The World's #1 Renewable Energy Network for News, Information, and Companies.

Harnessing the Sun’s Energy with Tiny Particles

Engineers at U.S.-based Sandia National Laboratories, along with partner institutions Georgia Tech, Bucknell University, King Saud University and the German Aerospace Center (DLR), are using a falling particle receiver to more efficiently convert the sun’s energy to electricity in large-scale, concentrating solar power plants.

Falling particle receiver technology is attractive because it can cost-effectively capture and store heat at higher temperatures without breaking down, which is an issue for conventional molten salts. The falling particle receiver developed at Sandia drops sand-like ceramic particles through a beam of concentrated sunlight, and captures and stores the heated particles in an insulated container below. The technique enables operating temperatures of nearly 1,000 degrees Celsius. Such high temperatures translate into greater availability of energy and cheaper storage costs because at higher temperatures, less heat-transfer material is needed.

Central receiver systems use mirrors to concentrate sunlight on a target, typically a fluid, to generate heat, which powers a turbine and generator to produce electricity. Currently, such systems offer about 40 percent thermal-to-electric efficiency. The falling particle receiver enables higher temperatures and can work with higher-temperature power cycles that can achieve efficiencies of 50 percent or more.

“Our goal is to develop a prototype falling particle receiver to demonstrate the potential for greater than 90 percent thermal efficiency, achieve particle temperatures of at least 700 degrees Celsius, and be cost competitive,” said the project’s principal investigator, Sandia engineer Cliff Ho. “The combination of these factors would dramatically improve the system performance and lower the cost of energy storage for large-scale electricity production.”

The project is funded up to $4 million by the Department of Energy’s SunShot Initiative, which aims to drive down solar energy production costs and pave the way to widespread use of concentrating solar power and photovoltaics.

Falling particle receiver technology was originally studied in the 1980s, and Sandia researchers are working to address challenges that hindered greater acceptance of the concept. Among the issues are mitigating particle loss, maintaining the stability of falling particles, increasing the residence time of the particles in the concentrated beam and reducing heat losses within the receiver cavity.

Ho and his colleagues at Sandia have been working to address these issues by studying the effect of an added air curtain, created by a series of blower nozzles, to help particles fall in a stable pattern and reduce convective losses. Adjusting the particle size and how sand is dropped has also helped, ensuring more of the sand gets heated in a pass and makes it to the collection bin at the bottom. Researchers are also investigating the benefits of using an elevator to recirculate particles through the aperture a second time to increase their temperature.

“Given our unique facilities at the National Solar Thermal Test Facility, we have the capability of developing prototype hardware and testing the concepts we’ve simulated, which include innovations such as air recirculation and particle recirculation. Advanced computing lets us do complex simulations of the falling particle receiver to understand the critical processes and behavior,” Ho said. “We’re very encouraged by our progress and look forward to further developing this enabling technology.”

Falling particle receiver technology is expected to lead to power-tower systems capable of generating up to 100 megawatts of electricity. The project is in its first of three years, and a test-ready design is expected in 2015.

RELATED ARTICLES

Solar panels

New Tool Helps Utilities Manage the Rapidly Growing Community Solar Market

Vince Font, Contributing Editor Community solar projects are among the fastest growing solar segments in the U.S with some estimates forecasting that community solar initiatives will be responsible for the addition of 500 MW (megawatts) of annual capacity...
Pope Francis

A 9-Minute Guide To Pope Francis’ Encyclical on Climate Change

Jim Lane, Biofuels Digest Pope Francis issued Laudato si’ (Praise Be to You) On the care for our common home, his second encyclical, concerning Catholic doctrine with respect to climate change, consumerism, and development.

Intersolar Europe 2015: Spirits Up, Stats Down

William P. Hirshman, Contributor Intersolar Europe, billed at the world’s leading exhibition for the solar industry, is indeed big. But Intersolar Europe 2015, one of five Intersolar-branded gatherings around the globe each year, was not as large as the an...
US Capitol

Republicans and Democrats Back Bill to Level the Playing Field for Renewable Energy

Vince Font, Contributing Editor U.S. Senators Chris Coons and Jerry Moran are leading a bipartisan effort to reintroduce tax code legislation aimed at leveling the playing field for renewable energy investment. The Master Limited Partnerships Parity Act w...

CURRENT MAGAZINE ISSUE

Volume 18, Issue 3
1505REW_C11

STAY CONNECTED

To register for our free
e-Newsletters, subscribe today:

SOCIAL ACTIVITY

Tweet the Editors! @megcichon @jennrunyon

FEATURED PARTNERS



EVENTS

NFMT Orlando

NFMT Orlando is a trade show and educational conference for facility pro...

Green Sports Alliance Summit

The annual Green Sports Alliance Summit is the world’s largest and...

SAP for Utilities

The SAP for Utilities conference is the most comprehensive SAP for Utili...

COMPANY BLOGS

Five Ways GreenLancer Creates High Quality Solar Designs

High quality solar designs don’t have to take weeks to get back to...

How To Ace A Presentation

Most sales professionals are asked to give presentations from time to ti...

More Middle-Class Massachusetts Residents Are Going Solar

Massachusetts is known for the Pilgrims, Boston cream pie and its excell...

NEWSLETTERS

Renewable Energy: Subscribe Now

Solar Energy: Subscribe Now

Wind Energy: Subscribe Now

Geothermal Energy: Subscribe Now

Bioenergy: Subscribe Now  

 

FEATURED PARTNERS