Context
- On average, non-fossil fuels or renewables add around 1,000 megawatts of power to the electricity grid each month (roughly five times the amount of power produced by a 250 MW nuclear plant).
- Policymakers believe that India must work quickly to develop viable energy storage options in order to sustain it operationally.
Relevance
GS Paper-3: Science and Technology- developments and their applications and effects in everyday life
Mains Question
What Is the Meaning of “Intermittency” in Renewable Energy? Discuss the difficulty that comes with it as well. (150 words)
The highlights
- India, the world’s third largest producer of renewable energy, has nearly 40% of installed electricity capacity derived from non-fossil fuel sources.
- This green push resulted in a 24% reduction in GDP emission intensity between 2005 and 2016, but it also created challenges with a grid that is increasingly powered by renewables.
The Renewable Energy Challenge
- The Lithium-ion storage battery option for grid applications is no longer considered viable.
- Energy storage is required alongside green energy sources to primarily balance out the variability in renewable generation, as electricity is generated only when the sun shines or the wind blows. This does not always correspond to the demand cycle.
- Due to the unpredictability of generation trends, renewables are not always a viable option for procurers such as state-owned discoms, which means they must still rely on thermal or nuclear generation to meet base load demand. Renewables combined with a viable storage option aid in overcoming this issue.
- The main challenge is the lack of natural gas to power gas turbines to supplement the growing RE capacity.
- India’s vast fleet of coal-fired power plants of 200 MW series is over 25 years old, runs on outdated technology, and cannot guarantee long-term reliability.
- As an intermediate goal for total transition, obsolete coal-based plants must be replaced with supercritical highly efficient coal-based plants. However, given the impending climate crisis, this may not be acceptable to the international community.
- The country currently has 404 GW of installed generation capacity, with a maximum demand of around 215 GW. The total electric power installed capacity from non-fossil fuel-based energy resources, primarily solar and wind, accounts for 42.3 percent of total installed capacity. Pumped-storage hydroelectric plants are seen as the most viable alternative to compensate for the intermittent nature.
What Is the Meaning of “Intermittency” in Renewable Energy?
- Renewable energy cannot always produce energy at all hours of the day; this is referred to as intermittency.
- During peak times, for example, solar and wind farm energy production in Europe has been known to fluctuate between 0 and 23 and 24GW of energy, respectively. While these peak production periods provide a significant amount of energy, the intermittent nature of renewables is defined by the unpredictable breaks.
What is the operation of pumped-storage hydroelectric plants?
It stores energy in the form of gravitational potential energy of water, which is typically pumped from a lower elevation reservoir to a higher elevation reservoir when renewable power is available, and then releases it to move a turbine to generate electricity when renewable power is unavailable.
Alternatives include
- The government is currently considering two alternatives: hydrogen and hybrid generation models blended with off-stream pumped storage.
- In 2023, as the hidden challenges of RE (Renewable Energy) transition become more concrete, the government is making a renewed push on both technologies.
- The cabinet has approved a policy to increase green hydrogen production and capitalise on its potential as a fuel.
- The Union Ministry of Power has also completed a survey of all pumped hydro sites, and hydro PSUs have been directed to pursue pumped hydro schemes.
- The Ministry of Power has also written to the Union Coal Ministry, requesting that opencast mines be considered as potential future sites for pumped hydro.
Conclusion
- Because pumped-storage hydroelectric plants can store power and then release it when needed, they function similarly to a giant battery.
- The need of the hour is to reduce the percentage of coal-based capacity by closing inefficient fleets while adding new flexible capacity to meet load requirements.
