorkers.

Thomas Edison

Nikola Tesla

George Westinghouse

Early, before the electricity, natural gas was made to light the streets and homes of people which were very dangerous. If the lamps went out the gas would continuously get accumulated in the room which eventually will lead to an explosion as there were no shut off valves or to control or detect any malfunction.

Edison and DC system

Poster: Edison's Electric Lamps

Eliminating these limitations, In 1879 Thomas Edison invented the first commercially viable incandescent light bulb which emitted light when heated by passing a low current. Soon he made a design for a complete system for lighting and power distribution method. On September 4th 1882 Edison opened the first electric utility to the mankind, the “Pearl Street Station”, in the heart of lower Manhattan financial district, New York, after many delays and cost overruns. Edison knew that this newly created product is going to be expensive and need to reach many customers in order to survive. However Edison’s choice of Direct Current (DC) made his product into a limited range and he could not transmit the power very far without losing tremendous amount of energy. So basically he would need a power plant every kilometer to provide consistent power to the public. As a consequence of it Edison’s distribution system and being a major investor in DC power, had a web of electric wires overhead, it has sometimes said that they blocked the sunlight at some places.

Edison's DC Distribution Network

Thomas Edison’s competitor George Westinghouse made his company, the “Westinghouse Electric” to perfect the Alternating Current (AC) as Westinghouse saw the future of the electrical industry hinge on long distance transmission. In this contest, Tesla was the key person who influenced AC system of Westinghouse electric company.

Tesla’s intervention

Nikolai Tesla, a Serbian born inventor perhaps the most important contributor to the development of human history as the inventor of power to change night into day, who paved the way to all of our modern electric conveniences with a simple flip of a switch, who envisioned the ground breaking concept for a new electric motor, for which the patent became the induction motor, which would go on to be the standard electric motor of the world.

In 1884, age 28, Tesla moved to New York with little money, to work for Thomas Edison. In fact Tesla redesigned Edison’s electric generators. Though Edison used Tesla’s brilliance, Tesla became unsatisfied with the compensation given to him and left Edison Tech eventually.

Paving the Battle

Tesla knew that there would be a better way to transmit power economically than the DC system and was determined to invent a new system, which would eventually be the global trend - the AC poly-phase system. In 1887 Tesla filed 7 new patents with designs encompass in Alternating Current.  The millionaire entrepreneur George Westinghouse thought that those inventions of Tesla will be the key to success in this battle and purchased all of the patents.

As future endurance of the products from both Edison and Westinghouse would largely depend on the electrification method, the war was initiated and developed gradually to ensure quality of relevant electrification systems. This was not a mere battle between Thomas Edison vs. George Westinghouse, this was essential as the technology won would dominate the industry for the foreseeable future.

For the next 2 decades, the battle of currents began both sides fighting for their own survival, even may be taking bitter turns. Expect the rest of the war of AC vs. DC from EnergyzEE.

Article By: Nirmal Undugoda

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Posted in: Utility and Social

Importance of Sampur Coal Power Plant

Learn from past

“Power-cuts will be imposed from end of this month as hydro-power generation has been hit by a prolonged drought”. Walking back in our memory lane to 1994 era, this is a common heading in most of the newspapers. If I take you to the power generation situation in Sri Lanka exactly 10 years back, year 1994, 95% of total generation was made out of hydro-power whereas only the rest was made out of thermal power.
(More info: http://energyzee.blogspot.com/2013/04/norochcholai-coal-power-plant-in.html)

According to this circumstance, hydro power generation alone was not enough to accommodate the electricity demand during the severe drought period. Therefore, to overcome the impending power shortages, an idea for establishing a coal power plant had been emerging. Eventually that idea became a reality through Norochcholai coal power plant which was commenced in 2006 and first phase with 300MW added to the national grid in 2011.

Requirement of Sampur

Since existing total installed capacity in the country including Norochcholai power plant, would not be enough to cater the ever increasing electricity demand in the future, a new coal power plant with 500MW was suggested to establish in Sampur, Trincomalee.

With the contribution of both Norochcholai and Sampur coal power plants, the percentage of coal power electricity generation from the total electricity generation in Sri Lanka can be increased up to 55%. If the Sampur coal power plant cannot be completed and linked to the national grid by 2016, the operation of diesel power plants which is reduced to a certain amount now, has an inevitable room for increasing and that would lead to an uneconomical effect to the electricity pricing of the country.

Agreements with NTPC  

This project is a joint venture agreement between the Ceylon Electricity Board (CEB) and the National Thermal Power Corporation Ltd. (NTPC) of India. Both parties signed to the initial agreements in 2006 and implementation of the power plant would be carried out with equal equity (50:50) contributions by NTPC and CEB.

