Monday, April 15, 2013

Hydro Power in Vermont: The Expert's View

A few days ago, I posted about some controversial renewable energy projects in Vermont.   I didn't mention hydro projects.  Basically, I don't think in-state hydro is going to expand very much in Vermont.  Still, hydroelectric power is pretty important in New England, so I need to discuss it.

Here's my Vermont-centric description of the Future Of Hydro.

In-State Hydro Right Now

 Historically, Vermont receives about 10-12% of its power from in-state hydro. I show two charts that show this percentage.  One is about two years old, showing 11% in-state hydro in Vermont.

Vermont Electric Supply
From 2010 PSB Sustainability Presentation 

One is more recent, showing 12% in-state hydro for Green Mountain Power, which supplies over 70% of the electricity in this state.

From current Green Mountain Power web page on Fuel Mix.

Green Mountain Power (GMP) website's hydro page describes Vermont's long history of hydro power. GMP itself has a fleet of 32 hydro stations, many of which include recreation areas. There are about 80 active hydro sites in Vermont.

Views on New Hydro in Vermont's Future

I don't expect in-state hydro to expand very much in the future.

VPIRG and the Coalition for Energy Solutions: In 2009, VPIRG issued a report on Repowering Vermont, and the Coalition for Energy Solutions reviewed this in their own report Vermont Electric Power in Transition in early 2010. On hydro, the two reports pretty much agree.  The VPIRG report expects only 15 MW growth of in-state hydro. The Coalition report is not sure that even that amount of hydro expansion is feasible: When thinking about building many small dams, the effects on tourism should be considered. In general, small free-flowing streams are part of the Vermont landscape, and a great tourist draw...(Full disclosure: I am one of the authors of the Coalition report.)

Renewable Energy Vermont (REV) is upbeat about hydro, but they admit that By and large all existing dam sites in Vermont have already been developed, with no new projects commissioned since 1993. Environmental concerns, a burdensome licensing process and difficult economics have been primarily responsible for the lack of new dams coming on line.  Despite this, REV is hopeful about small, community-scale, run-of-the-river hydro.

Hydropower Illustration
From REV
In August 2010, the Burlington Free Press ran an article Hydroelectric dams resurgent in Vermont. It isn't much of a resurgence, though. This article is really about refurbishing: the two dams described as coming on-line soon are on the sites of existing dams, and together the dams would generate only 3 MW of power.

The same article says that  A 2008 report assembled by the Agency of Natural Resources published estimates in the 50 MW range, which it termed “broad-brush assessments.” (The report) also noted that Vermont’s stewardship of its water resources probably would supercede the licensing of any new hydro dams.

A Department of Public Service (DPS)  presentation in 2008 includes several projections of how much new hydro is available in Vermont.  The numbers range from 25 MW to 322 MW. The DPS projection says that 25 MW can be built.  The high projection is from the Department of Energy: this estimate stands alone with so big a number, and seems to be based on the idea that every river, stream and brook in Vermont would have a hydro plant.

In Conclusion: Very Little New Hydro For Vermont

 I think that existing dams in Vermont will be refurbished and upgraded, with some increase in power supply.  Estimates of 15 to 25 MW seem reasonable to me.  As a whole, I think the state of Vermont will follow the guidance of the Agency of Natural Resources report:

Vermont’s stewardship of its water resources probably would supercede the licensing of any new hydro dams.


Hydro Outside of Vermont

As far as I can tell, while existing dam sites are being refurbished, the national trend is not in favor of more hydro projects. In the United States, hydro seems as likely to be dismantled as to be built. A year ago, for example, the Hydro Review website ran an article by Elizabeth Ingram: Exploring the Reasons behind Dam Removal.  The dams that were removed were located in the western United States.  Nearer to home,  the Edwards Dam was removed in Maine, in 1999, on the basis that it interfered with fish migration.

Low-head hydro that does not require a dam is much discussed. However,  I find few examples of such systems being built, perhaps because the economics are unfavorable.  Refurbishing an existing dam site is the most common way of adding hydro capacity at this time. If I am wrong about this, I hope my readers will correct me.
Hongping Hydro Station, China

Small hydro is being greatly expanded in China.

Further Reading:

To read about the biggest Vermont in-state hydro sites, I recommend Bob Hargraves post on the Energy Safari visit to Comerford Dam.

The five hydro plants on the Connecticut River are due for relicensing, and hearings will begin soon.  However, these plants are not counted as in-state hydro for Vermont. The Connecticut River is the border between Vermont and New Hampshire, but the state of Vermont begins at our shoreline, not in the middle of the river.  So New Hampshire has the hydro plants as well as responsibility for the bridges.


Anonymous said...

I was part of a study group at a university that looked at run-of-the-river hydro (no dam) for a very high flow rate source, which was the Ohio River. The first thing you need to know is that the generators must have pretty much of a straight flow through the generating tubes. And the first thing you learn about the natural flow of a river is that it isn't straight, the flow is basically all over the place. So that means structures must be emplaced to effect a flow straightening, and that means environmental impact on the river, both upstream and downstream. One of the upstream effects is backup and ponding, essentially like an open-ended reservoir. Well, as soon as you announce that you might be impacting the riverbank land upstream, what happens? Basically a bunch of lawyers get together and start buying up the land, so they can file lawsuits to either recover damages or force you to modify your project, probably to the point of being uneconomical, either way. So I have very little hope that low-head or run-of-the-river hydro will go anywhere.

Howard Shaffer said...

There is a reason that the very small hydro sites were not developed long ago.
They don't generate enough energy to pay a living wage to the operators, or to pay for the construction and maintenance.

Small hydro sounds good, until the numbers are done. If someone wants to build and run one as an environmental hobby, fine.

The again the Agency for Natural Resources will have something to say.

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Unknown said...

Due to big dam projects, small hydro-power projects lost their values. again commencement of small hydro-power projects will bring new revolution. Great work.