Water Power: Out with the New, In with the Old

Below is the original version of an article I wrote for GE’s ecomagination site (full disclosure: I am being paid for the ecomagination article,.. but not for any extra views I drive to it). Water power has been fairly invisible in recent years as wind and solar have stolen the spotlight, but I think we’re going to see a lot more attention put on it soon (and have already begun seeing that in 2012). We’re planning a “water power” page for CleanTechnica that will be a bit like the solar and wind pages we have, which will certainly include some of the info below, but we’ve got much more than this planned for the page, as there are so many water technologies bubbling up right now. But this is a big piece of the pie, so here’s the full, original piece (for the version published on ecomagination, check out the link above):

Water wheels were a common source of power in the late 19th and early 20th centuries, but most European and U.S. water wheels are rusted and broken now. They are a distant memory, or a prop to be included in a picturesque country house. However, there is growing interest in harvesting energy from low-flow, low-head streams for individual homes, businesses, or communities. There is a great deal of energy potential from such streams. Are we going to return to the traditional water wheel of yesteryear? No, but new technologies available today could help us make more use of this decentralized, renewable energy source.

Solar and wind energy are well-known renewable energy options that are quickly growing in use around the world. Both have seen record-breaking growth in the past few years. Tremendous growth is projected to continue in the years to come, as well. But solar and wind won’t provide the world with all of its energy needs. They may not be ideal for some locations, and they may need to be supplemented by other energy sources in some locations.

Other than the ubiquitous wind and the tremendously powerful sun, one of the most abundant natural resources on our planet is water, and flowing water carries a great deal of energy. Just think of the feeling you had when you walked into a medium- or fast-flowing river or stream, or decided to test your strength against a breaking wave.

While wave power, tidal power, ocean thermal power, and other “water power” options exist, this article only discusses the most readily available water power option today — small or micro hydro.

Small Water Power (or Micro Hydro) Potential

New micro hydro (aka microhydro or micro-hydro) could produce 30,000 megawatts of decentralized, local power in the U.S. alone, according to a 2006 study. To put that into perspective, that’s enough power for up to about 30 million homes.

“We keep telling lawmakers that there’s tremendous growth potential in the industry. We are far from tapped out,” Jeff Leahey, director of government affairs for the National Hydropower Association, says. “We can access existing infrastructure today and build tens of thousands of megawatts in communities around the country.”

The map below shows what percentage of a state’s electricity sales could be provided from new micro hydro.

All of this small hydro potential could be tapped with “run-of-river” projects (projects not requiring dams) or projects that make use of existing dams.

“There are over 81,000 dams around the U.S. and only 2,400 of them have any electrical generating capacity,” Stephen Lacey of Climate Progress reports. “Many of the power-less 78,600 dams are close to existing infrastructure, making it easier to build and maintain a project compared with a centralized wind or solar farm located far away from where the electricity is used.”

The question, however, is what technology will be able to capture that energy and efficiently turn it into electricity for a home, business, or community.

Water Power is a Site-Specific Challenge

Water wheels of the past are not efficient enough by today’s standards, even though such water wheels were widely used well into the 20^th century.

However, there are numerous technologies currently available or being developed. The best option depends on the location of the project, the head of water, volume flow, and other site-specific factors.

An excellent book on this matter is Serious Microhydro: Water Power Solutions from the Experts. This book delves into the details of micro hydro more than probably any other. The author has written three books on micro hydro and is “an award-winning renewable energy project developer with decades of experience operating, installing, designing, selling and teaching about” the technology.

One key point Serious Microhydro makes clear is that there is no one-size-fits-all solution in this technology sector. There are many micro hydro options, each with their own benefits and downsides. Serious Microhydro includes numerous case studies of projects using a variety of technologies in locations all around the world. In the end, the important thing for each project is determining (or inventing) the right technology for the resource you are trying to tap.

Some of the technologies in use today include Pelton turbines, Frances turbines, Kaplan turbines, Banki turbines, Ossberger turbines, and Gravitation watervortex power plants. However, this is only a handful of the many technologies available.

Micro Hydro is in Our Past.. and in Our Future

Water has been used for ages to help humans perform their work more efficiently, run large machines, and create electricity. GE actually built a “record capacity water-wheel generator for Niagara Falls” in 1918. While other energy sources have taken the spotlight in the past few decades, water is flowing back into discussions about how to sustainably power a growing world population.

Micro hydro isn’t going to power the world. It’s just one piece of the pie. And there are important regulatory hurdles to get over before it can start growing in use at rates like solar and wind (if it will ever match those options). But there is no doubt that it could be a more significant source of the world’s power in coming years.

Decentralized power is a popular ideal that improves power security and reliability while also providing individuals and communities with more of the economic fruits of electricity production. Micro hydro is a decentralized power option that has growing following of supporters, is worth utilizing on countless sites around the world, and is likely to play an important role in our future electricity supply.