Status of HVDC

National Grid may be perceived as a mesh of interlinked transmission lines, interconnecting different electrical regions, viz., Northern, Eastern, Western, Southern and North - Eastern regions of the country.

This is required to optimally harness the generating resources, confined to certain regions of the country, by facilitating transfer of power from such regions to the other regions which are not adequately endowed.

other projets are

>>> Two numbers of 1500 MW HVDC bipoles :

one in Northern region belonging to powergrid (+500KV, 1630 ckt. Kms. HVDC bipole carrying bulk power from Singrauli/Rihand Complex to Delhi)

and

the other in Western region belonging to MSEB (+500kV, 1504 ckt. kms. HVDC bipole transmitting bulk power from Chandrapur to Padghe).

Interconnection of different contiguous regions through HVDC back-to-back links located at;
Vindhyachal (500 MW) connecting Northern & Western region,
Chandrapur (1000 MW) connecting Western & Southern region,

and

Gazuwaka (500 MW) connecting Eastern and Southern regions.

NECCESSITY OF CREATION OF NATIONAL GRID IN INDIA

POWERGRID is working towards achieving its mission of Establishment and Operation of Regional and National Power Grids to facilitate transfer of power within and across the regions with reliability, security and economy, on sound commercial principles".

Following are the reasons for the formation of National Grid

1) The exploitable energy resources in our country are unevenly distributed, like Coal resources are abundant in Bihar/Jharkhand, Orissa, West Bengal and Hydro Resources are mainly concentrated in Northern and North-Eastern Regions. As a result, some regions do not have adequate natural resources for setting power plants to meet their future requirements whereas others have abundant natural resources. Demand for power continues to grow unabated. This calls for optimal utilization of generating resources for sustainable development. Thus, formation of National Power Grid is an effective tool to achieve this as various countries have adopted the model of interconnecting power grid not only at national level but also at international level.

2) Further, acquiring Right of Way (ROW) for constructing transmission lines is getting increasingly difficult, especially in eco-sensitive areas like North-Eastern Region, Chicken neck area, hilly areas in Jammu & Kashmir and Himachal Pradesh. At the same time, these areas are also endowed with major hydro potential of the country. This necessitates creation of �Transmission Super Highways�, so that in future, constraints in ROW do not cause bottleneck in harnessing generating resources. Inter-connection of these highways from different part of the country would ultimately lead to formation of a high capacity �National Power Grid�.

3) Thus, developments in power sector emphasize the need for accelerated implementation of National Power Grid on priority to enable scheduled/unscheduled exchange of power as well as for providing open access to encourage competition in power market. Formation of such a National Power Grid has been envisaged in a phased manner.

4) Initially, considering wide variations in electrical parameters in the regional grids, primarily HVDC interconnections were established between the regions. This was completed in the year 2002, thereby achieving inter-regional power transfer capacity of 5000 MW.

5) In the next phase, inter-regional connectivity is planned to be strengthened with hybrid system consisting of high capacity EHV/UHV AC and HVDC links. Such a National Power Grid is envisaged to disperse power not only from Mega sized generation projects but also to enable transfer of bulk power from one part of the country to another in different operational scenarios say, in varying climatic conditions across the country: Summer, Winter, Monsoon etc.

6) Commissioning of links under this phase has already begun with the commissioning of 2000 MW Talcher-II HVDC Bipole, Raipur � Rourkela 400kV D/C AC transmission line having Series Compensation, augmentation of Gazuwaka HVDC (500MW) back to back link and Tala transmission system.

7) The inter-regional transfer capacity of 16,200 MW is available as on date.

8) Further strengthening of National Power Grid is envisaged through high capacity AC EHV lines, 765 kV UHV AC lines/ HVDC lines. This phase is planned to be implemented by 2012 when inter-regional power transfer capacity will be enhanced to about 37,700 MW by the end of XI Plan, depending upon planned growth of generation capacity.

Main functions assigned to NLDC

NATIONAL LOAD DESPATCH CENTRE (NLDC) has been constituted as per Ministry of Power (MOP) notification, New Delhi dated 2nd March 2005 and is the apex body to ensure integrated operation of the national power system.

