Chairperson Commissioner Gonzalez stated that in the past year, the SFLAFCO's work has been dominated by public power discussions that are similar to the tidal topic being discussed today. He stated that he had an opportunity to see presentations by Drs. Hassard and Neil, has spoken to the Department of Environment's Director, Jared Blumenfeld and Peter O'Donnell, Senior Energy Specialist, and is excited about the prospects of tidal power particularly here in San Francisco.
Jared Blumenfeld, Director, stated that the Local Agency Formation Commission was a perfect forum for airing issues of new technologies especially in the critical area of power generation here in the City and County of San Francisco. Every single day under the Golden Gate Bridge, 400 billion gallons of water passes through. Sometimes, that water can be going up to speeds of six knots. For the past 150 years, there has been a history of efforts to capture tidal power, not so much here in San Francisco, but around the world. There has been an effort to harness this energy that is clearly there and can be seen every day, but hasn't been effectively translated until recently efficiently into power.
One of the things that has been going on is that the San Francisco Public Utilities Commission and the Department of the Environment engaged in a community process which took over a year. Sixteen public meetings were held and an Electricity Resource Plan was produced. When you look at San Francisco from an electrical perspective, we are at the end of a peninsula. We have limited transmission coming into the City, and we have two aging power plants. One is the Potrero Hill Power Plant and the other is the Hunters Point Power Plant, both in the southeast of the City, both environmental justice issues. The leadership of Supervisor Ammiano and Leno put forward thinking initiatives on the ballot about a year and half ago--Propositions B and H. Those basically brought to the forefront the whole issue of solar renewable energy. The City's goal is to put more than 10,000 rooftops that would have panels which would generate roughly 60 megawatts of electricity. But the City's peak demand is about 875 megawatts, so the real question is if we're committed to getting to renewable power as the total source of San Francisco's power in the future, we have to look at a different range of alternatives. We're looking at wind. One of the alternatives that had not been explored until recently with a great deal of focus is tidal.
This is an opportunity today to examine two things, one is the technology that now exists that has revolutionized the way that we do business. The main problem in the past was that if you could imagine 300 feet of water moving anywhere of up to six knots underneath the Golden Gate Bridge of highly corrosive water, there is huge problems with anything that has moving parts, from an engineering perspective in terms of both the taut and the stress on the structures and the long-term durability due to corrosion, not to mention maintenance. There are additional environmental problems related to moving parts in the water because of marine mammals and other marine creatures. There has been a history of people seeing tidal power as something being not environmentally friendly. In large part, they were right, it wasn't. It wasn't something that this Department wanted to talk to or promote because it wasn't something we could get behind. Today, the technological revolution that we will hear about allows you to get power out of the tide with no moving parts under the water. By having no moving parts, you avoid all of those problems that existed in the past. Additionally, we have a large amount of ship traffic coming into the Port of San Francisco and Oakland and we didn't want anything to interfere with that navigation. The new solutions overcome those problems.
Today we will also hear from the U. S. Geological Service on what exactly is the resource that we have at our disposal. We are blessed with a City that is surrounded by water on three sides, so unlike many other renewable energy sources and in particular the wind and the sun, the tidal current is as consistent and predictable as the tide charts. So, 250 years from now I can tell you when the tide will be high and when it will be low. Unlike sun or wind, it doesn't rely on the weather being good or bad or even wave technology that really depends on the height of the wave and the power of the wave. This relies on the tides that are very predictable. In terms of when you look at electricity generation and the key elements in San Francisco as with most metropolitan areas is peak demand. Our peak demand is about 875 to 960 megawatts. So the real question is, what is the intersection between the tidal source that exists out there and peak energy demand? The interface between those two is that about 80 percent of the time the tide would provide a reliable resource for peak demand. It's been estimated that anywhere outward of 1000 megawatts exists underneath the Golden Gate Bridge. If you presume that it was 1000 megawatts and we use on average about 600, then on an average day you would have 600 megawatts that we'd be using and 400 that we would not. That would roughly equate to more than $250,000 a day that should the infrastructure exist, we could sell down the peninsula. So not only is it something that we can use for our own internal needs, but it also would provide much needed City revenue.
In terms of where we go next, the goal of this meeting from my perspective is to try and convince the audience and the LAFCo that what is really needed is a one megawatt pilot project. Does this really work? The only way to find out and do it in a scientific and thorough way is to do a one-megawatt pilot program, and the speakers will address that particular issue.
Another issue that the LAFCo is examining is Carol Migden's legislation that would allow for community aggregation. Should the City pursue that route, community aggregation would allow the City to decide what electricity we would be buying. At the moment, the utilities make those decisions for us, so we have the mix of nuclear, even coal, gas, and some renewables. Should the City decide that they want a percent of that electricity to come from tidal, then a power purchase agreement could be created that would allow a manufacturer and a placement firm to actually use that power purchase contract to allow for a note of credit for this to be built. We see it as an option that needs to be explored if only for environmental justice reasons. At the moment all of our power is coming from one sector of the City of the southeast. There is an unacceptable burden on that population. We also have issues like global warming, which is significant for San Francisco. This is a zero emission, zero pollution option. So today is the first time we can really look at this issue and hopefully, the panelists will be able to answer any questions from the public.
