Renewable Energy

2007 Volume V

Introduction

With concerns about the impact on the environment of our current use of fossil fuels and our national energy security, renewable energy is in the news on a daily basis. Many students have seen Al Gore's movie "An Inconvenient Truth" and are familiar with some of the issues relating to energy use, but they may not know much about the science related to renewable energy. The aim for this seminar was to discuss the science related to current sources of energy and potential future sources of energy, with a focus on renewable energy. We can learn much about sustainable energy use by studying natural processes. Nature has solved the renewable energy problem through the process of photosynthesis that is carried out by green plants. Plants are amazing chemical factories and provide a working example of renewable solar energy conversion, but this is often not appreciated. By understanding how plants carry out the processes of solar energy utilization, we can obtain some answers to the question of how we can harvest solar energy by using processes of artificial photosynthesis.

My own interest in science stems from my hands-on experiences as a child. Therefore, many demonstrations were included in this seminar — at least one demonstration, and frequently 2-3, in each seminar meeting. These demonstrations were chosen so that they could actively involve the students and at the same time illustrate the scientific principles related to renewable energy.

The book by David Walker entitled "Energy, Plants and Man" was used as the primary text for the seminar. A special issue of Scientific American on "Energy's Future Beyond Carbon" (September 2006) served as a supplementary "text". The first week of the seminar focused on photosynthesis. The seminar began with a discussion of how plants use light to convert carbon dioxide and water into sugar and oxygen gas. This was followed by discussions on the nature of light and the fundamental steps by which light is absorbed by plants and converted into chemical energy. Demonstrations of the colors in light using diffractions glasses and a spectrophotometer aided these discussions. Plant pigments were discussed next, together with demonstrations on light absorption/emission by pigments extracted from plants and algae, and on pigment separation by using paper chromatography. The process of carbon fixation was discussed and was "photographically" illustrated by making starch pictures on geranium leaves (although this demonstration was not as successful as I had hoped). In the second week of the seminar, we delved into various forms of energy, including wind, geothermal, solar, and nuclear. A highlight of the week was the production of biodiesel fuel from cooking oil that culminated in the combustion of biodiesel fuel in an oil furnace burner. The seminar ended with a discussion of energy use in the future that included progress in development of systems for artificial photosynthesis and fuel cells.

The curriculum units developed from this seminar are suitable for elementary to middle school to high school students. In all of the units, the science content is integrated with language arts, mathematics and social studies to provide a balanced program that meets the literacy requirements of the school system. The Fellows have prepared extensive lists of materials that can be used in the classroom or as resources. These materials include books that the children can read, textbooks that the teachers can use, demonstration sourcebooks, suppliers of equipment, useful computer software, and addresses of sites on the world wide web. Several of the Fellows developed units around a theme or activity related to photosynthesis, including a remarkable 3D model-based unit on the fundamental processes of photosynthesis. Other units are related to sources of renewable energy for the future, such as wind and solar energy, as well as the impact of our energy use on the planet Earth. The units include a number of excellent activities that will engage the students' interest and teach them about renewable energy.

I would encourage all teachers of elementary through high school students to review these curriculum units. These materials provide a valuable resource for incorporating topics of science and society related to "Renewable Energy" into the classroom.

Gary Brudvig