Pump up the energy:
GE is transforming intermittent energy on the grid

As the world becomes increasingly conscious of the need to use clean energy, it is producing more renewable energy than ever. Globally, renewables’ share in total energy capacity expansion was a whopping 82%1 in 2020. With more Renewable Energy (RE) being generated in India, the need for storage has also gone up manifolds. Installation of power generation capacity experienced a compound annual growth rate (CAGR) of 17.33% between 2016-20.2

Storage solutions range in size and cost, and Pumped Storage Power (PSP) is the solution preferred by 90%3 of the world’s RE producers. As India’s energy demand is expected to reach 15,820 Terawatt-Hour (TWh) by 20404, pumped hydro storage, being the most economical and advanced storage technology for long discharge duration, will play a significant role in accommodating the increased demand.

PSPs provide electricity in a snap

Let’s say millions of Indians are watching the Cricket World Cup final on TV. They all take a break at the same time after an innings gets over. They are getting cold drinks from refrigerators, heating the tandoori chicken they ordered and so on, skyrocketing electricity consumption.

Power plants need to react quickly to supply extra energy to the grid. PSP plants take very less time, about a minute or two, to start a turbine and reach maximum output. When the gates of a PSP plant open, water flows down from the upper reservoir to a lower reservoir, driving turbines that generate electricity.

Now, the second innings of our World Cup cricket match has begun. Fans are once again glued to their TV sets and no longer using their refrigerators, ovens etc. Any extra electricity supplied to the grid now could result in voltage overload and damage to equipment. A PSP plant can stop producing electricity in an instant in times of surplus energy. By closing its valves, the water flow from the upper reservoir stops, stopping power generation.

When wind and solar plants produce excess electricity, turbines reverse their operation to pump the water up to the higher reservoir, enabling the absorption of sudden drops in electricity demand.

GE’s technology and experience help organizations optimize their power projects. A world leader in pumped storage plant equipment, GE supplies in-house capabilities not only to turbines and generators but also to the rest of the electrical plant.

Excess RE used, not wasted

In conjunction with wind or solar, PSPs can generate more energy. When sunshine is at its peak, more solar power is produced than what RE farms can supply to the grid. A variable speed pump in a PSP can better utilize this excess power than a fixed speed pump.

For instance, if 150 MW solar power has been produced, a fixed speed pump system comprising four units of 100 MW each will not be able to use the additional 50 MW power – it can only work with power in 100 MW increments. However, a variable speed pump will channel the entire 150 MW power, using the excess 50 MW to operate in pump mode and send water up to the higher reservoir for storage.

PSPs increase Indian dams’ power generating capacity

PSPs require little land, making them suitable in India, where displacement of people is often an issue. India’s old dams can utilize excess energy better with a PSP. 

Although India’s tallest dam, the Tehri Dam in Uttarakhand, commenced operations in 2006, it is adding a PSP plant now. GE Renewable Energy’s Hydro Solutions has manufactured four 250 MW variable speed PSP units, which will add 1000 MW to the dam’s existing 2400 MW5 power generation capacity.

The Main Inlet Valves (MIVs), which cut off water flow in the PSP when needed, are over thirteen feet long. They are the largest spherical valves manufactured by the GE team. The valves weigh 350 tons, which is 1.5 times the weight of the Statue of Liberty.

The Tehri Dam is a major source of irrigation for the Rabi wheat crop grown in Uttar Pradesh and Uttarakhand. The dam also supplies drinking water to seven million people.

Another project, Kundah Power House in the Nilgiris, is one of the largest pumped storage electricity generating projects in Tamil Nadu. It is estimated to contribute 500 MW of electricity to the national grid by the end of 2023.6 Both the Tehri and Kundah projects use GE’s advanced pumped hydro storage technology to ensure a reliable power supply in all seasons.

Benefits galore

The benefits of GE’s pumped storage plant are many. Its large scale suits long discharge durations for daily or even weekly energy storage applications. It incurs low storage costs compared to other platforms, but its multi-functional capabilities of water management, irrigation control, water distribution and water waste control have more potential to meet diverse challenges.

With its ability to react to network fluctuations in milliseconds, GE’s current hydro storage technologies provide plant owners flexibility, reliability, availability, output and efficiency in equal measures. Renewable and sustainable, it has a lifecycle of more than 40 years for the electromechanical equipment and 100 years for the dam.   

Conclusion

PSPs give millions of people clean power when they want it, in a matter of seconds. Whether it’s a sports match, a heatwave or any other event making unexpected demands on the electricity grid, you can rely on PSPs to keep on your lights and screens.  

As India’s production of RE increases, it can rely on PSPs to best utilize excess energy by storing it. They can improve the country’s energy security and transition into a low cost, low carbon electricity system.