Assessing hydro’s true potential10 February 2000
You know untapped hydro potential is out there but your next biggest step is determining if it is feasible. Technology and economics are just part of the equation these days as social and environmental considerations play a greater role. If you had a report detailing undeveloped capacity with potential impacts, surely you’d be half-way there? As Suzanne Moxon reports, hydro developers in the US are on their way
According to US Congressman John Shadegg, the development of new hydro power facilities should be a key consideration for the US power industry. Writing in Energy Daily on 21 January 2000, Shadegg explained how nearly 30,000MW of additional power could be added to the system through the development of new hydroelectric schemes or the installation of turbines at existing sites.
This may look good in theory but putting hydro power projects into practice in the twenty-first century can be a lengthy and complex task. Even if you know there is vast untapped potential out there, the biggest hurdle you face is seeing if it is environmentally feasible. The US may not have fulfiled its true hydro power potential just yet but how accurate are such estimates of undeveloped hydroelectric capacity in today’s environmentally sensitive industry?
Keen to identify the country’s available energy resources to meet expanding demands, the US Department of Energy initiated a National Energy Strategy in 1989. What came to light was an inconsistency in the estimated undeveloped hydroelectric potential. As no agency had previously determined this capacity on site characteristics, stream flow data and available hydraulic heads, figures were not well defined. They ranged from FERC’s estimate of 70,000MW to the US Army Corps of Engineers’ theoretical estimate of 580,000MW.
To rectify this, the DOE established an inter-agency Hydropower Resource Assessment Team to determine the country’s true hydro power potential. Representatives from Alaska Power Administration, the Bureau of Reclamation, Western Area Power Administration, the Army Corps of Engineers, Bonneville Power Administration, FERC, Idaho National Engineering and Environmental Laboratory (INEEL) and Oak Ridge National Laboratory put together a preliminary assessment of US hydro power resources in February 1990. However, after scrutiny from groups in the hydro power industry, their estimate of 52,900MW was found to include errors and redundancies. As with all previous estimates, no consideration had been given to the environmental, legal and institutional constraints of developing hydro power projects. DOE realised that more work was needed and this was the cue for INEEL’s contribution.
Along with Oak Ridge Laboratory, which would give its environmental expertise, INEEL was asked to produce a software program to assess the likelihood of developing hydro in the US. The result
was the Hydropower Evaluations Software (HES) — both a database and a probability factor computer model. A menu-driven software application, it is a tool for obtaining a more accurate assessment of undeveloped hydro power capacity in the US.
HES considers a set of uniform environmental attributes to assess the likelihood of realising undeveloped hydro power resources in regions and states. These include cultural, geological, historical and recreational values. Consideration is also given to fish, wildlife, endangered or threatened species; whether the site is protected or is on a tributary with such protection; and whether the potential site is located on national park land, Indian reservations or
other such areas. HES uses the environmental attribute data to give an overall project suitability factor. A combination of attributes will result in a lower suitability factor as multiple environmental considerations reduce the likelihood that a site may be developed to its full capacity.
Work on the software program began in 1990. Jim Francfort from INEEL explains that it will not answer all questions and stresses it does have its limitations. ‘This is not like the user friendly programs we use today,’ he says, ‘and it was not really built to be used on PCs. The software was designed to help obtain and calculate information for the accurate study of hydro power resources. The reports generated from the software are the most valuable tool.’
The basic modelling process for HES started with FERC’s hydro power resource assessment database. Described as the best available national inventory of undeveloped hydro power capacity at existing or potential sites, this information was reviewed by INEEL and entered into the HES model. The data were then assessed using the National River Inventory. Carried out by the US Park Service, this identifies environmental values along river reaches. Information from the Inventory was matched to undeveloped sites as identified by the FERC database.
INEEL was keen that all participating states should review the information. ‘We had good co-operation with the states,’ Francfort explains, ‘and we needed their input as they have the best information on their own environmental resources.’
HES results were presented to the appropriate natural resource and energy departments within each state. The developers were then able to validate, provide input and update environmental and physical attributes of undeveloped hydro power sites. Some states were also able to provide information on previously unlisted sites with hydro potential.
Most states were keen to provide information to HES and were given small grants to aid their input. ‘No one got rich,’ Francfort laughs, ‘but we real-ised that we were asking the state depart-ments for several weeks of work here.’
A few states initially did not want to take part. They believed there would be little point as, due to the fish values in areas such as the northwest, there would be very limited development. But in the end all but two states were able to provide input.
‘They realised that the attitude we had was not that these are the sites we have found which can be developed,’ says Francfort. ‘We were saying these are the undeveloped sites and here are the constraints to developing them.’
Francfort started collating the state information in 1992 and all work had been finished by 1997. The final report of the statewide assessment was published in December 1998. But is there a possibility that, as some of this data is eight years old, it may no longer be valuable? ‘Some studies were finished in the early 1990s,’ Francfort admits, ‘but this will not compromise the quality of the data. When tracing undeveloped hydro capacity you find that it does not change much. There will probably be about a 1% difference but this is not significant.’
Of the 5677 sites assessed using HES, 389 already have hydro power facilities, 2527 are without power and 2761 are undeveloped sites. The Hydropower Resource Assessment Team’s original estimate of 52,900MW has been amended to 30,000MW. The majority of the hydro power sites (53% or 2990) are located in California, Colorado, Idaho, Maine, New York, Utah and Washington. Louisiana has the greatest undeveloped hydro power capacity remaining (89%), and 25 states have more than 50% of the original hydro power capacity remaining for development after the HES model is applied.
Francfort says that the results from the state reports mimicked his expectations. ‘It petty much worked how I thought it would,’ he says. ‘Looking at the data and the states there are not any surprises. In the southeast there are not many pristine rivers and there was not much reduction in capacity here. But in Montana, Oregon, Washington and Idaho, where there is a lot of fish and a great need for pristine rivers, there was a much bigger reduction.’
Feedback from the HES final report has been good. ‘The states think that it is a reasonable and accurate report,’ says Francfort. ‘And American Rivers has even taken a look. As we all know, they do not want to see any more development of dams, but they thought it was a reasonable assessment.’
After eight years of work to put these state reports together, who is using them? Not surprisingly, potential hydro developers are finding them to be the most valuable. ‘We have good feedback from them to say that it is very helpful,’ Francfort said. ‘For developers it gives them the first cut at sites as environmental considerations have already been looked at. This is so important, as developers spend a lot of money on environmental assessments and reports these days.’
The Hydropower Evaluation Software has helped to illustrate the importance of environmental issues when assessing hydro power development. Although the application of the HES model to current data reduces state and regional totals for undeveloped capacity, the fact is that potential sites still do exist in the US.
‘We didn’t want to end up with really high estimates of undeveloped capacity,’ says Francfort, ‘as that was not what we were about. We recognised the impor-tance of looking at all environmental, legal and social impacts on potential hydro developments. And to my know-ledge this is the first and only assessment of undeveloped hydro resources to take any of these values into account on a national basis.’