Hydroelectricity: Quebec’s True Power

Among the world’s current ways of producing electricity on a large scale, hydroelectricity has the lowest impact on the environment and is technologically the most efficient. Forty percent of Canada’s freshwater is within the borders of the province of Quebec, where 4500 rivers flow. It is mainly because of Quebec that Canada is the world’s second largest producer of hydroelectric power. The province has an installed capacity of 35 gigawatts, accounting for 39% of Canada’s total. On a per capita basis, Quebec’s capacity is 4430 W and the country’s is 2620 W.  In contrast, the capacity of China, the world’s largest hydro producer in the world, is 150 W per capita and that of the U.S. is 240 W.
To put these numbers in perspective, the average electricity consumption of a U.S. family of four is in the neighborhood of 50 kWh per day. 50 kWh/day/4 capita= 50 kWh * 3 600 000 J/(24h*3600 s/h/4 capita)  = 521 W/capita.
A few years ago, a colleague and I brought our students to the Beauharnois power plant, which is just off the southwest tip of the island of Montreal. With figures from our guides, I realized how efficient hydroelectric plants are. They mentioned that the volume of 3 Olympic-sized pools flows through its turbines every second and that there is a 24 meter height difference between the turbine’s water input and output. After looking up the size of an Olympic pool and using E= mgh, I estimated the water’s potential energy. They mentioned that the 38 units in the kilometer wide operation generate about 1911 MW of power, so I calculated 90% efficiency. Some research revealed that the efficiency of  hydro-generating stations is indeed somewhere between 90 and 95 %.
When we got a close look at the large rods connecting the turbine and generators, and we removed our jackets, it was obvious that the small percentage of heat loss is still a lot of energy. It comes from copper and magnetic losses that result from the large currents induced in the stator’s coils and from  the continuous movement of the rotor’s particles in the changing magnetic fields, respectively. They don’t have to worry about heating the premises in winter, but the 40 o C and above  internal temperature in the summer leads to short shifts for the employees.
Quebec all out commitment to the James Bay project, which included building the world’s 8th largest facility, led to environmental and native land issues. Flooding of large areas of land introduced mercury into rivers. Bioaccumulation then led to elevated concentrations of the toxic metal in fish and potentially in humans. When consumed by humans regularly, mercury(Hg) messes up the tertiary and quaternary structures of important proteins in the nervous system. The Mercury Agreement between the Crees and the Quebec government ensured constant Hg-monitoring and set the goal of restoring fisheries in the area.

But once hydro generators operate, they emit comparatively little greenhouse gases, and no SOX or NOX. After the James Bay project was completed, most homes in large cities like Montreal and Quebec, have switched from heating oil and natural gas to electricity. Even at that, the nationalized power company, Hydro Quebec has been able to sell surplus power to the states of New York and Vermont.

With one hockey team having moved to Colorado; the other not having won a Stanley Cup in 21 years and with separatist sentiment waning perennially,  true power in Quebec lies in  hydroelectricity.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s