The recent call by our honorable prime minister for a 9-minute light blackout to be observed by all households brought about a lot of conversation on grid stability for the request. What it made people realize is how low flexibility we have in our current transmission and distribution infrastructure to accommodate such small requests and the lengths the authorities have to go through to maintain the stability of the energy infrastructure. To understand the basics, one needs to go back to the first principle of energy that can neither be created nor be destroyed; it can only be converted from one form to another. Our Energy supply chain can broadly be classified into three blocks- Generation, Grid (Transmission & Distribution), and lastly Consumption. What it means is any energy produced by generating stations will either have to be consumed or stored. In the current state, since the grid has almost nill storage, the only option it has is to match instantaneous demand with generation. So what it needs to do is predict energy consumption and try and match production with the same. In particular, it asks the load following generation sources to match its variable demand. Any mismatch will bring about anomalies in the power quality, which has the potential of harming the load appliances to damaging the grid infrastructure itself. India’s power sector has to date concentrated on power availability as a metric for growth. Power quality has always taken a backseat. Authorities and relevant stakeholders have to date failed to recognize the loss due to poor power quality, and consumers have looked for a way around for a solution.
Now we live in a time when there is a significant transition going on both Generation and Consumption fronts driven by efforts to decarbonize the energy value chain. In Consumption, With the increased penetration of Electric vehicles, we will see a significant change in consumption patterns along with the need to increase the capacity. In contrast, we already see increased penetration of non-load following renewable sources in our power mix along with a push for distributed generation. It will create significant pressure on matching the supply and demand on the grid. Technology solutions, like demand-side management, will be challenging to implement in the Indian context. So the already difficult situation is going to become more difficult, and hence to increase system flexibility and enabling this matching, developing storage options are need of the hour.
It makes commercial sense as well to develop storage projects. Let’s look at a few key parameters, India’s overall generation capacity stands at approximately 367 GW, the majority of which at this point is from thermal (62.7%). Our peak demand for the financial year 2019-20 was 183.8 GW growing at a rate of 4% every year; this means we will be adding close to 7 GW every year going forward, and this number should increase due to electrification of mobility. Now consider this that we were able to produce 182.5 GW representing a deficit of ~ 1.3 GW. So from an installed capacity of 367 GW due to various technical, commercial, and regulatory constraints, we were able to produce a maximum of 182.5 GW at any point in time. This increase in peak demand can be met using two options a) by increasing generation capacity or b) develop storage options to meet this increased load. The overall plant load factor of thermal plants for the same period stands at 56.4% down from 61% of last year. We are not utilizing our generation capacity to the fullest. Adding new generating capacity will put further downward pressure on the PFL. Considering the high fixed cost of setting and managing the plant, adding to generation capacity will be an unwise choice both commercially and technically.
The advancements in battery-based storage technologies have brought about modularity in storage options. The large size and favorable geography is no longer a necessity like with older non-battery based technologies (Hydro and CAES). We should be looking to develop distributed storage options, which can make our system more robust. Initially, targetting areas like industrial centers where consumers will be ready to pay a premium for enhanced power quality will make the returns for early investors more attractive. It will also take time for utilities to upgrade their software and hardware to learn to integrate these systems with their current support systems. A comprehensive policy push along with the transparent business model, is required to invite private investment in these projects. As the cost for these technologies is poised for sharp reduction, energy storage will not remain a technology or a cost problem.