As the world grapples with the challenges of climate change, energy security, and sustainability, one technology has been quietly serving as a stalwart ally: pumped hydro storage (PHS). This tried-and-true method of storing excess energy has been around for over a century, but its potential to support a 100% renewable energy grid has never been more pressing.
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Pumped hydro storage works by pumping water from a lower reservoir to an upper reservoir during off-peak hours when energy demand is low. When energy demand spikes, the water is released back down to the lower reservoir, generating electricity through hydroelectric turbines. It’s a simple yet elegant solution that has been used in countries around the world, from Norway to Australia, and everywhere in between.
One of the key benefits of PHS is its scalability. Unlike other forms of energy storage, such as batteries, PHS can be built in massive sizes, making it ideal for large-scale power grids. In fact, the world’s largest PHS plant, the Ludington Pumped Storage Plant in Michigan, USA, has a capacity of 2,172 megawatts (MW) – enough to power over 1.5 million homes.
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But PHS is not just a relic of the past; it’s also a crucial component of a low-carbon future. As renewable energy sources like wind and solar become increasingly dominant, PHS can help stabilize the grid by providing a reliable source of backup power. And because PHS can be built in conjunction with existing hydroelectric dams, it can also help to extend the lifespan of these critical infrastructure assets.
Despite its many benefits, PHS has faced challenges from competitors like lithium-ion batteries, which have gained popularity in recent years. However, PHS has some key advantages that make it well-suited to play a major role in the energy transition. For one, it’s significantly cheaper than batteries, with costs ranging from $200 to $500 per kilowatt-hour (kWh) compared to $300 to $600 per kWh for batteries. Additionally, PHS can provide energy storage for periods of up to several days, far outlasting the capabilities of most batteries.
As countries and companies around the world set ambitious targets to achieve 100% renewable energy, PHS is poised to play a critical role in making those goals a reality. Whether it’s supporting the growth of wind and solar, or providing a reliable source of backup power, PHS is the unsung hero of the energy landscape.
In the end, PHS is more than just a technology – it’s a testament to human ingenuity and our ability to harness the power of nature to create a more sustainable future. As we look to the years ahead, it’s clear that pumped hydro storage will continue to be a vital part of the energy mix, providing a reliable, renewable, and cost-effective way to power our homes, our businesses, and our communities.
