7 PM | Renewable hybrid energy systems as a game changer | 20th August, 2019

Context: Significance of Renewable hybrid energy system in India

• Off grid renewable energy technologies satisfy energy demand directly and avoid the need for long distribution infrastructures. A combination of different but complementary energy generation systems based on renewable energies or mixed (RES- with a backup of Liquefied Petroleum Gas (LPG)1/ diesel/gasoline genset), is known as a hybrid power system (“hybrid system”).
• Environmentally friendly power generation technologies will play an important role in future power supply. The renewable energy technologies include power generation from renewable energy sources, such as wind, PV(photovoltaic), MH(micro hydro), biomass, ocean wave, geothermal and tides.
• Since the RE resources are intermittent in nature therefore, hybrid combinations of two or more power generation technologies, along with storage can improve system performance.

Challenges facing by renewable energy:

• 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.
• While the cost of renewables has fallen significantly in the past few years, a major issue with renewables such as solar and wind energy is their intermittency in nature.
• Solar and wind power are not as easy to control as traditional fossil fuel plants, so power grids need to become flexible enough to handle last-minute changes in power generation.
• Distance is also an issue. In India, six states in the western and southern regions account for 80 percent of all of the country’s currently installed solar capacity, but only 38 percent of power demand.
• Renewable Energy as deployed today helps meet an energy need (kWh), but doesn’t help meet the peak by contributing capacity (kW) at the right time, which is India’s main challenge.
• Rooftop solar is far, far behind schedule to meet the 40GW goal. While small deployments naturally cost more than grid-scale farms, we have to dig deeper into who would install such systems.

Need for the renewable hybrid energy system:

• Limitations: Hybrid systems can address limitations in terms of fuel flexibility, efficiency, reliability, emissions and / or economics.
• Efficiency:Incorporating heat, power, and highly efficient devices (fuel cells, advanced materials, cooling systems, etc.) can increase overall efficiency.
• Conservation:conserve energy for a hybrid system when compared with individual technologies. 3/4^th achieving higher reliability can be accomplished with redundant technologies and/or energy storage.
• Maximization: Some hybrid systems typically include both, which can simultaneously improve the quality and availability of power. Hybrid systems can be designed to maximize the use of renewable. Resulting in a system with lower emissions than traditional fossil-fueled technologies.
• Complement: Solar and wind power being variable in nature pose certain challenges on grid security and stability. Studies revealed that in India solar and wind resources are complementary to each other and hybridization of these two technologies would help in minimizing the variability apart from optimally utilizing the infrastructure including land and transmission system
• Rapid depletion of fossil fuels has necessitated an urgent need for alternative sources of energy to cater the continuously increasing energy demand. Another key reason to reduce our consumption of fossil fuels is the growing global warming phenomena.
• Potential:Hybrid systems capture the best features of each energy resource and can provide “grid-quality” electricity, with a power range between 1 kilo watts (kW) to several hundred kilo watts.
• They can be developed as new integrated designs within small electricity distribution systems (mini-grids) and can also be retrofitted in diesel based power systems.
• Hybrid systems can provide a steady community-level electricity service, such as village electrification, offering also the possibility to be upgraded through grid connection in the future.
• Furthermore, due to their high levels of efficiency, reliability and long term performance, these systems can also be used as an effective backup solution to the public grid in case of blackouts or weak grids, and for professional energy solutions, such as telecommunication stations or emergency rooms at hospitals.

National wind-solar hybrid policy measures 2018:

• Hybridization of existing wind/solar PV plants: No additional connectivity/transmission capacity charges shall be levied by the respective transmission entity for hybridization at existing wind/solar PV plants if already granted transmission connectivity/ access is being used.
• Battery storage: may be added to the hybrid project
  • to reduce the variability of output power from wind solar hybrid plant
  • providing higher energy output for a given capacity (bid/ sanctioned capacity) at delivery point, by installing additional capacity of wind and solar power in a wind solar hybrid plant
  • Ensuring availability of firm power for a particular period.
• Regulatory requirements: The Central Electricity Authority and CERC shall formulate necessary standards and regulations including metering methodology and standards, forecasting and scheduling regulations, REC mechanism, grant of connectivity and sharing of transmission lines, etc. for wind-solar hybrid systems
• Quality: For wind turbines, solar modules and balance of systems, the technical guidelines issued by the Ministry from time to time for grid connected systems will be followed.

Way forward:

• Reaching the non electrified rural population is currently not possible through the extension of the grid, since the connection is neither economically feasible, nor encouraged by the main actors.
• Renewable energy sources are currently one of the most, if not the only, suitable option to supply electricity in fragmented areas or at certain distances from the grid.
• Hybrid systems have proved to be the best option to deliver “high quality” community energy services to rural areas at the lowest economic cost, and with maximum social and environmental benefits.

Source: https://www.livemint.com/opinion/online-views/opinion-renewable-hybrid-energy-systems-as-a-game-changer-1566235207654.html.