Natural energy flows

Summary: Natural energy flows are sources of energy that do not need to be processed with additional energy but, rather, naturally flow through the world and need only be harvested or otherwise put to work.

The term natural energy flows was popularized in environmentalism by the Hannover Principles, a document drafted by William McDonough and Michael Braungart in 1992, in anticipation of the Expo 2000 at Hannover, Germany. Natural energy flows are those sources of energy that are naturally flowing through the world already and need only be harvested or otherwise put to work; they include the flow of running water and the movement of the seas, the kinetic energy of wind, the solar radiation of sunshine, and the geothermal energies beneath Earth's surface. They are not coequal with renewable energy sources, which would include biofuel.

Constant Movement

Massive amounts of energy constantly flow along Earth's surface. The sun radiates some 28 × 10³² calories of energy every year, about 13 × 10²³ calories of which are intercepted by Earth. Of those intercepted calories, approximately one-third are reflected back into space. (This quantity, called the albedo, varies locally according to weather conditions and type of surface coverage; snow-covered land reflects the most energy, as much as 90 percent, while ocean surfaces reflect less than 10 percent, and cloud cover also influences albedo.) The rest of the solar energy is absorbed by Earth or its atmosphere. Almost half is converted into heat, some of which powers the water (hydrologic) cycle of evaporation and precipitation. A small amount of sunlight, about 0.2 percent, is converted into the energy of wind, water currents, and waves. Even less than that, 0.1 percent, is used by photosynthesis. A tiny amount of Earth’s energy (tiny, that is, relative to this solar energy) comes from other sources, the geothermal heat emanating from Earth’s core and the tidal energy resulting from the gravitational interactions between Earth and the moon. By contrast, sunlight accounts for tremendous amounts of Earth’s energy and leads to most other forms. For example, photosynthesis by plants turn solar energy into chemical energy and stores it as carbohydrates in the plant, which over a geologic timescale when buried under great pressures eventually becomes gas and petroleum deposits. Thus, even when humans are not harnessing natural energy flows, these flows are nevertheless the source of most of our energy.

McDonough was a New York City architect; Braungart, a German chemist. Together they, collaborated on a sustainable design they called “cradle to cradle.” The Hannover Principles articulated guidelines for the design of objects and buildings. The principles focused on interdependence with the natural world, the consequences of design decisions, waste and life-cycle assessments, the interrelationship between sustainability and human rights, and the responsible use of energy. With regard to natural energy flows, the document says, “Rely on natural energy flows. Human designs should, like the living world, derive their creative forces from perpetual solar income. Incorporate this energy efficiently and safely for responsible use.”

McDonough has elaborated on this in later writing—indeed, he and Braungart have spent much of their subsequent careers refining and elaborating on the ideas in the Hannover Principles. In particular, McDonough has downplayed the idea of interpreting the directive to “rely on natural energy flows” in a quantitative way, and he does not appear to support renewable energy quotas or quantified energy efficiency goals. Instead, he and Braungart call for a fundamentally new approach to design, not simply a more efficient version of current designs. He has proposed buildings that sequester carbon, fix nitrogen, and make oxygen and distilled water while powered by solar energy; in general, the Hannover Principles seem primarily focused on solar power among the renewable energy sources.

Energy Management

The call for reliance on natural energy flows has been referred to as energy management, analogous to waste or water management. It is concerned with more than just the sustainability of its energy sources, in other words. Using natural energy flows reinforces and explicates humankind’s connection to the planet by thriving from its already extant mechanisms, such as wind and water currents. The usual view of advocates is that natural energy flows alone—indeed, even solar power alone—are sufficient to meet humans’ energy needs and that not attempting to use them to meet those needs is letting them go to waste.

There has been some suggestion that the use of natural energy flows may have environmental consequences that have not yet been made clear because their use is not yet widespread enough to understand the consequences of their use. John Holdren, one of President Bill Clinton’s science advisers and Director of the Office of Science and Technology Policy under President Barack Obama, while publishing extensively on climate change and the need for proactive policies to reduce anthropogenic emissions, has also insisted that there is no known energy technology with negligible environmental impact. Windmills may harm avian life; hydropower frequently disrupts ecosystems; reservoirs and solar collectors need land to occupy; and some collection of geothermal energy is nonrenewable.

Bibliography

"Global Energy Flows in Transition." Rural 21, 22 Mar. 2023, www.rural21.com/english/a-closer-look-at/detail/article/global-energy-flows-in-transition.html. Accessed 2 Aug. 2024.

McDonough, William, and Michael Braungart. Cradle to Cradle: Remaking the Way We Make Things. New York: North Point Press, 2002.

McDonough, William, and Michael Braungart. The Hannover Principles: Design for Sustainability. New York: W. McDonough Architects, 2003.

Rogers, Elizabeth, and Thomas Kostigen. The Green Book: The Everyday Guide to Saving the Planet One Simple Step at a Time. Foreword by Cameron Diaz and William McDonough. New York: Three Rivers Press, 2007.