The news that the world’s largest tidal turbine – 1 MW in size – will be installed off the coast of Scotland near Orkney should come as no surprise.

Primitive tidal mills operated in the England date back to the 11th century. During the 18th century, several tidal mills popped up in Western Europe. The first modern tidal plants borrowed from conventional hydropower concepts by relying upon dams or barrages. La Rance, France still boasts the largest such system in the world, supplying 240 MW of capacity since 1966.

Scotland is the hot spot for tidal power in all of northern Europe, with the Pentland Firth often described as the “Saudi Arabia of tidal power.” The U.K. and Ireland also feature among the best tidal sites in the world, because they are relatively close to people. Some from these islands near the European coast may argue with this assessment, but when compared to the U.S. — where 95% of the nation’s tidal resources rise and fall off the coast of remote Alaska — it becomes clear it is all a matter of perspective.

Tidal stream turbines often look suspiciously like wind turbines placed underwater. Tidal projects comprise over 90 percent of today’s marine kinetic capacity totals, but the vast majority of this installed capacity relies upon first generation “barrage” systems still relying upon storage dams (see forecast below.)

Pike Research will be issuing a revised forecast of ocean energy technologies next year, with lower capacity totals given the lack of progress on carbon regulations and the lingering recession, but this 2009 forecast shows how tidal systems dominate the near-term market for ocean energy technologies.

What is the scientific basis of tides?

Tides result from the gravitational forces of the moon and sun interacting with oceans. (Because of its proximity to the earth, the moon actually exerts about twice as much influence on tidal patterns as the sun.) The ever-changing relationship between the moon, sun, and earth causes the ocean to rise and fall at regular intervals. These bulges are frequently referred to as “semi-diurnal” tides.

These tidal streams become concentrated pools of kinetic energy ideal for power generation, when passing through narrow channels, an inlet into a bay or other passages between two land masses. While the tidal resource is much less abundant than wave energy resources, its power density is greater. Most waves move at the pace of approximately one meter per second; tides typically move at least twice that speed at two meters per second. A doubling of the speed of tidal streams will result in eight times the amount of potential energy since power density is determined by the cube of water speed.

The Electric Power Research Institute has projected that a 100 MW tidal stream turbine project could generate power at a cost of 6 to 9 cents per kilowatt hour, which is competitive with wind, geothermal and other mainstream renewable technologies.

The basic selling points for tidal as follows:

•Tidal resources have the highest power density of any of the marine renewable technologies, hence the lowest cost estimates.

•Unlike many renewable resources including solar and wind power, tidal resources can be accurately predicted literally years in advance.

•Tidal devices are typically sited below the ocean surface: they can’t be seen; can’t be heard; and, in most instances, would not interfere with shipping or other maritime uses.

While physics is on the side of tidal streams if compared to wave energy resources, the size of the resource is much smaller. Most experts estimate the wave resource to be two to three times the size of the world’s tidal stream resource.

I recently had an interesting conversation with Andy Balding, Director of Powertrain Engineering for Lotus Engineering regarding the generator internal combustion engines (ICEs) used in plug-in hybrids.  There were a couple a of points that he made during the conversation that I felt were interesting and deserved some further consideration.

Regarding the engines themselves, Balding points out that the engines do not have to be the high-tech ICEs often used in traditional vehicles.  In order to achieve the maximum balance of acceleration, low emissions, and fuel efficiency in a traditional vehicle, ICEs need to be able to run at high RPM and incorporate complicated variable valve timing and injection systems.  These systems improve the efficiency of the burn of fuel in the cylinder.  However, as automakers look at building serial plug-in hybrids (vehicles with no mechanical connection between the ICE and the wheels), a lot of this technology is likely unnecessary. 

I think this is a very intriguing concept.  By reducing the complexity the ICE, automakers can lower the cost and potentially, the weight.  The engine, for the most part, will only run at one speed.  The engine can be optimized for that one speed and remove technology that is not necessary. 

In a recent video of the Chevy Volt running with the generator ICE running, it showed a sub-30 mpg fuel average while the engine ran in charge sustaining mode.  While GM denies this is true, I would not be surprised if during the charge sustaining mode, the engine is getting lower gas mileage than an ICE powered-car in some situations.  The key being, of course, that the ICE generator would not run as long and it would run at a constant speed.

The other interesting point that Balding made is that consumers will have a bit of an adjustment to the way serial plug-in hybrids sound.  He mentioned that consumers will likely not be accustomed to the disconnect between the ICE noise and their foot action.  Balding made the comparison to the air conditioning in a home.  Once turned on, the air conditioning comes on and off without the homeowner purposely starting or stopping it. 

As the driver presses on the accelerator pedal in a plug-in hybrid, the ICE may not make a sound (as the electric motor runs off of battery power).  However, after reaching cruising speed for a while the ICE may start for a period of time, then shut off and restart again (depending on the battery state of charge).  Noises from the ICE starting and stopping may have little correlation with the specific actions of the driver, unlike in a traditional vehicle where stomping on the accelerator results in a growl from the ICE.