Speakers
Julia Curtis, Climate Protection Division Manager, Department of the Environment, made a presentation and gave an overview comparing renewables with comparing tidal power to wind and solar. Topics discussed were renewable energy and its importance to San Francisco; San Francisco's commitment to renewable energy; benefits and concerns of renewable energy resources; history of tidal power; and tidal energy is a real alternative.
Dr. Ralph Cheng, Senior Research Hydrologist, United States Geological Survey, made a presentation on tidal energy and made an assessment of the Bay's natural resource, the tide. Topics discussed were using the UnTRIM and TRIM Models to estimate tidal energy potential; numerical modeling.
Dr. John Hassard, President and Dr. Joseph Neil, CEO, HydroVenturi, Power Industry and Technology Specialists, made a presentation on tidal energy in San Francisco Bay and how we actually operationalize a one-megawatt power pilot proposal. Topics included an introduction to HydroVenturi; power module being deployed in Grimsby, UK; the Rochester Power System; and San Francisco Bay 1MW System.
Dr. Tony Jones, Director, Practical Ocean Energy Management Systems, made a presentation on the HydroVenturi technology as applied to the San Francisco Golden Gate from an Oceanographers Perspective and discussed environmental issues.
Copies of all presentations are available at the Clerk of the Board's Office, Room 244, City Hall.
Commissioner's Question and Answer Session
Question: Chairperson Commissioner Gonzalez: the module that you had a picture of that was being used in Grimsby, how many were installed?
Answer: Dr. Neil: we actually installed just the one. Once you have built and installed one and watched how one operates, the rest is predictable. All of the phenomena are relatively linear. The system in Grimsby had a specific goal. It was to insure that our modeling and the predictions that we had made in the laboratories were accurate. It wasn't so much to optimize power production, though that obviously is a goal.
Question: Chairperson Commissioner Gonzalez: when we talk about the possibility of a one-megawatt pilot program in San Francisco, how many of those modules are we talking about?
Answer: Dr. Hassard: that the idea is that we would be installing twenty such modules in Iceland to make one megawatt. It depends on the tidal characteristics and the speed of the water. The site in Iceland, which we know very well, there are twenty such systems.
Question: Commissioner Schmeltzer: when you say a module, you mean the eight-foot diameter height is a module?
Answer: Dr. Hassard: that is correct. It is also important to note from what you saw from the video, the configuration of the venturi for San Francisco and most other ocean sites would be of a different geometry, but the principles are the same.
Question: Chairperson Commissioner Gonzalez: I know that you mentioned Iceland, did I hear a mention of Scotland also?
Answer: Dr. Hassard: about the six best sites in the world would include Scotland, Iceland, and San Francisco, so we are picking the best sites to start with.
Answer: Dr. Neil: we have a program, which San Francisco would be the third deployment that we do. We are looking at Scotland and Iceland as experimental and actually producing power, not just test sites.
Question: Chairperson Commissioner Gonzalez: the sense I got from the module but also the other diagrams is that these modules can work in almost a building a block way. You just essentially would stack them or put them side to side. Is that accurate?
Answer: Dr. Hassard: Yes, there are many reasons for this. One is that it is much easier to build. If you have modularity, construction costs are much smaller and can be handled by a normal boat yard. Another issue is that you can stack them and configure them to any given tidal race. You don't have to have multiple designs according to the particular sites you have chosen. A third reason is that should you have used your best estimates on environmental impact and you get them wrong, then you can always remove modules. We don't anticipate this. Particularly, if we can use Dr. Cheng's software, but if it should happen and we can take units off until we know there is no possibility of environmental impact.
Answer: Dr. Neil: in fact, we can balance environmental concerns with power production by using the modularity of the system, so it is not as if you have to deploy a massive great power system right across the bay.
Question: Chairperson Commissioner Gonzalez: can you give me some idea of what the depth is under the bridge and what advantages or disadvantages there are related to that?
Answer: Dr. Cheng: underneath the Golden Gate Bridge the water depth is about 100 meters or 300 feet. The area of deep water is a relatively small region where water shallows up quickly on either side of the bridge.
Question: Chairperson Commissioner Gonzalez: so your thoughts on the advantages or the disadvantages of that depth?
Answer: Dr. Hassard: a 100 meters is not optimal. It is about 40 meters deeper than what we would like it to be. Sixty meters is better for us because that is the limit that divers can go. We don't need divers very often, but occasionally in installation we will need divers. We like depth because it turns out the system works better if it is further down. We can make the system work in ten meters of water even in fact two meters, but with extra engineering. Anywhere between ten meters and sixty meters is perfect for the system.
Answer: Dr. Neil: I would like to add that one of the interesting things brought up by Dr. Jones is the profile of plankton flotation. What we can do with the system is begin to deploy it to the bottom of the bay and build it up until you are sure that you are not impacting the profile of flotation of certain types of plankton to minimize any kind of impact on that critical bio-mass. The other thing is that we don't have to be up to the surface or anywhere near the surface in order to function correctly, and therefore, we are significantly distancing ourselves from the navigation channel. So we are leaving lots of water above the system. It doesn't have to be up to the surface.
Question: Chairperson Commissioner Gonzalez: I appreciate Dr. Hassard, the reference to the minimum amount of depth that you can work with. What do you need to allow for ships to be able to get through?
Answer: Dr. Hassard: I don't know the required clearance depth for the ships going in and out of the Golden Gate, but in the Solent, which is the southern part of England, the maximum we need to leave is 18 meters. Probably in San Francisco it is about the same, maybe about 25 meters.
