A small-scale hydroelectric facility requires that a sizable flow of water and an adequate head of water is available without building elaborate and expensive facilities. Small hydroelectric plants can be developed at existing dams and have been constructed in connection with water level control of rivers, lakes and irrigation schemes.  By using existing structures, only minor new civil engineering works are required, which reduces the cost of this component of a development. 

In other, more rugged regions of the country, it is possible to develop relatively higher heads without elaborate or expensive civil engineering works so that relatively smaller flows are required to develop the desired power. In these cases, it may be possible to construct a relatively simple diversion structure and obtain the highest drop by diverting flows at the top of a waterfall or steeply falling watercourse. 

Examples of small-scale developments

Small-scale hydroelectric facilities have become more popular over the past two decades.  Many new sites have been created and older, existing sites have been refurbished.  Examples of such sites are the Cordova Dam  and the Almonte Upper Dam. 

Types of small-scale developments

Small-scale hydro stations are classified in the table below.

In large facilities, custom design detailed engineering is required. Small-scale hydroelectric developments have to be approached quite differently to achieve economical feasibility.  

Over the last twenty-five years, efforts have been made to reduce development costs by improving all phases of project development. Some of the innovations produced by these efforts are:

• Improved methodologies for hydro resource assessment and project identification
• Improved methods of hydrologic assessment
• Standardized designs of turbines and generators
• Standardized requirements for connection to grid 
• New contracting methods – turnkey
• Improvements in computational technology
• Standardized civil designs and partial development 

Learn how to plan a small hydroelectric facility.

The benefits of small hydroelectric energy

Environmental benefits

Small-scale hydroelectric developments do not take up much space and they rarely cause significant shoreline flooding or required river diversions. Large-scale projects, however, can create adverse environmental impacts such as shoreline flooding.  Most of the negative environmental impacts of small-scale hydroelectric developments can be avoided in part or in whole by a good design and appropriate construction and operating practices.

Click here to learn more about environmental impacts and preventative measures. 

Reducing risk of transporting fuel supplies (fossil fuel generation)

Fuel supplies must be transported over long distances. The risk of fuel spills is significant, especially in remote areas of Northern Canada where the roads can be ice covered and the environment is ecologically fragile.  In urban Canada, the risks to public safety from collisions or derailments in crowded road or rail corridors are also significant. 

Socio-economic benefits

The most obvious social benefit of small hydroelectric developments is the supply of reliable low-cost electric energy to provide the comforts of modern living.  Small-scale hydroelectric developments can provide a competitive source of reliable and inflation- proof energy.  Small-scale hydroelectric energy is an especially attractive alternative to traditional high-cost diesel generation that currently provides electric energy in most remote communities across Canada. Compared with diesel generation, small-scale hydroelectric developments offer other interesting advantages such as:

• they use a local resource and therefore produce electricity at a stable price that is not subject to the fluctuations of the international oil market
• they provide more economic benefits to the region by way of construction employment and use of local services, 10% to 25% of capital cost
• they provides greater opportunities for local residents to learn and upgrade their construction skills
• they provide an opportunity for wealth creation, notably, for First Nations.  Click here to see a list of small hydroelectric projects developed by First Nations.  

Business benefits

Over the last decade, the small-scale hydroelectric industry has contributed about $100M per year to the Canadian economy in manufacturing and services and added about 30 to 50 MW yearly to Canada’s power supply. Canada’s small hydroelectric manufacturers and service providers, such as consultants and financiers, also export to overseas customers.

Constraints imposed on small-hydro developments

Constraints that challenge small-scale hydroelectric development include the following issues:

Cold climate requirements

Small hydroelectric design must provide for control of frazil ice and pipeline freezing – factors that add to capital expenses and operating costs

Fish protection

At sites where fish migration is a concern, small hydroelectric developers may have to provide expensive preventative measures such as fish guidance or habitat compensation.

Institutional

Often, small-scale hydroelectric developers sell the output of their plants to regional or provincial grids.  Because purchase contracts and interconnection requirements are not standardized, project preparation and design costs are higher.

Regulation

The regulations focus more on large-scale hydroelectric issues than on small-scale hydroelectric issues that sometimes impose disproportionate demands on small hydroelectric developers.