Storage start-up Energy Vault has secured $110m of funding from Japanese corporate giant SoftBank, reflecting soaring interest in technology designed to overcome the variability hurdles to mass deployment of wind and solar.

Switzerland-based Energy Vault claims its technology, based around ‘storage towers’ of custom-designed bricks, replicates the gravity-based approach of large-scale pumped-hydro storage, but at lower cost and without the need for water or particular topographies. Instead of water, the 35-ton composite bricks are hauled upwards by crane to store energy and released for discharge, controlled by custom-designed software.

Energy Vault – which plans to demonstrate its first 35MWh storage tower in Italy this year – secured the funding in a Series B round from SoftBank Vision Fund. Energy Vault already has partnerships in place with construction specialist CEMEX and India’s Tata Power.

Energy Vault solves a long-standing and complex problem of how to store renewable energy at scale,” said Akshay Naheta, managing partner for SoftBank Investment Advisers. “The company’s integration of proven technologies with 21st century material science and machine vision software provides a solution that reshapes the unit economics of renewable energy while being restorative to the environment.”

Energy Vault is far from the only storage innovator pursuing its “mission to enable renewable energy to replace fossil fuels 24 hours a day” by cost-effectively storing variable wind and solar output for release when needed.

In the past few weeks Recharge has reported how Google spin-off and molten-salt specialist Malta has attracted a raft of billionaire investors.

Highview, with its liquid-air cryogenic energy storage, already has commercial projects in the pipeline; Siemens Gamesa has built its hot-rock thermal-storage commercial pilot project, and is expecting to offer the technology commercially in 2021; while wind pioneer Henrik Stiesdal is due to begin operation of a 1MW/24MWh hot-rock commercial pilot next year, with a view to commercialising the system within the next two years.