September 7, 2010 - quick takes

A few quick links today.

With the death of Ocean Energy Institute founder Matt Simmons, the organization is casting about for new direction and leadership.

The Maine PUC has opened an RFP for long-term contracting with ocean energy resources.

Meanwhile, in the UK, the Severn tidal barrage project is in jeopardy.

August 20, 2010 - Korean tidal power

Today, a quick look at tidal power development in Korea.  The 254 MW Sihwa Lake Tidal Power Plant in South Korea is scheduled to be ready to run as early as this December.  When it does, it will become the largest-capacity operating tidal power plant in the world, as it will dethrone the 240 MW Rance Tidal Power Station near Saint-Malo in France.

Sihwa Lake was formed in 1994 by the construction of a seawall to impound fresh water for agriculture and to help mitigate flooding.  However, as the impounded water became more and more polluted and thus useless for agriculture, the country responded by allowing seawater to flow in in 2004.  To develop the tidal power resource, the developer installed ten submerged bulb turbines into the tidal barrage.  These 25.4 MW turbines run when the tide floods in; the tide drop does not produce power in this configuration.  While this may be less efficient than an ideal scenario in which flows are more controlled and harnessed in both directions, this unpumped flood-based power production mechanism balances energy against other policies like land use and conservation.

Sihwa Lake isn't Korea's only tidal power project in development.  Daewoo has signed a contract for an 812 MW tidal barrage near Ganghwa Island; this project is scheduled to be completed in 2015.  Closer to islands west of Incheon, the government is exploring a 1,320 MW tidal power station for later this decade.

June 9, 2010 - tidal power in Maine: the Passamquoddy Power Project

Maine's historic wood and stone tide mills were just going dark in the 1930s. At the same time, larger tidal power projects were in the works. Chief of these was the Passamaquoddy Power Project, a large project designed to generate 300 to 500 MW of capacity.

In 1919, having returned from dam siting and building in South America, Dexter P. Cooper took some rest and relaxation on Campobello Island, just over the New Brunswick border from (and only accessible by road from) Lubec, Maine. As the August 1935 article in Popular Science put it:

With nothing to do, Cooper spent whole days watching the tides swirl past the island. He calculated the billions of horsepower going to waste. As a sort of hobby, he began imagining ways of putting the rising and falling water to work. In the end, he became convinced of the entire practicability of harnessing the Fundy tides.

What Cooper envisioned was the construction of five huge dams connecting various points and islands near the junction of Passamaquoddy Bay and Cobscook Bay. Cobscook Bay would be effectively walled off from Passamaquoddy Bay. As the Bay of Fundy's tide rose in Passamaquoddy Bay, the topography would make Passamaquoddy fill much faster than Cobscook. Once a five-foot head was built up, the penstocks would be opened and Passamaquoddy would fall down into Cobscook, spinning turbine generators along the way. Under expected conditions, the head could build up to as much as 18 to 23 feet. At low tide, gates would open and equalize the water levels.

Tidal projects have always had to deal with the effects of lunar time changes. Each night, the moon passes its zenith about 50 minutes later than the night before. In older times, this meant that the milling could only take place for part of the day, and not necessarily at convenient times. The Passamaquoddy project included an early pumped storage reservoir. A 180,000 horsepower pumping station at Haycock Harbor was to pump seawater into a 13,000 acre reservoir at 130' above sea level.

If you've ever been to Lubec, or if you follow tidal power projects, you probably know that the Passamaquoddy Power Project was never completed. I'm looking at the "why", to see what we can learn from history.

June 7, 2010 - historic tidal energy: tide mills and

I've been looking into the history of tidal power and coastal use policy. The Winnegance story is illustrative of the kind of resources and opportunities that exist along the coast of Maine and many other states, as well as the kinds of conflicts that arise through development of these resources.

One classic conflict is between energy development and environmental protection. For dam proposals, whether tidal or in rivers, one of the common considerations is the impact on fish. Recently, this came up in the Fort Halifax dam case, where a lack of agreement over fish passage resulted in 2008 in the depowering and removal of the 1908 dam.