Answer: Dr. Cheng: it is shallower than that. Outside of the Gate, there is an area; the shallow region called "potato patch." There is a channel being dredged, the NOAH maintains that channel to be about sixty feet. I assume for the boats coming into the bay, they would clear about sixty feet that would provide sufficient clearance.
Question: Commissioner Schmeltzer: what size would the footprint of the turbines that are on the shore be? I know you had an illustration of what is under the bridge, but what size are we talking about?
Answer: Dr. Hassard: we are working with a company called Turbo Genset, and they build units right now which are 150 kilowatts and 450 kilowatts. The 150-kilowatt system has a footprint 3'x3'x3'-these are small units?
Question: Commissioner Schmeltzer: for the whole building?
Answer: Dr. Hassard: that would be 150 kilowatts. But if you have megawatts, you are looking at seven of those so it would be two or three desks worth. It's not a huge footprint. It is very efficient because they are low temperature and therefore, relatively high technology and simple to build.
Question: Commissioner Schmeltzer: optimally, how far away from where the system is would that building be?
Answer: Dr. Hassard: one of the advantages of our system is that the energy is transmitted by air and in principle can go over kilometers. The optimum distance is close by because there are frictional losses over any distance, but we envision transmitting the air power over perhaps 200 meters maximum.
Question: Commissioner Schmeltzer: then how close to the grid?
Answer: Dr. Hassard: we need a grid connection, and various sites that we are looking at we would have to have that nearby. That is an extra cost, which we have not yet fully priced.
Question: Commissioner Schmeltzer: I know you said the Grimsby was just one unit and you weren't looking at maximizing power production. But is there some point at which-I assume the price on this is not linear and that there is some point at which you need a minimum number of units for this to be worthwhile?
Answer: Dr. Hassard: you get great economies of scale. We have done other costings at other places. For example, in Canada we would be looking at something like $1,000,000 per megawatt installed. As you get more and more installed, the prices go down because some of the capital costs like the installation costs are fixed. And the site surveys are fixed; the environmental impact studies are fixed. So definitely as you go to multiple megawatts, the price per megawatt is going down.
Question: Commissioner Schmeltzer: from a smaller number of units or under a megawatt. Is that sort of a minimal level you would need to make?
Answer: Dr. Hassard: it is actually the cost of the grid connection which dominates and so below a megawatt is hardly any point connecting to the grid. One of the things we are looking at however is having smaller sub-megawatt systems which have co-located hydrogen production. This is still in the future, but it is actually closer to us than most people realize.
Question: Commissioner Schmeltzer: you talked about how it was possible to do this on rivers or other water that is flowing in one direction. What is the size of something-I guess we are still talking about any diameter pipe. A river does not strike me as necessarily having the same. You have different characteristics. Here we are looking at something that moves faster at certain times, it slows down, it is not generating all of the time. A river you would be generating all of the time.
Answer: Dr. Neil: the fundamental principle is that you are creating from moving water-you are creating suction which is then exploited and actually transferring low grade kinetic energy into high grade kinetic energy which drives the turbine. That fundamental principle can be exploited either in a tidal race by putting a device which exploits movement backwards and forwards. But even in tidal, you can have tides that are very different in profile going in and going out. The Bay Area is quite unique in that the tide comes in and out from a single point and therefore can be captured at that point. But there are tidal races that we have looked at where the in-tide is some degrees off from the out-tide. There, you would have to deploy uni-directional tidal systems. The whole system is devised to really exploit moving water in one direction. Even the bi-directional system would be two uni-directional systems put back to back. That is probably the best way to think of it. So, it can be deployed in a river system. The way that it is exploited in Grimsby is similar to a run of a river system.
Question: Commissioner Schmeltzer: my point was not to really focus on rivers because I think the idea of putting more generation in a river in California is not what any of us are looking at. My question was more about if you are saying you just need moving water, and it almost seems like tides is not the optimal way to get that unless it is just the size of what's available in the tides and there are certainly lots of water systems in California that have water continuously moving through them in a single direction.
Answer: Dr. Cheng: I think there is a critical energy density. A certain amount of energy must be there to make it work. In other words, if water moves, you have a little venturi effect here, but it may not be cost effective. You need a certain amount of energy there. That's why I thought we can use a mathematical model to first assess what we build-first, where is the energy distribution? What is the up-most choice of locations that you propose to install the devices?
Answer: Dr. Hassard: you asked the question, how much energy in rivers? We looked at some rivers in Canada, and I agree with you, I don't think there are any rivers in California where you want to do it. But in Canada, there are plenty and we looked at some installations in the Frasier River coming into Vancouver, and you get five to ten megawatts from some of the systems we were proposing there. As Dr. Neil said, these would be optimized for one direction.
Question: Commissioner Ammiano thanked the Department of the Environment and Commissioner Gonzalez for bringing this presentation to LAFCo's attention. I really do see that there really will be a significant role here in San Francisco in the energy future of the City. But, I do have several questions about how we proceed. We are limited in the locations that this power can be assessed by San Francisco, and I want to be sure that whatever we do, we pursue a tidal technology that will produce the greatest peak power yield with the fewest impacts. I have some questions for the Department. The technology that we are considering today, has that been certified by the environmental or engineering perspectives by the California Energy Commission or the U. S. Department of Energy? If not, what would be the process for such a review?
