Innovation Blog

Back to the Future II —  Jason Pontin: Futuristic Renewable Energy is Here!

By Shlomo Maital



Jason Pontin is editor and publisher of MIT Technology Review, a magazine that tracks new technologies and has some 2.6 m. readers worldwide.  Here is his take on near-future advances in renewable energy, as presented to the MIT Enterprise Forum of Israel annual event, May 5, Tel Aviv:

    “Carbon is the current product of the energy industry.  Heat and light are byproducts.  This will stop.  Each year, 1,366 watts of solar energy strike every squ. meter on the earth.  Yet today solar energy supplies only 1 % of US energy needs.  The largest solar project in the U.S. is Exelon Solar City in Chicago. (Sunny Chicago? Related to the fact it is President Obama’s city, and the project was funded by stimulus package money, or 80% of the total $60 m. cost).  There are 32,292 solar panels, covering 41 acres, generating 10 megawatts, enough for 1,500 homes.  It costs $6/kilowatt to build – far too high to be profitable. All such solar energy programs are heavily subsidized.

    “We need breakthroughs!  Here are five blue-sky energy technologies that could provide such breakthroughs.  They focus on new ways to generate, transport and store solar or nuclear energy:

  • Plasmonic Solar:  These are thin-film solar panels, developed by Harry Atwater at Caltech (California Institute of Technology).  [According to Wikipedia:  Plasmonic solar cells (PSC) are a class of photovoltaic devices that convert light into electricity by using plasmons. PSCs are a type of thin-film SC which are typically 1-2μm thick. They can use substrates which are cheaper than silicon, such as glass, plastic or steel. The biggest problem for thin film solar cells is that they don’t absorb as much light as the current solar cells. ]
  • Artificial photosynthesis [Dan Nocera, MIT]:   Research is being done into finding catalysts that can convert water, carbon dioxide, and sunlight to carbohydrates.  This is a way of storing energy, a crucial element of capturing solar power.  Nature does this with ease – it is called photosynthesis.  Inventors are trying to replicate it.  The cobalt catalyst from MIT’s  Dr. Dan Nocera of MIT is  “providing strong results.”
  • Software defined Thermal Solar.  In this technology, towers collect energy from mirrors. The mirrors are costly. Bill Gross (inventor of the original Google ad  interest-related model) is the pioneer of this method; “his eSolar’s proprietary sun-tracking software coordinates the movement of 24,000  1 meter-square mirrors per 1 tower using optical sensors to adjust and calibrate the mirrors in real time. This allows for a high density of reflective material which enables the development of modular concentrating solar thermal (CSP) power plants in 46 megawatt (MW) units on   parcels of land, resulting in a land-to-power ratio of 4 acres (16,000 m2) per 1 megawatt”.  [This implies that 62.5 sq. miles (or a desert area of 8 miles by 8 miles) of reflectors could supply all of Israel’s electricity needs. ]
  • Liquid Batteries:  [Don Sadoway, MIT];  One of the biggest challenges currently facing large-scale solar energy technology is finding an effective way to store the energy, which is essential for using the electricity at night or on cloudy days.  The primitive storage method today is to pump water up a hill during the daylight hours.  In 2009, Sadoway proposed a liquid metal battery that could be used in stationary energy storage systems.   “No one had been able to get their arms around the problem of energy storage on a massive scale for the power grid,” says Sadoway. “We’re literally looking at a battery capable of storing the grid.”
  • Superconducting DC transmission:   [Phil Harris, Tres Amigas].  Thomas Edison once observed that electricity is a way of TRANSPORTING energy, not creating it.  How can solar power be easily and quickly transported? Tres Amigas has the answer.  “The Tres Amigas renewable energy market hub will be a multi-mile, triangular electricity pathway of Superconductor Electricity Pipelines capable of transferring and balancing many gigawatts of renewable power between the three Interconnections.  Similar to highway rotaries used for traffic flow control, multiple power transmission lines from each of the Interconnections will feed power into and out of the Tres Amigas SuperStation through multiple AC/DC converters, each connected by DC superconductor cables.  Tres Amigas, which will be a balancing authority, will help ensure the efficient and reliable flow of power from multiple renewable generation sources in all three power grids to customers across a wide area of the U.S., Canada and Mexico.”
  • And: a sixth, still-distant but amazing dream:  Nathan Myrhvold’s Travelling Wave Reactor:  from wiki: “A traveling-wave reactor, or TWR, is a type of conceptual nuclear reactor that can convert fertile material into fissile fuel as it runs using the process of nuclear transmutation.   Once started, TWR’s reach a state after which they can achieve very high fuel utilization while using no enriched uranium and no reprocessing, instead burning fuel made from depleted uranium, natural uranium, thorium, spent fuel removed from light water reactors, or some combination of these materials.   TWRs could theoretically run, self-sustained, for decades without refueling or removing any used fuel from the reactor.” Former Microsoft guru Myrhvold is putting his own fortune into this, and plans to build a TWR in China.