I had the privilege recently to work with a very talented team on a one-of-a-kind engineering
project that was equal parts challenging and rewarding. Our task: commission the solar collector
system for a concentrated solar power plant half way around the world. The project was a complete
success, but it would not have gone so smoothly without the help of the Observatory data
visualization library, which we relied upon throughout every stage of the project,
from design to execution to ongoing maintenance. The experience also served as a proving-ground
for the Observatory library itself as we stress-tested it in a variety of different
configurations and scenarios with real-world consequences. The examples that follow
serve to illustrate Observatory's versatility, as well as the crucial role of
good visualizations in software and engineering projects.
At the top of this article is an aerial view of the project site near Port Augusta, Australia,
which is owned and operated by Sundrop Farms.
The solar field is comprised of 23,712 individually controlled mirrors (called heliostats),
each one about the size of a picnic table (just over 2 square meters).
The solar field acts like a giant magnifying glass:
each heliostat is oriented to reflect the sunlight onto a
specially-designed receiver that sits on the top of a tower near the field
(i.e. that glowing thing in the upper right of the image).
The concentration of light heats and boils water inside the receiver,
which in turn is used to produce electricity
and desalinate seawater. Sundrop Farms uses these outputs to fuel and feed
produce (in this case, tomatoes) that is grown in greenhouses adjacent to the solar field.
Sundrop Farms has put together
some great videos
if you are interested in learning more about
their technology.
The central challenge in the design and operation of solar fields
like this one is accurately orienting each mirror so that it reflects
sunlight to the desired target, which is typically hundreds of
meters away. Errors in pointing of even 1 degree are way too high.
In order to ensure safe and efficient absorption of sunlight,
each mirror has its own designated target on the receiver's surface,
and performance will degrade if mirrors miss their targets by
more than about 1/20th of a degree! The visualization on the right is a
representation of the so-called aim-points shown overlaid on a 3d
model of the receiver. The dark area is the light-absorbing surface,
and there is one ray shown for each heliostat in the field.
The rays are colored based on a metric used in the design of
the aim-point strategy. We used visualizations like this one to
design the aim-point strategy itself and to verify that our code
is working as expected.