Google’s RE<C renewable energy research project has recently open
sourced a new tool and a significant amount of data to support future
CSP (concentrating solar power) heliostat development.
HOpS Open Source Site
HOpS, heliostat optical simulation, is an open source software tool
for accurately and efficiently performing optical simulations of
fields of heliostats, the actuated mirror assemblies that direct
sunlight onto a target in CSP applications.
Google used this tool to help evaluate heliostat field layouts and
calculate heat input into a CSP receiver for power production. HOpS
works by passing "packets" of light between optical elements (the sun,
heliostats, and elements of the target surface), tracking shadowing
and blocking masks along the way. For our analysis goals, this
approach gave our researchers more flexibility and accuracy than
analytic tools (such as DELSOL or HFLCAL), and it was easier to set up
for thousands of runs than using ray tracers. Output from the
simulation includes heliostat efficiency, target irradiance, and more,
while an included shell script facilitates plotting heat maps of the
output data using gnuplot.
REC-CSP Open Source Site
The REC_CSP open source project contains data sets and software useful
for designing cheaper heliostats.
Available on the project site are:
1. Thirty days of three-dimensional wind measurement data taken with
ultrasonic anemometers (sampled at ~7 Hz), recorded at several near
surface elevations. The data is presented in the RE<C wind data
collection document and is available for download on the open source
2. A collection of heliostat aerodynamic load data obtained in a NASA
wind tunnel and graphically represented in the appendix. This data is
available for download on the open source site here.
3. Matlab software for high-precision, on-target heliostat control
with built-in simulation for testing. This is essentially the same
software used in the RE<C heliostat control demonstrations and
described in the accelerometer sensing and control system design
documents. The source code is available for download here.
Video: Demonstrating single and multiple heliostat control
By Ross Koningstein, Engineer, Google RE<C team
+1 256 274 4225