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Hydroelectric power has a long history in Montana, and in fact hydroelectric dams currently account for one-third of Montana's total electric power generation, second only to coal-fired power plants. Though most of the potential large-scale hydro sites in Montana have been developed, there is still much potential for smaller hydropower systems. Moreover, small hydro projects are free of the significant environmental impacts of large dams, since they do not require flooding large areas of land to create reservoirs. Technically, small-scale hydro systems are between 100 kW and 10 MW, and micro-hydro systems are smaller than 100 kW.

Components of a micro-hydro system typically include: an intake structure to screen out debris; a pipe or canal to transport water from the intake to the turbine; and the turbine and generator, which convert the flow of water to electricity. Like other renewable energy systems, micro-hydro systems can be grid-tied or off-grid. Many remote homesites in Montana are near streams that have the potential to produce electricity with very small hydro generators. These systems generally stand apart from the larger electrical system (i.e. they are "off-grid" installations) and produce power for just one homesite or ranch. If your site is located near power lines, you can consider connecting to the grid and participating in a net-metering program.

How do I design a micro-hydro system?

Water rights are an essential starting point for these systems, so you should contact the Montana Department of Natural Resources for questions about access. Once you have determined access, the next step is to determine the flow rate of the river or stream and the head (the vertical drop from the intake to the turbine). These last two factors will determine the power output potential for your system. If you're unsure how to measure these (or even if you are!) you should talk to your installer to determine these factors and what your power output potential is. This will help inform your decision on whether or not to build.

If you are interested in integrating a micro-hydro system into existing infrastructure, it is important to note that most traditional hydro turbines convert all of the pressure potential in a pipeline to power. This makes it difficult to use pipelines that are normally used to deliver water to residences because a minimum amount of water pressure is needed for the houses, and the turbines will reduce that pressure in order to produce energy. Recent developments in turbine design have resulted in turbines that can be used as pressure reduction valves that still deliver water at a useful pressure on the outlet side of the turbine. These turbines have opened up the potential of using many existing pipelines for hydro projects that were not possible before. Talk to your installer about this option.

How much will it cost?

Since each micro-hydro system is unique in design, size, and the degree of infrastructure development, it is difficult to provide generalizable estimates for project costs. Once you have worked with an installer to design your micro-hydro system and estimate its annual electricity production, the Department of Energy provides guidelines for how you can estimate the total cost of installation and compare it to your potential energy cost savings over time. Many micro-hydro systems require minimal maintenance and last quite a long time, so cost savings over the life of the system can be important to consider. One of the best ways to ensure your renewable energy system pencils out financially is to invest in energy efficiency measures. To learn more, see our resources on Efficiency and Electrification.

What incentives and tax credits are available?

Visit our Financing and Incentives page for more information on your options. You should also learn about how net metering will help you get the most out of your investment. (Yes, small hydro systems can be net metered!)

Where can I find an installer?

The column on the right hand side of this page lists a number of installers operating in Montana. These companies are all MREA members! You can also visit our full Installer Directory for an interactive map of installers.

Where can I find more information?

A partial list of books on micro-hydro:

  • Guide to Hydropower, Canyon Industries Serious
  • Microhydro: Water Power Solutions from the Experts, Scott Davis
  • Guide on How to Develop a Small Hydropower Plant, ESHA and Celso Penche
  • Planning and Installing Micro-Hydro Systems, Chris Elliott
  • Hydropower Engineering Handbook, John Gulliver and Roger Arndt