Wind-Solar Hybrid: A Perfect Balancing Act For 24 Hours
Coupling wind and solar could ensure round the clock supply stability
Wind-Solar Hybrid A Preamble
My first visit to a wind turbine site was in 1998 on a hill range top. It was spanned about 21 km in the southern part of Maharashtra in India. I can recall, that time we use to discuss often the possibility of alternate use of the vacant lands kept in between the wind turbine towers in order to maintain appropriate spacing.
During that period, in India nobody was even thinking of standalone solar energy parks, therefore it was difficult to find out any alternative use of those vacant lands on a mass scale.
Though I believe due to cloudy and foggy weather condition of that particular site across six months in a year, that wouldn’t have been a suitable site for solar energy, whereas other many wind parks situated in deserts, barren lands, hilltops, and seashores across India can have a good potential for solar as well.
Commercial-scale harnessing Solar energy started in India at the end of 2009 and till 2018 both wind and solar were maintaining their existence separately under the umbrella of Renewable Energy.
What Is Hybrid Renewable Energy
So, the answer to our casual discussions during 1998 came into a reality in 2016, when a draft for ‘National Wind-Solar Hybrid Policy’ was released by the MNRE (Ministry of New & Renewable Energy), and following that in 2018, the final policy was announced.
This had opened up the door to make a common wind-solar park utilizing the maximum of available lands, infrastructures, and other resources, consequently gaining an edge in the capital investment and pricing front.
Wind-solar combination at the same location can make the most efficient utilization of available land and grid integration infrastructures. It can better the generation profile also and when the battery energy storage system (BESS) is added, it can supply a very well-balanced grid-level supply round the clock.
However, battery storage is not feasible at this moment due to cost factor, will take a couple of more years of technological development to come to commercial competitive status.
Now, even without BESS, the wind-solar hybrid is well capable to supply an uninterrupted energy supply to the grid. This hybrid can potentially play a major role in the country’s ”next wave of renewables growth.”
A report by IEEFA (Institute of Energy Economics and Financial Analysis) & JMK Research narrates that wind-solar hybrid has the potential to grow rapidly in India and expected to produce around 11.7 GW by the end of 2023.
Who Are The Hybrid Pioneers In The world
This hybrid concept for grid supply was launched in the NSW Southern Tablelands, Australia in 2018, and western Minnesota, the USA in the year2019.
At this moment more than 50 wind-solar hybrid projects of MW scale are in the pipeline around the world. Some of them are either in operation or under construction and some are at an initial stage.
India’s First wind-solar hybrid project was a group captive project launched by an IPP (Hero Future Energies) in April 2018 only. It was situated in the State of Karnataka and was a combination of 50MW of wind and 28.8 MW of solar.
When Did Hybrid started In India And Present Status
December 2018, SECI (Solar Energy Corporation of India) launched India’s first-ever wind-solar hybrid auction, and with that country’s grid supply hybrid projects gained momentum.
Though SECI had invited tender for 2.5MW initially, later it was reduced to 1.2MW but then also, it remained undersubscribed by 150 MW. Subscription received only for 1,050 MW. Looking at the response SECI had finally decided to auction 80% of the bid capacity i.e. 840MW.
In 2019 SECI launched a further auction for a 1.2 GW wind-solar hybrid project and the third auction of 1.2 GW was floated in January 2020. Both were received lukewarm responses.
According to Mercom India’(clean energy news and insight company), SECI so far had tendered a total of 4.9 GW of wind-solar hybrid projects out of which 1.56 GW had been auctioned.
Actually from 2017 to 2020 was a period of inactivity in Indian renewable energy space because of many reasons. Now that bouncing back is expected, state-promoted hybrid energy projects are attracting investors.
Moreover, the hybrid energy system has drawn the interest of some private developers like CleanMax and Continuum Wind Energy, they have now started putting up hybrid parks for third-party sale/open access model for corporate consumers.
