Andrea Sorri / Business Development Director, Government / City Surveillance /
Critical Infrastructure at Axis Communications
A wind farm’s perimeter, its entire area, and all of the devices it comprises as well as the people who have access to the area must be taken into account when protecting remotely located installations.
Although wind farms offer a green solution to energy issues, some people object to them due to a perceived impact on the historic and scenic value of the wind plants locations, or due to their expected noise and impact on birds. Because of this unwillingness to accept wind-power plants, they are sometimes sabotaged, endangering the system’s operations and efficiency. Integrating surveillance and security systems thus becomes of primary concern to protect these investments.
A wind farm’s perimeter, its entire area, and all of the devices it comprises (including its operational aspects such as turbine efficiency and system maintenance) as well as the people who have access to the area must be taken into account when protecting remotely located installations.
Wind park surveillance generally involves several challenges, the first one being the installation’s location which is often isolated, remote, and not easily accessible by its owner or by police authorities. Other critical issues include unfavorable climate conditions in winter and in summer, as well as the free access of wild animals to the area.
Traditional surveillance systems such as microwave barriers, sensors, microphones and trampling sensors involve significant trade-offs for wind farm applications because in most cases the wind-farm perimeter is not clearly defined. Another issue with these systems is the impossibility to remotely check on site events.
Recent network technology, such as the tower mounted camera, provides a more effective security solution because it combines thermal-imaging cameras with video analytics software and HDTV cameras in a single platform.
Although analog camera-based systems that use IR illuminators are more versatile as far as their installation is concerned, these systems also require a complex infrastructure because each camera and each illuminator needs hardwired power cables which must be connected to an electric junction point, leading to electromagnetic effects and distortion. Due to environmental variables, especially regarding atmospheric agents and seasonal conditions, it is difficult to attain reliable results as far as alarm quality is concerned.
These surveillance systems are therefore not the most advantageous. Even their integration would not constitute an ideal solution. From an economic standpoint, the two technologies – analog cameras and IP illuminators – would continue as two independent units operating in parallel.
Recent network technology, on the other hand, provides a more effective solution because it combines thermal-imaging cameras with video analytics software and HDTV cameras in a single platform.
Because they can record the heat that radiates from any kind of object, as well as from people, animals, and vehicles, thermal cameras can detect temperature changes and view objects in total darkness and other harsh conditions without requiring an external light source. These cameras can also recognize a moving object, for example, crossing the border of a protected area, and based on the number of pixels and algorithmic outcomes, it can discriminate as to whether or not the image represents an actual alarm event. Event images are transmitted to the operations center where alarm conditions can be effectively assessed. Then lighting systems or additional deterring devices can be activated as required.
These newer systems have a wide field of view and are not limited to an area’s perimeter. The system can extend to the entire area. In addition, the cameras are installed on the same poles used for perimeter barriers, or simply installed on a support. There is no need for IR illuminators. Lights are switched on only during alarm events and animals can roam freely.
But thermal cameras alone do not produce images that enable reliable identification. Visual feedback is supplied by additional video cameras offering HDTV resolution images that can target an alarmed thermal camera’s area through pan, tilt, and zoom functions. Video cameras can also inspect an installation’s details and plan maintenance operations.
These three video technologies complement and support each other. A system designed with them would let an operator carry out a detailed analysis of remote alarm events in real-time, using the Internet protocol over cable, wireless or 3G/4G, and future technologies. Thermal cameras can detect and monitor critical conditions, including those located the farthest from turbine areas, from any angle, while the HDTV resolution of PTZ dome cameras are activated by alarmed thermal cameras. After activating a specially designed lighting system, high quality video would also be available even at night or in poor lighting conditions. Both types of cameras, IR and visual, also support Intelligent Video functions with software that uses advanced algorithms take into account and foresee a wide range of site specific variables that traditional technologies cannot handle. Such software can require a configuration process, which must be performed by properly trained personnel, but these configuration processes have been greatly optimized compared to previous systems.
Combining such a system with other sensors to maximize the protection level is an additional advantage that may be useful for especially critical conditions. Adding data sources such as professional intrusion detection sensors to an initial thermal + HDTV camera installation becomes a reasonable option.
When intelligent-video cameras are used with thermal versions, the installer’s expertise is of paramount importance. For this reason we recommend to have at least 6 pixels available for each object.
As for data security, there are no threats thanks to the use of multi-level password access, IP address filtering, digest authentication, user access log, IEEE 802.1X network access control, HTTPS encryption as well as SD card or NAS storage. Another advantage: The use of non-proprietary VAPIX and ONVIF-based open systems allow for easy integration of devices made by other manufacturers as well as the systems’ scalability, and the system provides the flexibility to add new cameras in the future.
When selecting an Axis Partner with Axis Academy qualifications you can rest assured that a wind farm is equipped with the best that technology has to offer now and tomorrow. We offer our partners the required skills through the “Axis Communications Academy” training program.
When it comes to the off-shore installations, thermal cameras combined with the right dedicated analytics can also inform in advance with abnormal presence in the windfarm zone and alert with potential collisions.