- India’s renewable energy scenario
- Renewable energy challenges
- What is Renewable Hybrid energy system?
- Example of Renewable Hybrid energy system
- Future of Hybrid System
- Solar-wind hybrid policy
- Way Ahead
Renewable hybrid energy systems as a game changer
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Why it was in News?
Solar Energy Corporation of India (SECI) recently conducted two auctions for wind/solar hybrid projects, in which only 1.56 GW was taken by two firms against a total of 2.4GW on offer.
India’s renewable energy scenario
- India has added 65-70GW of wind and solar capacity so far, with wind and solar contributing 9.5% of generated energy in 2019.
- Recently, the government set the target of installing 175 GW of renewable energy capacity by 2022, which includes 100 GW from solar and 60 GW from wind (10 GW from bio-power and 5 GW from small hydro-power).
- If this target is achieved by 2022, the share of wind and solar could exceed 15-16%.
Renewable energy challenges
Renewable energy has three inherent challenges,
- It relies on intermittent sources, producing energy only when the sun is shining or wind is blowing.
- Its output is constrained to specific hours of the day.
- Its use leads to lower utilization of transmission lines.
- This can create issues in matching peak power demand with renewable output (e.g. in evening hours when solar energy is not available), and raise costs of transmission.
- Experience in countries which have achieved renewable energy penetration of over 15% indicates that other flexible energy resources (such as hydro or gas-based power) should be used along with solar/wind power.
What is Renewable Hybrid energy system?
- A hybrid energy system usually consists of two or more renewable energy sources used together to provide increased system efficiency as well as greater balance in energy supply
- A hybrid system can combine wind, solar with an additional resource of generation or storage.
Example of Renewable Hybrid energy system
- In India, solar output is maximum between 11am and 3pm, while wind output is highest in late evening and early morning.
- Peak demand for power is reached in the evening hours of 6-9pm, which cannot be catered to by either wind or solar.
- Hence, if one can store some energy during excess renewable generation hours and release it into the grid during peak demand hours, the combined hybrid system can produce 24×7 clean energy in response to varying levels of demand through the day.
- The storage can take many forms, such as batteries, pumped hydro or mechanical storage through flywheels.
- The intermittency of wind and solar could also be balanced by adding a fast ramping source of power (such as an open cycle gas turbine).
- The overall output of the hybrid system can thus be matched against a required load on an hourly basis. In this way, it can provide both baseload (minimum power) and flexible power (both peak power and low power requirements).
Future of Hybrid System
- Hybrid systems are expected to become increasingly cost competitive, driven by reducing costs of battery storage and solar energy.
- An optimal combination of solar, wind and storage can deliver stable 24 X 7 power even at today’s costs of around ₹6-7/kWh.
- This cost is significantly higher compared to coal plants. However, lithium-ion battery (used in Hybrid systems) costs are expected to fall.
- Similarly, costs of solar energy have decreased from ₹4.63/kWh in 2016 to ₹2.50/kWh and may fall as low as ₹2/kWh in the next 3-5 years.
- If economics of hybrid systems approaches the suitable levels, they can potentially be competitive with 30-40% of existing coal-fired stations in India.
- They can therefore become a viable solution to meeting future baseload power requirements, all at zero carbon emissions and future cost-inflation proof.
- Moreover, more than 50 hybrid projects have already been announced/under construction globally, with Australia and US being the leaders.
Solar-wind hybrid policy
- India’s ministry of new and renewable energy released a solar-wind hybrid policy in 2018.
- It provides a framework to promote grid-connected hybrid energy through set-ups that would use land and transmission infrastructure and manage the variability of renewable resources to some extent.
- As per the policy, a wind-solar plant is recognized as hybrid plant if the rated power capacity of one resource is at least 25% of the rated power capacity of other resource.
- Renewable hybrids can play a key role in helping India accelerate the decarbonisation of power generation and lowering the cost of electricity in the medium term.
- However, there is need to ponder between building new coal-fired plants and renewable hybrids.
- There is also need to think on how should investors, who are evaluating existing stressed coal-fired assets, put a value on them 5-7 years ahead.
- Most importantly, what policy and regulatory changes need to be made so that India can fully capture the potential of Hybrid energy should be the main focus of energy policies.