IBM’s solar collector can meet global energy requirements if built across 2% of the Sahara’s land area. A highly advanced cooling network, seen in the likes of the Aquasar supercomputer, makes it possible.
Solar power has always been a very promising alternative to our current energy sources; its supply is predictable and plentiful (at least in some parts of the world), but most importantly, clean and renewable. Numerous countries have started to appreciate this, most notably Spain with its rapidly expanding concentrated solar plants. However, to achieve widespread adoption, there are two major obstacles that need to be tackled first: low conversion efficiencies, which currently lie at around 20% if conventional photovoltaic (PV) cells are used, and high costs. IBM believes it has overcome these with its High Concentration PhotoVoltaic Thermal (HCPVT) system.
The HCPVT system utilizes a concentrating parabolic dish to focus the sun’s rays onto an assembly of triple-junction PV modules at its center; this is unlike your standard solar concentrator, which focuses the rays onto a tube of water. A power equivalent to that of 2,000 suns is effectively transmitted to the modules, and the result is a system that can convert 80% of the solar energy it captures into useful energy. An exceptional 30% of the solar energy is converted into electricity, as the PV cells operate more efficiently under concentrated sunlight. The other 50% is stored as thermal energy by means of a highly advanced cooling network, currently used in the Aquasar supercomputer, which not only prevents the modules from melting, but also makes the system feasible and much more cost-effective.
How far we’ve come from those tiny solar cells on our calculators!
The cooling network is comprised of micro water channels that pass through the PV cells at a proximity of tens of microns to their constituent chips; the direct heat transfer to the water is 10 times as effective as air cooling, ensuring that the cells are kept cool. Simultaneously, the thermal energy that would normally be dissipated back to the atmosphere is stored in the cooling water, and can then be used for other purposes, such as air conditioning or providing clean drinking water.
IBM envisions its solar solution being adopted in remote villages around the world to provide basic necessities such as electricity and water, but more ambitiously as a main source of energy in the desert regions of Africa and the Arabian Gulf. If sufficient solar collectors are installed, this clean energy could eventually be distributed to neighboring regions as well. With its low cost design, which is three times lower than comparable systems, giving a cost per kilowatt-hour of 10 cents (equivalent to coal power station costs), this vision may very well be realized.