The memorandum of understanding for  the  Sampur Coal Power Project  will be signed later in June once the cabinet approval is granted to the cabinet paper which has already been submitted.
           
Profile of NTPC

NTPC Limited is the leading electricity utility company in India. Based in New Delhi, NTPC currently has an electricity power generation capacity of 41,184 MW and it has plans to reach 17,000 MW by 2017. Apart from the core business of engineering, construction and operation of power generating plants, NTPC is engaged in providing consultancy to power utilities both local and overseas.

Reasons for the delay

The original reason for the delay of the commencement of this project was not having a agreed Power Purchase Rate in the agreement arrived at by the NTPC and the CEB in September 2011.  The reasons for this disagreement were excessive heat rate(the quantity of coal required to generate a unit of electricity)  and higher operational and maintenance cost involved with the power plant.

The heat rate was stated as 2,600 kilo calories to generate a unit of power from the plant and this was not in acceptable level according to energy experts in the field. The excessive heat rate would result in the coal plant maintaining a low efficiency level and sought changes to a more moderate level.

Current situation

But after the rounds of  negotiations which CEB had with NTPC,  they have agreed to reduce the heat rate  down to 2,160 kilo calories during the first year of operation.The NTPC has also agreed to reduce the Operation and Maintenance cost  up to a certain extent during these negotiations.

Will coal reserves be diminished in the future?

Frankly saying, we should agree with the fact  that coal mines will be diminished one day  and  producing electricity using coal power would no longer be a viable option in the future. But until then coal would be the most economical source to meet the rapid increase of electricity demand. Some may argue this future increase of demand might satisfied through renewable sources like wind and solar more economically and environmentally friendly. But it is actually not when capacity cost and reliability come into play.
(More info: http://energyzee.blogspot.com/2013/01/norochcholai-power-plant-coal-vs.html)

Repeating the history 

Due to the dragging of the implementation of Norochcholai CPP, we had to experience power cuts in the recent past. Repeating the history, implementation of Sampur CPP is getting delayed over the past few years. So there is no wonder if we have to face another power-cut or a price hike by 2017.

Reference

http://www.hcicolombo.org/index.php?option=com_news&task=detail&id=3354661
http://www.ceylontoday.lk/27-25733-news-detail-sampur-to-lose-big.html
http://www.thesundayleader.lk/2013/02/17/indias-entry-into-lankas-power-sector-delayed/
https://en.wikipedia.org/wiki/NTPC_Limited
http://www.dailymirror.lk/news/29576-sampur-agreement-likely-to-be-signed-this-month.html
http://dbsjeyaraj.com/dbsj/wp-content/uploads/2012/07/SM71812.jpg

Article By: Harshani Amanda
Contributors: Shamil Rupasinghe and Akila Pramod

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Posted in: Power System

From an engineering trainee’s diary _Transmission line planning

The following article is based on my experience as a trainee electrical engineering undergraduate in “Lighting Sri Lanka-Hambanthota Project (LSHP)” under Ceylon Electricity Board (CEB).

Transmission and distribution lines are the live veins of a country’s power system. They simply interconnect generating stations, grid substations and distribution substations. In Sri Lankan context, we have generation voltages around 13.5 kV, transmission voltages of 132 kV and 220 kV and distribution voltages of 33 kV (CEB) and 11 kV (LECO and small portion of CEB). The ultimate objective of a power system utility such as CEB is to keep the above mentioned “live veins” as healthy as possible while keeping the generation cost and other operating costs at a minimum while maximizing customer satisfaction. In order to achieve those objectives designing, planning and construction of transmission lines along with timely and proper maintenance, must be carried out with extreme care.

Planning is the initial stage of any transmission or distribution line development project. Planning process can be divided into three stages namely, long term planning, medium term planning and operation planning.

Long term planning

Long term planning emphasizes on topics such as need of construction of new transmission lines, development and introduction of new technologies for transmission (e.g. introducing HVDC system to Sri Lanka) and distribution (e.g. introduction of equipment such as “Fuse saver” to improve reliability of distribution system). Basically Transmission and generation planning branch of CEB carries out the above mentioned planning functions. Long term transmission planning is carried out as a rolling plan with a time horizon of ten years. This plan will cater the growing demand for electricity while incorporating new technologies to enhance the performance of the existing system.

Medium term planning

Medium term planning consists of defining characteristics of system voltages, transmission and distribution lines and substations etc. The time horizon is much shorter than that of long term planning.

Short term planning

Operational or short term planning involves in maintaining the quality and availability of the power system. Regular maintenance and unintended interruption handling falls under operation planning. Generally, this segment of planning is done by area engineers.

During my time in LSHP, I got the opportunity to study the planning process of 33 kV medium voltage lines. During the planning, answers to the following questions need to be obtained.

