The Mactaquac hydroelectric dam 20 km upriver from Fredericton is a major source of electricity in New Brunswick. Although only halfway through its expected life, it requires major refurbishment. Is spending $8.9 billion to fix a 60-year-old power generation station really the best path forward?
NB Power must answer this important question soon. The utility’s decision will impact the future price of electricity and its ability to pay down its crushing debt.
Three considerations are how much electricity the dam generates, the maximum power it can produce, and how “dispatchable” it is. Power is dispatchable if it can be turned on, up, and down as needed.
Mactaquac is an important source of clean, renewable energy. The key question that will impact future energy costs is: how does the cost of refurbishment compare with building a new alternative source of renewable energy generation? An additional consideration: how many new jobs would the alternative create in New Brunswick?
About Mactaquac
Mactaquac generates about 1.6 Terawatt-hours (TWhs) of electricity annually each year, about 12 per cent of the electricity NB Power sells in the province.
Mactaquac can produce up to 668 megawatts (MW) of power which is significant since the power load on the whole provincial electricity grid ranges between 1,000 MW in summer to over 3,000 MW at peak points during the coldest days of winter.
The amount of power Mactaquac can generate at any given time depends on how much water is flowing in the river. The power output can be adjusted but dam can not store hours of full power output. Generally, more water flows in the spring and fall and less in summer and winter.
So, Mactaquac generates 1.6 TWhs of electricity each year and can produce up to 668 MW of power that is dispatchable if there is enough water.
An alternative using wind
Could wind power do the same job as Mactaquac?
About 110 wind turbines would produce up to 670 MW and annually generate more electricity than Mactaquac. These turbines could be located in multiple sites across the province.
Like river water, the amount of wind available to drive turbines changes by season, more in the winter, spring and fall but less in summer.
Wind power can also be dispatchable by using energy storage. An energy storage facility which stores up to four hours of 670 MW power would provide even better control over power than Mactaquac.
Of course, new wind farms should only be installed where the local community is fully engaged and supportive. A decision to replace the Mactaquac station with wind power would need to start that engagement process soon.
How do the costs and job creation compare?
The cost of wind turbines is about $2.3 million to $2.7 million per MW installed so replacing Mactaquac would cost up to 670 MW x $2.7 million = $1.8 billion. Each 100 MW of wind power creates about 10 full-time jobs so the new wind farms would create about 67 ongoing full-time jobs, in addition to the jobs required during construction.
Among the many energy storage options, one stands out because it could make productive use of abandoned New Brunswick mines: compressed air energy storage (CAES). This technique stores energy underground in the form of compressed air. When power is needed, the compressed air is released to spin turbine generators. Based on estimates from the Pacific Northwest National Laboratory and from CAES projects underway in California and Australia, the cost of a four-hour 660 MW CAES installation is likely close to $2.5 billion and would create 25-40 ongoing full-time operations jobs.
Total estimate for wind turbines and storage: $4.3 billion. That’s less than half the current estimate for the Mactaquac refurbishment. The savings would be reduced somewhat by the cost of installing transmission lines where needed to connect the wind farms to the grid. In addition to the initial construction and installation jobs, about 100 new full-time operations positions would be created.
The wind farms could be sited anywhere in the province where the wind flows are suitable, making new job creation an important factor in securing community buy-in and local sustainability.
Power generator sustainability
The Mactaquac refurbishment project is intended to add about 40 years of life to the hydroelectric power station.
The life span of wind turbines is about 25 years. At that point only the wind turbines would need to be renewed since the towers and foundations can be reused. Also, the generator parts can be recycled or reused and the blades will either be recycled or repurposed into construction material.
The life span of a compressed air facility is estimated to be about 50 years. The machinery is above ground which makes for easy recycling, renewal and/or reuse of components.
Even with the cost of renewing the wind turbines in 25 years, the total cost for 40+ years of power would still remain far below that of the estimated $8.9 billion Mactaquac refurbishment project.
The decision to refurbish the Mactaquac power station no longer seems to make economic sense because the cost of wind and storage has dropped so much over the last decade. It is time to rethink the plan for electricity for New Brunswick given the far more affordable options now available to us. Wind and storage systems not only are affordable and sustainable but also provide opportunities for job creation in new areas of the province where community sustainability is a priority.
Tom McLean is a member of the Core Group of the Coalition of Responsible Energy Development in New Brunswick (CRED NB) which is developing a strategy for affordable renewable electricity supply in New Brunswick.
