Hybrid Capacitors, as batteries of the future appears to be an imminent possibility.
Having an edge over super-capacitors, the hybrid variety uses a combination of non-faradic electrode of double layer capacitor and an electrode with a faradic electrode of pseudo capacitors in a compatible electrolyte to form cells.

• The pseudo capacitive electrode with their high capacitance value provide high energy density (being asymmetric in nature)
• Use of gel type electrolytes, which demonstrate a positive improvement in performance levels, resolves the problem of electrolyte leakage

There are numerous advantages of using hybrid capacitors. The major one, which gives the hybrid capacitor an edge over other competitive technologies, is depicted in the graphical representation above. It decidedly emerges that the hybrid capacitor stands out in terms of power density aspects, & is fairly competitive with conventional batteries with respect to Energy Density.

With the enhanced deployment of Wind & Solar energy systems, the need for exploring & adopting some efficient & effective storage systems to operate the electric grid efficiently has become a necessity.

Energy storage systems must be developed to include two levels Namely:

1. Storage at “generation level”. This would help create an “operating reserve”, enable “load leveling” & instill “black start capability” in micro-grid networks.
2. Storage at Transmission & Distribution Levels. At this level, the system would address “Power Quality”, “Transmission line stability” & “Power oscillation damping”

There are a host of storage systems, which are under active consideration, and there is a need to examine all possible systems before adoption. The selection process of a suitable storage system, must take into consideration the following:

• Characteristics
• Economic Viability &
• Technological fitment

Most prominent amongst those being researched upon are the SMES (Super-conducting Magnetic Energy Storage) & Hydrogen Storage Systems, which hold a great promise for the future. Numerous teething problems need to be resolved before large-scale adoption.

Extensive R&D efforts are underway for realizing the idea of “Hydrogen Economy” to be a successor of the fossil-fuel era. The greatest advantage of using hydrogen gas as a storage system emerges from the fact that it has the largest energy content of any fuel, making it a very good ‘vehicle’ for holding and distributing energy. It can hold up to 120MJ/kg, and therefore a relatively small amount of hydrogen is needed to store significant amounts of energy. The stable chemistry of hydrogen also means you can store energy longer than any other medium.

On the other hand, “Superconducting Magnetic Energy Storage” (SMES) is another viable method of energy storage based on the fact that a current will continue to flow in a superconductor even after the voltage across it has been removed. When the superconductor coil is cooled below its superconducting critical temperature it has negligible resistance, permitting the current to flow even after a voltage source is disconnected.

The energy is stored in the form of a magnetic field generated by the current in the superconducting coil. It can be released by discharging the coil.

Due to its very high cycling capacity and high efficiency over short time periods SMES is very well suited to high power short duration applications. They are used in many voltage stability and power quality applications. On-site SMES is suitable to mitigate the negative impacts of renewable energy in power quality related issues, especially with power converters – needed for solar photovoltaic and some wind farms – and wind power oscillations and flicker.

All landmark achievements leading to distinctive & noteworthy techniques or technology have been a result of highly compelling needs, & such accomplishments have, more often than not, the capability of transforming entire Systems & processes in a variety of fields.

“Operations Research” for instance, is a discipline, which deals with the application of advanced analytical methods to arrive at better decisions quickly. This is an offshoot of methodologies developed by military planners during World War-II. The technique has thereafter, made substantial and everlasting in-roads into industries ranging from petro-chemicals to airlines. Numerous inventions like GPS, Nuclear Technology, Night Vision devises, duct tapes, Internet, which are so commonly used in daily life, have their origins to their development to meet the needs of the Armed Forces.

Maintenance Management & Maintenance Philosophies likewise are no different and have travelled a long distance since the First World War, to the present state of art, and the credit of the development can be, to a large extent, claimed by the commercial aircraft industry. The progress of the maintenance philosophy is depicted diagrammatically below, highlighting major milestones crossed on the way.

The approach of MSG -3, which is on a continuous path of refinement, made possible with ever- evolving technological advances, demonstrates that if functional failure of a system has no effect on operational safety, or has no significant economic significance, there was no need for a routine maintenance activity.

One point that stands out from this historical review is, that there is a tendency to continuously add on maintenance tasks / actions in the maintenance schedules making the entire process un-wieldy with a pseudo sense of enhanced reliability. A pragmatic view of all such inclusions needs to be taken to ensure we attend to critical areas with our exact purpose in mind. That will help retain a lean and efficient maintenance function.