Answer: Mr. O'Donnell: I believe we have someone from the California Energy Commission in the audience today. We have been talking to them. I have shown them various technologies to look at. We have a request to do a workshop up there to present this to people. This is too new. It is only since the BC Hydro report of about October last year that there has been a clear statement of the technology, how it is modeled, what the generation potential would be. As to the Department of Energy, they are interested in looking over our shoulder, but in essence, and I don't mean this critically, they don't have anybody up to speed on evaluating these things. That is part of the model here. We invite the state and the nation to look over our shoulders as we go forward. It's very much a local model at this point if that works for us.
Question: Commissioner Ammiano: but it would eventually require some sort of certification?
Answer: Mr. O'Donnell: certification, yes. It would have to be permitted through FERC, through NOAH. And if they are not the permitting agency, they will be the commenting agency because they are all intrigued by this, and they all have the right to raise specific issues.
Question: Commissioner Schmeltzer: there are a lot of environmental groups that are active in hydro permitting for dams. I was wondering if we have gotten any feedback from them about this technology particularly with regard to fish?
Answer: Mr. O'Donnell: I have gone in and spoken to several groups. I don't really want to name names. The general trend is we like this in concept. We reserve the right to study the environmental impact reports before we really take a position one way or the other, but the fact that we are not burning anything intrigues everybody.
Question: Commissioner Ammiano: given that there is this range of potential tidal technologies on the market, how does the Department propose to deal with this in terms of engaging in a competitive process to review the various technologies that are out there now? And I am sure there will be more, and I am sure there will be many changes.
Answer: Mr. Blumenfeld: our goal is to create power with the least environmental impact. The specifics of the RFP that should go out would be focussed on (a) environmental impacts; and (b) efficiency, namely how much power can be generated. So, there are some pretty great concerns around the barrage system that has a big tidal head. There are significant issues around the blade systems, both in terms of the engineering and the impact on marine mammals. The reason we brought this technology to your attention today is the first one that came to our attention that didn't have those large environmental negatives. There may be other competing technologies that we haven't seen that would also make the cut.
Question: Commissioner Ammiano: in terms of the SFPUC, would it be the SFPUC or PG&E that would be in charge of the wheeling, the siding, the transmission, and the grid interconnection for tidal power? What are your proposals to involve the SFPUC in the technology review?
Answer: Mr. Blumenfeld: HydroVenturi and the Department of Environment had a meeting in Room 201 about a few months ago that Supervisor Gonzalez helped host. At that time, we brought in HydroVenturi to talk to Ed Smeloff, Fred Schwartz and others. In terms of how we eventually get into the grid-one of the challenging questions when we look at how to close down Hunter's Point is that most of the interconnection at the moment is in the southeast of the City. That has led to a continued problem of placing fossil-fuel-burning sites in a particular place. For me, it would be the ultimate reversal of environmental injustices if you could have a nice air turbine site right in Pacific Heights.
Question: Commissioner Ammiano: we might have co-generation. I know that as we move forward, we'll get more detailed answers to these questions because I really do think that this is a fantastic opportunity for the City. But, we are talking about the main goal being minimal environmental disruption and impact. What kind of assessment approach are you recommending to review the potential environmental issues? I think it would be useful to involve Save the Bay in such a review. They are very reputable and have been around a long time.
Answer: Mr. Blumenfeld: we have communicated to Save the Bay, Blue Water Network, and others. As we move forward, there are two legal processes. It is our impression that the land is actually owned by the federal government and the National Park Service. There would likely have to be a CEQA, a California Environmental Quality Act review, and a NEPA, a National Environmental Policy Act review. So, an EIR and a very thorough environmental impact that would take a lot of time. I think in the numbers that Dr. Neil presented a large portion of that $4,000,000 probably more than half would go towards environmental impact reviews. We envision over the next two years the majority of time would be spent working with the community and engineers and environmental processes to determine whether this can fly. We are not going to be pushing something that has impacts that are unacceptable to the community, state, or other regulators.
Question: Commissioner Hall: thank you for your presentation-very informative and certainly sounds like an interesting concept for modern-day energy. What is the exact size of the modules that you think may be appropriate for our Bay out here? Just the one module?
Answer: Dr. Neil: I have to make it absolutely clear that the modules that we have produced for Grimsby is a very specific site and design. But, fundamentally, what we would be designing for deployment in the Bay would be very similar in size, if not in profile because the technology requires a venturi effect and there is a physical parameter that you respect. Depending on the type of design that we decide is most efficient and effective for the one megawatt system, I think you can safely assume that it is about twenty times bigger than the module you see on the pictures here, maybe twenty of those.
Question: Commissioner Hall: all I need is a ballpark figure. If you are talking about one megawatt, what will that give us in terms of power and in terms of reality, how many modules are we going to need to satisfy our needs and what size are those modules?
Answer: Dr. Hassard: the way to envision this is if you imagine a container in the back of a trailer tractor, two of those would be something like 200 kilowatts, so for one megawatt, you want ten such containers.
Question: Commissioner Hall: asked, so we would need ten containers about the size of a tractor-trailer.
Answer: Dr. Hassard: imagine those stacked up. You could stack them up like Lego.
Question: Commissioner Hall: you couldn't stack them because you would be encroaching.
Answer: Dr. Hassard: you could put them into a linear or parallel design.
