A good step in the Right direction, a closed loop system would still be the only version at this time however, that I would look to support with more research funding.

PS- the pressure problem I was talking about was at the sea floor surface and in the vent fracture system below. If you try to cap the vent to utilize it’s pressure for a heat exchanger or flow in the pipe to the surface it will cause a backpressure in the fracture system below the vent forcing the pressurized hot fluid out other fissures and away from the vent you capped.

That’s not correct. Right now in nature, the vents are exiting at 3 or more m/s into an environment that’s 3700 psi. I would have to have a pressure far greater than that within the pipe to cause your scenario to happen, and the pressure in the pipe will actually be quite a bit less than that because of the far lower density of the hot water.

PS- the pressure problem I was talking about was at the sea floor surface and in the vent fracture system below. If you try to cap the vent to utilize it’s pressure for a heat exchanger or flow in the pipe to the surface it will cause a backpressure in the fracture system below the vent forcing the pressurized hot fluid out other fissures and away from the vent you capped.

That’s not correct. Right now in nature, the vents are exiting at 3 or more m/s into an environment that’s 3700 psi. I would have to have a pressure far greater than that within the pipe to cause your scenario to happen, and the pressure in the pipe will actually be quite a bit less than that because of the far lower density of the hot water.

Assumptions:

Seawater Specific Gravity 1.03

2,500 m depth

3740 psi (258 bar) ambient pressure

350o C vent temp

Surface vent temp 340o C

Perfect insulation

12.13″ (31 cm) ID pipe diameter

50% efficiency of steam turbine

Ocean temp at bottom 2o C

Surface ambient 15o C

Platform 30m above water line

Findings:

83 MW energy producible

Energy density (83 MW/area of 31 cm pipe) roughly 1 MW/10 cm2 pipe area, or about 3.3×10^6 more intense than solar radiation

>100m/sec (218 mph or 360 kph) steam velocity at surface

30 KT/day steam (25,000m3)

Useful surface temp 340o C

Useful surface pressure 70 bar (1015 psi)

25,000 tons/day delivered to surface

25-35 kg solid/ton

25,000 tons x 25-35kg solids/ton = 625,000 kg- 875,000 kg solids per day

Assumptions:

Seawater Specific Gravity 1.03

2,500 m depth

3740 psi (258 bar) ambient pressure

350o C vent temp

Surface vent temp 340o C

Perfect insulation

12.13″ (31 cm) ID pipe diameter

50% efficiency of steam turbine

Ocean temp at bottom 2o C

Surface ambient 15o C

Platform 30m above water line

Findings:

83 MW energy producible

Energy density (83 MW/area of 31 cm pipe) roughly 1 MW/10 cm2 pipe area, or about 3.3×10^6 more intense than solar radiation

>100m/sec (218 mph or 360 kph) steam velocity at surface

30 KT/day steam (25,000m3)

Useful surface temp 340o C

Useful surface pressure 70 bar (1015 psi)

25,000 tons/day delivered to surface

25-35 kg solid/ton

25,000 tons x 25-35kg solids/ton = 625,000 kg- 875,000 kg solids per day

I do have a design in mind that might mitigate even more the impact of the system. It would be a modification of the cap over the vent which would allow a small amount of the hydrothermal fluid, perhaps 10%, to escape sideways while the bulk would be carried up the pipe.

That small amount might be enough to allow the vent communities to survive while also allowing exploitation of the fluid.

Ian, your concerns are certainly valid. One thing you should keep in mind is that the journey from ocean floor to surface at a 3m/sec velocity takes about 13 minutes. That is not very much time for heat to escape. In fact, the computer model only assumed a 10 degree C temperature loss from vent to surface. Because of that there will be little deposition on the surfaces, but one good material would be ceramic.

Corrosion is definitely an issue, as is the acidic fluid (roughly as acidic as vinegar), but it will be possible to borrow heavily from the geothermal industry that is dealing with these issues now.

The lifespan of the vents is an issue as well, but we’re still talking several decades as a minimum. That should be enough to recover all costs by far, and it would only require moving a short distance to the new vents that spring up to replace old ones.

Your observation about the submarine cables is good, and in fact I have a second patent on a wholly new method of electrical power transmission that doesn’t use copper at all. The driving force behind it was the obvious need for a better, cheaper way to carry the power longer distances.

There are several possible ways of dealing with the chemical content, but one way is to return what isn’t needed to the bottom of the ocean where it originated. As long as strict controls are in place and the only products returned are those that started there, I don’t see it as pollution.

I do have a design in mind that might mitigate even more the impact of the system. It would be a modification of the cap over the vent which would allow a small amount of the hydrothermal fluid, perhaps 10%, to escape sideways while the bulk would be carried up the pipe.

That small amount might be enough to allow the vent communities to survive while also allowing exploitation of the fluid.

Ian, your concerns are certainly valid. One thing you should keep in mind is that the journey from ocean floor to surface at a 3m/sec velocity takes about 13 minutes. That is not very much time for heat to escape. In fact, the computer model only assumed a 10 degree C temperature loss from vent to surface. Because of that there will be little deposition on the surfaces, but one good material would be ceramic.

Corrosion is definitely an issue, as is the acidic fluid (roughly as acidic as vinegar), but it will be possible to borrow heavily from the geothermal industry that is dealing with these issues now.

The lifespan of the vents is an issue as well, but we’re still talking several decades as a minimum. That should be enough to recover all costs by far, and it would only require moving a short distance to the new vents that spring up to replace old ones.

Your observation about the submarine cables is good, and in fact I have a second patent on a wholly new method of electrical power transmission that doesn’t use copper at all. The driving force behind it was the obvious need for a better, cheaper way to carry the power longer distances.

There are several possible ways of dealing with the chemical content, but one way is to return what isn’t needed to the bottom of the ocean where it originated. As long as strict controls are in place and the only products returned are those that started there, I don’t see it as pollution.

And the arcane language is so readable; “I don’t see the floaty-ness being an issue.”

Thanks for the terrific comments, really educational.

And the arcane language is so readable; “I don’t see the floaty-ness being an issue.”

Thanks for the terrific comments, really educational.

It’s also necessary to add up all of the parasitic loads and costs so you can determine if there is enough resource sites of sufficient scale to sustain a manufacturer. Transmission to a load center alone is typically such a large cost that a resource of a GW+ is minimally necessary to amortize lengthy subsea transmission and at least a dozen such sites relatively close, (<200 nm?), to load centers are needed to amortize the development of the initial plant design.