Plutonic Power is a Vancouver based energy generation company that has proposed the creation of many hydro-electric power generation installations within BC. The company’s flagship project is the 196MW East Toba and Montrose project due for completion in 2010. They have proposals for a lot of projects in the works, twenty-four of which have a combined total capital cost of around $3 to $4billion dollars. The majority of their proposals are based on run-of-the-river techniques.
Run-of-the-river is purported to be good in terms of environmental impact – no large dammed areas and large bodies of water stored behind dams, rather the energy is derived from naturally flowing water which has a pressure head simply by virtue of the terrain over which the river is flowing. The steeper the terrain and larger the flow of water the larger the kinetic potential energy available to be siphoned-off and passed through a series of turbines.
The Plutonic website contains a lot of information about the positive side of run-of-the-river projects as do other websites run by companies involved in similar projects. What is not so clearly explained is that the infrastructure required to put the run-of-the-river project in place is often very significant and is impactive to the environment.
The damage to the environment includes the roadways to access the site for construction and maintenance, the invasive transmission lines which require set-back distances to the tree-line that greatly increase the area of trees that need to be felled to actually get the electricity out from these remote locations. In addition, the water that is returned to the river is much reduced in flow rate so the natural distribution of sediments and nutrients can be greatly altered from the original state of the river.
A common policy seems to be to occasionally flush the river to remove settled sediments but this is not the same as the natural processes usually at work in the eco-system and it cannot compensate for the water flow loss over that section of the river that has been bypassed. These run-of-the-river systems are not like the weir and water-wheel systems in days of yore.
Another drawback for run-of-the-river projects is that very often they will produce peak power in the late spring to early fall from rain and snow-pack melt run-off. This spring-fall power comes at a time when BC Hydro does not actually need to have the extra power produced since at that time it will have its own dams filled and will most likely also have to ‘spill’ its own water due to over-capacity.
The peak demand for electricity in BC is during the winter and not the summer. The temptation would then be for the operators of the run-of-the-mill plants to try to operate later in the season when the river flow is lower and there is more likelihood of damage to the eco-system from unexpected events such as lower river flows, greater than expected sediment, etc. This also happens to correspond to the spawning and breeding times for salmon so the potential for further impacts to the salmon population is clear.
One area in particular that Plutonic Power has proposed for major development is in Bute Inlet, with seventeen sites around 150-200kms north of Powell River, BC, with a combined output of 1027MW (about the output from two latest generation CANDU nuclear reactor) and an estimated capacity to generate 2,980GWh per year (the CANDU operates 24 hours a day for 365 days of the year so it produces a lot more power – 7,900GWh). This is not to advocate for nuclear power, but to try and put the proposed run-of-the-river project into perspective. BC Hydro generates and buys around 54,000GWh of energy per year). The optimistic greenhouse gas offset number of displacing 2 million tons of CO2 per year is based on displacing emissions from a gas-fired and coal power-plant.
The Wilderness Committee reports that Plutonic Power is working with American giant General Electric to create the enormous 1027 megawatt private hydropower project in Bute Inlet, the largest proposed private power project in the province.
The fact of the matter is that the run-of-the-river power-plants are likely to displace existing BC Hydro greenhouse gas emissions (GHG) rather than replace significant amounts of gas or coal power generated GHGs. This occurs since BC Hydro mostly buys cheap GHG-intensive night-time power from Alberta; and the run-of-the-river generates power throughout the day and not just at night. BC Hydro power generation is almost 95% very-low GHG emissions from large scale hydro. Using the example of BC Hydro emissions at around 30tons per GWh for the Site C Peace River hydro-dam proposal (versus the 670tons per GWh for the Plutonic operations in their assumed offsetting of gas and coal powerplant GHGs), actually gives the ‘savings’ at 0.09 million tons of CO2 and not 2 million tons.
A more accurate appraisal is to compare the construction greenhouse gas costs, road system and including the loss of forest for transmission lines (conservatively estimated to be 2400 hectares of forest for a 200km long transmission line and 5tons per hectare carbon sequestration from the forest and soil), impacts to the river eco-system and surrounding pristine wilderness. Just the forest loss itself translates into 4tons/GWh. The Site C dam output is an estimated 4800GWh and located all in one place, according to a BC Hydro report.
So, interpreting figures can lead to different conclusions. As for run-of-the-river projects, and the BC Hydro mandate to be energy self-sufficient for the province of BC, it would seem prudent to actually wait and see how some of the run-of-the-river projects actually operate for a few years to accurately evaluate their environmental impact, rather than go and create numerous run-of-the-river projects that potentially destroy pristine eco-systems without proof of concept being validated.
Putting more effort into saving energy consumption is money better spent and avoids BC Hydro having to pay for expensive run-of-the-river power when cheaper power is available from power stations already operating.
If absolutely needed, then a Site C type installation seems to be the lesser of the two evils – one ugly earth scar in a single location with high efficiency rather than hundreds of smaller, just as ugly scars that potentially will lead to more widespread eco-system damage. We know that the hydro dams have operated safely and for a very long time in BC, although not without considerable environmental consequences, but what is not clear is if large scale implementation of run-of-the-river is what is needed right now, nor whether they are in the best interests of British Columbians.
Resources
Plutonic Power: www.plutonic.ca
Bute Inlet: www.vancouverisland.com/Regions/towns/?townID=4037
To find out more about BC Hydro's Site C read their report.
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written by Arlis Owen , August 17, 2010