For a perimeter surveillance, thermal and standard IP cameras are used with video intelligent software for intruder recognition.
Day cameras need to install a IR lights for night vision, therefore at night performance is reduced at long distances Thermal cameras work with same performance in day or night. Thermal based intrusion systems have better and less false alarms.

Adding PTZ cameras for intrusion detection in perimeter is a good idea. They will help to confirm the alarm and identify the intruder.
In several scenarios this is a must. False alarms are reduced to the minimum.

Wind Farms used to take large areas, and can be difficult to survey.
Cameras for road surveilling and motion detection with access control system in each turbine are the standard.

Outdoor surveillance system used to be very susceptible with weather conditions. Camera lens can get dirty or wind can move them.
Software must to be maintained or updated as well.
A system without maintenance will stop working fine in several months. Maintenance must to be done every year.