• When the new distribution line or upgrading of the existing line is required?
• What will be the capacity of the line? 
• How many circuits are needed?
• What is the quality of the supply and the reliability level?

In order to find successful and acceptable answers for the above questions, a large amount of data is required. The data requirement can be fulfilled by using the already available data and through surveys.

Concerns on planning

Accurate technique(s) of forecasting is a must for a successful transmission planning because the time period required to complete a transmission project, from planning to commissioning, may sometimes extend up to a decade. But within that time, the society, or in other words the beneficiaries of the transmission project, will change drastically. The living standards of the people will rise, new industries may be established and rapid development of infrastructures may attract more and more people to the area (in Hambanthota district, the electrification level was 66% at 2006 and now it is almost 100%). When forecasting, all such dynamic facts should be taken into account. One must not forget that such transmission line, plan and design at present, constructing in another two years and commissioning in another five years must  at least last for another three or four decade in operation.

Preparation for Planning

Generally an electrical study is carried out in planning stages for a proposed transmission line. The areas such as power flow study,system stability and dynamic performance,selection of voltage levels (generally, the standard voltage levels are used in Sri Lanka as a practice),voltage and reactive power flow control (mostly for transmission lines),insulation and over voltage design,conductor selection,loss calculation,and protection scheme design should be carefully analysed for reliable planning.

Financial viability

Even a sound electrical design might be rejected by final decision makers, if the project cost is not financially feasible. Financial and economic aspects play a vital role in any engineering development. and the designers should be able to justify the expenditure for the project against the expected benefits. Thus, a proposed design should be checked for both economical and financial feasibility using analytical tools such as Net Present Value (NPV), Internal Rate of Return (IRR) and Cost to Benefit Ratio (CBR) etc.
Finally, the optimum design is selected based on the economic and technical analysis. But the factors such as capacity and the prior experiences of the electricity utility and local constraints also govern the decision.

Transmission line design and construction 

My training diary is further filled with notes on transmission line designing and construction as well. I’m more than happy to share some insight from those areas in the upcoming articles.

Expressing my gratitude

I would be obliged to Mr. S. Bogahawatta, the project director of lighting Sri Lanka Hambantota project for his immeasurable support extended to my team during our internship in the project.

Terminology

HVDC -  High voltage direct current (HVDC) is a electric power transmission system uses direct current for the bulk transmission of electrical power.

Fuse saver - Fuse saver is a new class of intelligent, compact and low cost single phase circuit breaker that minimizes interruptions by protecting spur line fuses from blowing on transient faults

Article By: Ayantha Sampath

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Posted in: Power System

Adapting to the Sri Lankan load profile _ Importance in understanding load profile

Battle between drought and electricity demand

“Switch off a light and save for future”. This is not a strange slogan for Sri Lankans as it was regularly being broadcasted through various media channels within the last few months. In recent times, ceylon Electricity Board has been experiencing in a crucial crisis due to the inability to satisfy electricity demand in the country, which adversely impacted on the generation plan and financial estimations. Main reason for this was unexpected drought prevailed. Water levels of all the reservoirs were low and hydro generation was strictly scheduled for a limited time period.

Countries such as Sri Lanka have to inevitably face numerous problems under such weather condition, since generation from hydro sources contributes to a significant portion of total generation in the country. Hydro and other sources weigh 40% and 60% from total generation respectively in a period with average hydrological conditions. Hydro generation came down below 20% during this season and the deficit of electricity demand had to be purchased from independent power producers (IPPs) who generate power using diesel, incurring substantial amount of rupees during the peak time.

DSM as a solution

As an immediate solution to mitigate the problems arises, supply side had to be equipped with demand side management (DSM) tools. As a basic step, supply side tried to control the electricity demand by managing consumer behavior towards energy saving. This was the point where above mentioned slogan came into play through public media like Television, Radio, Newspapers, Social network…etc. All these urged to save electricity by avoiding unnecessary usage.  As night peak hours from 6.30 p.m. to 9.30 p.m. are more critical in this case, their attention was mainly focused on night peak hours. Though morning peak hours from 5.30 am to 6.30 am deliver less impact, as electricity consumers, our attention should be given to that period as well. This campaign was successful to a certain extent with the theme of “Janawiduli balagara”.

But the real situation is, consumers don’t have a proper understanding about these peak hours and the advantages of saving electricity during peak hours.  It might be an easy task to stimulate consumers towards positive attitudes in energy saving, if they have a clear view and understanding regarding the load profile of Sri Lanka.

Behavior of load profile

Load Profile is a chart in which electricity demand is plotted against the time, 24 hours of a day. The shape of this chart is almost same on all five weekdays. But it gets deviated slightly on weekends and holidays. Following graph represents the load profile of a normal weekday.

