WHAT SMITH IS DOING

Green Building

Ada Housing Project

A new 10-unit apartment-style dormitory with a central common area will be built to house students enrolled in the Ada Comstock Scholars program. Each unit will have two bedrooms, a full bathroom, an eat-in kitchen, and a living room. This building has been designed to minimize thermal and electrical energy loads by using a few simple techniques. The primary components are thick walls and ceilings with lots of insulation (R-50 and R-70 respectively) and tall triple-glazed windows. In addition the building will have direct-digital temperature controls, heat recovery ventilation, energy efficient (Energy Star) appliances and lighting, and solar panels for domestic hot water production. The added insulation in the walls and ceiling has already paid for themselves by reducing the size of heating and cooling systems. Energy Star has been working with the design team and the project has earned a 5 Star+ rating, their highest.

Engineering and Molecular Sciences Building

With its emphasis on sustainability and energy efficiency through numerous design, construction and operational initiatives, Smith’s new building for engineering and molecular sciences will be at the forefront of energy-efficient architecture.

The 140,000-square-foot building, tentatively scheduled for groundbreaking in 2007, will incorporate numerous initiatives in its design and use in order to reduce the consumption of energy resources and the costs of operation and to serve as a teaching tool for sustainable design.

Click here for more information on the role of sustainability in the building process

The Cogen 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 thermal and electrical base loads of our campus, Smith College will increase operational efficiency and decrease energy costs, while significantly reducing emissions of greenhouse gases that contribute to global warming.  Smith College retained the engineering firm of vanZelm Heywood & Shadford to formulate a utility infrastructure master plan, which included a cogeneration feasibility study. The estimated economics were very favorable, and the proposed system could efficiently serve Smith's electrical and thermal loads. A 3500-kW generator, driven by a gas turbine that can burn natural gas or diesel fuel, was recommended.

On the thermal side, the exhaust from the gas turbine will pass through a Heat Recovery Steam Generator (HRSG) to provide heat for buildings and hot water. This will also add efficient and reliable steam capacity to Smith's aging boiler plant.

On the electrical side, 3500 kW can serve the campus base load year round, while still reserving a small block of power to be purchased from the local utility. The ability to self-serve a major portion of the electrical load will be of major importance when electrical rates increase dramatically as deregulation progresses and fuel costs continue to rise.

The cogeneration project will use the same type of gas turbine that is commonly used in jet engines.  Want to know how a gas turbine works? 

The Smith College Board of Trustees approved the proposed cogeneration plant in Spring 2005. A third-party review of the vanZelm study was performed by Bosland Engineering in Summer 2005, with favorable results. The project has proceeded to the detailed design phase.

Smith College campus is an excellent candidate for cogeneration because of the following:

• Electricity is distributed from central location
• Steam is distributed to almost all campus buildings from a central location
• The electrical load is fairly consistent throughout a typical day and throughout the year
• A substantial summer heat load exists that can be served by steam
• Electric costs are expected to rise dramatically in the near future (Spring 2007)
• Substantial capital costs will be incurred upgrade aging boilers in the near future
• Campus expansion is expected to increase cooling and electrical loads
• Smith would like to minimize our impact on the local and global environment

The cogeneration plant will increase the efficiency of energy utilization from 45% for conventional power generation systems (burning fossil fuel in boilers and buying electricity from the grid, as we do now) to as much as 85%. Therefore, conventional systems require 65% more energy than the integrated systems, as shown in the diagram below. This will help prolong the availability of fossil fuel (natural gas and fuel oil) and reduce our dependence on dirty coal, imported oil, and nuclear energy.

With conventional systems (the left side of the diagram), 130 units of energy are purchased by the utility to provide 35 units to the customer. At the boiler plant, 59 units of energy are purchased to provide 50 units of heat. The combined efficiency is 85/189 = 45%. Most of the losses are in the form of waste heat from electricity generation, rejected to cooling towers, river water, or the ocean.

Cogeneration (right side of the diagram) uses 100 units of fuel to deliver 35 units of electricity and 50 units of heat. The efficiency is 85/100 = 85%, a huge gain because the heat is used at the facility instead of rejected to atmosphere.

Gas turbines with catalytic exhaust cleanup are one of the cleanest means of generating electricity, with emissions of oxides of nitrogen (NOx, a precursor to smog) far below Smith's existing steam boilers and the mix of generation systems that provide the grid with electricity. Natural gas and diesel fuel have far less sulfur content than the #6 fuel oil used in the boilers, so sulfur dioxide (SO2, a precursor to acid rain) emissions will be almost eliminated. Because of their relatively high efficiency and cleaner fuel, gas turbines emit substantially less carbon dioxide (CO2) per kilowatt-hour (kWh) generated than any other fossil technology in general commercial use.

Smith's greenhouse gas emissions will be essentially cut in half when the cogeneration plant comes on line.

The proposed cogeneration system, a 3500-kW gas turbine with HRSG, will be a reliable source of high-quality electricity, providing substantial operational cost and environmental emissions benefits. The financial benefits provide an attractive payback while the steam generation capability provides a necessary upgrade to the boiler plant. As energy costs continue to rise, the efficiency and flexibility of a cogeneration system will provide Smith College with a measure of energy independence.