I agree that this cycling of the ICE on a plug-in hybrid will likely take some adjustment for consumers.  Though, I suspect the challenge lies with manufacturers to help consumers understand the normal cycle of the ICE in a variety of conditions.  Without this education, dealers may find themselves inundated with concerned owners.

In recent analysis of vehicle sales by segment, the differences between traditional internal combustion engine (ICE) vehicle sales and hybrid (HEV) sales show that hybrids are not competitive in several key segments within the U.S. The small car segment accounts for 20% of U.S. sales, but only accounts for 12% of HEV sales (with only 2 models available). While the midsize car segment with the popular Toyota Prius accounts for 68% of HEV sales (a total of 11 models available) compared to 31% for the segment among ICE vehicles. An indication that both manufacturer and consumer acceptance in this segment is strong.

There are several reasons that HEVs may not be capturing the same level of small car market share as the ICE small cars, though price and value are certainly one of the key issues. In this segment, many consumers are inclined to go for solutions that don’t break the bank, such as flex-fuel vehicles or high-efficiency or turbo ICEs. If product plans are representative of an automaker’s opinion, there appears to be some agreement with this strategy as high-efficiency ICEs with improved fuel economy with minimal cost increase seem to be the direction many are headed with new products (for example, the Chevy Cruze and Ford Fiesta). This leads one to expect that the growth of plug-in vehicles in this segment will likely be niche vehicles, similar to how small luxury cars are niche vehicles within the small car segment.

Beyond cars, consumer demand continues to push the development of trucks, whether that’s crossover SUVs or full-size pickup trucks. Midsize/large SUVs and pick-up trucks combined account for about 27% of the U.S. new vehicle market, while sales of hybrids in these segments combine for about 3% (a total of 4 models, all GM). This mismatch between share of ICEs and HEVs is the result of several factors, cost of the vehicles, fuel economy gains that require many years of use to see payback, and lack of availability.

The prevailing assumption is that most consumers won’t pay for small improvements from HEVs in fuel economy in big truck segments, and that assumption is likely correct. The cost recovery for a $4,000 to $8,000 premium for the HEV version likely takes many years to pay back with fuel economy gains that net savings of $300 to $500/year (based on a 12K miles per year driving cycle and $3/gallon gas price). Even at double the gas price, paybacks on expensive HEVs system are at least 5 years or longer. Additionally, let’s not forget that truck buyers in the bigger vehicle segments are often looking for specific towing or cargo capabilities that HEVs have to live up to, which in some cases may drive the cost of the HEV even higher.
The differences between HEV and ICE segment market share point to an opportunity within these segments for other less-costly technologies such as high-efficiency ICEs, start-stop hybrids or turbo-diesel engines.

I just finished writing how it will take time before we see any specifics on the vague “platform” announced by Cisco and Itron. I guess time is up. Cisco announced the intention to acquire Arch Rock Corporation, the long time IP-based wireless sensor network technology company. So much for needing patience….

I should have seen it coming. We sat down with Arch Rock back in May, where they previewed an impressive, very well thought out, end-to-end, IP-based AMI software platform, formally announced in June. This leverages all the important existing and emerging standards. And with Arch Rock folks active in most of the relevant committees, their pre-standard implementations should be well informed.

The big problem I saw in the Arch Rock effort was a business issue: they aimed to license the platform to existing smart grid vendors, most of which already had products in the market and aggressive IP-based R&D underway. I thought it highly unlikely Arch Rock could get major players to dump their own efforts and outsource this key architectural component, and thereby spur the market for a generic IP-based ecosystem for sub-1 GHz wireless communications. I still think I was right – Arch Rock couldn’t – but Cisco can, as evidenced by the big Cisco/Itron strategic alliance.

The Arch Rock platform will undoubtedly undergo some evolution in the collaboration with Itron, leveraging Itron’s experience in successfully deploying large-scale AMI mesh networks. The value of this experience should not be underestimated. In a similar arena, some in the IP community mocked the ZigBee wireless mesh networking stack as a bloated mess, until these once warring groups started collaborating (thank you, NIST!). The word on the street is they’re struggling to keep the new IP-based ZigBee stack within the same code footprint and functional capabilities as the existing ZigBee PRO stack, but the ultimate collaboration should result in a stronger standard and products. 

So the path forward on the Cisco/Itron platform appears significantly clearer. Starting with Arch Rock’s technology, Cisco adds their special sauce, and Itron integrates it all into the OpenWay platform, refining it along the way. None of this is a slam dunk, as Itron only knows too well and Cisco/Arch Rock may need to learn.  What will happen to Arch Rock’s hardware products is unclear, but I would expect them to fade away. The competitive threats to other AMI vendors such as Silver Spring Networks and Trilliant are now clearer (and stronger), though they at least now have a reasonably detailed product spec to push against instead of a vague platform ghost.

All in all, if a standard AMI communications platform is the goal, then I cannot imagine a better combination than Cisco’s architectural breadth, Itron’s experience (and savvy), and Arch Rock’s technology. I may not be ready to cry “bingo” yet, but I think we at least have “b-i-n” in place. Now let’s see where the “g-o” will come from….