1898 & Co. Blog

Untapped Hydro Capacity Can Advance Clean Energy Goals

Written by Doug Houseman | April 21, 2022 at 7:50 PM

It’s time to look at something that any country can do to advance cleaner energy while utilizing local resources and creating local jobs.

According to the U.S. Department of Energy (DOE), there are nearly 91,000 dams in the U.S., of which only about 2,300 are currently capable of producing large amounts of electricity. Another 1,400 smaller dams have varying capabilities to generate electricity.

The biggest and tallest of these dams are those producing nearly all hydropower in the U.S. But that leaves around 87,300 dams that do not produce any power at all. Yes, it is well known some people want to remove all dams. So, there is a disagreement on investing in dam renewal, or adding power plants to existing unpowered dams.

Those 87,300 nonproducing dams are not all created equal, but some are large enough to provide an additional 60 gigawatts (GW) in aggregate capacity. This would be a nice incremental increase to the 80 GW of net summer hydro generating capacity that the U.S. Energy Information Administration says was available in 2021.

Most of these currently nonproducing dams would only be capable of producing 1 megawatt (MW) of capacity, and those would need power purchase agreements (PPAs) of at least $70 per megawatt-hour (MWh) in order to be economical.

However, according to a recent DOE report, a significant share of this incremental 60 GW of power production could be provided by dams that could feasibly provide more than 1 MW in capacity, and these could operate with PPAs of $50/MWh or even as low as $25/MWh for some. This is based on 2021 economics provided by the DOE. This would be equivalent to the same energy that could be produced on 7.5 million acres of solar, based on the U.S. average capacity factor for solar.

These dams already exist and they are performing useful flood control activities in many cases — something that will become far more important if storms increase in intensity. They also provide recreation, irrigation and other services for the nation.

If the government were focused on this enticing opportunity with a program like Title 17 from the DOE’s Loan Program Office, it could create local jobs with clean energy production loans. Funding totaling approximately $500 million for dam upgrades is available. While the smallest dams may not be in the money, many of the 2-MW and larger dams may be, given favorable geographic locations and market conditions.

Some of these dams have been built in series on the same river, offering the ability to not only produce electricity, but pumped storage as well. It is estimated that more than 36 GW of low-cost pumped storage could be created from existing dams without disrupting their current purposes. Most would offer eight hours or more of storage at the dam’s nameplate capacity. A few could offer as much as several days of pumped storage. This would more than double the U.S. pumped storage capacity for electricity.

In the last 60 years, dams that produce power have consistently been rated as being in better condition than nonhydroelectric dams of the same size and age. Adding hydropower capacity to these dams would improve spillways, controls, monitoring and safety, due to more regular inspections. These are all benefits that go beyond retrofitting these dams for power production.

The independent system operators (ISOs) will be hard-pressed to find ancillary services in 20 years. Powering these dams would offer more flexibility for those ISOs and improve the profitability of the dams for the owners because they would be able to stack benefits and provide more options for how to market the dams’ capabilities. With FERC 842 requiring primary frequency response from inverter-based resources, even on the distribution system, these dams offer a perfect complement to solar and wind, providing that reserve energy to meet this requirement and the ISOs’ changing requirements for primary frequency response.

Let’s not start a program to build more dams. Rather, let’s start a program to make existing dams safer and more useful.

 

Significant power infrastructure changes are needed in order to meet ambitious goals for renewable energy.