How green is your hydro?

Over the past few years, there has been widespread deregulation of the electric power industry in the US. In states where deregulation has occurred or is planned, one of the issues with which policy makers, power marketers, and power customers are grappling is the question of what constitutes green power. This debate has been further stimulated by recent White House Executive Orders on environmentally preferable purchasing and energy efficiency, by the adoption of environmental management systems by a growing number of large corporate energy customers, and by the public positions adopted by environmental stakeholder organisations.

Hydroelectric power production has been caught squarely in the middle of this debate. On the one hand, US hydro power enjoys a strong position as a reliable energy source producing virtually no greenhouse gases. This advantage has particular appeal in the wake of the Kyoto Protocols calling for worldwide reductions in CO2, methane and other greenhouse gases. Hydro power also benefits from its reliance on naturally flowing rivers rather than on mined or harvested fuel sources.

On the other hand, hydro power dams have been criticised for disrupting migratory fish passage along rivers, altering riverine and riparian habitats, and impacting stream flows.

Unsurprisingly, a confusing array of policies and definitions has emerged. For instance in California, the city of Santa Monica, regarded as a leader on environmental issues, specifically excluded hydro power from its green energy purchasing strategy because of its concerns about environmental impacts. The power content information label developed by the California Energy Commission lists small-scale (less than 30MW) hydro power production as renewable, while larger hydro facilities are listed alongside fossil fuels and nuclear power. Nationally, the US General Services Administration, the agency responsible for power purchases in federal buildings, has excluded hydro power from its definition of renewable power. Additionally, the Federal Trade Commission (FTC) and the National Association of Attorneys General (NAAG) are defining what can be legally inferred by the use of the words clean, green, and renewable.

This confusion has spread into the energy certification arena, where traditional stakeholder groups have stepped in to assume the mantle of third-party certifiers. For example, American Rivers is an organisation that has worked actively in the political arena on issues related to river ecosystems, and has served as an environmental stakeholder in the federal relicensing process for US hydro power dams. In that role, American Rivers has frequently taken positions recommending significant changes to dam operations, or opposing relicensing altogether. Now American Rivers has developed certification criteria intended to separate low impact from high impact hydro.

Accepting responsibility

Clearly there is much at stake in these debates and developments, not only for the hydro power industry, but also for the environment.

Firstly, it is important to clarify the objective, obtaining facts regarding the true environmental impacts of hydro power systems. Secondly, we should help to frame the debate in a more realistic context. Approaches such as that endorsed by American Rivers, in which hydro power systems are pitted against one another, do not really reflect the choices that energy customers face. If hydro power capacity is reduced or shut down, the lost electricity generation must be derived from other sources. Therefore, the real choice within a region is not between various hydro power plants, but rather, between hydro power and the other forms of electricity production that would replace it, at the same scale and at the same level of reliability.

We need to develop and use scientific methods that make it possible to consider the full range of environmental impacts and benefits represented by all types of electric power production. Criteria that are developed exclusively for hydro power fail to provide an accurate comparison of the actual choices that energy customers must make.

Finally, we should take steps to keep politics separate from the facts. While stakeholders offer an important voice in the discussion of environmental issues, certification is best left to a neutral third- party with no vested interest and no political agenda.

Taking action

Certification provides an important opportunity to help settle the debate about the environmental footprint of hydro power production, and its appropriate role in the future of electricity generation. One interesting approach to certification is outlined by Scientific Certification Systems (SCS) of Oakland, California.

SCS is recognised as a neutral third-party certifier of environmental claims in the US, with a 15-year track record in a range of industries. In the area of energy certification, SCS is utilising a methodology — life cycle impact assessment — which has been developed in an international context, as part of the ISO-14000 standards. The methodology evaluates environmental impacts during each stage of operation, including power plant construction, operation, and dismantling, and power transmission. This assessment includes an evaluation of impacts on habitats and species, the issues of greatest concern to hydro power producers and stakeholders.

SCS insists that all of its studies intended for use in the marketplace first undergo independent peer review. This ensures that individuals with regional expertise have an opportunity to review the methodology and findings before they are published.

The Safe Harbor operation

Safe Harbor, constructed in 1931, is located on the lower reach of the Susquehanna river in Pennsylvania, US, and operates essentially as a run-of-river project. The powerhouse has a generating capacity of 417.5MW and a hydraulic capacity of 110,000cfs. There are two other large conventional hydroelectric plants downstream, and one facility upstream.

The power Safe Harbor produces is primarily distributed within the Pennsylvania–New Jersey–Maryland (PJM) region of the mid-Atlantic US. Overall, PJM’s power is generated by a combination of fossil fuel, nuclear and hydro power facilities, with minor contributions from additional renewable sources.

I decided that certification of Safe Harbor would provide the opportunity to help settle the debate about the environmental impact of various forms of electric power production. I was particularly struck by the approach outlined by SCS.

The certification process for Safe Harbor was straightforward, involving data collection related to each of the life cycle impact categories. In terms of measuring disruption to terrestrial and aquatic habitats, SCS examined data related to physical impacts to the site, anadromous and resident fish, transmission line and substation disruptions, roads and other developments, migratory shore birds and mudflat habitat. American Shad was identified as a key species,

based on its commercial significance to the region and the annual migration path through the section of river regulated by the Safe Harbor power plant.

Safe Harbor staff were able to draw from data they had collected for a previous benchmarking study.

According to the study, the findings ‘support a conclusion that the Safe Harbor facility’s impact on anadromous fisheries of the Susquehanna River is low, owning to very efficient fish passage capabilities’. This was largely attributed to the use of turbine technology that minimises losses of out-migrating juveniles and out-migrating post-spawned adults.

The Safe Harbor facility was calculated to disrupt approximately 27% of the upstream American Shad migrants, a worst-case calculation based on the assumption that all fish lifted at the downstream hydro facility swim to Safe Harbor.

Data for the out-migration showed Safe Harbor affects only 2-3% of the juvenile fry. In relative terms, the Safe Harbor facility was shown to be responsible for only 4.7% of the total fish mortality along the four-dam lower reach of the Susquehanna river.

In terms of disruption to terrestrial and aquatic habitats, the total net disruption was calculated at 1129.6 acres. Over 880 acres of aquatic and floodplain forest habitats were disrupted as a result of the construction of the powerhouse and

dam; 27 acres of forest lands due to the roads, operator’s village, and substations; and 470 acres of upland forests attributable to transmission lines. On the other hand, there was a net gain of 250 acres of land due to siltation, including the formation of mudflat and shallow water habitat crucial to migratory birds.

In all other impact categories, the effects attributed to Safe Harbor were either negligible or minor. In all categories, Safe Harbor’s impacts were well below the PJM average. Based on these findings, the facility was certified as an environmentally preferable energy source.

Where to now?

Safe Harbor is owned jointly by Baltimore Gas and Electric and Pennsylvania Power and Light. Both companies will use the findings of the SCS study to answer customer inquiries, to serve as the basis for market claims, and to help inform the larger policy making process surrounding energy and its environmental impacts.