Flipping eggs in non-stick frying pans, my pacifist family taught me that ‘good-for-nothing’ war can, at times, actually be good for something: technological development. Teflon non-stick technology was first used in the Manhattan Project to make seals resistant to uranium hexaflouride and was regarded as a military secret. The Teflon trademark was registered in 1944 with the aim of post-war commercial use of the new product.
Destructive warfare for all its bloodshed and loss tends to accelerate technological development. Positively, in later peacetime, these military tools may evolve into non-military devices; such as radio antennae, Teflon, microwave ovens, even sanitary towels, canned food, affordable chocolate; and in this case - the world’s most efficient solar energy system. Announced as the world's most efficient solar electricity system, Ripasso Energy’s state-of-the-art solar energy dish is also a by-product of military technology.
A key element in Ripasso’s solar innovation is an engine invented nearly 200 years ago in 1816 by Reverend Robert Stirling in Edinburgh. Stirling engines (that use alternate heating and cooling of an enclosed gas to drive pistons, which then turn a flywheel) were not commercially developed until 1988, when Swedish defence contractor Kokums started making them for submarines. Ripasso’s CEO Gunnar Larsson worked in the Swedish defence industry for 20 years and realised what a clean and efficient generator could mean for renewable energy systems. He wanted to bring military technology from the ocean into the sunshine, so he resigned as CEO of Kokums and licensed the technology to start Ripasso.
Ripasso’s Concentrated Solar Power (CSP) system works by combining a parabolic mirror with a Stirling engine. The 12 meter diameter mirror dish looks like a satellite dish, but its job is to focus the sun’s energy on a tiny hot point which then drives the Stirling engine. Ripasso Energy has commissioned the first units of their CSP plant with parabolic dish and Stirling Power Converter (SPC) under the bright South African sun.
These solar dishes have set a world record in converting solar energy to electricity. 34% of the sun’s energy hitting the mirrors is converted directly to grid-available electric power. The massive 100 square metre dishes slowly rotate, following the sun. Light clicks and taps fill the still desert air as they constantly adjust to capture the maximum solar energy.
The technology to move into efficient renewable energies is not only from snazzy Silicon Valley innovations and investors; sometimes the answers are in revitalising past engineering solutions and appropriating them for contemporary innovations. A zero-emission engine invented by a 19th-century Scot via some Swedish military submarines have led to the most efficient solar energy systems.
new, state-of-the-art solar energy dish is the most efficient in the world. 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.