Question: Commissioner Hall: so we are really looking at probably about 100 to 140 feet if you stacked them linear one after the other. Is that correct?
Answer: Dr. Hassard: that is right.
Question: Commissioner Hall asked is the technology based upon resting on the ocean floor or do you suspend it at different times?
Answer: Dr. Hassard: this would depend on the velocity profile and we are so excited by Dr. Cheng's work because he has clearly done a lot of work in studying that. You want to get the maximum velocity, and so we may have to depending on Dr. Cheng's assessment suspend it above the surface of the seafloor. In the cut, we're going through the Golden Gate for example, the water is quite fast down at the bottom because the bottom is scoured out. It would depend on the exact site, which you end up choosing. Right now I can't answer that question exactly.
Question: Commissioner Hall: I think you said there was the maximum velocity or suction which it takes to move the turbines. This is all based on suction?
Answer: Dr. Hassard: that is correct.
Question: Commissioner Hall: there is no moving parts of these modules? It is suction. So it would be sixty feet if there are areas under the bridge or around the bridge that are a hundred feet. Obviously for maximum performance, it would have to be suspended or could it be placed on the floor?
Answer: Dr. Hassard: I think the Golden Gate has been very helpful in people identifying the scale of the issue; however, it is very unlikely that we would be putting the first megawatt under the Golden Gate. In fact, I would be very much against it. We would find sites where the positioning of these units would be much simpler. I imagine we will find a site that is perhaps thirty or forty meters deep and install the one-megawatt pilot there.
Question: Commissioner Hall: somewhere in the Bay though?
Answer: Dr. Hassard: correct.
Question: Commissioner Hall: would that be resting on the floor preferably or suspended?
Answer: Dr. Hassard: my favorite choice would be on the floor because the marine engineering is so much simpler. We would put pilings into the seabed and then attach a platform onto which these units would sit and be attached very strongly.
Question: Commissioner Hall: so you would need an area that was at least 100 feet long to get any sufficient measure of energy that we could use?
Answer: Dr. Hassard: right.
Question: Commissioner Hall: over the top of this there is a screen or grid. Am I correct?
Answer: Dr. Hassard: in front and over.
Question: Commissioner Hall: you all know as well as I do that one of the things that is super important to aqua life is the ocean floor. I would want more knowledge of how this would affect the ocean floor and the flow of the aquamarine life, around, through, above, and on that screen. I like the idea, but I am posing questions that we are going to have to look at. I think it would have dramatic impact upon shrimp and different sea-life that spawn on the ocean floor. What type of material are these modules made of?
Answer: Dr. Neil: the construction today is just steel.
Question: Commissioner Hall: I hope it's not that aluminum. Are there are prototypes in existence now and where are they?
Answer: Dr. Neil: it is in a place called Grimsby in the east of England where the river Humbugh exits and into the North Sea.
Question: Commissioner Hall: how many do you have at that site?
Answer: Dr. Neil: we have one system operating there.
Question: Commissioner Hall: one system of how many modules?
Answer: Dr. Neil: one module.
Question: Commissioner Hall: I would like you to forward as much material as you can as we go along.
Answer: Dr. Hassard: we take the environmental issue as priority number one. I will address the plankton that Dr. Jones mentioned. This is the one area that does require research. Our feeling is that providing we are below about twenty meters, we are probably not going to have a problem because most of the plankton is in the sunlight. The plankton needs the light. So if we are in the dark, we probably will be okay. We are not going to take that for granted. When it comes to fish life, particularly salmon, all of the places that we are looking at, they care a great deal about salmon and that is how it should be. We have to make sure the salmon will go through. That is probably the most important driver for our design. We have to make sure the salmon get through without any damage to them. For that reason, as Dr. Neil said, we get rid of those nozzles, so there is no chance of the salmon bashing into the side of the venturi themselves.
Question: Commissioner Hall: it is not just the salmon I am concerned about, but the actual aquamarine life that breeds on the bed of the ocean. Now you would be talking about a half a dozen to a dozen of these modules eventually, and that would take up quite a bit of the ocean floor, create quite a barrier that would at least be ten to fifteen feet high, I assume.
Answer: Drs. Neil and Hassard: more than that.
Question: Commissioner Hall: I would be curious to find out about the flow of the Bay because you are going to dramatically impact that flow. You are capturing the energy from that water.
Answer: Dr. Hassard: one of the people we have been talking to comes from BP, the oil company. He was citing evidence from oil rigs from the North Sea in England, and he says the old rigs are favored by sea life, they enjoy the structures, and they provide protection and homes for all sorts of the fish and shrimp life. We're not necessarily claiming that for our system, but it is at least a possibility that we can engineer it.
Question: Commissioner Hall: I am sure we have old fishing vessels on the bottom of the Bay that have never been pulled up. It is just a concern. If you could forward any material you come across relating to this.
Statement: Ms. Young: if there are questions that cannot be answered today and the information can be provided by the experts at a later time, we can in fact get that information, provide it to the LAFCo Commission and also post it on our website.
Question: Chairperson Commissioner Gonzalez: Dr. Neil and Dr. Hassard-Supervisor Hall asked you about Grimsby. You have a plan to install twenty modules in Iceland. When do you think that is going to happen?
Answer: Dr. Neil: we are in negotiations right now.
