The next test for renewable energy

Why in News

India’s expanding renewable-energy capacity has increased the significance of storage, transmission networks and dependable electricity delivery.

Prelims Pointers

• Installed capacity and electricity generation are different.

1. Gigawatts (GW) measure power capacity.

2. Gigawatt-hours (GWh) measure electrical energy generated, consumed or stored.

• Solar and wind power are variable. Their output changes with sunlight, wind conditions and time.

• Solar photovoltaic and solar thermal technologies work differently.

1. Photovoltaic cells convert light directly into electricity and produce direct current.

2. Solar thermal systems capture solar energy as heat, which can be used for heating or electricity generation.

• Dispatchability is the ability to supply electricity when required. 

• Energy storage shifts electricity from periods of surplus availability to periods of greater demand.

1. Batteries store energy electrochemically.

2. Pumped storage uses electricity to pump water uphill and generates electricity when the water flows back down.

• Curtailment means reducing available generation because of grid constraints or other system requirements.

• Transmission networks carry electricity from generating stations to demand centres. 

• A two-way Contract for Difference (CfD) settles the difference between an agreed strike price and a market reference price.

1. When the reference price is lower, the generator receives the difference.

2. When it is higher, the generator pays back the difference.

• Smart meters record electricity use and communicate data, supporting demand management and grid operations.

• Clean-energy supply chains depend on minerals, processing capacity and manufacturing capabilities. Dependence on a few suppliers can create energy-security risks.

• Non-fossil capacity includes renewables and nuclear power.

Prelims Traps

• “Battery storage cannot be a Distributed Energy Resource because it does not generate primary energy.” This is incorrect.Battery storage, biomass generators, fuel cells and rooftop solar photovoltaic units are Distributed Energy Resources. (UPSC Prelims 2024)

• “Solar photovoltaic cells directly produce alternating current.” This is incorrect. They produce direct current. (UPSC Prelims 2014)

• “A higher share of installed renewable capacity necessarily means the same share of electricity generation.” This is incorrect. Generation also depends on resource availability, operating conditions and curtailment.

• “A Contract for Difference guarantees electricity delivery whenever required.” This is incorrect. It addresses price differences, not physical dispatchability.