Solar-powered Valve Actuation: An Update
The use of solar power in industrial and municipal valve actuator applications goes back several decades; however, technological advances in solar
power efficiency and storage mean that
today, it has become a practical,
dependable alternative for many isolated locations.
In the early days, solar power was
used in noncritical applications that
required low power consumption, prima-
rily to supply monitoring of valve-related
and process data at remote locations. As
solar power technology evolved, applica-
tions expanded along with the sophisti-
cation of the technology.
A key factor of whether or not to consider solar power for an application
relates to available energy and consumption. Two examples would be a 36-
inch valve or gate operating at 1,000
psi on a crude oil pipeline and a 96-inch
sluice gate in 25 feet of head water at a
remote dam site. The two would require
about the same force and amount of
energy to operate. In both these cases,
users would find bringing utility power
to the sites cost prohibitive, which triggers the process to consider solar power.
In these scenarios, the pipeline company needs to be able to close the valve
in an emergency in response to environmental and safety concerns. The water
utility needs to maintain an appropriate
level in its reservoir through the winter,
which means changing the outlet gate
position as the lake level rises or falls.
Both applications need to sense process
conditions, transmit information, move
a load and do it all off grid. Solar power
can be more cost effective in such cases
and requires less maintenance than gas
or diesel generation systems if the loads
can be managed.
High in the Andes Mountains between Argentina and Chile, 14 valve sites are connected by fiber
optic cable to the pipeline command center. Solar panels provide power for the station during the
summer months and a turbine wind generator takes over during the winter. A control building
houses the communication equipment and the hydraulic power unit (lower right). The 16-inch
pipeline is buried, but the hydraulic actuator mounted on the valve extension can be seen above
grade (lower left).
One of the ways technology has
improved in the solar industry is that,
in the last 10 years, panels have