New innovations of old technologies: Renewable energy storage systems
- Innovative companies are redesigning energy storage technologies for a more sustainable grid.
- Investment in long duration energy storage (LDES) is key to developing renewable energy.
- In the race for renewable energy storage systems, startups mustn’t overlook the high-value potential of upgrading existing technologies like pumped hydro.
While there’s been a proliferation of energy storage innovations, two of the most common systems have demonstrated their energy capacities over the years: pumped hydropower and electrochemical batteries. Now, these two stalwarts are getting upgrades.
Enel wants to take a deep dive into the new innovations of old technologies to show that innovation doesn’t always mean reinventing the wheel. Startups can improve existing technologies to meet the needs of a sustainable future.
Why is it important to invest in renewable energy storage?
It often costs more to store energy than it does to produce it. So, even though renewable sources like solar and wind are cheaper than coal and gas, they are more expensive to store than fossil fuels. Moreover, renewable energy sources tend to fluctuate – while you can burn coal whenever you want, you can’t control when the sun shines or the wind blows. Cheap, efficient and renewable storage is imperative.
Long-duration energy storage (LDES), a system that can store energy for more than 4-8 hours, is crucial to developing a grid that can run off intermittent renewable energy sources. This is important for the environment and for investment. A study by McKinsey estimates that by 2040, LDES deployment could result in a decrease of 1.5 to 2.3 gigatons of CO2 equivalent per year, or around 10 to 15 percent of today’s power sector emissions. In the United States alone, LDES could reduce the overall cost of achieving a fully decarbonized power system by around $35 billion annually by 2040.
The race is on for developing innovative energy storage systems, and there’s no shortage of contenders, including flywheel, thermal energy, compressed air, and mechanical systems, to name a few. The problem is that none of these technologies check all the boxes: low cost, scalable, and energy efficient.
While some companies are searching for new ways to store energy sustainably, others are looking for ways to improve existing technologies. Two technologies – pumped hydro and electrochemical batteries – have already proved their energy-storage capacities. Now, it’s time to make them even better.
Renewable energy storage #1: Pumped hydro
Pumped hydro storage is truly the unsung hero of LDES. In 2021, pumped hydro storage accounted for 96% of global storage power capacity and 99% of global storage energy volume. This is only expected to increase. According to the IAE, pumped hydro storage will account for more than half of new hydropower capacity additions in Europe by 2025, which will play a critical role in decarbonizing the power system and plugging gaps in energy demand.
While pumped hydro storage may seem like a ground-breaking technology, these systems have been around since the 1980s. This technology relies on two reservoirs at different elevations. After water is pumped from the lower reservoir to the higher reservoir, it then flows back down to the lower reservoir, spinning turbines to generate electricity.
Pumped hydro storage is so popular because it’s large scale, cost effective, and sustainable. However, it also has some downsides. First of all, it isn’t a completely efficient system: only about 80% of energy is regained from when it is pumped up to when it is released. Second, there are geographic complications. Pumped hydro storage systems are typically built in or near rivers, and sometimes seas, meaning that not all locations are suitable. When they are, they are often expensive and difficult to build. It’s hard to imagine a pumped hydro system with sprawling lakes in urban settings like New York City or Rome. Startups that innovate ways to overcome these scalability and accessibility challenges will gain a competitive edge in the marketplace.