Cogeneration Explained

Joanna Schroeder

WASILENKOFF headshot-1The country is beginning to hear a lot about cogeneration, or cogen, but what it is exactly? How is it different, then say, a traditional electricity plant? To get the low-down on cogen I spoke with Chad Wasilenkoff, CEO of Fortress Paper whose company has been working with cogeneration and recently put its first cogen project online.

Q: Can you explain how cogeneration is different than a traditional electricity plant? For example, “wind” can provide power to the grid but is not considered cogen.

A: Wind will run a turbine and produce electricity similar to cogeneration. The difference is cogen also produces energy mechanically with steam to turn the turbine but also uses the thermal energy produced in the industrial process for additional energy needs. In conventional systems the heat is an unused byproduct of energy production. Cogen can also uses waste material as the energy source and in our case residual biomass from the paper making process.

Q: Obviously, cogeneration is not a new idea. Why do you think there is such a small rate of adoption/use of cogeneration in North America?

Cogen OutsideA: Cogeneration plants are capital intensive and the costs involved have to be balanced with the costs of other energy sources in the area. For industrial installations cogen works well for operations that use a lot of power, steam and heat. Cogen also tends to be more suitable in areas where the heat can be utilized. An example is Denmark where some cities get 95 percent of heat from cogeneration sites. There are also some small scale cogeneration units on the market for the individual homeowner.

Q: The potential for cogeneration is quite large. For cogen to reach its full potential, what would need to happen? Would there need to be legislation, tax credits, etc?

A: Yes assistance with financing, preferential pricing tax credits etc. would all help cogen to reach its full potential. Cogeneneration is already part of many plans for expanding renewable energy, According to the International Energy Agency (IEA).

Q: Fortress Paper has made a significant investment in cogen at your Fortress Speciality Cellulose Mill in Thurso, Québec where you have constructed a cogen facility. Can you give the readers of DF more information about this project?

A: The Fortress Specialty Cellulose mill capex for the Cogen Plant was over Canadian $120 million and included a new turbine and generator with cooling tower and condenser, new biomass boiler, and new water treatment system among other items.

According to the IEA, “The costs of heat and/or power production from bioenergy depend not only on the technology and operational scale but also on the quality, type, availability and cost of biomass feedstocks, and on the pattern of energy demand (especially whether a steady demand exists for heat), meaning that cost estimates inevitably span a wide range. The investment costs for a biomass plant with a capacity of 25‐100 MWe are between USD 2 600/kW and USD 4 100/kW. With a fuel cost of USD 1.25/GJ to USD 5/GJ, the electricity cost would be between USD 0.069/kWh and USD 0.15/kWh at a 7% discount rate (IPCC, 2011). The capital cost of co‐firing is much lower (USD 430/kW to USD 900/kW, depending on configuration), and at the same fuel costs, co‐firing provides electricity at USD 0.022/kWh to USD 0.067/kWh (IPCC, 2011).”

Q: What are the pros and cons of co-generation plants?

Generator 2A: Cogen plants are more efficient at capturing energy as part of the industrial process and can use residual waste from some industrial process that can result in less landfilling etc. Cogen can stabilize the balance sheet as it can provide a steady income for industrial sites and optimize the energy balance of an industry with high energy needs and also provides savings on the cost of energy lost in transmission. For power plants, there is a more efficient use of natural gas or coal as cogen provides a higher energy yield. In addition, cogen technology could provide power for a plant while in a blackout.

The major con is that cogeneration plants are capital intensive and require cooperation from the utility and having the infrastructure in place to be able to take on the additional power generated. Plus there needs to be access to feedstock. In addition, the scale of a biomass plant may be limited by seasonal variations in heat demand.

Q: What advice do you have for other industries when it comes to adopting/investing in co-generation technologies?

A: I encourage the investing and adopting of cogeneration as it is a more efficient use of energy sources such as natural gas or in our case it better utilizes natural resources. And with biomass cogen can provide a more sustainable power supply for future generations.

Alternative energy, bioenergy, biomass, Electricity