Sandia Energy: National Solar Thermal Test Facility

Sandia national laboratories

The Sandia National Laboratories National Solar Thermal Test Facility is a one-of-a-kind testing facility for solar energy technology. Equipped with leading research facilities, it’s designed to further the large-scale production of solar energy by providing experimental engineering data that can be used for the design, construction and operation of systems in solar thermal electrical plants.

What is the National Solar Thermal Test Facility?

The National Solar Thermal Test Facility (NSTTF), located in Albuquerque, New Mexico, is the only test facility of its kind in the whole of the United States. Operated by Sandia National Laboratories on behalf of the Department of Energy, it is designed to test the components and systems that support the development and improvements in concentrating solar power (CSP) technology.

The facility was constructed in the 1970s in response to rising fuel costs. Rising fuel costs created the need for a cleaner, more renewable source of energy and as studies revealed the potential for solar energy to produce electricity on a huge scale, this looked like the answer. The NSTTF site was built to support research into related solar energy technologies.

What does it offer?

At the National Solar Thermal Test Facility, Sandia offers a complete testing environment for a variety of different solar and non-solar activities. These include:

  • Thermal flash simulation
  • Thermal performance testing and thermophysical properties measurement
  • Solar array and solar applications testing
  • Space technology systems testing
  • Air-to-ground testing

Facilities 12 main features

  1. Heliostat field - this includes 218 heliostats, all of which are individually controlled and produce flux levels over 300W/cm2. By providing more than 6MW of total power, this facility supports the government’s SunShot goals (an initiative to support the adoption of solar energy and make it more affordable). It is also used for astronomy experiments and thermo-nuclear test simulations.
  2. Solar tower - this 200 ft concrete tower located at Sandia National Laboratories can support testing for CSP experiments. It features three test locations on the north side and top of the tower. Some of the equipment inside includes air compressors, generators, pressure-relief valves and air coolers.
  3. Molten salt test loop - this enables the testing of molten salt hardware over a high temperature at high-flow and high-pressure. Like the heliostat field, this supports the SunShot initiative by helping to develop thermal energy storage costs equal to $15kWhth.
  4. Rotating platform - the outdoor platform rotates 360 degrees and is operated by computer controls. It was originally built at Sandia to allow for more accurate and rapid thermal performance testing of solar collecting devices. Today it is used to test components under different solar angles of incidence.
  5. Solar furnace - this uses a heliostat to reflect the sun onto a fixed mirror dish for experiments. In total, the furnace can provide 16 kW of thermal power and peak flux up to 500 W/cm2. Its applications include simulating the thermal effects of nuclear explosions on materials and testing the thermophysical properties of materials in concentrated sunlight.
  6. Dish test facility - this site currently includes two SNL developed solar dishes, ten Stirling Energy Systems dishes and six Infinia dishes. Industry partners are able to use this facility to test the long-term reliability of solar dishes.
  7. Engine test facility - this is made up of two test cells and a data/control room.
    • Test cell one is designed to investigate the efficiency, power output and reliability of heat-powered engines.
    • Test cell two is currently used to test bench-scale solar receivers (devices that absorb solar energy and transfer it to a heat engine).
    • Data/control room is fully equipped to monitor tests. The data acquisition system measures, displays and stores the data while video cameras capture the tests on coloured film.
  8. Assembly bay - the assembly bay is a 2500 square foot warehouse located next to the test cells where tests can be prepared. It houses a 5-ton crane, workbenches and welding tools.
  9. High-flux solar simulator - with this simulator, Sandia offers another one-of-a-kind tool. It allows researchers to carry out accelerated lifetime ageing tests on materials under high temperatures and high flux.
  10. Apartment complex - this complex provides a controlled environment for high-temperature experiments. Equipped with chemical and fire detection sensors, customised ventilation system and fire extinguishing powder, high-temperature experiments of up to 850°C have been performed here.
  11. Concentrated Photovoltaics - 110kWe of Sunpower’s C7 low-concentration solar panel systems have been installed at the facility. They are used to test the reliability of the systems, as well as to test new components. The companies SNL and SunPower work together at this facility to improve the technology.
  12. Optics lab - this part of the NSTTF is full of optical equipment and tools that facilitate the optical characterisation of the facets on heliostats and solar dishes.

Who can use the NSTTF?

Sandia welcomes everyone to use their facility for research and experiments. Past users include government agencies, universities and private companies. There are several ways for non-Sandia researchers to contract with the company in order to use the facility. To discuss your options and specific testing, contact Sandia at

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