Answer: Dr. Hassard: in Iceland, you can only do it in the summer. We are hoping to get it done soon if not it is going to be next summer. It's either this summer or next summer depending on our funding profile.
Answer: Dr. Neil: we are also intending to deploy in Scotland almost the same thing. It has to be during the clement months, which means in the summer, I think.
Question: Commissioner Schmeltzer: going back to the fish, it sounds like there is not a whole lot of information available about how this might affect our endangered species fish in the bay, particularly the salmon. I believe under the California Endangered Species Act there are a few others. I know this will have to be evaluated in the EIR and EIS process, but what information do we already have that might be useful or what information would we have to find out in order to make those determinations?
Answer: Dr. Jones: yes there are endangered species in the Bay. The main point that I was bringing out was that different fish all react to what I call the bow wave differently and that needs to be addressed. I did not have an opportunity to do a complete and thorough research on that aspect of it. I am not too worried about the larger fish. I am more interested in the smaller juvenile fish, which would probably be of a greater concern. I guess it all depends on whether the modules are sitting on the bottom or if they are up off the bottom. There may be ways for the fish to pass that if they are able to detect this bow wave, then they will be able to avoid it.
Answer: Dr. Hassard: the danger to fish is the sudden change in pressure. We believe that the maximum pressure drop is such that it's within the salmon's range to deal with. Salmon rapidly do go from the depth to the surface very quickly. Other fish as Dr. Jones has pointed out, we don't know yet. We will need to do a study.
Answer: Dr. Neil: one of the things is that we are in a situation here where we don't have the answers because the technology is new and because fish species and fighter plankton are so regionally specific that we will not know the answer until you try a demonstration system or a pilot system in a given environment what the actual effect would be. One of the nice things about this system is that should it prove viable both environmentally and economically, it would be very easy to expand it rapidly and produce huge amounts of power. Should it prove detrimental, no one would necessarily be prone to giving away two or three million dollars. It's not an extraordinary amount to pay to investigate the possibility that they could be a massive contribution to our energy systems without significant environmental impact. Basically, until we try it, we won't know and the cost of trying it is pretty low.
Question: Commissioner Schmeltzer: from a permitting perspective if you can't show that you're not going to take endangered species, that can be a barrier.
Answer: Dr. Neil: absolutely, we understand that.
Public Comment Question and Answer Session
Question: Randy Hayes, Rainforest Action Network and Vice-President for the Commission on the Environment for the City of San Francisco: we are in a dangerous situation in terms of climate change and one-megawatt pilot. I understand how we need to assess data. The City should be looking at the various types of tide-power systems and have a one-megawatt project of each basic type so that we don't put all of our eggs into one basket and to help with the learning curve. As Supervisor Ammiano pointed out, we have our peak energy needs, but during off-peak it would be great to dedicate a high percentage of the power to make hydrogen. When you make hydrogen from water and possibly even sea water with green electrons, we can power MUNI and the City auto fleet and the local delivery companies as early adopters to prod along this hydrogen aspect of the energy equation as well. My last point is that I wasn't clear whether the City would be guaranteeing any energy purchase packages with such a pilot project?
Question: Mr. Jerry Grace, Oakland resident: he was surprised to hear the information about renewable tidal energy and commended everyone working on this project. The maps and information are not included here and should be to make people aware of what is going on. He recommended that television (NBC) be made aware of renewable tidal energy so it can be publicized more. There are a lot of fish, birds, ducks and oil in the water. I don't understand why the oil is in the water and why the ships going in and out of the Golden Gate Bridge cause oil all over the ground. This happens too many times. How would you make water clean?
Question: Tom Roberts: I want to start off with a comment or question about the tidal power being in phase with load. If we were in most cities, peak summer demand would be directly in phase with solar insulation. But tides since they change daily are not directly in sync with any evening or afternoon loads so I would ask the Department of the Environment if you are time averaging to say that the 80% of the energy being in phase with demand is partially because we don't have a huge peak summer demand by people running air conditioners in San Francisco. I hope that makes us ideal for this technology, but it is a limitation compared to solar in just one regard. I had a couple of questions about the technology itself and the video we say what looked like large vertical wings, but it looks like your technology is strictly a cross-sectional change. The Venturi is a cross-sectional change-there isn't any external wings causing the velocity change. Is that correct?
Question: Dr. Joseph Neil, CEO, HydroVenturi: the water has to be accelerated through the system. That's the fundamental way that it actually works. What we do is create that acceleration by putting first an obstruction and then giving it a place to go. By constricting the flow, it accelerates through the water.
Question: Mr. Roberts: he understands the Venturi principle. What I am asking is you showed us a cylindrical object with a cross-sectional change that causes the velocity change. The video seemed to show these large vertical wings. I just wanted to make sure there is nothing external.
Answer: Dr. Neil: it is very much the same. It is just a slight difference. That is in fact an early design, and we have many different designs to exploit the same fundamental principle.
Question: Mr. Roberts: are any animals or fish going through the throat of the Venturi or are you trying to screen them all out?
Answer: Dr. Neil: we grill off the system so that marine life cannot go through. The grill is designed so that the grill itself is smaller than the cross section of the spaces between the wings and therefore, anything that does get through will go through very quickly.