The above load profile extracted from the energy balance 2010, illustrates the variation of electricity demand for a day within year 2010 with an average hydrological condition. It is apparent that the Sri Lankan load profile is fluctuating significantly between numerous peaks and valleys. Two specific time slot of this graph could easily catch the eyes and those are well-known as the peak hours.

Peak hours are the time periods in which the electricity demand is significantly higher than the average demand level. As per the diagram illustrates, 5.30 a.m. to 6.30 a.m. period is identified as “Morning peak” and period from 6.30 p.m. to 9.30 p.m. is identified as “Night peak”. It is evident that demand is very low during the midnight and early in the morning. The time slot from 2.00 a.m. to 4.00 a.m. reports the lowest demand within a day which could be identified as the “Base load” of the system.

Next article of this series will bring you a comprehensive analysis of load profile, a discussion on the criticality of peak hours and the importance of providing a general understanding about them to the public in the way of effective utilization of electricity.

Terminology

IPP- Independent power producer is an entity which is granted with permission to generate electricity for sale to utilities and end users

Supply side- This includes all the bodies that are responsible for power generation, transmission and distribution

DSM-Demand side management is a method of encouraging the consumers to use energy efficiently and effectively.

Article By: Janaka Lakmewan

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Posted in: Utility and Social

Zero Energy Building Concept

Action towards energy saving

In this fast moving competitive world, “energy” plays a major role due to the limitation of availability and the cost of utilization. As people try to grab the maximum portion of energy available, no doubt that the globe will further suffer from this energy crisis. Before the problem goes worse, it’s better to take necessary and prompt actions to at least mitigate the energy crisis.

In most of the countries throughout the world, buildings are responsible for more than 40% of energy use. As it is very much important to reduce the energy usage and conserve energy, it’s better to pay attention towards the concept of zero energy building. Although zero energy building concept is not a novel idea, implementation of the concept in a practical environment is new to a country like Sri Lanka.

Zero energy building concepts

Zero energy building has been defined in many ways. But the gist is that the net energy consumption and carbon emission should be zero . In a simpler explanation, building produces sufficient energy to feed its energy need. Zero energy buildings can meet all their energy requirements from low cost, locally available, non polluting renewable energy sources. The two major sectors of energy consuming buildings are domestic and industrial. Thus,it’s essential to consider both types of buildings with respect to the zero energy building concept. 

Zero energy concept for industrial buildings 

As the phenomenon of global warming strikes alarms gradually, putting the blue planet in danger, measures are mandatory to dampen the negative effects of it.Commercial buildings have been identified as a major contributor in increasing global warming. Increasing energy efficiency and on site power generation in buildings can reduce the negative impact on the environment. It is worthwhile spending a fraction out of huge profits generated to make the building less energy intensive. 

Domestic approach

This concept is not a far fetched dream to houses. Though it is difficult to convert existing houses into this form, newly constructed houses can be planned well in advance to ameliorate energy efficiency. Necessary guidance may be needed by the architects to make their designs energy efficient, having zero energy houses as the ultimate goal.

A deeper look 

Realization of “Zero energy building” concept is a multi folded exercise and  main components comprise of  on-site energy generation, indoor lighting, sun control and shading devices,natural ventilation  and water conservation. Further, “ Zero energy building” concept presents numerous advantages to its users like reducing the cost of living, isolating the building from future energy price increases, improvements in reliability and the increment in the value of the building parallelly to the increase in energy costs.

Though the story sound fairy, implementation encounters many complexities. All of the above mentioned components and inherited benefits will be discussed extensively in the next couple of episodes of this article. 

Article By:

Tharangi Gunarathna

Muditha Karunathilake

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Posted in: Sustainable Energy and Policy

Norochcholai Coal Power Plant - In retrospect - Treading the wrong path

I believe we have reached the conclusion that coal power was a more suitable option in electricity generation for Sri Lanka through the previous article which discussed the fact comprehensively. This particular article follows it up with the discussion of initial groundwork of the Norochcholai coal power plant and irreparable mistakes occurred along the way. The sole intention is to narrate the history of the power plant, explaining the episodes as they were, preventing any political influence.

The necessity of a coal power plant

Let me take you to the power generation situation in Sri Lanka exactly 10 years back, year 1993, and compare it with the situation in year 2010.

(Source: Sri Lanka Energy Balance 2010)

It is evident that in 1993, 95% of total generation was made of hydropower and that portion has dropped to 53% by 2010, while thermal generation has increased from 5% in 1993 to 47% in 2010. This points us to the fact that by early 1990’s almost all the potential large hydro resources in the country has been utilized to produce electricity and further increase in demand caused the introduction of thermal generation in large scale. Further, to maintain the reliability and stability in an ever growing power system, thermal generation is essential. Walking back in our memory lane to the previous article, we concluded that coal power is one of the best options to maintain such status.

