Concentrating solar power emerging

Developments for the SunShot Initiative are underway to reduce the cost of energy systems and make the technology more robust for future users.

04/25/2013


ISS SourceSolar energy is feasible and the potential benefits can be staggering, however, the costs remain a barrier to full adoption.

There are now two solar energy goals: Make the technology cost efficient and make the technology more robust.

That is where Ranga Pitchumani, the John R. Jones III Professor of Mechanical Engineering at Virginia Tech, comes in.

Pitchumani is working toward achieving the goal set out in February 2011 in U.S. Secretary of Energy Steven Chu’s Dept. of Energy SunShot Initiative. Its objective was to reduce the installed cost of solar energy systems by about 75% in order to allow widespread, large-scale adoption of this renewable clean energy technology.

Following the initiative, Pitchumani started directing the Concentrating Solar Power (CSP) program for the SunShot Initiative.

“The SunShot goal is to get solar energy technologies to achieve cost-parity with other energy generation sources on the grid without subsidy by the year 2020. That’s an aggressive mission that calls for several subcomponent innovations and ingenious system designs to drive costs down, while improving efficiencies,” Pitchumani said.

“Concentrating solar power technologies use mirrors to reflect and concentrate sunlight to produce heat, which can then be used to produce electricity,” Pitchumani said. These technologies present a distinct advantage over photovoltaic (PV) cells in their ability to store the sun’s energy as thermal energy, and represent a subset of the SunShot Initiative.

Pitchumani and his research group at Virginia Tech developed novel thermal energy storage technologies for concentrating solar power applications.

“Fossil fueled power plants pose a potential risk to the environment through an increased carbon footprint, and my efforts are in supplanting fossil energy with renewable sources including solar energy,” Pitchumani said. “Concentrating solar power plants capture the solar energy and store it as heat, which can, in turn, be used to drive a turbine and produce electricity. In fact, studies have shown that CSP with thermal energy storage also facilitates greater incorporation of other renewables such as wind and photovoltaic on the grid. That’s a win-win on all fronts,” Pitchumani said.

“Due to the intermittent nature of solar energy availability, it is often desirable to store thermal energy from a concentrating solar power plant for use on demand, including at times when solar energy is unavailable such as during cloud cover or overnight. Energy can be stored either as sensible heat (in solid or molten media), latent heat (using phase change materials), or as products of a thermochemical process, of which latent heat and thermochemical storage offer high volumetric energy density and potentially high power cycle efficiency, provided costs can be tamed,” he said.

In his role, Pitchumani oversees a team of several program managers, technical, financial and support personnel, who actively manage the awards in the portfolio. During his leadership, the SunShot Concentrating Solar Power Program launched over $130 million in new funding initiatives since October 2011.

Concentrating solar power plants could provide for low-cost energy generation and have the potential to become the leading source of renewable energy for future power generation. In the U.S., several large-scale commercial plants (e.g., Ivanpah Solar Electric Generating Station (SEGS), Crescent Dunes Solar Energy Project, and Abengoa Solana Generating Station) are currently under construction, with some getting ready to fire up in a few months, that would more than triple the total capacity of Concentrating Solar Power-generated electricity to about 1.8 GW and place the U.S. as one of the global leaders in CSP capacity.

On a worldwide scale, studies suggest concentrating solar power technology systems could provide approximately one-quarter of the global electricity needs by 2050, Pitchumani said.



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