A remarkable new electricity supply paradigm is developing that brings to the forefront the question of how much hydro might ultimately be developed in North America.
Since the heyday of hydropower development — more or less from the 1930s through the 1960s — the resource has been subjected to all manner of constraints. However, as we move through the 21st century, things are changing, and it may be worth revisiting long-held beliefs about the "way things are."
Traditionally a low-cost source of electricity, in many instances hydro now finds itself being compared to other renewable, low-carbon power supply alternatives that are at the high end of the cost spectrum.
Today, hydro can properly keep company with the members of two key categories of electric generation sources:
— Conventional — along with nuclear, coal, or natural gas-fueled facilities
— Renewable, low-carbon — along with wind and solar (and possibly nuclear) power sources
A substantial price premium often is paid for power from renewable, low-carbon sources. This power typically is the highest-cost electricity in generating portfolios. If these high prices were available to hydro, they could support major additions to capacity. If other constraints were relaxed, how much hydro could be developed?
A look at what other countries have achieved can provide a basis for speculation, and a country's "theoretical potential" offers a good place to start. This theoretical potential is the maximum amount of energy that could be produced from making use of hydraulic resources, considering topography and precipitation. While tapping out the full theoretical potential is not feasible, some countries take greater advantage of their hydraulic resources than others. Worldwide, only about 8% of hydropower's theoretical potential is utilized. In Europe, the average utilization of theoretical potential is 18%. Austria, Italy, and Ukraine stand out with utilizations of 25% or more; France, Portugal, and Sweden each exceed 30% utilization. (Hydro star Norway, which produces 99% of its electricity from hydro, utilizes 20% of its theoretical potential.)
In North America, Canada utilizes about 16% of its theoretical potential, and the U.S. only 6%(!).
Just catching up to average European utilization — 18% — appears to be something that Canada likely will achieve, and surpass, in the relatively near future. However, for the U.S., a three-fold increase in conventional hydro — from about 80,000 MW to 240,000 MW — will be required. Yet, based on what other countries have done, this is not pie-in-the-sky thinking.
Don't forget about pumped storage ...
Active electricity storage — a.k.a., pumped storage — is a proven tool that enables mixed-source generation and transmission systems to operate more reliably and efficiently. The U.S. is woefully under-built. To become on par with Europe, for example, the U.S. needs to triple the amount of installed pumped storage — to about 100,000 MW. (Of course, Canada, with large amounts of active storage available in hydro reservoirs, does not have a significant need for pumped storage.)
While we're talking about waterpower ...
It's worth mentioning that ocean, tidal, and stream power technologies have substantial long-term promise. To date, assessments show that the resources are sufficient to warrant investments to develop and prove these technologies, so that they can become bona fide contributors to renewable, low-carbon energy supplies.