Funding Opportunities and Finding a site

The relevant authorities at that time have also agreed to the idea for a coal power plant as a general plan has materialized and the search for funding opportunities has begun.

The most prominent funding opportunity for the proposed coal fired power plant was provided by the Japan Bank for International Cooperation (JBIC). By early 1990’s JBIC had agreed to fund a feasibility study on the development of a coal fired power plant and fund the subsequent construction of the plant. Four potential sites for the power plant have been identified at that time, three in Puttalam area and one in Gampaha District. Trincomalee had also been a potential site, but it was rejected due to the security situation prevailed in that area. The whole southern coastal belt was rejected by then government under the convincement that building a coal power plant would cause a detrimental impact on the environment.

After studying the merits and demerits of the possible sites selected, it was decided that Narakkalli in Puttalam area as the most suitable site for the plant, mainly due to the adequate coastal area available and less density of population in that area. After official requests sent by the Sri Lankan government to Japan, feasibility study on the plant started in 1995 under the funding from JBIC, and during the study the site was moved further southwards. Even though the original name of the area is Narakkalli, the site went by the name of “Norochcholai” as it was the name of the nearby town.

Protests against project and setbacks triggered from them

The point where things started going wrong occurred in 1997 where the whole project and the ongoing study became highly politicized due to the constant upheavals from the pressure groups. The first considerable resistance on the basis of environmental impacts and resettlement issues, came from the Catholic clergy of the area with the backing of the people from the area and especially the politicians. Politicians were more concerned over there vote base of the area rather than the actual need of the whole country which lead to the situation where between 1997 and 2004, the project would have been approved by the political regime several times, and also would have been “cancelled” or “suspended” several times by the same regime, typically when elections were approaching.

Consequences of delayed implementation of the plant

Amidst this political tug of war, it was the electricity customers in the country who suffered as the government was forced to build 10 oil fired power plants within the time period in which the construction of Norochcholai power plant had been delayed. Political schemes and personal benefits outweighed the actual need of the country as politicians and powerful personnel nested in elevated positions in the hierarchy constantly backed up the construction of the oil fired power plants stating numerous justifications while the coal power plant project was shunned aside hoodwinking the general public with stories of deceit.

As a result of this the electricity customers suffered day by day in the face of ever rising price of crude oil which increased their electricity bills regularly, while the more cost effective and sustainable option of the coal power plant was neglected. This is evident clearly when the crude oil prices and coal prices in that time frame are considered, as the crude oil prices increased dramatically, the coal prices were relatively stable.

Commissioning of the plant

While general electricity customers suffered from the poor decision making triggered by political schemes, the whole power system of the country was setback several years as the coal power plant was to produce electricity from 2004, although luckily in 2004 the project was resurfaced under a new government and people with clear vision up in the hierarchy. But unfortunately at that time funding from Japan was not possible due to various reasons hence government turned to China and a deal was struck to build the plant under Chinese funding which was to produce electricity from 2011, almost exactly 7 years behind the schedule.

Up to now the background of the Norochcholai power plant was discussed and more details of the actual project will be discussed in the next article.

(This article is based on “Norochcholai Power plant: A postscript” by Dr Tilak Siyambalapitiya which was published in The Sunday Times on Sunday March 20, 2011 http://sundaytimes.lk/110320/BusinessTimes/bt09.html)

Article By: Asith Kaushalya

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Posted in: Power System

Light the Lights - Comparing options for domestic lighting

There is a diverse range of lighting fixtures and lamps available in the domestic market where each lamp has its own advantages and disadvantages. The diagram below shows some of the basic lighting technologies which are popular in the local market for savvy. But this article mainly focuses on domestic lamps, their advantages and disadvantages and how they can be utilized optimally to serve your requirements.

Basic Lighting Technologies

Terminology

Incandescent Lamps

Incandescent Lamp

The incandescent lamp is a very commonly used lamp type in household applications. If stated in simple terms, the basic operating mechanism of an incandescent lamp is passing of an electric current through a tungsten spiral which heats up to such a level as to emit light.

Advantages

• Inexpensive 
• Dimmable
• A dimmer, which is generally a variable resistor, installed in series with the lamp, renders the capability of controlling the current through the lamp and thereby, the capability of dimming it.
• Great Colour Rendering Capability (100 – the maximum possible)
• Due to the extensive colour rendering capability, colours of objects in the illuminated area can be viewed realistically. Therefore, incandescent lamps becomes the ideal choice for places where differentiation of colours of the objects is of greater concern, such as in jewellery shops. 
• No mercury (environmental friendly)
• Unlike CFLs or Fluorescent Tubes, Incandescent lamps do not contain mercury. Therefore, they do not support environmental pollution or poisoning due to mercury, during disposal of the lamp.
• Fast switching
• Due to the absence of warm up time or pre heating time, incandescent lamp can be turned on instantly to produce full brightness. Further, frequent switching does not affect the lifetime of the lamp. Thus, incandescent lamps can be used where fast switching and frequent switching is a necessity.

