The whole country witnessed a major blackout on Saturday night, which interrupted daily routines and social and economic life. It is a technical issue requiring serious investigation and non-political discussions and debates. Blackouts have occurred in many countries in the past including, the US, Brazil, Indonesia, Malaysia and India. The latest blackout in India was in 2012. There were two blackouts on successive days on 30th and 31st July, affecting 300 and 700 million people, respectively. Overdrawing of electricity by certain Indian states and weak interregional transmission were cited to be the major reasons. There are many reasons for such blackouts to which there are solutions and safeguards, depending on how much economic and technical resources and manpower are applied. Formal investigations have been ordered and one has to wait till their conclusions. However, we would like to give the reader a context and perspective to the problem. We will discuss some of the problems and solutions in a non-technical language as is possible.
The following are the most common reasons for blackouts: 1) Mechanical breaking of transmission tower or cables or parts thereof; Discontinuity of the link for whatever reasons affects larger areas. There may be technical reasons for mechanical breakage; there could be the reasons of civil unrest or terrorism as well; 2) Accidental Generator breakdown: power generators can breakdown accidentally or due to poor maintenance. There are solutions like (n minus 1) meaning that the system design is such that even if the largest generator gets off for whatever reasons, the system survives; 3. There may be overdrawing of power in certain regions or as a whole which can give rise to blackouts. That is why there is load-shedding. If load is not shed adequately and timely, there could be a massive system-wise blackout. That is what occurred in India in its last blackout of Tuesday-2012; 4) Inadequacy of automation; there is a monitoring system called SCADA through which the system is monitored and even controlled. Level and depth of control may vary. It can be real time or may have response time of varied duration. Power disruptions expand in milli and micro-seconds and if the response time is larger than this, timely corrective actions like isolation cannot be taken; 5) Cyber attacks: Power control centers and other computer equipment in the system may be attacked through computer viruses and computers may be misled or may be shut down. Cyber attacks have occurred on Iran’s nuclear enrichment facilities destroying many centrifuges and allied equipment; 6) Fogging is cited to be another important reason which is compounded by smog. Solid particles, possibly adding to the water conductivity. Transmission cables are suspended by cantilever links which are covered by insulators. Insulators can malfunction and fail due to fog and smog. Normally, coatings are applied through spraying or dipping. Some people say, it can also be sprayed in installed conditioning MD NTDC, some years back, had complained the lack of resources for not being able to undertake timely changes. This appears to be the problem, as most knowledgeable sources have stated this to be the possibility although formal investigations would yield the definite results.
The biggest issue is integration and cascading. There are advantages of integration of the grid, as it enables countrywide sharing of power resources — natural and infrastructural — which is unequally spread. There is an economy of scale and larger market affording lower costs and prices. But as integration increases, the breakdown consequences increase. There is an unfortunate phenomenon called cascading or domino effect-breakdown in one part of the grid expands into the other until the whole system breaks down. There can be an uncontrollable phenomenon like war in which an integrated network country-wide breakdown may be extremely dangerous and consequential. Thus, there is a mid-point to the integrated optimization. On security grounds, there is therefore a case for dividing the country into two independent transmission grids which should be seriously considered and studied. Other solutions are the solutions of the problems that have been discussed; more adequate automation, insulator replacement or on-site treatment, better maintenance and general improvement of the transmission system. In the medium to long term, with the advent of renewable resources like solar and wind power distributed generation will emerge which should reduce the problem. Also electrical storage is emerging and getting cheaper by the year. Electrical storage, initially, of smaller capacity, widely distributed may also help solve the problem.
The aspect of transmission has been somehow neglected, while there has been almost sole focus on generation. We have excess generation capacity which gives rise to circular debt and leaves little resources in the system for improvements elsewhere. The task is difficult, but has to be somehow managed.
(The writer is former Member Energy, Planning Commission, author of several books on Energy)
Copyright Business Recorder, 2021