The Co-Gen Project
Cogeneration, also called Combined Heat and Power (CHP), is an efficient, clean and reliable approach to generating power and thermal energy from a single fuel source. By installing a cogeneration system designed to meet the heating and electrical demands of our campus, Smith has increased operational efficiency and decreased energy costs, while significantly reducing emissions of greenhouse gases.
Smith now has to buy only a fraction of its power from outside sources and has increased its energy use efficiency from 45 percent for conventional generation systems (burning fossil fuel in boilers and buying electricity from the grid) to as much as 85 percent. This increased efficiency and reduced dependence on conventional systems will help prolong the availability of fossil fuels and reduce dependence on dirty-emission coal, imported oil and nuclear energy. Eventually, the steam generated can be used to chill water for air-conditioning, reducing the cost of the higher power demand in the summer.
Smith began moving to this system with a central plant cogeneration feasibility study completed by the engineering firm vanZelm Heywood and Shadford. In 2006 students with Smith's Picker Engineering Program collaborated with vanZelm on the cogeneration project, studying renewable fuel options for the plant's boilers.
Why Cogeneration Is Better
Anyone who has paid a utility bill lately knows the impact of rising fuel and delivery prices on household costs. Imagine paying for 24-hour usage in every room, office and common space serving 2,600 students and hundreds of employees!
As those on campus turn on the lights and settle in front of their computers, few realize that Smith College uses $6 million worth of energy every year to heat, cool, light and power the college. That's enough to completely power 2,500 homes for one year—and already includes significant conservation measures taken over the past several years. Older boilers use a heavy heating oil that poses emission problems. Likewise, the energy the college purchases from power companies is inefficient: the generation process often wastes nearly 70 percent of input as heat to cooling towers and delivers about 30 percent to the customer. Meanwhile, energy costs are rising about every six months.
The Construction Process
The project requires large-scale asbestos abatement, demolition and preparation before delivery of the necessary construction equipment, a boiler and a 3.5-megawatt generating turbine similar to that of a jet engine.
When the 250-ton crane arrived on campus in August 2005, and a 16-foot by 32.5-foot opening was cut in the old boiler plant's roof, the heavy lifting began. First, the huge crane was scheduled to remove approximately 200 tons of obsolete equipment either on top of or inside the plant—including coal pulverizing equipment and storage hoppers, three 1947 boilers and other miscellaneous apparatus. In mid-December the crane lifted in the new 35-ton package boiler followed by the 39-ton $2 million turbine. The new system began making steam in test runs in 2007.