Disadvantages

• Low luminous efficacy (8 to 24 lm/W)
• The notable disadvantage is the low luminous efficacy of the incandescent lamp which ranks this lamp in the tier of low efficiency. 
• Lifetime of this lamp is short due to evaporation of the Tungsten filament, typically after 750 to 1000 hrs

Tungsten Halogen

Tungsten Halogen Lamp

The Tungsten Halogen is an advanced form of the Incandescent lamp. Similar to the Incandescent lamp, the filament of the Tungsten Halogen lamp is made of Tungsten metal. But the gas filled inside the Tungsten Halogen bulb is a pressurized halogen, usually Iodine or Bromine, under a pressure of 7 to 8 atm.

To withstand the high pressure involved, the glass bulb is made stronger and thicker than in a conventional incandescent lamp. The halogen gas molecules are capable of capturing the evaporated tungsten atoms from the heated tungsten filament and redepositing them back on the filament. This halogen cycle enables the filament to reach higher temperatures and to produce more luminous flux. Additionally, it increases the lifetime of the lamp.

Tungsten Halogen lamps are used in household lighting, especially as spot lights. They are also used in automobile lamps.

Tungsten Halogen lamps possess advantages and disadvantages similar to incandescent lamps.

Advantages

• Small and light in weight
• Dimmable
• Great Colour Rendering Capability (100)
• No mercury (environmental friendly)
• Fast switching  
• Higher life time than Incandescent lamps as the Tungsten-Halogen cycle reduces the evaporation of the filament. Typical lifetime is 2000-2500 hrs.  

Disadvantages

• Low luminous efficacy (12 - 35 lm/W)

Fluorescent Tube Lamp

Fluorescent Tube Lamp
[Photo: http://www.edisontechcenter.org/lighting/Fluorescent/PreheatFluorescentLabeled80.jpg]

The working principle of fluorescent lamp is different from filament lamps.

The electrodes at the two ends of the lamp are heated up so that they start to emit electrons. Emission of electrons is governed by the ballast and the starter. These electrons collide with the atoms of argon (noble gas) near the electrodes of the tube and ionize them. This starts an avalanche ionization process throughout the lamp, creating a path for the current to flow through the lamp. Subsequently the electrons get the opportunity to easily collide with the vaporized mercury atoms. During these collisions, ultra-violet (uv) photons are released. When these photons meet the phosphorous layer of the tube, visible light is emitted.

Fluorescent tubes are very useful in efficient lighting of houses and offices. They are ideal for areas where diffused lighting is necessary rather than focused lighting.

Advantages

• Higher luminous efficacy (80 – 100 lm/W)
• Long life - typically 20,000 hrs
• Diffused light - To places where diffused light is necessary
• Fairly good CRI value (75-85)

Disadvantages

• Cannot dim with a series variable resistor.
• Switching frequency and voltage variations directly affect the life time
• Higher the switching frequency, lower the useful lifetime of the lamp. Higher the voltage increments than the rated voltage, lower the useful lifetime of the lamp. (Note: useful lifetime is the time period until the luminous flux output of the lamp drops down to 70% of the rated luminous flux output.)
• Not environmental friendly due to mercury content.
• Cannot turn on quickly as it needs a warm up time of few seconds.

Compact Fluorescent Lamps (CFL)

Compact Fluorescent Lamp (CFL)

The CFLs have a similar working principle to that of the fluorescent tubes. CFLs normally come with electronic ballasts integrated to the lamps themselves. They are designed to fit in to the holders generally used for incandescent lamps, making it easier for the consumers to replace incandescent lamps with CFLs without any special changes to the existing wiring arrangements.

CFLs are an energy efficient substitute for incandescent lamps in situations where colour rendering capability is not vital.

Advantages

• High luminous efficacy (50 to 85 lm/W)
• It should be noted that the luminous efficacy of CFL is lower than the fluorescent tube but greater than the incandescent lamps.
• Longer life - typically 6,000 to 12,000 hrs
• Fairly good CRI value (80)

Disadvantages

• Not dimmable with a series variable resistor.
• Mercury content pollutes nature at disposal
• Switching frequency affects the lamp adversely

LED (Light Emitting Diode)

LED (Light Emitting Diode)
[http://www.edisontechcenter.org/lighting/LED/ScrewInBulbLEDarray326.jpg]

LEDs are type of semiconductor diodes, which emits light when they are forward biased. The mechanism of light emitting has to be explained at the atomic level. But that process can be explained in simpler terms.

