The manufacture of any "green" product should be part of the accounting of its environmental impact. Many of the metals and elements used in a solar array are not produced using "clean" methods - for instance, mining the metals and creating the cells, and transporting the materials to the site.
One objective of finding alternative energy is to find a way to reduce the use of coal, petroleum products and natural gas, all of which produce greenhouse gasses upon combustion. However, manufacturing the equipment that will itself produce alternative energy has an initial environmental cost, too: most manufacturing and transportation is still done the old-fashioned way, employing electricity produced by burning oil, natural gas or coal.
In order to figure out how many greenhouse gas emissions (GHGs) the solar array's manufacture and installation was responsible for, a process called SMART (System of Measurement and Reporting on Technology) was used. The process traces the sequence of manufacturing, transportation and extraction of the materials used to create the array, and comes up with a number that quantifies the greenhouse gases saved (or not) at the end of its life.
The assessment determined that the array will indeed save greenhouse gasses: it was calculated that the array will save a cumulative 69 tonnes of greenhouse gas emissions from entering the environment by 2013. Although, for the first year of its life, the array actually created 8 tonnes of GHGs, the following year it saved 8.9 tonnes, for a net gain of 0.9 tonnes of C02e effectively removed from the environment. The array saves GHGs every year after that until its projected end-of-life (anywhere between 25 to 50 years). All told, the Centre's solar array is indeed a successful environmental initiative, although not an economic one were it not for its research and teaching benefits.
|PV module production||Material components of the PV modules – silicon, glass, aluminum, etc. – as well as their assembly and transportation.|
|Mounting fabrication||The mounting structure was made locally of steel and aluminum stock.|
|Inverter production||Converts direct current to alternating current for the electrical grid. Packaged and supplied as a single component.|
|Balance of system production||Components not identified elsewhere including the isolation transformer, electrical wiring, boxes, fuses, switches and miscellaneous hardware and instrumentation.|
|Installation||Installing the components that make up the system.|
|Sunshine||The array's source of energy. This also effects building operation through heat and light.|
|PV generation||The operation of individual components during the lifetime of the array.|
|Building operation||Electricity use in the building (HVAC, lighting, office equipment).|
|Shading||A secondary purpose of the array's facade mounting, shading moderates the effects of sunshine on building operations.|
|Maintenance||No regular maintenance is required except periodic repair of the inverter.|
|Decommiss- ioning||Should the system reach the end of its life before the building itself, it can remain in place to provide shading or be dismantled for recycling.|