Damless hydro

Damless hydro or Damless hydro-electric is a renewable technology based on capturing the kinetic energy of rivers, channels of chutes, spillways, irrigation systems, tides and oceans without the use of dams. Mankind has been benefiting from the “energy of moving water…since before the Roman Empire” to power waterwheels for mills and the billows for blacksmiths . Ultimately, the harnessing of water power into usable energy developed into hydroelectric power via dams. However, due to the sheer size of the infrastructure of a dam, they have many collateral effects. For example, the damming of a river “blocks the movement both of fish upstream to spawn and of silt downstream to fertilize fields” . In addition, “the vegetation overwhelmed by the rising water decays to form methane – a far worse greenhouse gas than carbon dioxide” .

Damless hydro electric power options exist in the form of tidal power, wave power, and stream or river power. In today’s current Green energy mind set, Fortune 500 companies strive to develop and market their environmentally friendly methods and products.

Since no dam is required, damless hydro may dramatically reduce the following:

1) The safety risks (of having a dam), avoiding the risk of a flash flood caused by a breached dam
2) Environmental and ecological complications 
3) Need for fish ladders
4) Silt accumulation in basin
5) Regulatory issues
6) The initial cost of dam engineering and construction
7) Maintenance 
8) Removing silt accumulation

History

Since the time of Ancient Mesopotamia, water wheels have provided power to grain mills. The Romans as well as Ancient China made use of undershot and overshot water wheels to power their mills and billows as well as aid in mining. Water powered grain mills progressed to paper and steel mills and ultimately into electric power. Dams are the primary means for hydro-electric power in the 21st century.

Effects of Dams - Reasoning for conceptualizing alternatives

Dams are massive edifices that require man power and regular maintenance. Dams have a widespread affect on their surrounding ecosystems. For example, when a river is dammed the water rises and floods the previously dry vegetation which dies and begins to decay. The decaying process releases methane, a harmful greenhouse gas. Furthermore, silt accumulation becomes a problem. Over time the silt from upriver accumulates and eventually fills the lake, meaning that dams are only a temporary solution. A natural flowing river carries sediment along its path which works as a natural fertilizer for the surrounding area. This creates two problems for the ecosystem, one it is no longer as fertile; as well as, additional maintenance due to the dredging of the silt. In other words, dredging means to smooth out the lake bed or remove built up sediment. The final concern to environmentalists is the migrating wildlife affected by the damming of rivers. Migratory fish are unable to swim upstream to spawn or downstream to the ocean. Moreover, besides wildlife the human residence of the area will be displaced by the dammed water.

Benefits of Turbines

Hydroelectric power is not the largest source of electricity; however; it “now supplies about 715,000 megawatts (MWe) or 19% of world electricity.” In the United States, “only about 10% of the total energy production comes from hydropower and only 20 percent of the nation’s hydropower potential has been developed” . The amount of electricity that a hydroelectric plant can generate “is dependent upon the vertical distance through which the water falls (the “head”)”. Manufacturing companies such as Underwater Electric Kite, UEK, have used their knowledge of hydroelectric power from dams to develop damless hydro electric turbines. In addition, Joe Holden, the inventor of the Rolls Royce Jet engine afterburner used in today’s fighter jets has used his experience to build his own damless hydro-electric turbine. The damless turbines can be implemented in the bottoms of rivers or streams as well as on the ocean floor. In the rivers, the turbines are positioned so that the current turns the turbine and produces the power. Depending on the conditions this can be very productive, and can produce more power than a wind turbine due to water’s density. Furthermore, since the turbines are not housed in the giant infrastructure of a dam many more units can be installed. The reason for a dam is to produce the water pressure. In the case of the river turbines, the natural flow of the river is providing the power. The design for an ocean turbine is similar to a river turbine. The unit is secured to the ocean floor where the current is strong in order to power the turbine. However, currents can often shift with seasons and the weather. So, the inventors at Underwater Electric Kite, UEK, developed a turbine that pivots like a windsock. As the current changes, the turbine pivots so as to keep the turbine at maximum electric output.

Drawbacks of Turbines

An environmental issue that has not been solved in the transition from hydro electric power in dams to damless hydro power is fish mortality. As fish pass through a dam’s water intake and into the turbine the fish would often be killed. The blades of the turbine striking the fish could easily kill them. Additionally, the change in pressure from the water intake though the turbine and out the spillway is a causes of the mortality. In the tested damless turbines, fish mortality is still an issue. Manufactures are striving to develop fish friendly turbines. The water flow through the turbine creates a suction and if a fish swims too near it will be sucked into the turbine and potential be struck by one of the blades. In addition to the turbines that are designed for the ocean currents that are generally constantly flowing, there have been turbines designed to harness the power of ocean tides. However, there are few locations where tidal barrages, as this concept is called, can be implemented. Furthermore, at the locations where tidal barrages are a viable option the tide would only be able to power the turbines for 10 hours of the day due to the ebb and flow cycle of the tides. On the other hand, tides are very consistent and thus easily predictable which could allow for other options to be functioning during the times when the tides are not moving in or out.

Locations of River Turbines

The Mississippi River is the home of the “nation's first commercial hydrokinetic turbine, which harnesses the power from moving water without the construction of a dam.” Specifically, the river turbine was placed in the Mississippi River near Hastings, Minnesota. The turbine, capable of producing 35-kilowatts, was “positioned downstream from an existing hydroelectric-plant dam and — together with another turbine to be installed soon — will increase the capacity of the plant by more than 5 percent” (4). The design used in today’s wind farm’s turbines has been altered to function similarly underwater. These underwater wind farms or tidal turbines “are propelled by tidal currents instead of wind” . New York City’s East River is the site of the “largest test of this new type of power production” (11). The six 35-kilowatt turbines with 16 foot diameter rotors which spin as close as six feet from the water’s surface are “scheduled to be installed by mid-March in a channel that's off-limits to large vessels”. During the testing phase the turbines will “provide power to a supermarket and a parking garage.” Based on the results of the testing the Virginia-based company “Verdant Power hopes to add hundreds more turbines, potentially reaching a total capacity of as much as 10 megawatts — enough to power 4000 homes” . The East River testing “should answer real-world questions, such as whether the rotors will become encumbered by barnacles” . If the viable river and estuary turbine locations are made into hydroelectric power sites “researchers estimat[e] that [the United States’] rivers and estuaries could provide up to 130,000 gigawatt-hours per year — about half the yearly production of the country's dams” .