Why Hybrid Element Is Extremely Pertinent To India’s RE Sector
The government of India is considering it as a game-changer. Wind-solar- BESS(at a later stage) hybrid system would be a practical solution for the supply of balanced and stable grid-level renewable energy without the intermittence due to natural high and low of wind or solar.
India is a country, where sunshine is available in abundance throughout the year. All most all its windy sites are also located either in long coastal lines, deserts, barren lands or on hilltops, where plenty of sunshine is also available throughout the year.
Wind typically rises during the evening, goes to peak at night, and lasts till early morning. So, a combination of wind and solar can be complementary to each other in 24 hrs. cycle time.
Another focus area is India’s commitment to reduce carbon emissions. Currently, 75% of countries energy requirement is being supplied by burning fossil fuel. After China and the US, India is the third-highest emitter of CO2 in the world.
India's government is committed to expanding its renewable energy capacity from the present around 88 GW to 175 GW by the end of 2022 and to further expand it to 450 GW by 2030.
Wind-solar hybrid due to its inherent quality of nearly stable and uninterrupted grid-level supply could play a game-changing role to achieve these targets.
A hybrid balanced and stable renewable energy supply to the grid can reduce the intermittency problems, thus can reduce the dependency on conventional thermal power plants cutting the consumption of fossil fuel and consequent carbon emission.
The third factor is cost-efficiency. Wind-solar hybrid wind parks will use the same substations for grid integration, the same piece of land (more or less), and common other resources to run the park and that will reduce the investment and running cost to a considerable scale.
For rural India where the grid supply is not available, small clusters of the hybrid system can light up the life of villagers for twenty-four hours throughout the years, with the support of a small battery backup system.
What are the advantages?
Some of the advantages have already been discussed in the previous paragraphs. India no longer can depend solely on traditional thermal plants for its round-the-clock requirement of continuously increasing electricity demand.
Renewable energy is a cleaner and cheaper resource for electricity but with the disadvantage of intermittency. Wind usually is suitably available for power generation during the evening, pick up at night, and get reduced as the sun rises.
Solar plants on the other hand start working along with the sunlight, typically between 8 AM to 5 PM. So, naturally, both are complementary and when coupled through a technological system, can supply near stable and uninterrupted power supply for 24 hrs.
Hybrid also increases the PLF (plant load factor) of the system. When individually the PLF of wind is typically 28% and PLF of solar is typically 18.7%, a hybrid wind-solar system can raise the PLF to a level of 41.8% typically.
It also has cost efficiency. It is claimed that a hybrid co-located wind-solar system is around 8% cheaper than a standalone solar park. This benefit comes out due to shared infrastructure, shared data collection system, operation & maintenance facilities, asset management, and common point of interconnections.
A calculation shows that a hybrid wind-solar co-located park with 250MW capacity can derive sustainable cost efficiency. A split ratio of 20 (wind): 80 (solar) without battery backup can achieve a Levelized tariff around INR 2.49/KWh (UScent3.32/KWh). This is very attractive.
What is the future
Wind-solar hybrid is the next big thing in India in renewable energy space. The climatic condition of the country is well suited to wind-solar hybrid projects as India has plenty of exposer to sunshine in its vast wind-rich locations across the country.
India has a big target to add renewable energy into the national grid by 2030. That can be achieved by the way of maximizing the use of available land resources and improving generation. The hybrid system can be proved to be a boon in this respect.
Conventional thermal power plants in the country are getting old and continuously coming under stress to meet the increased demand for electricity for this developing vast population. The cost of production and maintenance of these plants is also increasing regularly and may go out of viability in the future.
On the other hand, the cost of wind and solar energy has dropped considerably. In comparison to the coal-based power plant, it has come down to a level where it is around 35% cheaper even in standalone mode, so would be more in a hybrid system.
Wind-solar hybrid parks on a big scale can potentially increase this benefit further, thus can help India to lower the cost of electricity generation and accelerating the country’s decarbonization program.
It is highly expected that the policy and regulatory environment in the country will also evolve in parallel to capitalize on the huge potential of the concept of the wind-solar hybrid system in the medium and long term.
