A submersible water desalination apparatus includes an array of generally parallel water separation membrane cartridges each having a water separation membrane, an impermeable cartridge wall surrounding the membrane, and a product water collection tube that collects from inside the cartridges at least partially desalinated product water passing through the membrane, and through which the at least partially desalinated water exits the cartridges and enters a product water collection manifold. The cartridges are mounted in a perforated divider plate. In embodiments, a) the manifold is adhesively bonded to a plurality of the collection tubes, orb) the divider plate is adhesively bonded to a plurality of the cartridge walls or ends, or both a) and b). The adhesive reduces the likelihood of leakage at the manifold or divider plate.

A submersible water desalination apparatus includes a plurality of water separation membrane elements, a product water collector that receives product water from the membrane elements, and a variable output motorized submersible pump having a suction side that receives product water from the product water collector and a discharge side that pumps product water away from the apparatus through a product water conduit for surface or subsurface use. An automatic control or coupling is employed to reduce the pump output upon the occurrence or onset of suction side cavitation, and discourage or prevent cavitation over a range of product water flow rates from the membrane elements.

A submersible water desalination apparatus includes a plurality of water separation membrane elements, a product water collector that receives product water from the membrane elements, and a variable output motorized submersible pump having a suction side that receives product water from the product water collector and a discharge side that pumps product water away from the apparatus through a product water conduit for surface or subsurface use. An automatic control or coupling is employed to reduce the pump output upon the occurrence or onset of suction side cavitation, and discourage or prevent cavitation over a range of product water flow rates from the membrane elements.

A submersible water desalination apparatus includes a plurality of water separation membrane elements, a product water collector that receives product water from the membrane elements, and a variable output motorized submersible pump having a suction side that receives product water from the product water collector and a discharge side that pumps product water away from the apparatus through a product water conduit for surface or subsurface use. At least a portion of the product water is used to lubricate and optionally also cool at least a portion of the pump, motor or both the pump and motor.

A submersible water desalination apparatus includes a plurality of water separation membrane elements, a product water collector that receives product water from the membrane elements, and a variable output motorized submersible pump having a suction side that receives product water from the product water collector and a discharge side that pumps product water away from the apparatus through a product water conduit for surface or subsurface use. At least a portion of the product water is used to lubricate and optionally also cool at least a portion of the pump, motor or both the pump and motor.

A deep ocean water extraction apparatus has a collection pool having an outer shell with a maximum diameter, a lesser diameter at a mostly closed bottom, and an open top of a diameter smaller than the maximum diameter, outflow tubes with pumps extending horizontally from an opening through a side wall of the shell, an opening through the bottom covered by a rigid disk having a plurality of tube openings through which descending collection tubes of common length are connected, and flotation elements attached to the descending collection tubes at a plurality of points spaced down the depth of the collection tubes. The apparatus is characterized in that water is pumped out of the collection pool, and common pressure on the surfaces of the collection pool and the surrounding ocean water, causes water to flow up the collection tubes into the collection pool.

A deep ocean water extraction apparatus has a collection pool having an outer shell with a maximum diameter, a lesser diameter at a mostly closed bottom, and an open top of a diameter smaller than the maximum diameter, outflow tubes with pumps extending horizontally from an opening through a side wall of the shell, an opening through the bottom covered by a rigid disk having a plurality of tube openings through which descending collection tubes of common length are connected, and flotation elements attached to the descending collection tubes at a plurality of points spaced down the depth of the collection tubes. The apparatus is characterized in that water is pumped out of the collection pool, and common pressure on the surfaces of the collection pool and the surrounding ocean water, causes water to flow up the collection tubes into the collection pool.

Systems and methods are described for sequestering carbon stored in organic matter while minimizing the release of carbon dioxide (CO.sub.2) and methane (CH.sub.4) into the atmosphere, with the carbon (C) being stored as char or coal through the coalification process. Organic matter will be moved to submarine hydrothermal vent fields where the extreme heat in the water will drastically accelerate the degradation of the material and destroy microbes that normally consume the organic material and release the carbon as CO.sub.2 or CH.sub.4. The oxygen level in the heated water around the vents is extremely low. The water surrounding these vents can reach temperatures of 400° C. (750° F.). Exemplary implementations may include constructing hydrothermal borehole vents to harness the energy continuously released from the Earth's core in the form of volcanic heat.

An energy harvesting system is positionable at an ocean surface to harvest energy from a hydrothermal vent surrounded by cooler ocean water. The system includes an energy storage device positionable proximate to the ocean surface. A cable capable of conducting electrical energy is joined to the energy storage device. An energy harvesting structure is joined to provide electrical energy to the cable. The energy harvesting structure can be positioned proximate to the hydrothermal vent to harvest energy therefrom.

An energy harvesting system is positionable at an ocean surface to harvest energy from a hydrothermal vent surrounded by cooler ocean water. The system includes an energy storage device positionable proximate to the ocean surface. A cable capable of conducting electrical energy is joined to the energy storage device. An energy harvesting structure is joined to provide electrical energy to the cable. The energy harvesting structure can be positioned proximate to the hydrothermal vent to harvest energy therefrom.