Micro-Hydro Energy Systems Fact Sheet

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Islands Trust Local Planning Committee, 2014 
 
FACT SHEET
 
MICRO-HYDRO ENERGY SYSTEMS 
 
 
The rural nature of the Islands Trust Area is one of the characteristics that makes it unique and valued by 
residents and visitors alike. Yet such remote locations can pose unique challenges for service provision, including 
electricity. Recognizing the importance of using low-impact and renewable energy sources, island residents are 
increasingly turning to innovative technologies that are sensitive to the environment and the rural character of 
the landscape. Micro-hydro energy systems can fulfil these criteria for electricity generation, and can provide a 
complement to existing technologies like solar photovoltaics. 
What are micro hydro energy systems? 
Although definitions may vary among different agencies, BC Hydro defines micro hydro developments as those 
with an installed capacity of less than 2 MW (2,000 kW). (The Province of British Columbia refers to run-of-river 
and micro hydro projects as “small hydro”.) Micro hydro projects are located where there is sufficient annual 
precipitation and landscape gradient to ensure that a stream has a consistent and steady natural flow. Electricity 
is produced by directing some of the water to a generator via small dams or diversion channels. Diverted water 
is returned to the stream below the powerhouse or generator. 
How are they used? 
Micro hydro installations can provide power to an isolated home or small community, or are sometimes 
connected to electric power networks. Their most likely application in the Islands Trust area would be very small 
systems – called pico or nano hydro systems – which supply only a few kilowatts of capacity, and which may 
operate only seasonally depending on water flow. These systems are common in rural BC for independent 
supply where there is no access to the electric power grid. Very small systems are typically run-of-stream, 
meaning that pipes are used to divert stream flow, rather than storing the water behind a dam. Micro hydro 
systems can also complement photovoltaic solar energy systems because in many areas water flow, and thus 
available hydropower, is highest in the winter when solar energy is at a minimum.  
How much electricity can micro hydro energy systems produce? 
In general, the site determines the capacity of the system to produce electricity. Power potential is a function of 
head (the change in elevation of the water) and the available flow. Although hilly or mountainous sites are best 
suited to micro hydro, systems can be constructed to take advantage of heads as low as 2 feet. Operating 
efficiency depends on factors such as turbine efficiency and pipe friction, which usually results in systems 
between 55 and 65 percent efficient. A 10-kilowatt micro hydro system can typically provide enough power for a 
large home or a hobby farm. However, power generation can be limited during periods of low stream flow due 
to low precipitation or tempera

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