Wild Energy
The free, wild energies that play over a site
are the driving force behind climate and weather and are major
design components. Solar, wind and water energy, and the chemical
energy in the soil, are so prevalent that we may tend to take
them for granted unless they present a problem. The truth is that
they can always be used as a resource and should be considered
in our analysis of site and user needs.
Solar energy (direct, diffuse and reflected) is variable on a
site dependent upon latitude, vegetation cover, slope aspect and
orientation, and regional air quality. For example, the closer
the slope is to being perpendicular to the incoming rays of the
sun the greater the intensity of radiation. It is a driving force
for all plant growth and can be modified to some extent by design.
In design we create solar traps, shading devices, orientation
to gain solar heating, and so on. Areas may be sited near a water
body to take advantage of light being reflected from it. Solar
energy is there just waiting to be captured for use.
Architectural Graphic Standards (Ramsey and Sleeper, John Wiley
& Sons) provides information on solar angle, path and radiant
energy at various latitudes. Developed by architect Victor Olgyay,
AIA, the information is illustrated and explained in a format
that is usable by designers.
Wind energy is highly variable from area to area. In some places
there is enough wind to drive turbines for generation of power.
In other areas, wind causes soil erosion and drying making windbreaks
an important element in design. In yet other areas, planting can
be made to concentrate wind movement for cooling. Weather stations
in many areas keep track of wind direction and force throughout
the year and publish "wind roses" that are particularly
helpful to designers. Site conditions such as hills and valleys
can have a major influence of wind patterns so the more local
the data the more useful it is. Wind on the site can be modified
to a large degree through siting and placement of buildings and
plantings.
Water entering the site is a source of energy. A site may have
streams or rivers as a permanent source of energy. More often
we need to look at rainfall and its storage as the energy supply.
The most important factor in use of water energy is to capture
the water in quantity as high on the site as possible. From that
point it can be used again and again as it is released through
the site. Direct water power is enhanced by steep site gradients
but water converted to plant biomass becomes a form of stored
energy as well.
Chemical energy is collected in the soil. While it is a latent
form of energy it is important for growth of plants. Plants build
their structure by conversion of solar energy to biomass using
water and soil nutrients. The energy producing capability of soil
can be enhanced by composting and other soil building techniques.
