Ocean Energy Overview Video Text Version
Below is a text version of the presentation given by E. Ian Baring-Gould of the National Renewable Energy Laboratory (NREL) at the Low Carbon Communities in the Caribbean Workshop in March 2011. The workshop was held at NREL in Golden, Colorado.
So, what I'm going to do is just kind of provide an introduction to the ocean energy systems that we're looking at here, talk through the three technologies that are truly viable when we look at ocean energy — waves, current and then the thermal gradient, OTEC and things of that nature — and then do a quick conclusion. We have a researcher at the laboratory, Dr. Bob Thresher, who's been in the wind industry for a very long time and over the last ten years has really focused on ocean technologies. His first comment when pulling together this presentation was to just put up one slide that said, “Come back in ten years.”
And I think that's kind of the indication of where we are in the technology, and we'll certainly go through this and then we can answer the questions that people have. Here are some basic estimates on the resources, primarily in the United States, looking at wave current, ocean current, OTEC and then the gradient technologies. Certainly, a fair amount of work has been done to get initial assessments of what the resources are in various parts of the world, but they're all very locally dependent. And so, one of the critical first steps — and we can get to this, again, at the end — is really to start looking at what resources you have available in the islands.
So, clearly, current and gradient are technologies that could be very viable. Wave, maybe not so, but understanding what your local ocean conditions are so that you can start looking at what technologies you could implement when those technologies come about. I think this slide is a pretty good indication of where we are in regards to technology development and you see here tidal, tide current wave and salinity — the number of kilowatts of installed capacity in the world. And so, when we're talking about a megawatt of current technology that's been installed — two megawatts that have been installed throughout the world. That's not a technology that is truly ready for prime time.
In all of these cases, these are demonstration projects that have been implemented, that people are using; very little understanding about what the costs are, what the power production from these units are. Again, this is installed capacity, so it's easy to get an installed capacity number as opposed to a generation number. So, we're still very much in the early phases, and this is a chart of wind turbines — clearly, wind turbine technology — and how it kind of started with small pilot projects and has increased up to the turbines that we see today, and kind of going through all of the stages that need to happen to be able to get to a truly viable market.
The common thinking that's out there is the marine hydrokinetic — are back in this time frame. So, it's comparing the wind industry to the late ‘70s, early ‘80s in regards to the technology development. There's a few products that are out there. They seem to work reasonably well, but these are one-off pilot projects, not commercially viable. They're breaking all the time and people are working on them to improve the technology, but they're not there yet. And so, there's a lot of process that I'll talk about it in a second to get from where we are as kind of a beginning technology up to the more developed technologies that we're seeing for wind and solar, geothermal, biomass and those areas.
There is a pretty robust program worldwide looking at developing the hydrokinetic resource, primarily — the United States has a somewhat large one. UK has a very large one. The European Union has a scaled-back one. So, there's a fair amount of money that is going into the development of the hydrokinetic technology, but we're still a little ways off. And so, I mean, the goal by 2030 to deploy 20 gigawatts of hydrokinetic is a goal that the US government is looking at. Again, that's 20 years in the future, installing only 20 gigawatts of total capacity. So, a good demonstration of where we are, and I think this next slide really kind of demonstrates this.
Up here, we have timelines of conceptual R and D prototype testing, demonstration projects where we're looking at up to five megawatts of installed capacity, small commercial projects up to the 50 megawatts and then large 100 megawatts. And then, on the bottom part of this is kind of all of the things that we need to do to be able to get to truly deployed projects. The sighting and permitting — environmental research — none of these things have really been done. Baseline studies to understand the technology, research into kind of the policy of the market development, economics — we're here in 2010 and, basically, where we are is what's shown on this chart. We have a few demonstration products.
A few organizations with governmental funding are putting demonstration projects in the water and people are learning a lot about the technology at this point, but they're prototypes at this point in time. So, to move forwards, we really need to address these five areas in a lot more clarity. The cost reductions that's driven by system-reliability performance and cost — system and testing — so, we need to get systems in the water, operating, so that we understand the unique conditions that the marine environment gives us. The development of an evaluation and a performance standard — none of that exists right now.
So, how do you put a standard in place? How do you understand how much energy it's actually producing, under what conditions? How do you compare the different technologies that are out there in the marketplace or will become put out in the marketplace? So, how do we understand the technology and are able to evaluate that on a level playing field? Resource modeling — as I said, we've got a little bit of information in regards to the global resource, these very kind of global studies. But, clearly, a lot more work needs to be done on the resource assessment to understand what is available specifically in locales so that we understand whether we're looking at economic projects or not, and then understanding the environmental effects.
