IBM Research uses supercomputer tech to “harness the energy of 2,000 suns”

A collaboration of Swiss institutions, including IBM Research, has announced that it’s developing a highly efficient, low-cost photovoltaic system that’s capable of concentrating “the power of 2,000 suns.” The collaboration claims that the system, which is targeted at dry regions such as southern Europe, Africa, the south west of North America, South America, and Australia, will have an overall efficiency of 80% — and, miraculously, be able to provide a source of fresh water, too.

The High Concentration Photovoltaic Thermal system [PDF], or HCPVT for short, combines Airlight’s concentrated solar power (CSP) tech with IBM’s microchannel water cooling tech. In essence, the HCPVT system consists of a large parabolic dish that tracks the sun, with mirrored facets that concentrate the sun’s rays on a cluster of photovoltaic chips — which is where the real magic occurs. The HCPVT system uses triple-junction photovoltaic chips, which can harness the energy of three different wavelengths of light, compared to the single wavelength captured by a conventional single-junction photovoltaic cell.

 

Furthermore, these triple-junction chips (pictured right) are kept cool using IBM’s microchannel cooling, allowing the chips to continue operate nominally at a solar concentration between 2,000 and 5,000 times. This technology, called Aquasar, was originally developed by IBM to efficiently cool supercomputers, which require extraordinary cooling solutions to keep their densely-packed processors at an acceptable temperature. For complete details of Aquasar, see our explainer. In essence, though, each photovoltaic chip is cooled by a network of tiny, water-filled microchannels, “inspired by the hierarchical blood supply system of the human body.”

These microchannels are so efficient that the complete HCPVT system can recover up to 50% of waste heat, bringing the total system efficiency up to 80%. But that’s not all: The hot water, which reaches temperatures of 90 Celsius (194F), is then passed through a porous membrane desalination system, producing clean, drinkable water. A square meter of microchannel-cooled photovoltaic chips would produce between 30 and 40 liters of water per day. A large installation would provide enough water for a small town. This hot water could also power an adsorption refrigerator, too, providing air conditioning — though, in reality, the ability to produce drinkable water will probably take precedence over cool air.

Zooming out from the micro, the macro-scale details of the HCPVT system are equally important. According to IBM Research, this system is only economically viable because the structure is fashioned from concrete and the primary optics are composed of inexpensive pneumatic mirrors (thin, reflective metal films pulled tight with pneumatics). All told, this equates to a system cost of below $250 per square meter of mirror, which is apparently “three times lower than comparable systems.” The levelized cost of energy from the HCPVT system — the price that must be charged to break even over the system’s lifetime — is just 10 cents per kilowatt-hour (kWh).

By: Sebastian Anthony
Source: http://www.extremetech.com/extreme/154044-ibm-research-uses-supercomputer-tech-to-harness-the-energy-of-2000-suns