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Comments by Jim Baird Subscribe

On Nuclear and Renewables Shared Goal and Comparative Costs

Pump deep water to the surface and release more CO2 into the atmosphere than the fossil fuel industry is currently doing.

I also don't know where you come up with HVDC lines. The electricity will be converted to any of many different energy currencies. Many in the auto industry are looking to hydrogen. The problem is it is most often formed from natural gas with CO2 as the byproduct thus no gain for the environment.

OTEC can be combined with the production of supergreen hydrogen to reduce atmospheric CO2 and neutralize an acidifying ocean.

Your costs are also out of whack. Lau "At 2 cents per kwh, an OTEC plant of 12 megawatt capacity can generate 1.0 x 108 kwh of electricity worth 2,000,000 USD. The 12 million USD investment can be recovered in 6 years. With the expected OTEC plant life of 50 years, the net income would be more than 100,000,000 USD."

November 11, 2014    View Comment    

On Nuclear and Renewables Shared Goal and Comparative Costs

I think you are wrong about the vacuum. See again the Prueitt table in each instance the bottom pressure in the vapor channel is higher than the top pressure and this increases the delta T. He then uses a secondary cycle and boiler to drive the turbine. The temperature pressure diagram for CO2 also indicates it forms a liquid at 4C at a pressure of many atmospheres. I believe in the vicinity of 20 per the following.

Nevertheless pressures at 1000 meters are 100 atmospheres and need to be counteracted.

Lau uses a thickness to diameter ratio of 1 to 25 at 1000 meters. His proposal is outlined here.

I have proposed a counter-current fluid return system that uses a coiled pipe to buttress against the crushing forces per the following.

November 11, 2014    View Comment    

On Nuclear and Renewables Shared Goal and Comparative Costs

Melvin Prueitt with Los Alamos filed patent application US patent application 20070289303 A1 - Heat transfer for ocean thermal energy conversion. It is a heat pipe design and the application contains a table which shows the power losses for various working fluids. For NH3 for a plant with an output of 59.4 MW the pump requires 4.66MW giving a net output of 54.7 MW, which I think you would agree is a pretty hardy lunch. These calculations were made with a program call OTEC.exe which is proprietary to the DOE - I believe.

The consensus of the group I am working with is that CO2 would be the best working fluid for this kind of application but unfortunately Prueitt did not run the data for CO2.

James Lau, who is a PhD in physics did enthalpy calculations with CO2 using surface water temperatures of 25.5C and a cold sink of 5.5C and found that the turbine would produce 10.25J/g and the pump would require 2.8J/g for a net energy conversion of 7.45 J/g.

    
November 11, 2014    View Comment    

On Nuclear and Renewables Shared Goal and Comparative Costs

Agreed, this is preciously the approach we would like to take but even baby steps take funding.

Do not though then claim you didn't generate sufficient power when you don't have equipment with sufficient scale to do so.

November 11, 2014    View Comment    

On Nuclear and Renewables Shared Goal and Comparative Costs

Because you can move 35 times more heat a lot faster with the phase changes of the working fluid than you can by pumping the water. And where pray tell are you going to get the power to pump all of this water?

November 11, 2014    View Comment    

On Nuclear and Renewables Shared Goal and Comparative Costs

High capital costs are first a function of the cold water pipe, which due to its size requires large surface infrastucture to support it. Luis Vega point out in "First Generation 50 MW OTEC Plantship for the Production of Electricity and Desalinated Water" to produce 50 MW with the cold water pipe 138.6 m3/s (142,300 kg/s) of cold water is required. Only 2,750 kg/s of anhydrous ammonia as the working fluid is required however and since the density of ammonia is 682 kg/m3  this equates to 4 m3. You can move as much heat in this 4 m3 of the working fluid as you can in 138.6 m3 of water and thus you need much less pipe and surface infrastructure. Since the vapor condenses in cold water at a depth of 1000 meters there is little to no fouling of the surfaces. As to the evaporator the fouling can be addressed with either chloronation or ozonation. The design shown at http://www3.telus.net/gwmitigationmethod/100MWPlant.htm uses the byproduct of sea water electrolysis for this purpose. The output of the original prototypes was small, though Vega claims they did obtain a positive return, but this is mainly due to the size of the plants. Most consider 100MW is required to maximize the thermodynamics and noone has ever demonstrated a system anywhere near that size.

As Paul Curto, former chief technologist with NASA puts it, "the parasitic losses (using the heat pipe design) are cut in half. The costs for the cold water pipe are eliminated, along with the cold water return pipe and condenser pumps, the cleaning system for the condenser, and the overall plant efficiency approaches 85% of Carnot vs. about 70% with a cold water pipe.

The parasitic losses could be reduced as much as 50% and the complexity, mass (and cost) of the system reduced by at least 30%. The vast reduction in operating costs and environmental impacts would be worth investigation alone."

In a nutshell, that is what is different this time, yet not one cent has ever gone towards the investigaiton that is required to genuinely solve the climate problem. 