An electron releases energy when it drops from a higher orbital to a lower one. This energy is released in the form of a photon. A greater energy drop releases a higher-energy photon, which is characterized by a higher frequency.

Free electrons moving across a diode can fall into empty holes from the P-type layer. This involves a drop from the conduction band to a lower orbital, so the electrons release energy in the form of photons. This happens in any diode, but you can only see the photons when the diode is composed of certain material.

Visible light-emitting diodes (VLEDs) are made of materials characterized by a wider gap between the conduction band and the lower orbitals. The size of the gap determines the frequency of the photon. In other words, it determines the color of the light.

Lamps made using LEDs are available in the market and they have a much higher luminous efficacy; thereby saving a lot of energy.

Advantages

• High lifetime - typically 100,000 hrs
• High luminous efficacy (150 lm/W)
• No mercury content
• Fairly good CRI value (70)
• Dimmable using a PWM (Pulse Width Modulation) circuit.
• Durable 

Disadvantages

• High heat dissipation causes the need of heat sinks making the lamp bulky and costly.

References

• Seminar on LED Technology and Applications 2012, Regional Center for Lighting
• http://www.edisontechcenter.org
• http://www.howstuffworks.com/led2.htm

Article By: Supun De Silva

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Posted in: Sustainable Energy and Policy

Dr. Tilak Siyambalapitiya speaks - Generation situation and economics of Sri Lankan power sector

“When we talk about power generation situation, we have to consider three issues namely; adequacy of generation, cost of generation and the generation mix” said Dr. Tilak Siyambalapitiya, senior energy consultant, during an interview with EnergyzEE team.

Dr. Thilak Siyambalapitiya

Dr. Siyambalapitiya graduated from University of Moratuwa, and earned his PhD from the University of Cambridge. He carries 30 years of experience in the energy sector of Sri Lanka, as well as in the region. He has worked in Ceylon Electricity Board, and in Saudi Arabia, on power sector planning and policy. He is a Chartered Engineer, and a Past President of Sri Lanka Energy Managers Association. He is currently an international energy consultant, working with countries in Asia and Africa.

This is the first phase of the discussion the EnergyzEE team had with Dr. Siyambalapitiya.

Adequacy of power generation in Sri Lanka

What do you think about the current situation in terms of generation capacity in Sri Lanka?

“Sri Lanka has adequate generation capacity as for now, and if we continue with the generation projects that are ongoing as well as being planned, and build them on time, there should be no capacity shortages”.

Then why did we have power-cuts in August, last year?

“Last year was one of the driest years for hydro. As a result, annual hydropower generation dropped to 2700 GWh from the planned generation of 4100 GWh. But, one might ask, “there is so much of rainfall data for 100 years; therefore could this not be foreseen?” Yes, it is foreseen. If you take the long term generation plan published by CEB, the criterion on which generation planning is done is that the generation system should be able to meet the demand even if the third driest year in the history occurs again. If you take the long term plan prepared 10 years ago, we were to have the entire Puttalam power plant operational by now. But we have only one generator. Other two are still under construction. So if we had those two units as well, we would have an additional 600 MW.”

“Due to delayed implementation of the plan, we did not have adequate thermal capacity to meet this eventuality. And also, there were simultaneous outages of thermal power plants in August. Therefore we had shortages for a period of about three weeks. So if the plan was implemented on time, we would not have any difficulty at all.”

You have been continuously speaking about a similar situation occurring on the proposed coal power plant in Sampur.

“Well, our next crisis will be in 2017. In fact, electricity crises are easier to predict than human actions, because at least we have some data. I said average rainfall could have given us 4100 GWh last year, but actually we got 2700 GWh. We know the limits. Basically plus or minus 30% from the average is what we get. Therefore, although rainfall is so variable, we know the boundaries, and therefore we can plan for it.”

“Most of the current oil-fired power plants are to be retired by 2015. Given how projects are being implemented, 2017 is another critical year because Trincomalee power plant is not ready yet. Its construction work is yet to be started. To have a big power plant ready by 2017, the construction work should have started now. It takes a minimum of four years to build a big power plant. But we are nowhere near starting the work. Therefore, 2017 will be critical again.”

“And of course, if the rainfall is bad in 2017, the authorities can blame the weather. But we don’t have to blame the weather because the rainfall statistics are known. The ‘real reason’ is not the bad weather, but the delay in starting the projects. That delay becomes visible and acute, when rainfall goes below the average. As I said, if the plan is implemented on time, there should be no problem persisting. Otherwise, what are planning engineers for? CEB is maintaining four full time planning engineers just to plan the generating system in the future. There should be no problem if their recommendations are implemented.”