Fish protection came up with the dams and mills at Winnegance as early as 1892. In that year, the Supreme Judicial Court of Maine considered the case Oliver v. Bailey. On February 24, 1892, game wardens on patrol came across a bass net that had been strung across Winnegance Creek by John Oliver, whose property abutted the stream. This was prohibited by a special act passed in 1885, which regulated the level of water behind the dam as well as the catching of bass in Winnegance Creek.

The Court's opinion notes the the local history and alterations to land use based on commercial needs:

prior to 1837 Winnegance creek was an Inlet of the Kennebec river; that in that year, under the charter granted in 1835, the dam was erected across said creek, and northeast of the public highway, extending from the Bath to the Phippsburg shore; that sawmills on the dam were erected, and gates constructed, for the purpose of sawing lumber; and that the dam so erected, and the mills so constructed, thereon, had for their purpose the utilization of water to be held In the creek above said dam by the operation of said gates.

The Court's opinion provides an interesting look into how the tide mills played a major role in shaping the local landscape:

It was also agreed that since said date, at different times, as business might warrant, the several mills upon said dam have been in operation; that the owners of said mills each have above the same, and between the dam and the highway, booming privileges. In which to place their logs, and that the same were set off and allotted to the several owners of the mills on said dam, wherein each might place and hold his logs for use; that the flood gates in said dam are 18 feet wide, would admit scows, lighters, and rowboats, and that such had at times passed through said gates, and under said highway; that, at a certain time of tide, mastless scows, skiffs, and boats can pass under said highway, provided the owners of the booming privileges leave an opening so to do; and that there has been place left by the owners of said booming privileges for craft, of the kind and type designated, to pass up said creek.

The court again addressed the impacts of the tide mill development on navigation and commerce:

It was also agreed that the bridge connecting the city of Bath and the town of Phippsburg has been maintained by both for many years; that said bridge is built, legally, of cobwork spiling, and across the channel are stringers, affording a space under said bridge from 30 to 40 feet long, that gundolos may pass through up and down; that some 40 years ago a schooner was built and launched In the creek, and taken out to the Kennebec river, by removing a portion of the dam sufficient to give passage to said schooner from the creek Into the river; that the lighters mentioned, carrying boards and wood of some kind, have occasionally passed through the gates, and under the bridge; and that the millowners, when the tide had reached its flood, have all the gates so constructed that, at the beginning of slack water, they close, and the water is held for the purpose of running the mills constructed on said dam.

Oliver argued that the regulations were "intended only for the protection of salt-water fish, or fish that migrate between salt and fresh water". Oliver argued that the 1835 legislative dam authorization and 1837 dam construction, use of the upstream pond for booming logs, and limited navigation through the dam, "separated Wlnnegance creek above the dam from the general body of the tidal waters of the state, and taken it out of the above-cited statutes for the protection of migratory fish."

The Supreme Judicial Court disagreed, stating, "The statutory protection of these fish is as important now as before the erection of the dam." Oliver lost his case, and presumably his net.

In Oliver's case, the court wrestled with the question of whether the tidal power development had so fundamentally changed the landscape as to take Winnegance Creek from tidal to non-tidal status. The court concluded that, in light of environmental considerations, it had not. There may have been other more subtle issues in play in the 1892 case, but it provides an interesting window into the past history of tidal energy development in Maine.

I'm curious how this issue would be addressed today. What are the inshore effects of tidal barrage and related power technologies? Today these issues might not come up in the context of game wardens, but the descriptions of the tide mills' impacts of navigation, commerce, and fisheries all have relevance to modern tidal power development.

Soon to come: more Winnegance history, and a look at how things were for the much larger Passamaquoddy Power Project in the 1930s.

June 4, 2010 - tidal power in Maine, a history, part 1

Humans have harnessed the mechanical energy of tidal fluctuations for a long time -- at least as far back as the Romans in 600 A.D., and possibly as early as 200 A.D. The exact mechanisms vary, but the basic idea is to convert the potential energy of water that has been lifted by a high tide as it falls to a lower elevation. Typical sites are on tidal estuaries or rivers: sheltered from the effects of open ocean waves, but salty enough to have a significant tide.

