The variations in wind and solar energy, and the lack of adequate electricity storage facilities, result in about 15-20 per cent of all renewable energy generated in India going to waste, according to a top official in Panasonic India’s energy division.

“On average, if 24 hours is the potential of electricity generation, then you can easily say that 15-20 per cent is wasted because the grid can’t manage the kind of variation in the electricity sourced from wind and solar generation,” Atul Arya, Head, Energy Systems, Panasonic India told The Hindu in an interview.

The variability of generation from renewable sources—where wind changes direction and speed on an hourly basis and solar intensity can vary by the minute—is not that big a problem if renewable energy forms a small proportion of the overall grid, as it does currently in the national grid, Mr Arya said.

“But if you look at state-specific grids, then the picture changes,” he added. “For example, look at the Tamil Nadu grid. Percentage-wise, wind is pretty high in the Tamil Nadu grid and that is what is creating problems for them. With wind changing its speed and direction, it becomes horrible from a grid stability point of view.”

Discarding Power

The typical strategy in India at the moment, Mr Arya said, is to simply discard the unstable power without it ever entering the grid.

“So you are generating but not using it in the grid,” he said. “It gets wasted. Electricity is something you either use immediately, or you cannot use it at all.”

That’s where storage technology comes in.

Storage technology can ensure that no matter the wind or solar generation, what you get out of the generation-cum-storage unit is a uniform output, “which is great for the grid”, according to Mr Arya.

As far as battery technology goes, lithium-ion batteries—the kind used in cellphones—have emerged as the technology of choice since they outperform all the other competing technologies in terms of size, capacity, efficiency, and environmental impact.

“Lithium-ion does not seem to be going anywhere in the next decade,” Mr Arya said. “And if you include the fact that even electric cars use that battery, then you can expect greater R&D and investment in this technology in the future.”

Sector Incentives

The Central government has been pushing renewable energy hard since it came to power, but there it is still moving relatively slowly on storage technologies, something that a few policy decisions could rectify, according to Mr Arya.

“There is an amount of realisation in the government and the ministries in understanding the subject, but yes, it is quite new,” he said. “Maybe it will still take some time (for government policy to gain traction).”

Apart from announcing tax incentives for storage technology manufacturing, such as is being done for the IT sector, other steps like viability-gap funding can also boost the sector.

“The government currently only recognises gas-based plants as the service providers to boost generation whenever it falls short of demand,” Mr Arya said. “But it doesn’t recognise energy storage for this purpose, something that is already happening in the western world.”