Solar energy, radiant
light and
heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as
wind and wave power,
hydroelectricity and
biomass, account for most of the available
renewable energy on earth. Only a minuscule fraction of the available solar energy is used.
Often Solar powered electrical generation relies on heat engines and photovoltaics. Solar energy's uses are limited by human ingenuity, and the finite resourced to build the sys. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes.To harvest the solar energy, the most common way is to use solar panels.
Solar technologies are characterized as either passive solar or active solar, depending on the way the energy is captured, converted and distributed. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the suns seasonal orientation, selecting materials with favorable thermal mass, which will capture and radiate solar energy, light dispersing properties that will disperse light energy, or designing spaces that naturally circulate solar heated air.
Construction of an Affordable Greenhouse. The capstone project for
Queen’s University 4th Year Mechanical Engineering Class,"
Engineering for Sustainable Development", is to design and construct an Appropriate Technology with a quantifiable engineering result. This project is to construct a greenhouse, review the heat requirement on the system for the whole year; then, based on the materials and conditions selected, review costs associated with this and build a scaled model.
This project is the first step to easy community greenhouse development - the goal of the affordable greenhouse is to:
- Improve greenhose design and awareness for residential application.
- Demonstrate the feasibility (i.e costs) of a greenhouse in the winter months and determine the best time to install such a system for optimal crop yield.
Due to the materials selected and the cold Canadian Spring, it is not effective to construct until late April. But with better material selection and innovative greenhouse designs, it is hoped that constructing miniature greenhouses will become common practice.
The blueprints for the construction of an affordable greenhouse are included; for this greenhouse a single pane Polyinyl chloride (PVC) covered greenhouse was reviewed. Heat losses and calculations were done in MatLab using constants from the Canadian Climate Normals website and sunlight radiation from Queen's University Living Building.
-Happy growing!