So, how do hydrokinetic turbines interact with their environment and what kind of impacts are we going to see when we start putting large quantities of hydrokinetic technologies into the water? And DOE has a program that is really looking at all of these areas, both on a technology-development front as well as on a market acceleration. So, currently, the Department of Energy program is looking at these. Certainly, the UK program is looking at all of these but is trying to move the ball forward so that we have viable technologies in the upcoming years.
So, looking at kind of an overview of where we stand from the technology standpoint, but looking at the devices that we have out there — wave devices. There's a number of different flavors in regards to wave absorbers, attenuators, oscillating wave columns. So, a number of different technologies that are available, looking at wave technologies. Two devices here. Certainly, the modeling effort — looking at swaying devices and then a couple of prototype testing, but really trying to understand the interactions between the waves and the actual devices, tools to look at power gradients. All of these types of things are areas on the performance spectrum that we're looking at, both from an analytical point of view as well as deploying prototypes.
And then, certainly, the reliability and survivability of the technology once you get it into the ocean. Current devices are similar in this regard. A number of different devices that we see out there in the spectrum — an axial flow device that you can put in rivers, cross-flow, more like small wind turbines that you put in there. So, a number of different technologies that people are looking at and then testing. This one is — all of these, clearly, are prototype testing that is going on. This one — quite interesting. That's in the Bay of Fundi and when they pulled that out after the initial test, all the blades had been ripped off of it. So, that's kind of the level of where we are. This turbine they put in the East River and it worked quite well but, again, they broke all the blades off that one as well after about a year of operation. Certainly, still in the early phases of the technology development.
From a research perspective, lots of different work going on; looking at the strength of blades; computer modeling to simulate what the forces are. A lot of this building off the work that's been done in the wine industry because a lot of these technologies are similar in characteristic. Clearly, these have a lot in common with the wind turbine blades, but certainly in a higher-viscosity environment. The cross-flow — the circular ones — are like vertical-axis wind turbines. Again, a lot of the computer models that were developed for the wind industry are being applied to the hydrokinetic so that we can build better turbines that will end up working over the long term.
The next one is thermal gradients, and that breaks into two flavors — the OTEC and what we see here is the global map of OTEC potential. So, looking at thermal gradients, OTEC certainly — most people know the basics of the OTEC technology, but it's using the delta temperature, and I have another slide that goes into the different cycles. But, clearly, the issues are needing to drive the cost down and, again, get pilot projects that are working at it. Lockheed Martin is the company right now that's kind of promoting the technology. They have a ten-megawatt unit that they would like to test and they're currently out looking for funding in the order of $300 million to build a test prototype ten-megawatt OTEC plant.
So, that's really where the OTEC field stands at this point. All of the other projects that have been implemented as a pilot phase are no longer functional. And so, it's really trying to get the initial technology out there. Looking at the different OTEC cycles, we have an open cycle and a closed cycle. It's just depending on — the open cycle uses the fluid. It's basically the same technology. One of the advantages, however, of the open cycle is that you also can produce desalinated water. So, with the combination of the power generation and the desalination of the water, that can move you along and improve the economics of the project.
The closed cycle — very similar, except instead of using the water itself as the operating fuel, you use something like ammonia, and the same process still exists. The last technology is the seawater air conditioning, and it was brought up yesterday as something that we can certainly look at. Only a few examples that have been put in place, but they've been put in successfully and kind of the anecdotal information that we have gotten is, basically, if you're doing new construction then this can make a lot of economic sense. If you're trying to retrofit existing facilities, it's more of an economic question. It becomes more complicated, but certainly a viable technology to look at, using the cool temperatures of the water to replace air conditioning.
So, in regards to kind of the fields in the Caribbean, the kind of general recommendation is, the technology is not ready. And so, the first thing to do is to start looking at the resources that you have available because, clearly, the resources are going to drive what technology is viable once the technology kind of moves along the design curve. So, working with your universities to identify local resources — the University of Florida has a pretty active program. Looking at temperature gradients as well as where the currents along the coast of Florida are.
So, understanding what options you have from a resource perspective and what those resources look like — whether you have a very good resource or a mediocre resource — and understanding those so that in five years or ten years, when the technology is advanced to the point where it's not even commercial, necessarily, but quasi-commercial, you know what your resources are and you know what the conditions are where you would implement these technologies. So, there is clearly a lot of thermal potential in the Caribbean nations, and so the OTEC is clearly a technology that should be looked at. But, again, you need to assess that very carefully and then we need to wait for the OTEC Technology to advance, unless any of you have $300 million that Lockheed Martin would, I'm sure, love to use for you. So, again, understanding the resource and then waiting for the technology to be developed to the point where we can take advantage of it.