How it Works

Building an on-site renewable energy system is probably the most visible way of greening your campus energy use. These projects are often more time consuming and costly than purchasing green power or renewable energy certificates. However, they often provide additional value on campus such as hands-on learning opportunities and publicity. There are several options for an on-site project, each having their own resource needs.

Things to Consider

What Type of System

If you are considering an on-site renewable energy system, the first step is to do a resource assessment to determine the best type of project for your school’s location.

Some general considerations for popular green energy resources:

Solar:  Solar energy can be harnessed to generate electricity through the use of photovoltaic (or PV) cells.  Solar power is clean, renewable, and quiet. Its modularity, along with the vast availability of solar energy, makes it relatively easy to site. Typically universities using solar energy have arrays of solar modules mounted on building rooftops or incorporated into a building structure, providing power close to the energy load.  Solar arrays can vary in size from watts to megawatts. 

Wind:  Turbines come in varying sizes, from 1 kW to 3MW, and vary in the amount of space necessary to operate. Turbine installation is often most feasible in non-urban areas due to siting and permitting considerations.  For example, a 250kW turbine can be 130 feet tall with a 98 foot sweeping blade. About 1 acre of land and average wind speeds of 15mph at a 50-meter height are needed for a turbine of this size. 

Biopower: Typically biomass energy production can be divided into the categories of biopower (for electricity generation) and biofuels (for petroleum substitutes).  Power is most commonly harnessed from methane from a landfill, sewage treatment plant, or agricultural waste.  These projects need a supply of methane gas and some type of power conversion technology like an internal combustion engine.  

Cost

The cost of setting up an on-site project will vary significantly depending on the scale and type of project. Seattle University installed solar panels in three locations to generate a maximum capacity of 5.3 kW of electricity at a cost of $32,346 in 2005. At Carleton College in Minnesota, a 1.65 MW wind turbine project cost $1.8 million in 2006.