Power systems, thermal management and cooling technologies are critical for wide employment of directed energy weapons

A directed-energy weapons (DEW) are ranged weapon systems that inflicts damage at a target by emission of highly focused energy, including laser, microwaves and particle beams. Potential applications of this technology include anti-personnel weapon systems, missile defense system, and the disabling of lightly armored vehicles or mounted optical devices

Laser weapons use high power lasers to damage or destroy adversary equipment, facilities, and personnel. The technology provides major advantages for military applications due to High precision and rapid on-target effect, precise and scalable effects, Avoidance of collateral damage caused by fragmenting ammunition, Low logistics overhead and minimum costs per firing. Laser weapons have already been employed on warships and military trucks. After warships US has plans to employ laser weapon on airborne platforms.

Earlier this year, NAVSEA released its latest Naval Power & Energy Systems Technology Roadmap led by the Electric Ship Office, which stated that the US Navy was “on the cusp of revolutionary changes” that will take the form of “high-power pulsed mission systems”. “These include directed energy weapons such as lasers and stochastic electronic warfare systems, radiated energy systems such as the air and missile defense radar, and advances in kinetic energy weapons, including electro-magnetic railguns,” said Stephen Markle, the director and program manager of PMS 320.

The development of laser weapons requires many critical technologies, first is development of lasers capable of generating powers in kilowatts to megawatts range to be able to produce useful damage effects on the target. For instance, to destroy anti-ship cruise missiles would require a beam of 500 kilowatts and demand megawatts of power.

Laser weapons require  energy storage technologies that will allow a ship to fire multiple shots from a high-powered laser without taxing the ship’s electrical system. Future all-electric ships may generate enough power that additional
energy considerations are not necessary but older ships may need to be back fitted with these weapons as well. If the ship’s power generation system is unable to directly power the laser, then energy storage methods must be considered. These “energy magazines” would provide the necessary power for multiple engagements, and then be recharged during downtime.The four candidates are Lead acid batteries, lithium ion batteries, supercapacitors, and flywheels.

Existing lasers generally dissipate two-thirds to three-quarters of the energy as heat, requiring still-bulky cooling equipment to avoid overheating damage. If an laser  is 25% efficient, then for every kilowatt of energy leaving the weapon there are 3 kW worth of heat to be removed from the system. Scaled to hundreds of kilowatts  this results in massive new loads on the ship’s cooling system. Air cooling can yield an unacceptable delay between shots.