“The problem is, now people are arguing about ‘Coal Trinco’ (Sampur) power plant without making a decision. “Do we really need it?”, “Can’t we make it a gas-fired power plant?”, “Do we have to do it with Indians?” are such arguments. Therefore, the project is getting delayed, and we will be in trouble.”

Then what would be the solution for this, under your opinion?

“As I always say, decide first for the long term, and then look for any quick solution for that window. The mistake we have been doing in the past, since about 1992, is that we don’t make decisions on the elements of the long term plan. Then, say about two years ahead of a crisis, suddenly everybody wakes up and says that we must do something for this. Then various bright ideas come in; for example, one such bright idea is “Let’s advertise saying that we need 300 MW in two years. So, let the private sector propose how they can bail out the country with 300 MW and deliver in two years.” But we know that nobody can build a decent 300MW power plant in two years. The only thing you can do is buying a readymade one. You can’t get any readymade Nuclear, Coal or Gas power plant; the only readymade power plant you can get is an oil-fired one. So we get the private sector to do what they like, what they can do. The politicians and funding organisations such as ADB, World Bank would like that very much because we are getting private sector to do power generation; so we are breaking the monopoly of the government and CEB in the business of power generation. Nobody discusses the real issue that we are getting a wrong type of power plant. And that’s why we have a legacy of 10 oil-fired power plants, all done by the private sector. So all I say is, that’s a short term unqualified solution.”


“Let’s take things as of today. It’s true that decision on Trincomalee has been delayed. We can’t keep crying about what happened in the past. So today, we should fast track it, and see how we can get it by 2017. Even if we can’t get it by 2017, we can get it by 2018. Then of course, we know that a crisis is coming up in 2016, 2017. Then we can get CEB planners to quantify the likely severity of this crisis. Then if we can get over it by having load shedding for about two months selectively, then perhaps we can tell the customer in advance about the problem and keep them well informed until we recover it with our long term solution. So the solution to the crisis is deciding first and making realistic decisions.”

“We have been discussing with India for the last six years, in terms of this particular power plant, but still there is no conclusion. I don’t think any decent government or even a private sector company would negotiate anything for six years. If it doesn’t work out, you should look for some other opportunities. In my view, we have had enough discussions with India. For whatever reason, may be economic or political or whatever, they can’t reach an agreement.”

“But there are other avenues. We can invite joint CEB – private sector partnership. We have local companies who have now experience in building private power projects. And what we basically need is USD 500 million of investment, and it’s not a huge amount for our private sector now, but the offers must be competitively selected, and as the Electric Act says, Government must be a shareholder. Negotiated agreements with the Sri Lankan private sector have been seen to be very expensive.”

“Otherwise, Japanese may still be willing to finance the Trincomalee power plant, provided that it is a ‘super critical’ power plant. Super critical power plants operate at much higher temperatures and pressures, and they are usually about 2% more efficient than the conventional technology. But, there is a catch. Super critical power plants are big. The smallest unit size is 600 MW. So, as a single generator, 600 MW is too large in our tiny power system. The issue is the risk. If the big generator trips, there will be a system blackout. So, it’s also a choice that can be made, if we want, whether to take the risk or not. We can inform the public about the risk of possible blackouts, and make a decision to build a super critical power plant. But, as demand grows, that problem too will also fade away by 2020 or so. Our peak demand will be much higher then, and a 600 MW single generator will not be an issue.”

How do you compare the power generation situation in Sri Lanka with other developing countries in the region?

“If we compare ourselves with India, Pakistan, Bangladesh and Nepal, our immediate neighbours in South Asia, we are the only country that provides adequate electricity throughout the year. Nepal is having 12 hour load shedding in winter. In summer, Bangladesh sheds about 30% of the demand. India sheds 12% and Pakistan sheds up to 50%. There are electricity riots in Pakistan; people are going in procession asking the government to give them electricity. So, Sri Lankan generation situation is better when comparing with those four countries in the region.”

“However, Maldives is completely different from them. Maldives is a tiny neighbour but has a lot of financial resources. They provide 24 hour electricity to all the islands using diesel generators, at a subsidized price.”

“Elsewhere in the Asian region, most of the countries meet the entire requirement; there is no long term load shedding. In terms of adequate capacity, we are comparable with them. But, in terms of reliability, countries like Singapore, Malaysia and Thailand far ahead of us."

“Overall in comparison with developing countries in the world, we are not at the top, but somewhere in the middle.”

The discussion continued to the areas of cost of generation and generation mix in Sri Lanka. You can meet Dr. Siyambalapitiya again through EnergyzEE soon. Stay in touch with EnergyzEE.

Article By: Kalindu Sachintha Wijesundara

Interview By:
    Kalindu Sachintha Wijesundara
    Asith Kaushalya
    Dilini Hansika Dharmawardhana
    Mihirani Kethumalika
    Chathuri Harshani

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Posted in: Utility and Social