 
November 10, 2014    View Comment    

On Nuclear and Renewables Shared Goal and Comparative Costs

A plan that actually adds up would first have to comply with the laws of physics or more particularly the laws of thermodynamics.

The IPCC identifies storm surge and sea level rise as the greatest risks and therefore costs associated with climate change. These are both direct consequences of ocean surface warming which power storms, moves heat towards the poles where it melts icecaps and causes the oceans to expand. Heat pipe OTEC could move a great deal of this heat to the benign safety of the depths where the coefficient of expansion of ocean water is less and it has the potential to replace all fossil fuels. Wind, solar and nuclear are carbon free but ocean heat on the surface means the effects of climate change will be with us for 1000 years so if you want to address climate change in the short term only one source of power will accomplish this and at the same time reduce trillions in costs expected to be incurred as a consequence of sea level rise and storm surge in the years ahead.

If you aren't accounting for the benefits of a technology your plan will never add up!

And by the way, OTEC uses no land, produces power 24/7 and has the potential to draw down atmospheric CO2 when combined with Greg Rau's supergreen hydrogen technique.

November 10, 2014    View Comment    

On Renewables Now Cheaper Than Fossil Fuels In Developing Countries

Why stop at costs? How about the benefits? The IPCC identifies storm surge and sea level rise as the greatest risks associated with climate change. These are both direct consequences of ocean surface warming which powers the storms, moves heat towards the poles where it melts icecaps and causes the oceans to expand. Heat pipe OTEC would move a portion of this heat to the benign safety of the depths where the coefficient of expansion of ocean water is less and has the potential to replace all fossil fuels. Wind, solar and nuclear are carbon free but ocean heat on the surface means the effects of climate change will be with us for 1000 years. If you want to address climate change in the short term only one source of power will accomplish this.

November 10, 2014    View Comment    

On World's Scientists Have 'High Confidence' In The 'Irreversible Impacts' Of Climate Inaction

Joe this simply ignores the fact that climate change is essentially ocean surface warming.

Stephen Rahmstorf, one of the lead authors of the IPCC Fourth Assessment Report, points out in a recent RealClimate article, “Ocean heat content has increased by about 2.5 X 1023 Joules since 1970 (IPCC AR5). What would be the impact of that? The answer is: it depends. If this heat were evenly distributed over the entire global ocean, water temperatures would have warmed on average by less than 0.05 °C (global ocean mass 1.4 × 1021 kg, heat capacity 4 J/gK). This tiny warming would have essentially zero impact. The only reason why ocean heat uptake does have an impact is the fact that it is highly concentrated at the surface, where the warming is therefore noticeable (see Fig. 1). Thus in terms of impacts the problem is surface warming.”

Since the problem is surface warming, the obvious solution is to move that heat away from the surface and into the deeper ocean where the impact would be virtually zero.

A heat pipe is the fastest and most efficient way to move large volumes of heat. It also is a device that lends itself to the production of energy by the movement of vapor through a turbine. Estimates are the oceans can produce at least as much energy as is currently derived from fossil fuels with enough of these systems. This energy has a commercial value that would offset the cost of climate remediation and these costs are bound to decline with economies of scale and developmental experience as opposed to the ever increasing costs of harder and harder to obtain fossil fuels.

Ergo climate change is reversible with the right kind of energy production.

November 9, 2014    View Comment    

On Converting Global Warming to Global Energy

Keith, James Lau claims in an Alternative Energy eMagazine posts his design, which uses a deep water condenser, can produce electricity at an estimated wholesale price of 2 cents/KWH.  The capital cost of his 12MW plant is 12 million or $1/W. 

I can't vouch for this estimate but he is a PhD in physics with over 20 patents to his name.

 

November 5, 2014    View Comment    

On Converting Global Warming to Global Energy

Keith, a lot of the problems you cite result from the way OTEC is approached. The conventional way is to use massive pipes to bring cold water near the surface to condense the working fluid. Their size means the surface infrastructure also has to be large and surface heat is diluted making for the potential play out you suggest. There are also environmental problems associated with moving this much water and bringing water containing CO2 dissolved under pressure up to the surface.

The heat pipe design uses piping one order of magnitude smaller, 1 meter versus 10 meters for a 100 MW plant, thus the costs are at least 30 percent lower and the parasitic losses are halved. The Vega study, which is for the conventional design says electricity can be produces at a cost of less than 0.18 $/kWh, which is about the global mean. 

It is understood that the thermodynamics dictate that any plant less than 100MW will not be economically viable.

For the resource to play out using a heat pipe would mean surface heat has been reduced, which is precisely what the world needs. As Rahmstorf suggests the warming of the deep would be neglegible so the resource won't dry up on account of moving heat there.

Using CO2 as a working fluid and the heat pipe design these plants can be scaled to gigawatt capacities.

The group I am working with believes the reason OTEC has never been done on a sizable scale is because it has consistantly been approached in the same, and the incorrect, way.

November 5, 2014    View Comment    

On Converting Global Warming to Global Energy

Max, we never got into a breakdown on this but I would assume it was on an ongoing basis.
November 5, 2014    View Comment