Reinventing the Wheel - Teaching Old Hydro New Tricks

By x356039 - January 22, 2014

Disclaimer: The views expressed here are not the official position of the IWW (or even the IWW’s EUC) and do not necessarily represent the views of anyone but the author’s.

When discussing green, renewable energy something of a holy trinity of sources consistently emerges in every discussion: solar, wind, and water. Of the three the one receiving the least press these days as a possibility are those options and opportunities based on water power. This is understandable when one considers the first image that springs to mind when discussing the subject: towering tons of cold concrete caging the roaring rivers of the world to work for the whims of the wealthy and powerful.

There is little debate in spite of the incredible potential hydroelectric dams offer that they come at enormous environmental costs. At internationalrivers.org the consequences of these projects is summed up with very strong, damning words. In spite of the extensive studies regularly conducted on new dam sites the changes caused by construction lead to a number of unintended and deadly consequences for the local ecosystem. The most obvious is, of course, the diversion of the river's flow but the impact of this happens on more levels than immediately meets the eye. The creation of massive artificial reservoirs that result from the construction of these dams destroys the previously existing green water habitats of the rivers making them quite hostile to the native species. This leads to massive influxes of invasive species like snails, algae, and non-native predatory fish ensuring further ecological havoc. Added to this is the blocking of new sediment deposits, resulting in increased erosion and the lowering of the water table denying plant life of the needed moisture to thrive.

The negatives of hydroelectric dams don't stop there. Adding further insult to injury is the displacement of indigenous populations that often results from these massive building projects. According to a report titled, “Social Impacts and Social Risks in Hydropower Programs” submitted to the 2004 United Nations Symposium on Hydropower and Sustainable Development the number of people displaced in China and India over the past 50 years by such projects is staggering. Of the estimated 45 million people in China displaced by new industrial projects during this period at least half were forced out of their homes due to the construction of new dams with a new project in the Yunnan province expected to add tens of thousands more to their number. In India the number is believed to be at least fifty million and this trend shows no signs of slowing down. A recent report by Survival International argues hundreds of thousands of people are being displaced as we speak by new projects in Brazil, Malaysia, Guyana, Ethiopia, and Peru. The Ethiopian Gibe III Dam, expected to be the highest dam on the continent when it is completed in 2020, has already forced over 200,000 people from their homes and it still has six years to go.

If this was all there was to the story of hydropower then there is little doubt that any sane environmentalist would stay as far away from this source as possible and consign it to the same category as nuclear, coal, and other dirty sources of energy. Thankfully there are a number of recent innovations, many inspired by pre-industrial uses of water power, that show hydropower has a few more tricks up its sleeve that make it an equally necessary component in any green energy future. These new developments harness the potential offered by flowing rivers, the roll of the tides, and crashing waves in non-invasive, minimally impactful ways. What makes these even better is, like wind and solar power, these inventions can be implemented on a far smaller, more evenly distributed scale ensuring that all forms of renewable power remain truly grassroots power.

The first place we'll start is the one closest to the coast at the mouths of great rivers and bays. In much of the pre-industrial world rivers were used as a source of mechanical power through the use of simple waterwheels. The basic principle of these tools was quite simple. The wheel was placed in the running water, capture its movement, and would then be used to power simple machines. The use of waterwheels goes back for thousands of years as far as the Roman and Han Chinese Empires with some communities using them to this day. Some new developments in hydropower, likely inspired by this old proven principle, draw on a similar approach but instead seek to harness the vast potential of tidal flows. In 2012 Verdant Power ran a ten day test of a new turbine in New York City's East River. Verdant Power estimates that with a total of 30 such turbines it would be possible to generate a total of 34 kilowatts of electricity; about as much as one wind turbine. Unfortunately the test didn't work out as well as planned due to difficulties in preparing a turbine design that could withstand the tidal forces in the East River. Another example is from the Bay of Fundy in Maine where Ocean Renewable Power is proposing installing an array of underwater tidal power generators. It is true that, unfortunately, tidal power doesn't offer much potential in the immediate moment this is due to the relative infancy of these developments. Tidal power today is at the same place that wind power was two decades ago and according to Tim Ramsey, a project officer with the Energy Department, “It may only take us 10 years to catch up.” If this prediction were to come true there is an enormous amount of potential energy that can be tapped from the motion of the tides. The Ocean Energy Council estimates the Bay of Fundy alone, with its 25-30 foot tidal variations, has a potential between 800 and 14,000 Megawatt hours depending on the day.

Another potential power source that is being explored lies just offshore in the form of wave power. An even newer and more experimental technology this avenue nonetheless has considerable potential. The Bureau of Energy Ocean Management estimates the current wave energy potential of the United States' coastlines with the use of readily available technology at around 1,190 Terrawatt hours. In the Orkney Islands, far to the north of the Scottish coast, a team of engineers are working on a new turbine designed to operate offshore in the ferocious storm conditions of the notoriously rough North Atlantic. Where conventional waterwheels and tidal power turbines operate based on very simple principles the Orkney array works a bit differently. Massive buoys are anchored offshore and tethered to submerged pumps attached to the sea floor. When the waves move the buoys their bobbing and bounding moves the pumps, forcing pressurized seawater through a land-based turbine which generates the electricity. This is far from the only design with many others being tested out in a similar project in Oregon. The designs used by Ocean Power Systems also show a strong awareness of environmental consciousness with toxic hydralic fluids swapped out for simple rack and pinion gear systems. Every buoy is anchored by a tether strong enough to remain in place under the roughest conditions for a hundred years and is attached to two equally capable backup tethers.

Of all of these sources probably the most futuristic and exotic is a new approach being tested out in the high-rises of Hong Kong: hydroelectric plumbing! Executive director Daryl Ng of Sino Land, a Hong Kong property developer, has started a new program to take advantage of the pressure and movement of water in the megacity's many skyscrapers with one of the test projects at the Olympian Mall showing some promise. Ng's system involves installing small turbines in the pipes to capture the water's motions much the same way that all other hydropower systems work. While these turbines don't produce much, with the estimated yield if installed in all of Hong Kong's public water systems only being enough to power 24,000 homes, this is still again a very new technology. In spite of this there are other examples to show hydroelectric plumbing has great potential. In the town of Muhlau, Austria a similar system installed in the drinking water produces a total of 34 gigawatt hours of electricity annually.

What all of these technologies have in common is their greatly reduced environmental impact, the ease at which they can be employed on a widespread, distributed scale, and the enormous potential offered. These new forms of hydropower show great potential for only improving as the kinks in current designs are worked out and new breakthroughs improve the efficiencies. What's more, in spite of the largely corporate nature of the current projects, they offer great promise for freeing us from the highly centralized energy industry. Under the standard approach of coal, natural gas, nuclear power, hydroelectric dams, and new projects like concentrated solar arrays power is generated at a single location that is then distributed to the end users connected in their grid. Whoever controls the power generation, in effect,controls the flow of energy. With tidal turbines, wave arrays, and energy-producing plumbing along with other enormous opportunities like solar and wind power this is no longer possible or necessary. Power would be generated either on the spot or through a massive, evenly distributed grid that all of the participants feed into and pull out of. Such a decentralized grid, along with being theoretically more resilient to brownouts and blackouts, is impossible for a single producer to control and could be built now by people employing currently available technologies. As long as the construction, implementation, and use of these new forms of energy generation are under the control of the people who use them there is nothing to fear from the potential they offer our species and the biosphere.