How Much Incoming Solar Energy (Insolation)
Is Received
at Different Locations?
For
purposes of designing heating/cooling systems and other uses, average
insolation data are available for many sources. One is the US Department
of Energy's
National Renewable Energy Laboratory (http://www.nrel.gov/).
Their data are available on-line from the
Center for Renewable Energy and Sustainable
Technology (CREST): (http://solstice.crest.org/renewables/solrad/index.html).
The
amount of incoming
solar energy
(insolation) is measured with a radiometer. Average
monthly and annual values are reported in units of kilowatt
hours/square meter/day (kWh/m^2/day).]
ACTIVITY:
Select four or five of the available
locations.
Try to choose sites with approximately the same latitudes or
longitudes. For each, follow
the on-line instructions to:
1)
obtain name, latitude,
and longitude, and average, minimum, and maximum insolation
for each month and for the year.
2)
present the data
in a table or spreadsheet.
3)
pelect appropriate
parts
of the table and make graphs showing patterns in insolation. You should use
line graphs to show variations in average monthly solar energy values
at different locations, and bar graphs to compare average
annual values.
4)
Provide brief interpretations of
what you have learned. You
should be able to write at least one or two paragraphs about each part of
this project.
[Extension/extra
credit: The web site also
provides climate data. Design an investigation comparing solar radiation and climate conditions.]
1.
What factors may affect the amount of solar energy received at a location?
2.
What would be three things to consider in deciding where to locate a
radiometer site?
(Consider what should be done to avoid obtaining misleading data.)
3.
If skies over a location become more polluted from natural (ex.,
volcanic eruptions) or human (ex., vehicle or factory exhaust) sources,
what changes might occur in the amount of solar energy reaching the
surface?
Example
of Data from CREST web site http://solstice.crest.org/renewables/solrad/index.html
Station
data have been entered into an Excel spreadsheet, then Excel graphing capabilities have been used
to illustrate patterns of change.
City:
BOSTON * State: MA (WBAN No:
14739)
Lat(N): 42.37 Long(W): 71.03 * Elev(m): 5 * Pres(mb): 1015 *

Selected
Applicable Key Ideas and Performance Indicators from the NYSED MST Learning Standards,
especially Physical Setting/Earth
Science Core Curriculum
Standard
1--Analysis, Inquiry, and Design
Mathematical
Analysis:
--Abstraction
and symbolic representation are used to reach mathematical conclusions.
--Deductive
and inductive reasoning are used to reach mathematical conclusions.
--Critical
thinking skills are used in the solution of mathematical problems.
Scientific
Inquiry:
--The
central purpose of scientific inquiry is to develop explanations of
natural phenomena in a continuing, creative process.
--Scientific
inquiry involves testing of proposed explanations involving the use of
conventional techniques and procedures and usually requiring considerable
ingenuity.
--Observations
made while testing proposed explanations, when analyzed using conventional
and invented methods, provide new insights into phenomena.
Standard
2--Information Systems
--Information
technology is used to retrieve, process, and communicate information as a
tool to enhance learning.
Standard
4--Science
--The
Earth and celestial phenomena can be described by principles of relative
motion and perspectives.
Objects
in the solar system are in regular and predictable motion.
Earth's
motion and its changing position with regard to the Sun and move have
noticeable effects.
--Many
of the phenomena that we observe on Earth involve interactions among
components of air, water, and land.
Earth
systems have internal and external sources of energy.
Weather
patterns become evident when weather variables are measured.
Weather
variables are measured with instruments.
Weather
variables can be represented in a variety of formats.
Seasonal
changes can be explained using concepts of heat energy.
Standard
6--Interconnectedness
--Through
system thinking people can recognize commonalities that exist among all
systems and how parts of a system correlate and combine.
--Models
are simplified representations used in analysis, explanation,
interpretation, or design.
--Grouping
into a series provides a useful way to deal with the immense range and
changes that affect systems.
--Identifying
patterns of change is necessary for making predictions about future
behavior and conditions.
Standard
7--Interdisciplinary Problem Solving
--Knowledge
and skills of mathematics, science, and technology are used together to
make informed decisions and solve problems.
--Solving
problems involves a variety of skills and strategies, including effective
work habits, gathering and processing information, generating and
analyzing ideas, making connections, and presenting results.
Moon
and Tide Patterns
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