Main NLDC is situated at DELHI, while its reduant system is in KOLKATA.
NLDC at delhi was inauragted by power minister in Feb 2009

The main functions assigned to NLDC are
 

1. Supervision Over the Regional Load Despatch Centres.
2. Scheduling and dispatch of electricity over the inter-regional links in accordance with grid standards specified by the authority and grid code specified by Central Commission in coordination with Regional Load Despatch Centres.
3. Coordination with Regional Load Despatch Centres for achieving maximum economy and efficiency in the operation of National Grid.
4. Monitoring of operations and grid security of the National Grid.
5. Supervision and control over the inter-regional links as may be required for ensuring stability of the power system under its control.
6. Coordination with Regional Power Committees for regional outage schedule in the national perspective to ensure optimal utilization of power resources.
7. Coordination with Regional Load Despatch Centres for the energy accounting of inter-regional exchange of power.
8. Coordination for restoration of synchronous operation of national grid with Regional Load Despatch Centres.
9. Coordination for trans-national exchange of power.
10. Providing Operational feedback for national grid planning to the Authority and Central Transmission Utility.
11. Levy and collection of such fee and charges from the generating companies or licensees involved in the power system, as may be specified by the Central Commission.
12. Dissemination Of information relating to operations of transmission system in accordance with directions or regulations issued by Central Government from time to time.

All-time high peak power demand in the country

A record peak power demand of 99,027MW was met on 21st September, 2009 during evening peak hours. Last year during this period maximum peak demand met in the country was around 84,885MW. Thus a growth of 16.7% has been observed in meeting peak demand in the country. The highest peak availability has been possible due to improved hydro generation, revival of thermal units which were under maintenance and strong inter-regional links established by Power Grid Corporation of India Limited (POWERGRID), a Navratna PSE under Ministry of Power and the Central Transmission Utility (CTU) of the country.



It is expected that peak availability of power in the country may reach in six digits very soon. In terms of energy, total consumption on 21.09.09 was 2.20 billion units as compared to 1.82 billion units on 21.09.08 resulting in rise of about 21.1%. The hydro power generation was 472 MU, i.e., 7.4% increase as compared to 439 MU on the same day last year.

Indian Government committed to evolve credible and sustainable National Energy Efficiency: By Shinde ( Power Minister )

Shri Shinde representing India in the Ministerial Forum of the International Energy Agency in Paris on 15th October 2009 delivered a key note address on Energy Efficiency.

The Union Minister for Power, Shri Sushilkumar Shinde has said that Government of India is committed to evolving a credible and sustainable national energy efficiency agenda to stimulate a market transformation in favour of energy efficient technologies and products. Shri Shinde informed that the impact of the policies and programmes of Government of India on energy efficiency, duly verified by an independent agency has shown that during 2007-08 and 2008-09, the savings in energy were about 10.7 billion kilo watt hours, equivalent to an avoided capacity addition of 2128 MW.




The International Energy Agency is a body comprising 28 Member States which are mainly developed nations. In this Ministerial Meeting, non-members India, China and Russia have been invited as partners in dialogue. Shri Sushilkumar Shinde is leading the Indian delegation to this Ministerial Meeting wherein a joint statement between India and IEA outlining the roadmap for cooperation between India and IEA regarding Energy Security and Energy Efficiency was issued. Mr. Shinde in a detailed intervention outlined various initiatives that India had taken towards increasing energy efficiency and thereby also ensuring environmental protection in line with the Indian National Action Plan on Climate Change released by the Prime Minister.



The Minister pointed out that the National Mission for Enhanced Energy Efficiency (NMEEE) is one of the eight national missions under the National Action Plan on Climate Change which seeks to upscale the efforts to create a market for energy efficiency which is estimated to be around Rs. 740 billions or over 10 billion Euros. The Mission seeks to create a conducive regulatory and policy regime to foster innovative and sustainable business models to unlock this market. As a result of the implementation of this Mission over the next five years, it is estimated that about 23 million tonnes oil equivalent of fuel savings- in coal, gas, and petroleum products, will be achieved along with an expected avoided capacity addition of over 19,000 MW. The consequential carbon dioxide emission reductions are estimated to be 98.55 million tonnes annually.



Elaborating further the Minister informed that the National Mission on Enhanced Energy Efficiency seeks to implement an Action Plan based on four major initiatives.

