Most efficient solar energy dish in the world uses engine developed in 1816

By Matthew Humphries May. 13, 2015 http://www.geek.com/science/most-efficient-solar-energy-dish-in-the-world-uses-engine-developed-in-1816-1622697/

Swedish company Ripasso Energy has created a new, state-of-the-art solar energy dish, which it believes is the most efficient in the world. One of the key elements of Ripasso’s system is an engine originally thought up nearly 200 years ago in 1816.

Ripasso’s CSP system works by combining a parabolic mirror with a Stirling engine. The 12 meter diameter mirror dish looks like a typical satellite dish, but its job is to focus the sun’s energy on a “tiny hot point” that then drives the Stirling engine.

Unlike other, similar systems, Ripasso’s uses no water to produce electricity. The Stirling engine is a closed-cycle regenerative heat engine that uses an enclosed gas to drive pistons and turn a flywheel. The large dish constantly turns to ensure optimal solar energy capture from the sun, the hot point powers the Stirling engine, and electricity is produced.

As for efficiency, it easily outperforms the photovoltaic panels in use today. Those panels typically convert 23% of the sun’s energy to electricity, however, making that usable on the grid means efficiency drops to just 15%. The Ripasso CSP system converts 34% of the sun’s energy to grid-ready electricity. Each dish can produce 85 megawatt hours of electricity every year, enough to power 24 homes for the same period of time.

That impressive efficiency combined with no water being required already makes Ripasso’s system highly desirable and usable in some of the hottest (and remotest) parts of the world. CEO Gunnar Larsson has been working on the system since 2008 when he licensed the tech from the Swedish defense industry (they use the engine in submarines). Now with private funding and working dishes, it shouldn’t be long before the CSP system has its first commercial installation.