Hydroelectricity - Energy Policy Analysis: A Conceptual Framework - page 145

because in many areas water flow, and thus available hydropower, is highest in the winter when
solar energy is least.
Micro hydro facilities may be constructed with either little or no reservoir capacity, so that
water coming from upstream must be used for generation at that moment, or allowed to bypass
the generator. Hydroelectric stations constructed with little or no reservoir capacity are known as
“run-of-the-river” facilities. A run-of-the-river project uses water within the natural flow range
of the river, requiring little or no impoundment (USDOE 2003, 4). A plant with no reservoir has
no storage and is therefore subject to seasonal river flows and may serve only as a peaking power
plant, while a plant with a reservoir can regulate water flow and serve either as a peaking or base
load power plant. Although most run-of-the-river hydro facilities would be considered small hydro
or micro hydro projects, a few large ones have been designed with up to about 1,000 MWe gen-
erating capacity. An example of a micro hydro run-of-the-river technology is the barge-mounted
floating power station developed by Eco Hydro Energy Limited:
The floating power station consists of an electricity generating device which is anchored in an
existing river system. Flexible rotor blades are mounted on an axis which rotates, providing a
turbine effect. Rotor blades are distanced from each other and are arranged along the rotor axle
in staggered rows. The rotating assembly directly drives conventional electromagnetic genera-
tors, providing electric power for immediate local consumption or for transmission to an existing
distribution grid.
The Eco Hydro system provides a low cost opportunity for power generation. As opposed to
traditional hydro-electric plants, there is no requirement for highly invasive construction pro-
cesses as the entire system can be towed into position and its location can be quickly changed
as required.
There is no population displacement, no loss of traditional lands. The activity of the flexible
rotor blades provides oxygenation of the river, which can repair damage done to a river's chemistry
and physiology by other human activity. This is beneficial for fish populations, the organisms
upon which they depend for food and aquatic plant life. The system's operators benefit from both
low capital and operation costs. There are no land-based construction costs.
Manufacture of the equipment occurs in a manufacturing plant distant from the power generat-
ing location. Once operational, the Eco Hydro system does not require the purchase and transpor-
tation of expensive carbon fuel, nor does it require maintenance of a land-based infrastructure.
The scale of power generation can be increased simply through addition of system units, limited
only by available water flow. (Eco Hydro Energy Limited 2005)
The floating power station is available in units ranging from 250 KWh to 150 MWh generating
capacity (Eco Hydro Energy Limited 2005). It may also be used in estuaries to generate electricity
from tidal currents.
PICO HYDRO
Pico hydro is a term used for very small hydro generation of under five kilowatts, comparable to
the output of the portable gasoline generators often in use in the United States today. It is useful
in small, remote communities that require only a small amount of electricity to power one or two
fluorescent lightbulbs and a TV or radio for a few homes (University of Nottingham. 2011). Even
smaller turbines of 200 to 300 watts may power a single home in a developing country with a drop
of only one meter (Williams 2007). Pico-hydro setups typically are run-of-the-river, meaning that