Question: Mr. Roberts: so something might go through the throat of the Venturi. What kind of speed is in the throat with the six-knot inlet? The final question was you are drawing air from the surface with the suction at the Venturi. Are you exhausting air underwater or is there a secondary water system that you had mentioned? If you are drawing air underwater, obviously with a pilot plant you are talking about a small volume of air. But if it's a large plant, you might have large concentrations of oxygen and nitrogen being induced locally, and I don't know what the effect on fish life would be with that effect.
Question: Kimia Mizany, Save the Bay: we have a few concerns, and we appreciate the fact that all of the environmental work has not been done to assess the impacts so you may have limited responses to some of these concerns that we have at this time. When you spoke of the depth of the mouth of the bay not being the optimal depth for this type of structure for tidal power, what specifically would be necessary to do to build the structure at that optimal sixty meters? Would this involve filling any part of the channel? If you could discuss what impact this tidal power structure as well as the induced suction force might have on sedimentation in the Bay, as increased sedimentation would contribute to increase turbidity, which would impair the water quality in the Bay?
Question: Timothy Blair, Earthsteward Technology and Synergy California: about changing siltation issues under the Golden Gate Bridge and I hope you can engineer for that. It depends upon what suspension the whole system is going to be above the seabed. I think this is a real exciting project and the foresight of the City to go forward is real important for that to happen that permits get approved to move this forward. At Romberg Center, the San Francisco State Marine Center on the Tiburon Peninsula, could be a perfect initial staging site to possibly do some of the research there. It's the old sub-net depot base or over by the Richmond ship channel are two possible places where you would have less impact in getting your infrastructure set up to start this project. The University would be a great place to teamwork. According to the charts, I saw the currents are very strong over at Romberg Center where a lot of the salmon are passing through all of the time. You don't have to respond to the written questions.
Statement: Commissioner Hall: this is one part of a series of different hearings relating to water energy. We are going to be talking about recycled water.
Statement: Gloria L. Young, Executive Officer: SFLAFCo will have a series of public hearings. This was the first one on renewable tidal energy. Our next one and it was mentioned as a part of the Department of the Environment's presentations in terms of tidal power and it is strategically located to support the desalinization. Our next public hearing will be desalinization on March 28 at 2:00 p.m. April 11 will be recycled water and ground water. May 23 will be solar power and conservation and then we will be discussing the final report on Community Aggregation, AB117 on June 20th. All of those dates are listed on our website.
Question: Male speaker: having been born here, this is an idea whose time has come. I have been mentioning it to Jerry Brown about ten years ago. Living out at Ocean Beach, I have one engineering question. I heard that Supervisor Hall asked that this would probably be built out of stainless steel. My question to the engineer is and especially to the rest of you, because I know about the corrosive elements of the salt water-I have lived here all of my life and I am constantly scraping it off my house--have you considered something like ceramic material or something else that would be longer lasting and would not look ugly in twenty years with rust spots?
Question: Tom McDonough: my colleague Joel Kohn had to leave earlier and wanted me to make this statement. The wholesale price of natural gas has doubled over the past three months. Natural gas fuels or electric power plants-we are facing yet another energy crisis. It is imperative to adapt alternative energy; tidal energy is the brightest hope for powering San Francisco into the future. On my own part, I commend you at HydroVenturi for your taut work and research. This has vast implications on a global basis for producing clean and powerful energy. But this is the beginning. Our impulse must be socked from other sources to insure that San Francisco has the best system it can conceivably have in this present time period and bring those into the future.
Question: Andrew Bozeman: thank you for a marvelous idea. I am from the Hunter's Point area and I thank Supervisor Ammiano for your great idea of putting a power plant in Pacific Heights as opposed to Bayview Hunter's Point. Considering the predilection of sealife to begin building homes on anything that stands still at the bottom of the sea and you have this grid up that prevents them from going through, but is a great place to start building. My question is how long will it last before they clog it up and it becomes inefficient?
Answer: Jared Blumenfeld, Director, Department of the Environment: in terms of the power purchase, which is Commissioner Hayes' first question, I think the goal here is that this is the beginning. We are racing ahead in some ways and excited about it, but it is the very beginning of this new technology. We do need to start with a one-megawatt pilot. We do need to make sure that all the environmental aspects are in place. That all the marine life is safe. But at the same time, we need to give the same degree of scrutiny that we would to power plant that we know has human impacts on health and our environment. So when you look at, this has a huge number of benefits. We also need to do a lot of environmental due diligence. In terms of power purchase, that would be predicated on us becoming a community aggregator and the California Public Utilities Commission is coming out with rules on aggregation in July.
Answer: Mr. Blumenfeld: the next comment was on the MTC and we obviously need to work with all the stakeholders, the Golden Gate Bridge Authority that I know some of the members of the Board sit on; BCDC. There are going to be a huge number of people to work with. This was just an opportunity to highlight the technology and bring it to the public for the first time.
Answer: Mr. Blumenfeld: in terms of bringing oil under the Golden Gate Bridge. I think San Francisco and certainly from my environmental background the need to have double hull vessels going through critical navigation points is an important one, and so as a matter of policy, the U. S. Government is also on the record with that.
Answer: Peter O'Donnell, Senior Energy Specialist, Department of the Environment addressed the issue in terms of tidal phase with peak and the fact that San Francisco has two peaks. The 78 percent figure is really projected over one calendar year and that tidal energy ramps out, peaks, and drops down over about a six-hour cycle four times in a twenty-four hour cycle. So you look at that four peaks a day cycling through peak sometime between 6:00 a.m. and 6:00 p.m. and tidal power will provide energy in that window about 80 percent of the time. That's the simple answer-it is a hard question.
