86
Research and survey vessels are, for the most part, equipped with diesel engines
and generators providing ample power for all the above requirements. Surface surveillance drones such as those used for port security may also be equipped with
diesel engines. Coastal ODAS buoys generally rely on solar panels and conventional marine deep-discharge lead-acid battery banks for house power. Autonomy of
buoys so equipped, limited only by battery life and solar panel integrity, extends
well beyond the customary 1 year deployment. Wind turbines may be used to supplement the primary solar system. Ocean gliders rely on battery banks using either
rechargeable lithium cells or disposable alkaline cells to provide power for pumping
the operating fluid and for house power (Rudnick et al. 2004). Sailing drones depend
on a combination of propulsive wind power and solar power for payload operation.
High frequency radar systems commonly rely on land-based electrical power
grids. However, an autonomous Remote Power Module (RPM) to support extended
autonomous HF radar unit operations has been designed, fabricated, and tested in
the challenging remote environments of the Arctic and subarctic Alaska (Statsewich
et al. 2011). The RPM incorporates three complimentary power sources: solar panels, wind turbines, and a biodiesel power generator, all backed by a battery bank.
Additional subsystems include command and control, satellite communications,
and power performance monitoring modules. Packaged in small units that two people can carry, the RPM is deployable using small vehicles, boats, or sled-equipped
snow machines. Commercialization of such modules will facilitate extension of current networks by allowing grid designs that minimize the number of stations necessary for efficient area coverage. Development of analogous modules incorporating
climate control for deployment in tropical regions will further extend possible
coverage.
A number of innovative solutions to power requirements of autonomous systems
are now in use for industrial applications or are currently under development for low
power applications. Dewan et al. (2014) describe electrolytic systems based on sacrificial anode sources, sediment microbial fuel cells based on redox differences
between the water column and organic-rich anoxic sediments, and piezoelectric
energy harvesters. Thermoelectric energy generators (solid-state thermal gradient
devices) mounted under solar cells are also being put into use to take advantage of
the large heat loss of conventional solar cells.
Wind- and wave-powered kinetic vehicles are described above. Kinetic generators using wave and current energy are now commercially available. Such systems
are designed for large power output but have yet to be miniaturized for instrument
operation (Dewan et al. 2014).
4.2 Ocean Observing Instrument Mounts and Housings
Instruments deployed in the ocean environment are subject to direct seawater exposure under partial or continuous submergence, to great depths in many instances.
Many sensors require direct contact with the ocean medium and their electronic
4 Environmental Constraints to Instrumental Ocean Observing: Power Sources…
Research and survey vessels are, for the most part, equipped with diesel engines
and generators providing ample power for all the above requirements. Surface surveillance drones such as those used for port security may also be equipped with
diesel engines. Coastal ODAS buoys generally rely on solar panels and conventional marine deep-discharge lead-acid battery banks for house power. Autonomy of
buoys so equipped, limited only by battery life and solar panel integrity, extends
well beyond the customary 1 year deployment. Wind turbines may be used to supplement the primary solar system. Ocean gliders rely on battery banks using either
rechargeable lithium cells or disposable alkaline cells to provide power for pumping
the operating fluid and for house power (Rudnick et al. 2004). Sailing drones depend
on a combination of propulsive wind power and solar power for payload operation.
High frequency radar systems commonly rely on land-based electrical power
grids. However, an autonomous Remote Power Module (RPM) to support extended
autonomous HF radar unit operations has been designed, fabricated, and tested in
the challenging remote environments of the Arctic and subarctic Alaska (Statsewich
et al. 2011). The RPM incorporates three complimentary power sources: solar panels, wind turbines, and a biodiesel power generator, all backed by a battery bank.
Additional subsystems include command and control, satellite communications,
and power performance monitoring modules. Packaged in small units that two people can carry, the RPM is deployable using small vehicles, boats, or sled-equipped
snow machines. Commercialization of such modules will facilitate extension of current networks by allowing grid designs that minimize the number of stations necessary for efficient area coverage. Development of analogous modules incorporating
climate control for deployment in tropical regions will further extend possible
coverage.
A number of innovative solutions to power requirements of autonomous systems
are now in use for industrial applications or are currently under development for low
power applications. Dewan et al. (2014) describe electrolytic systems based on sacrificial anode sources, sediment microbial fuel cells based on redox differences
between the water column and organic-rich anoxic sediments, and piezoelectric
energy harvesters. Thermoelectric energy generators (solid-state thermal gradient
devices) mounted under solar cells are also being put into use to take advantage of
the large heat loss of conventional solar cells.
Wind- and wave-powered kinetic vehicles are described above. Kinetic generators using wave and current energy are now commercially available. Such systems
are designed for large power output but have yet to be miniaturized for instrument
operation (Dewan et al. 2014).
4.2 Ocean Observing Instrument Mounts and Housings
Instruments deployed in the ocean environment are subject to direct seawater exposure under partial or continuous submergence, to great depths in many instances.
Many sensors require direct contact with the ocean medium and their electronic
4 Environmental Constraints to Instrumental Ocean Observing: Power Sources…