Affordable storage technologies key to bringing solar energy to scale in India

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This challenge has often been overshadowed by the other issue of pending dues to the state-owned distribution companies. But it does merit a much deeper focus, given the variable generation from renewable sources; the need for continual energy access in India’s far flung, off-grid areas; maintaining grid stability by matching demand and generation; and the lack of battery-related mineral resources in India.

The Energy Storage System Roadmap for India report estimates storage requirements for solar to rise over 3-fold from ~50 MWh in 2019 to ~175 MWh by 2022. With the country reaching only halfway in its target of 175 GW of renewable energy capacity by 2022 (which includes 100 GW of solar), storage solutions will hold the key to bringing solar energy to scale.

Storage-plus-solar options are inevitable for several segments. In off-grid or mini-grid systems, they can ensure round-the-clock power access. For e-vehicles, affordable and indigenous batteries can reduce the battery cost from the current ~50%+ of the car’s price, thus creating the needed traction in India’s e-vehicle sales.

Rooftop solar that otherwise faces an issue of varying net metering policies across Indian provinces, would benefit from storage as it would allow rooftop users to consume more of the power generated, while placing more solar systems on the grid without having to spend to expand it.

Further, it would not only help consumers avoid the high tariff of peak hours, which in India is in the evening when solar is not generated, but would also help better demand-side management. Grid-scale energy storage would improve the management of distribution networks, reducing grid congestion, voltage variations, costs and improving grid balancing, efficiencies and energy security.

Recent years have seen efforts to build India’s battery storage capacity. The 2019 National Mission on Transformative Mobility and Battery Storage includes phased manufacturing programs focusing on battery factories and e-vehicle manufacturing. Recent announcements include XNRGI USA’s 240 MWh lithium-ion battery factory in Haryana for rickshaws, e-bikes, etc.; Tecchren USA’s 200 MWh lithium ion battery plant and Ojovati Singapore’s lithium-ion battery plant in Andhra Pradesh; Phinergy Israel’s partnership with IOCLfor field-trials of its metal-air batteries for e-vehicles; Ather Energy’s MoU to set up a lithium-ion battery factory in Tamil Nadu; and Urja Global’s MoU to make lithium-ion batteries in Andhra Pradesh.

Three pronged challenge

While lithium-ion batteries became popular owing to their lightweight, compactness and a better charge-discharge efficiency, a three-pronged challenge plagues domestic manufacturing in India. Matching the price to the imported versions, especially those from China which benefit from its major subsidy programs, is one. Another is that the availability of two key minerals used in lithium-ion batteries is highly concentrated – lithium in Chile, Bolivia and Argentina and cobalt in the D.R. Congo. That implies India would still face a sizable import bill, just like it does under fossil fuel energy production. Last, R&D into alternative technologies are yet to pick up in a big way in India, not to mention the constraints related to technology-transfer it raises.

Nevertheless, India is making initial forays into alternative technologies. Pune-based Indian Institute of Science Education and Research and SPEL Technologies are co-developing a technology to generate functionalized graphene at lower costs, which would develop graphene supercapacitors (supercapacitors are electrical devices that store electrical charge).

Chennai-based Elicius Energy provides resources to companies using storage technologies, such as hydrogen fuel cells. These fuel cells offer clean power as well as an increase in the power density at lower upfront costs. Tata Power is pilot testing a 35MWh gravity storage installation with Energy Vault of Switzerland. Gravity storage elevates a mass while charging/storing energy and lowers it while discharging/using that stored energy. But a question remains regarding their affordability.

R&D partnerships

At the same time, the country should deepen R&D partnerships for alternative technologies. Last year, it did enter an agreement with China for cooperation in R&D to develop new technologies for solar cells from alternate materials. But much more is needed given India’s targets. For instance, Canadian researchers are working on green energy storage by developing a catalyst by combining non-toxic metals in an amorphous structure. Electrolyzers use this to convert electricity from renewable to chemical energy by splitting water to hydrogen and oxygen. The chemical fuels can be stored and converted to electricity.

SwitchDin of Australia enables virtual power plants and microgrids by integrating different brands of batteries and inverters in the market, thus leading to better monitoring and site management. Sodium technologies like saltwater batteries are coming into focus as they do not contain heavy metals and are easily recycled. In short, ramping up further R&D capabilities is the first step to develop affordable and efficient indigenous batteries.

Declining prices of battery systems globally (from US$1,000/kWh in 2010 to $230/kWh in 2016, as per a McKinsey study) along with falling solar tariffs, makes it an opportune time to scale up investments in battery technologies. The push towards e-vehicles in India, at least for urban public transport and government procurements, augurs well towards this goal. The reduction of feed-in-tariffs or net metering payments in India is another tailwind.

India must capitalize on this combination of tailwinds and opportune timing to develop affordable battery storage capabilities and achieve, at least to the best extent possible, its solar target of 100 GW by 2022.

The views and opinions expressed in this article are the author’s own, and do not necessarily reflect those held by pv magazine.