1. The first and probably the most important initiative is the Perform Achieve and Trade (PAT) scheme. This is a market based mechanism to enhance the cost effectiveness of improvements in energy efficiency in energy-intensive large industries and facilities, through certification of energy savings that could be traded.
2. He also said that the second proposed mechanism is the Market Transformation for Energy Efficiency (MTEE) to accelerate the shift to energy efficient appliances in designated sectors through innovative measures to make the products more affordable.
3. The Minister added that the third mechanism seeks to finance demand side management programmes in all sectors by capturing future energy savings. The proposed Energy Efficiency Financing Platform (EEFP) would help stimulate necessary funding for Energy Service Companies (ESCOs) based delivery mechanisms for energy efficiency. We have already initiated several measures to unlock the market for ESCOs. One of the most significant is the ESCO project in the agriculture sector in Solapur district of Maharashtra. The project will replace the inefficient pumps of farmers with efficient 5 STAR rated pumps, at no cost to the farmer. The costs are to be covered from the energy savings that will occur in the future.
4. Another initiative, he said is the Framework for Energy Efficient Economic Development (FEEED) which seeks to develop fiscal instruments to promote energy efficiency through measures like the Partial Risk Guarantee Fund (PRGF) and Venture Capital Fund for Energy Efficiency (VCFEE), Public Procurement of energy efficient goods and services and Utility based Demand Side Management (DSM).

Elaborating steps taken by Government a demand side management, he informed that the Bureau of Energy Efficiency has launched a scheme named Bachat Lamp Yojana that promotes replacement of inefficient bulbs with Compact Fluorescent Lamps (CFLs) by leveraging the sale of Certified Emission Rights (CERs) under the Clean Development Mechanism (CDM) Kyoto Protocol.
Lighting, which accounts for about 25% of electricity consumption, has a significant potential for reduction of the load while not compromising on the lumen output by use of energy efficient lighting in place of incandescent bulbs.


In addition, Energy Conservation Building Code was introduced recently, the standards and labeling scheme for equipments like Air Conditioners, Refrigerators, Distribution Transformers, Fans, etc. has taken off.



India has engaged constructively in several international fora in the area of energy efficiency. Prominent amongst them are the IEA, where India is part of the Demand Side Management Implementing Agreement and became the first non-OECD country to pilot a Task. We have joined the IPEEC recently and look forward to the cooperative activities under it.

One Unit of electricity saved by You ( In your House ) is equivalent to TWO unit of electricity generated ( By Power Plant )

Electricity must be generated, as and when it is needed since electricity cannot be stored virtually in the system.


How we can say that One Unit of electricity saved by You ( In your House ) is equivalent to TWO unit of electricity generated ( By Power Plant ). To prove this we have to consider the strcture of power system network.

Which is as follows

In India, for the coal based power plants, the overall efficiency ranges from 28% to 35% depending upon the size, operational practices and capacity utilization.

Then we transmit power through Transmission and Distribution Lines

The primary function of transmission and distribution equipment is to transfer power economically and reliably from one location to another.

If we consider the electricity flow from generation to the user in terms of cascade energy efficiency, typical cascade efficiency profile from generation to 11 – 33 kV user industry will be as below:

The cascade efficiency in the T&D system from output of the power plant to the end use is 87%
(i.e. 0.995 x 0.99 x 0.975 x 0.96 x 0.995 x 0.95 = 87%)



At the industrial end user premises, again the plant network elements like transformers at receiving sub-station, switchgear, lines and cables, load-break switches, capacitors cause losses, which affect the input-received energy. However the losses in such systems are meager and unavoidable.
A typical plant single line diagram of electrical distribution system is shown in Figure 1.3

The standard technical losses are around 17 % in India (Efficiency = 83%, as shown earlier).
But the figures for many of the states show T & D losses ranging from 17 – 50 %. All these may not constitute technical losses, since un-metered and pilferage are also accounted in this loss.

When the power reaches the industry, it meets the transformer. The energy efficiency of the transformer is generally very high. Next, it goes to the motor through internal plant distribution network.

A typical distribution network efficiency including transformer is 95%

and motor efficiency is about 90%.



Another 30 % (Efficiency =70%)is lost in the mechanical system which includes coupling/ drive train, a driven equipment such as pump and flow control valves/throttling etc.



Thus the overall energy efficiency becomes 50%.

(0.83 x 0.95x 0.9 x 0.70 = 0.50)   i.e. 50% efficiency).



Hence one unit saved at the end user is equivalent to two units generated in the power plant.

(1Unit / 0.5Eff = 2 Units)

Electrical Basics

Ohm's Law :- The amount of current flowing in a circuit made up of pure resistances is directly proportional to the electromotive forces impressed on the circuit and inversely proportional to the total resistance of the circuit at constant temp. condtion.

Ohms Law can be used to calculate a missing value in a circuit.