November 16, 2011 source: the Gates Notes
Bill Gates has posted a really good writeup on energy storage and the innovative company Energy Cache on his blog, Taking Energy Storage to a Higher Level. Energy Cache is a recent early-stage investment of Claremont Creek Ventures and we're excited about its new approach to storing electricity that could help lower the cost of clean, renewable energy for everyone. Stay tuned, there's a lot more to come from this company!
How does it work?
It's related to the very old idea of pumping water for storage in natural ponds and pools. It's also related to hydropower – generating electricity from the force of falling water – but on a smaller scale that doesn't raise the siting and environmental issues associated with new hydroelectric dams. The economic model doesn't require a huge amount of space or flooding a valley.
When the weather is windy or sunny, the Energy Cache system uses surplus wind or solar power to move heavy material to a higher elevation. When the power is needed, stored material is released to generate it. Simple as that, although there are still a lot of details to be worked out.
This system could help improve the economics of alternative energy, making it a more reliable supplement to fluctuating and peak energy needs. In the developing world, where many remote communities are disconnected from the energy grid, or where the grid is subject to frequent outages, Energy Cache could be a way of creating an affordable, efficient local energy storage solution.
The company has built a prototype that shows it can likely beat the economics of traditional pumped-water storage. It has patented the methodology and is building a full-scale system at a test location.
Read the full article and see the slideshow at thegatesnotes.com