“We travel through time on a cyclical path often returning to where we came.” Black Elk (1863-1950), a Lakota holy man, explained the symbolic power of the circle for his people in the book Tipi: Home of the Nomadic Buffalo Hunters (2007): “You have noticed that everything an Indian does is in a circle, and that is because the power of the world always works in circles, and everything tries to be round. In the old days when we were a strong and happy people, all our power came to us from the sacred hoop of the nation and so long as the hoop was unbroken the people flourished. … Everything the power of the world does is done in a circle… (p. 55).”
The Earth is a system of interrelated entities and elements that form an organic whole. It is bounded by a near-perfectly balanced atmosphere encircling our world. As an open system, Earth interacts with its surroundings by circling the Sun while energy flows in and out of the atmosphere and around the planet. The atmospheric sphere bounding our world regulates the Earth’s climate by absorbing and reflecting power from the Sun in heating and cooling cycles by day and night, by season, and through the ages. However, without the nearly perfect density and mixture of atmospheric gases in balance that surrounds our planet, this revolving circle of life becomes broken, and we would no longer flourish.
Even long before human times, the Earth has acted as a huge solar collector regulating its own temperature range by cyclical interaction with the Sun. Operating like the roof on a greenhouse, if the Earth’s atmosphere were to become too dense, the temperature range we enjoy would increase to a disturbing extreme. Scientists and explorers have recently observed significant melting of glaciers and polar ice as significant evidence of climate change.
In 2007, the United Nations’ Intergovernmental Panel of Climate Change reported that it is 90% probable human activity is a significant cause of global warming. While some controversy over the cause of climate change remains, there is little dispute that global temperatures have been increasing since the beginning of the Industrial Revolution, and the temperature increase is correlated along with increasing fossil fuel burning and a steady increase of greenhouse gases in the Earth’s atmosphere. As a result, the interest in and use of alternative energy sources has increased significantly. However, other energy sources and in particular, solar energy, have been utilized in some form by all of earth’s inhabitants.
People often look for new ways of doing things, and it is amusing how “innovations” are often rediscoveries of our ancestors’ ways. Ancient Greek, Chinese, and Anasazi people used solar energy for heating their living quarters. Socrates observed, “In houses that look toward the south, the sun penetrates the portico in winter.” People now use passive solar heating technology in ways that have been used for heating human dwellings for over a thousand years.
Photosynthesis in ancient algae, bacteria, and flora converted sunlight and carbon dioxide into organic compounds, and some of it became oil, coal, or methane. Solar energy is stored in these “bio-batteries” in the form of fossil fuels. However, the natural process of storing solar energy in fossil fuel takes much too long for humans to consider as a renewable resource. Solar energy remains an important means to conserving our natural resources and our energy security.
To achieve long-term sustainability and balance in our environment with the use of technology, we need much quicker cycle times than thousands of millennia to transfer energy from the Sun through burning fossil fuels to meet our energy needs. The Sun beams the most essential and plentiful clean energy to us every day. Solar technology options using solar panels and passive solar construction uses energy directly from the Sun to heat our buildings as the ancient Greek, Chinese, and Anasazi people did. Thankfully, we also have newer options to generate electricity from sunlight.
In 1839, a solar photovoltaic technology revolution emerged when French scientist Edmond Becquerel discovered the photovoltaic (PV) effect; he observed an increase in electrical generation when an electrolytic cell was exposed to light. In 1954, Daryl Chapin, Calvin Fuller, and Gerald Pearson developed the first PV silicon solar cell, with 4% efficiency, at Bell Telephone Laboratories. Today, monocrystalline silicon solar cells approach 20% efficiency, multijunction solar PV cells can reach 40% efficiency, and researchers are targeting 60% efficiency. Several other promising low cost solar PV technologies are also emerging, such as “thin film” Copper Indium Gallium Selenium (CIGS) and organic polymer solar PV paint. The U.S. Department of Energy predicts that within a few years, new solar PV technologies will be able to reach a system cost of only $3 to $4 per watt, which will produce energy at 8 to 10 cents per kilowatt-hour, comparable to present conventional electricity generation costs.
The present day solar revolution leaves many people with passive solar heating options that served our ancestors. Researchers are developing new biological and chemical technologies to give us new ways to store and use solar energy for a better and cleaner way of life. Solar energy is an incredible and awesome power that sustains life on Earth, and life will continue to flourish on our planet while we remain in harmonic balance with our environment as our organic spaceship Earth rotates and circles around the Sun.
Passive Solar House: The Complete Guide to Heating and Cooling Your Home by James Kachadorian Chelsea Green Publishing Company 2006.
Build Your Own Solar Heating System by Kenneth Clive Lucerna Publishing 2007.
Solar Water Heating: A Comprehensive Guide to Solar Water and Space Heating Systems by Bob Ramlow New Society Publishers 2006.
Photovoltaics: Design and Installation Manual by Solar Energy International New Society Publishers 2004.
Minnesota Renewable Energy Society (MRES),
Minnesota Office of Energy Security
St. Paul, MN
800-657-3710 (MN only)
Minnesota Solar Energy Industry Association, Saint Paul, MN
St. Paul, MN