What is Large Hydro?
Hydroelectric assets provide energy that is readily available, clean, and cost-effective. Large Hydro generates electricity by harnessing the power of flowing or falling water to produce mechanical/electrical energy.
A hydroelectric generating plant consists of a dam (to store water in a reservoir), a penstock (to channel flowing water), a turbine (to convert kinetic energy to mechanical energy), and an alternating-current generator (to convert mechanical energy to electric energy).
The electric energy, produced by the generators at low voltage levels, is transformed to high voltage energy and carried to demand centres by high voltage transmission lines. Terminal stations control energy flow in the transmission system. At distribution substations, voltages are reduced for the needs of residential and commercial customers or small and medium industrial customers. Large industrial consumers can accept electricity at medium voltages. In British Columbia, Large Hydro is defined as a hydroelectric power plant greater than 50 MW in size.
Why Large Hydro?
Hydroelectricity harnesses the power of flowing water without depleting the resource therefore meeting the definition of renewable.
It is also a clean source of electricity because it produces very few greenhouse gases, no other air pollutants, and no toxic waste by-products. Greenhouse gas emissions from Large Hydro projects in Canada are about 60 times less than those from coal-fired power plants and approximately 18-30 times less than natural gas power plants.
The feasibility of developing a site for hydroelectric generation depends on geography and water supply. The most favourable areas for hydroelectric development are mountainous regions, with rivers and heavy rainfall that are not too far from industrial centres, making it an advantageous technology to serve BC’s energy requirements.
With an average life span of 50 to 100 years, Large Hydro projects are long-term investments that can be upgraded to take advantage of the latest technologies. Large Hydro is an electricity source with long viability and low operation and maintenance costs.
Large Hydro in BC
Hydroelectricity is British Columbia’s largest source of electric power generation. BC Hydro is the largest electric utility in BC, operating 31 hydroelectric facilities and two thermal generating plants.
BC Hydro’s hydroelectric facilities provide over 95 per cent of the total electricity generated in the province – between 42,000 and 52,000 GWh of electricity per year during the past five years – and are typically located in remote areas or small communities throughout the Peace, Columbia, Vancouver Island, and Lower Mainland and Coast regions of BC. Most of BC Hydro’s 12,080 MW of installed generating capacity is located away from the province’s major population centres and delivered to customers through a network of nearly 80,000 kilometres of transmission and distribution lines.