In the late 19th century, two of the leading minds then engaged in the ‘war of currents’ to design the electric grid. The maverick entrepreneur, Thomas Edison, held many patents on the direct current (DC) technology and favoured a grid based on it. Nikola Tesla, a former employee of Edison and an engineer, proposed the alternating current (AC) technology.
The DC system was safer than AC — Edison famously demonstrated the dangers of AC by electrocuting a rogue elephant to death with it. But AC was eventually chosen as the technology for the grid owing to its efficiency in transmitting power.
The electric grid is counted among the most important innovations of the 20th century. However it has not seen a major technological innovation over the last century.
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In fact, if Tesla or Edison appear today, they will recognise the key components in the existing grid!
Many countries have woken up to the reality of an ageing infrastructure controlling their grid and have embarked on an ambitious programme to redesign and modernise it. The new design employs the latest advances in IT, is more reliable, affordable and efficient than the old one, and is aptly titled the “smart grid”.
The smart grid will incorporate clean sources of energy and will be secure against malicious attacks.
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Real-time pricing
One of the main drawbacks of the existing grid is an imbalance between supply and demand of power. The utility companies cope with this by designing the grid for maximum load, which sharply increases the cost of power. The smart grid will have mechanisms for communication and control to solve this problem.
An example is real-time pricing of electric power according to its demand. This is in contrast with today’s grid where the cost of electricity does not vary with load.
The electric meter at home will be transformed to a smart meter capable of communicating with the utility company and updating the price of power on a regular basis. Then, product companies can design intelligent appliances that adjust their behaviour according to the price of electricity reported by the smart meter.
Going green
Generation of electricity contributes to 40 per cent of the greenhouse emissions and the smart grid reduces this percentage by incorporating renewable sources such as solar and wind. It is proposed to increase the contribution of renewables to 80 per cent of total electricity output.
This poses a challenge as the energy from a renewable source varies during the day and does not follow the cycle of demand.
Also, electricity cannot be efficiently stored for future use and must be consumed as soon as it is produced. Hence, inducting renewables into the grid and matching them with the demand will require research on control mechanisms to ensure stability of the grid.
The smart grid offers incentives to consumers to install solar panels or windmills at home and sell excess power to the utility companies, thereby allowing the consumer to become a producer of electricity.
Faulty meters, pilferage
India has a huge electric grid: its transmission lines, in grid parlance, span more than 2,50,000 circuit km, and can circle the earth six times. But the antiquated grid is poorly managed and suffers from 30 per cent losses during transmission and distribution (T&D).
In comparison, the U.S. experiences T&D losses of 7 per cent.
The losses in India are mostly ascribed to faulty meters and pilferage of electricity.
The country also holds a dubious record for the largest blackout in history, when half the population went without power for a few days in July 2011. The cause was an imbalance between supply and demand, which tripped a part of the grid, followed by a domino effect that led to the collapse of the northern and eastern grids.
The newly set up India Smart Grid Task Force (ISGTF) has the mandate to introduce initiatives for a smart grid in India. A smart grid in India will reduce the T&D losses, prevent blackouts, and light up homes of a third of the population who have no access to electricity. The ISGTF should listen to the clarion call to modernise the grid.
(The author is a researcher at Bell Labs India. The opinions expressed here are his own and not those of his employer.)