The Solar energy Corporation of India (SECI) is organizing a stakeholder meeting to discuss the need to generate flexible and firm renewable energy with high plant load factor (PLF). The appropriate options and solutions suggested would be used in SECI’s future bidding methodology .

SECI has stressed that the three characteristics are essential to be built into projects to keep the future renewable energy capacity additions on track.  The consultation meeting is scheduled to take place on June 22, 2020, and it will be open to all the stakeholders, including distribution companies (DISCOMs), developers, organizations, and other government agencies.

Renewable energy has slowly become one of the main sources of electricity, like other conventional sources. Initially, the issues with the integration of renewable power with the grid were minimal, but now as the share of renewable energy in the power mix is increasing rapidly, various grid-related issues need to be addressed quickly.

The share of renewable energy (including large hydro) in India’s overall installed power capacity mix rose marginally to 36.2% at the end of the first quarter of 2020, from 35.9% at the end of the calendar year (CY) 2019, according to the data from the Central Energy Authority (CEA), and the Ministry of New and Renewable Energy (MNRE).

The consultation paper notes that currently, the PLF numbers for renewable energy projects are 20-25% for solar, 30-38% for wind, and 40-45% for solar-wind hybrid projects. The paper states that the PLF can be improved above 60% for the wind-solar hybrid projects by using energy storage systems.

Regarding the firmness of renewable energy projects, the paper states that given the must-run status of renewable energy projects, the DISCOMs must absorb the energy generated by wind or solar projects. Now, as the share of renewable energy in India’s power mix grows, it has become imperative to take care of the fluctuation in renewable power generation, which might pose a serious threat to the grid to absorb such infirm power. Along with this, the scheduling of this fluctuating renewable power will make it harder for the DISCOMs and generating companies to schedule power.

Several steps can be taken for the integration of renewable energy into the grid. The steps include energy storage capabilities in the grid network, scheduled curtailments, smart grids with micro storage networks, and adding the gas power projects into the grid network.

According to the paper, deploying energy storage at the grid level will add additional cost to the transmission network and thereby increase the cost of transmission of power. Already, the cost of transmission for renewables is expensive due to the poor utilization of the network because of low PLF.

Another solution for providing firmness is the hybridization of gas power projects, but it will not improve the PLF of renewable projects. The development of solar projects with storage is an ideal solution toward making the renewable power firm and also to improve the PLF.

Regarding flexibility in generation, the paper states that the electricity load today is dynamic, and it requires a certain amount of flexibility in the generation. Adding sufficient energy storage in the projects will address the concerns of the DISCOMs regarding the flexibility of renewable energy. To begin with, the flexibility of 20-30% is proposed, wherein the DISCOMs can schedule the power requirement between 70-100% of the contracted capacity of the project.

According to Mercom’s India Solar Project Tracker, SECI has overall tendered 3.6 GW capacity of solar-wind hybrid projects under the ISTS program (Tranche I to Tranche III) and auctioned 1.56 GW under Tranche I & II.

The paper further notes that to address the requirements of high PLF, firmness, and flexibility in renewable power, the solution is to develop solar-wind hybrid power projects with energy storage. Solar power is generally stable throughout the year, except for overcast conditions. The value of PLF greater than 60% can be achieved by adding 2.5-3.3 times of DC capacity with around 3 to 4 times of storage capacity with innovative mounting structure combinations.

The storage requirements can be reduced by appropriately adding wind capacity into the system. The wind power generation profile is different at different sites in India, and it can vary during various months in the year. As the solar generation is quite stable during these lean seasons of wind, the output requirements can be easily met. Therefore, by employing wind capacity in the solar project, the tariff can be reduced. All these combinations provide a firm output of about 12-16 hours in a day with the flexibility of around 20-30% of the output to provide flexibility to the DISCOMs.

Earlier, SECI announced the winner of its tender for 400 MW of renewable power on a round-the-clock basis. ReNew Power won the auction for the entire tendered capacity of 400 MW with a quoted tariff of ₹2.90 (~$0.038)/kWh. Under this tender, solar, wind, and hybrid projects can be developed. Moreover, the renewable power installations can be further augmented with necessary energy storage systems as per the developer’s requirements to meet the criteria of supply of power during the peak hours.

Recently, Mercom reported that according to a report published by the Lawrence Berkeley National Laboratory (LBNL), a large number of energy storage projects are being built worldwide, and there is a significant interest among policymakers in India as well. The report states that the sharp decline in the prices of lithium-ion batteries is going to transform how electricity from renewable sources is integrated into the grid.