How Solarcraft designed remote valve automation systems to meet the stringent site restrictions on the Santa Ynez Pipeline in Santa Barbara, California.

To preserve the ocean views and green spaces, Santa Barbara County mandates that pipeline assets and infrastructure are out of site. To meet these strict requirements, the valve station is constructed in a below ground silo. 

Solarcraft’s control systems are also housed in a silo, constructed adjacent to the valve station silo. At ground level, visibility of the system is limited to an octagonal roof that is powder coated desert tan color, small solar panels, a Starlink antenna, and an external interface hatch.

A segment of the pipeline passes through Santa Barbara County and faces Santa Barbara County’s strict environmental and zoning regulations. To preserve pristine ocean views and green spaces, pipeline infrastructure must be placed out of the line of site, relegating the infrastructure to be housed underground to minimize surface-level visual impact.The proposed valve sites are at locations where there is no access to utility line power. 

System Design and Engineering

Solar power is the ideal solution for reliable, safe autonomous power where no utility power is available. In fact, Solarcraft designed and built three systems for the client in adjacent Kern County that consisted of large solar arrays and 480VAC three-phase power for electric motor driven valve actuators. But because of the line-of-site restrictions and minimal footprint for the infrastructure, solar arrays and 480VAC three-phase power were out of the question for powering the Santa Barbara County valve systems. 

Since utility power was not accessible on-site, Solarcraft and the client developed a concept for charged battery packs which would be swapped out for discharged packs at regular intervals to operate the valve system controls and communications. These battery packs, consisting of three 48V 140Ah LiFePo4 batteries, are extremely heavy and require a truck-mounted crane to lift and replace the packs. A nitrogen sourced pneumatic valve actuator was specified instead of an electric motor actuator to open and close the valve. 

The Valve Sites: Underground Silos

The valve site consists of two eight-foot diameter underground silos. One silo houses the Solarcraft system with valve controls, communications and the battery packs that power them. The second vault holds the pipeline interconnect, the valve actuator, valve, and nitrogen bottles that actuate the pneumatic valve. At ground level, visibility of the system is limited to an octagonal roof, small solar panels, the Starlink, and an external interface accessible through a small hatch. 

Solarcraft designed a heavy-duty metal tower structure with a desert tan colored powder coated roof, weatherproof electronics and battery enclosures, and integrated elevator system that fits in the bottom of the silo. When fully extended, the overall height of the tower is 130", providing 42" of above ground access. It retracts to ground level, concealing the entire structure below the roof. 

A square frame and four columns support the structure, with the white powder coated equipment enclosure securely integrated inside the frame. When deployed above ground, the PLC controller, the cell modem, and Starlink equipment is accessible through a wide enclosure door. On the other side of the enclosure, the battery packs are housed in pull-out drawers for easier access during the swapping out procedure. 

The underground design requires a motor driven elevator  system and framework to raise the housing above ground level. The framework utilizes steel columns that nest inside one other and gradually extend to full height. This design is exceptionally robust and stable in order to handle the heavy equipment. As the unit is being elevated, rollers guide the columns to ensure that the linear actuator glides vertically and is perfectly aligned within the columns.Once above ground, the enclosure with the Programmable Logic Controller (PLC) can be accessed. The PLC is used for site control and monitoring, both onsite and remotely. PLCs receive alerts and alarms, such as low voltage alarms, and control solenoid valves and other devices. 

The system contains two battery packs that are comprised of three (3) 48-volt LiFePo4 batteries. The packs are capable of both onboard AC charging and solar charging. The packs are charged at the client’s facility and returned to the site to be swapped for the discharged battery packs. The solar charging capability has been retained and small solar panels have been installed on the octagonal housing roofs for trickle charging the batteries. 

Finally, an interface panel mounted on the top of the octagonal housing roof provides access when the system is retracted below ground level. The interface panel accesses communications to control and monitor the system, a reset button for communication gear, and the elevator that raises and lowers the unit. A key fob can be used to raise and lower the housing. In case of a loss of power, there is  a hand switch as well.Because of power limitations on the site, Solarcraft and  the client designed this valve system to utilize two high-pressure nitrogen bottles as the pneumatic power source for actuating the valve. The system sends electrical signals that control opening and closing a small solenoid valve that then sends pressure from the nitrogen bottles to the actual block valve. The pneumatic solution also has the 
advantage of stored energy to be used in case of an electrical power failure. 

A total of eight systems were built and deployed in Santa Barbara County. Despite the limitations and complexities of the project, Solarcraft engineers translated the project requirements into a workable solution that complies with Santa Barbara County’s stringent environmental codes. 

Testing the tower elevator structure at Solarcraft before shipping to California. Shown here in the extended position, 130" tall.

The tower in the retracted position, 90" tall. This view shows the control panel enclosure door with HMI interface. 

View of the control panel with PLC, communications, inverters and solar controllers.