Sunday, April 6, 2008

Summit Ends on High, Hopeful but Cautious Note: Act Now or Be Sorry Later; Hawaii Eyes Big Step

We started this blog to create buzz for ocean thermal energy conversion (OTEC), and as is often the case, something else happened. Beyond buzz, this blog took us to the Blue Planet Summit and exposure to some of the giants in the renewable energy and get-off-oil movement.

Henk Rogers and his Blue Planet Foundation team will have to hustle next year to top this year’s program – maybe produce three television shows instead of “only” two and invite more than “only” one Nobel laureate. The team’s downstream media and reports are bound to be as impressive as the Summit itself.

They’re also sure to be accented by blunt warnings about what must be done immediately to avoid environmental and economic catastrophe. As noted in yesterday’s post, two airlines that served Hawaii went under in the past week. If Hawaii represents the canary in the coal mine, the bird already has fallen off its perch.

But good things are happening here, too, and the Legislature is about to enact a solar water heater mandate for all new homes. As the Star-Bulletin editorializes today, solar systems “should be as much a part of home building standards as flush toilets” – especially in this sunny state.

Why a Blue Planet?

We listened intently much more than we talked at the Blue Planet Summit, but we did manage one microphone-in-hand comment about OTEC’s potential to replace fossil fuel for base-load generation in the islands.

Earth is the Blue Planet because it’s a water planet; 71 percent of the earth’s surface is covered by water, so the sun’s energy falls on and is absorbed mostly in the oceans. By some accounts, the energy equivalent of all that sunlight hitting the oceans is 250 billion barrels of oil each and every day.

OTEC converts that stored energy into electricity. The technology is a perfect fit for base-load electrical generation in tropical Hawaii, which imports oil to generate 90 percent of our electricity.

Solar water heating, solar photovoltaics, wind and wave energy, biofuels – they all will transition us to a post-petroleum economy. Nevertheless, we see OTEC as the biggest bang for the buck and major component in achieving the state’s goal of 70 percent reliance on renewable energy by 2030.

Indeed, the goal is so ambitious that it likely can be realized only with OTEC. 2008 would be an excellent time to begin.

(Want to know more about OTEC? Check out these two sites -- at the Department of Energy and at a site maintained by an Australian port city with OTEC ambitions.)


LightOnTheEarth said...

Hi Doug,
While OTEC is a fantastic technology, there are technical reasons that it has not yet been developed. I believe that these can be overcome, but it will take a new kind of practical thinking that I am not sure exists in either the electrical utility monopoly or in the renewable energy business.

To summarize, because of something called parasitic losses (friction of the water on the pipe walls), OTEC plants need to be floating (not land based) in order to have the shortest pipe run possible. This is the genius of the SeaSolar vision.

Unfortunately there are also limits to this vision and those come in the form of the undersea cable to transfer the power to land. If you have ever been on a ship in a big storm, you understand how immensely powerful nature is. I have been on a 700 foot ship 90 miles from the edge of a hurricane, and I can tell you that anything long attached to that OTEC ship would be rapidly torn away. The security of the electrical transfer to the shore from even 10 miles would be very tenuous at best.

The solution, I believe is to use the OTEC energy to produce hydrogen fuel from salt water electrolysers. This can be transferred by ship to the mainland where it can be used in fuel cells or to power combustion turbines. A broken connection to a transport ship is no problem. To an undersea high voltage cable, it is an enormous problem.
Jonathan Cole

Doug Carlson said...

Aloha, Jonathan. Thank you for your thoughtful comments. There seem to be a variety of approaches to implementing OTEC. I trust my engineer friends to find the solutions to make it workable either by land or by sea. I'll visit your website and hope to stay in touch. ~Doug