Question: Mr. Blumenfeld: I remember a study that BC Hydro did on fish kill as a result of the run of the river. Maybe somebody could talk about how many fish were killed in a yearlong study.
Answer: Mr. O'Donnell: the study I am familiar with is Blue Energy, Canada testing six in river trials of one month or less on a series of vertical access turbines and they tell me there was no fish kill, but I don't think that was a true environmental resource study.
Question: Mr. Blumenfeld: in terms of this particular system, the second question was feed in the throat.
Answer: Dr. Joseph Neil, CEO, HydroVenturi: we are fundamentally committed to protection of the environment. HydroVenturi's byline is power, not pollution. That is a fundamental parameter. We are very concerned to design and engineer the system to be minimally impacting in the environment in which it is deployed.
Answer: Dr. John Hassard, President, HydroVenturi: the six knot entrance feed would result in 24-knot, that is 48 meters per second water in the throat. We have a compression ratio of about 4-1, 5-1. In other words, the water speeds up by that same factor.
Question: Mr. Blumenfeld: in terms of exhausting the air. You suck the air in-where does it go?
Answer: Dr. Hassard: in one configuration for cleaning water of oil, we actually let the air into the primary circuit. In the power configuration, which is what we are proposing here, the air is re-circulated and does not end up in the water. We take that very seriously because that would be an environmental impact, which we wouldn't want and it would be a loss of power. We actually re-circulate the air into the system.
Answer: Mr. Blumenfeld: in terms of the save the bay question how to build a structure to sixty meters, my understanding is that from Ralph's presentation that there are a lot of areas in the bay that are sixty feet already.
Answer: Dr. Hassard: we do not have any intention of infilling any of these structures underneath the bridge or anywhere else. It would not be needed.
Question: Mr. Blumenfeld: what about the impact of the induction from the set of suction force impacting on sediment? The second question was siltation.
Answer: Dr. Neil: the fundamental thing here is that water is entering the system at normal velocity. It is then accelerated through the system and we clearly have to test what the overall impact of the system would be and nobody wants to assume that we are going to have minimal impact at the point where the device touches the bay. But, the fundamental truth is that the water really doesn't accelerate until it hits the system. It accelerates through the system and comes out the other side and then it is dissipated, so the energy is captured in the middle. We have to go back and look at exactly how this impacts sedimentation.
Question: Mr. Blumenfeld: Dr. Jones, we had a great model from Dr. Cheng on the tidal resource. Are there other models that can map sedimentation impacts so that you could run through this model and say this is how sediment will react? Do those exist?
Answer: Dr. Tony Jones, Director, Practical Ocean Energy Management Systems: not specific to the bay.
Answer: Dr. Neil: I think TRIM is the best software tool for this particular area by far.
Question: Mr. Blumenfeld: the next question was on permitting and the potential of different sites, Pt. Tiburon and Richmond ship channel. Mr. O'Donnell will address where a pilot can be done.
Answer: Mr. O'Donnell: a pilot by nature requires leadership from a community that is committed to doing this, and one megawatt would be rational next step. After that, one megawatt is done, then we might look at another site, Pt. San Pablo, Tiburon, Vallejo for the next phase, which might be 10 or 25 megawatts. Then you come back to another site maybe in San Francisco, certainly in the bay, for the next phase of installation. This will be a regional activity that will require a sharing of technology amongst communities and counties.
Question: Mr. Blumenfeld: the next question was about teamwork. I think a new technology like this will not go anywhere without working with governments, business, universities, the U. S. federal, state, and local governments. It will take more than a village to get this to happen, but hopefully it will. Then there was a question about the materials, ceramics versus steel.
Answer: Dr. Hassard: the steel systems in the docking Grimsby have been around since Napoleonic times, which is 200 years ago. We take the corrosion very seriously however, and we are looking at coating such as polyurethane, which is pioneered by the U. S. Navy in the last few years as a potential cover. We have not looked at ceramics-it seems very expensive, but we are willing to do so if someone has information about advanced ceramic materials. Right now, steel is the best material for us and if we can get sixty years lifetime out of it, that is probably going to be a good return investment. But we are very happy to look at other possibilities.
Question: Mr. Blumenfeld: the final question came from Andrew which is relating to clogging. If you have these meshes to prevent animals getting in. I know that for instance that rather controversial Hydro Project Three Gorges Dam is already silting and clogging. Obviously, these things can't work if something is in the way of them. So how do you deal with that specific issue?
Answer: Dr. Hassard: there is some indication that the barnacles that could be most damaging to us would have to have a minimum water speed before they can settle. What we are really concerned about is clogging in the center of the hydroventuri. That is where the water is going fastest. We think we have a good chance there. Also, investigating coatings like polyurethane, which the U. S. Navy has developed for the boats. We would never use tributil or any tin-based system. The fact is this is going to be a site-specific issue and Dr. Jones pointed out there are certain forms of marine life which actually like fast water because they get more nutrients that way. We will have to assess this. I think one of the jobs for the one-megawatt demonstrator would be to make a study of this issue.
Answer: Dr. Neil: we actually have given some thought to this problem and have designed the possibility to remove the protective grill, put in a new grill and clean the old one, have a system that shifts up and down basically. That is part of the design.