Q1Non-Conventional Energy Sources

(a) Non-Conventional Energy Sources vs Conventional Energy Sources

Non-conventional (renewable/alternative) energy sources are energy resources that are naturally replenished on a human timescale and are generally derived from ongoing natural processes - solar radiation, wind, tides, geothermal heat, and biomass - as opposed to conventional energy sources (coal, petroleum, natural gas, and to a large extent nuclear fuel based on mined uranium) which are finite, exhaustible fossil or mineral resources accumulated over geological timescales and depleted upon use.

• Availability: conventional sources are finite and depleting; non-conventional sources are renewable and, for practical human purposes, inexhaustible.
• Environmental impact: conventional sources (especially fossil fuels) emit greenhouse gases, particulate matter, and other pollutants on combustion; non-conventional sources are generally far cleaner, though not entirely impact-free (land use, manufacturing footprint, intermittency-related backup generation).
• Geographic concentration: conventional fuel reserves are geographically concentrated (creating import dependence for many countries); non-conventional resources (sun, wind) are more geographically distributed, though resource quality still varies by location.
• Cost structure: conventional plants have comparatively lower capital cost but ongoing fuel cost; non-conventional plants typically have higher upfront capital cost but near-zero fuel cost, since the 'fuel' (sunlight, wind, tide) is free.
• Reliability/dispatchability: conventional thermal plants can generate power on demand at controllable, steady output; most non-conventional sources (solar, wind) are intermittent and weather-dependent, requiring storage or backup generation for reliable supply.
• Technology maturity: conventional generation technology is mature and well-established over more than a century; several non-conventional technologies, while rapidly maturing, still have comparatively higher cost per unit of installed capacity in many applications, though costs have fallen dramatically for solar PV and wind in recent decades.

(b) Tidal Power

Tidal power is electrical energy generated by harnessing the rise and fall of ocean tides, caused primarily by the gravitational attraction of the moon (and to a lesser extent the sun) acting on the Earth's oceans, combined with the Earth's rotation - the resulting periodic rise (flood tide) and fall (ebb tide) of sea level creates a large moving mass of water whose potential energy can be converted to electricity, typically by constructing a barrage (dam) across a tidal estuary or bay with a large tidal range, trapping water at high tide and releasing it through turbines as the tide falls (or in more sophisticated schemes, generating during both the incoming and outgoing tide).

• Advantages: tidal power is highly predictable (unlike wind and solar, tides follow known, precisely computable astronomical cycles decades in advance), produces no greenhouse gas emissions during operation, has a very long operational lifespan (tidal barrages can operate for over a century with proper maintenance), and provides a steady, reliable, renewable energy contribution to the grid.
• Limitations: tidal power requires a specific site with a large tidal range (typically above 5 meters) and suitable estuary geography, making it geographically very limited (only a handful of sites worldwide are economically viable); it has very high initial capital cost for barrage/turbine construction; it generates power intermittently in phase with the tidal cycle rather than continuously (though predictably), requiring grid-integration planning; and large barrage schemes can significantly disrupt estuarine ecosystems, sediment transport, and local marine/bird habitats, requiring careful environmental impact assessment before construction.

In practical terms, the transition between conventional and non-conventional energy sources is being driven not only by resource depletion concerns but also by the falling levelized cost of electricity (LCOE) from solar photovoltaics and wind, which in many regions of the world (including large parts of India) has fallen below the LCOE of new coal or gas-fired plants over the past decade, even before accounting for the external environmental and health costs of fossil fuel combustion that are typically not reflected in market fuel prices. This cost convergence has shifted the discussion from a purely environmental argument for renewables to an increasingly economic one, with utilities and grid planners now routinely comparing renewable-plus-storage options against new conventional capacity on a pure cost basis.

A further important distinction lies in the scale and modularity of the two categories of generation: conventional power plants (coal, gas, nuclear) typically achieve their best economics at large, centralized scale (hundreds to thousands of megawatts), requiring significant transmission infrastructure to deliver power to distant load centers, whereas many non-conventional technologies - particularly solar PV and small wind - are readily modular and can be deployed at scales ranging from a few kilowatts (rooftop solar) to hundreds of megawatts (utility-scale solar parks), enabling distributed generation close to the point of consumption and reducing transmission losses, while also allowing incremental capacity additions that better match gradually growing demand without the large single-project capital commitment characteristic of conventional plants.

In summary, while conventional and non-conventional energy sources differ across nearly every practical dimension - resource availability, environmental footprint, cost structure, dispatchability, and technology maturity - most national energy strategies, including India's, do not treat them as mutually exclusive but instead pursue an integrated approach in which non-conventional sources progressively displace a growing share of conventional generation while conventional (and increasingly, storage and demand-response) capacity is retained to manage the intermittency of renewables and maintain overall grid reliability during the transition period.

It is also worth situating this conventional-versus-non-conventional distinction within the broader context of a country's overall energy transition strategy: no country transitions instantaneously from a conventional-fuel-dominated grid to one based entirely on non-conventional sources, and the practical transition pathway typically involves progressively increasing the non-conventional share of the generation mix over one to several decades, guided by considerations of grid stability, storage technology cost and maturity, and the pace at which conventional plants can be economically retired or repurposed, rather than an abrupt, immediate switch from one category of energy source to the other.

Tidal power, as one specific non-conventional source examined in this question, also illustrates a further useful classification within the broader renewable category itself: unlike solar and wind, whose output fluctuates according to essentially unpredictable, weather-driven short-term variability, tidal power's variability, while still significant on a daily cycle, is entirely predictable years in advance from basic astronomical calculation, giving grid operators a meaningfully different, more manageable type of variable-generation integration challenge compared to solar and wind, since tidal generation schedules can be planned and coordinated with other generation resources with near-perfect advance certainty, even though the tidal generation timing itself does not necessarily align conveniently with the timing of peak electricity demand.