Tide mills were common in Maine, especially just downriver from my house in Bath. At Winnegance, on the Bath-Phippsburg line, a bend in the Kennebec River with a natural cove made for optimal conditions for tidal power.

The History of Phipsburg, Maine, from George Varney's 1886 A Gazetteer of the State of Maine, describes some of the local resources:

At the north looms Parker’s Head, and at its south-western side is the inlet basin forming the tide-power known as Parker’s Head Mill Pond. Next succeed the harbor at Phipsburg Center, with Drummore Bay two miles above, with inlet and tide-power. Through Fiddler’s Reach, a curve of the Kennebec around the northern end of Phipsburg, we pass to Winnegance Creek, nearly three miles in length, and a basin at its extremity, forming two unsurpassed tide-powers, and separating Phipsburg from Bath and from West Bath except for a neck 200 rods in width, the Winnegance Carrying Place.

The History gives more detail on the Winnegance mills:

On the Winnegance Tide-Power, three miles from Bath post-office, and four miles from Phipsburg Center Village, have been sixteen mills, nine on the Bath side and seven on the Phipsburg side of the line. Some of these, however, were burned several years since. There are now ten sawmills and one grist-mill operating in the town.

So why Winnegance? The site was right, in that the coves and tide range were ideal. Furthermore, the site was near the mouth of the Kennebec River, where millions of logs floated downriver every spring and summer for processing into lumber, and loading onto schooners to send the boards to markets around the world. Many of the older houses in the Winnegance and Bath area, ours included, bear the marks of the kind of up-and-down tide-powered saws that operated there.

I'm curious to learn more about why tide mills largely vanished. (At Winnegance, the Morse & Sons Lumber mill still operates where the Morses have run it since 1801, but it no longer apparently harnesses the tides.) An interesting piece in Discover Maine Magazine points to the inconvenience of the timing of tidal power. If you are limited to tapping the ebb flow, the time of the peak drop will move -- at Winnegance, each high tide is 12 hours, 22 minutes later than the previous -- so some days, your power resource will only really be operative at night. I'm not sure this was enough to eliminate most of the tidal power development in Maine, but it was a start.

I'm also going to look at more ambitious historic tidal power plans like the Passamaquoddy Power Project.

2/19/10

Since transportation is such a large part of our energy consumption, transportation policy has implications on energy policy. Rail service can provide low-cost, low-carbon transportation for a variety of raw materials and products. That's why the Maine legislature is considering a proposal for $20 million in bonds to enable the state to purchase 240 miles of the Millinocket to Madawaska line. Word on the street is that its owner Montreal, Maine and Atlantic Railroad will begin the legal process to abandon the tracks as early as this week. If abandoned, this would eliminate rail service to about 20 companies, including some of northern Maine's largest employers.

More offshore tidal power! Portland, Maine-based Ocean Renewable Power is deploying its 60 kW underwater Turbine Generator Unit (TGU). (Note that 60 kW will make this the largest ocean energy device deployed in U.S. waters. You can see we have a long way to go.) This unit will be deployed on March 2 about 25 feet below the surface at a site off Shackford Head near Eastport (acme map). Tidal power captured by the underwater turbines will be stored in batteries on the barge, which are then shuttled back and forth by boat to the Coast guard -- what they're calling a "virtual transmission line". How efficient can that be?

Although the project has the capacity to power 20 homes, Ocean Renewable does not have its pilot-project license from the Federal Energy Regulatory Commission and thus cannot interconnect.

How about jobs? While spending about $5 million in the past year, Ocean Renewable has grown from 4 to 17 Maine-based employees, and has created or retained another 80 jobs total at companies around the state, including Stillwater Metalworks.

An article about citizen opposition to wind farms is interesting for a variety of reasons -- both its good summary of recent actions that can be seen as limiting wind generation, and the fact that it does not appear to be spurred by any particular event.

On the local level: Central Maine Power and Rockland are in a fight over tree trimming. Reminds me of the situation in Warren when MDOT widened Route 1.

Nationally: agreement has been reached on the removal of four dams on the Klamath, three in Oregon and one in California. Shades of Edwards Dam and the Fort Halifax Dam in Maine.