|
Asia-Pacific Forum on Science Learning and Teaching, Volume 6, Issue 1, Article 7 (June, 2005) Kit Fan CHO Solar energy investigation activities for primary pupils Experience sharing from a teacher of a solar energy school in Hong Kong
|
|
|
Asia-Pacific Forum on Science Learning and Teaching, Volume 6, Issue 1, Article 7 (June, 2005) Kit Fan CHO Solar energy investigation activities for primary pupils Experience sharing from a teacher of a solar energy school in Hong Kong
|
Solar Energy Activities
Soon after moving into the new solar energy campus in September 2003, I started to plan with my colleagues some solar energy activities for our pupils. It is easy to find plenty of information about the Sun, solar rays and their effects (e.g. climate, greenhouse effect etc.), energy sources and related environmental issues from the libraries or the internet. Hence, information searching and book report were two activities we planned for our pupils. However, when we explored the possibilities of any hands-on activities, we encountered some problems with the following considerations.
1. Resources: Budget is always a very serious constraint. The most ideal activities are those only require simple and cheap materials and tools. Of course, the availabilities of worksheets of some feasible activities and external support are helpful.
2. Abilities of pupils: The activities should not require any sophisticated skills, such as electrical wiring. Safety is also another important issue.
3. Relevance to curriculum: The topic "Resources and Environment" in the Primary 5 General Studies curriculum was identified to infuse the solar energy activities. As a new General Studies curriculum would be implemented in the coming year, we hoped that the activities could achieve some learning outcomes recommended in the new curriculum, such as:
- to develop motivation and skills to explore, investigate and generate solutions for scientific problems emerging from the study of the material world, use of energy, living things and the Earth and beyond;
- to develop an interest in exploring the technological world and perform technology activities creatively to solve simple problems in daily life.
(Curriculum Development Council, 2002)
After surfing the web, three possible pupil activities for the studies of energies "generated" by sun rays were found.
1. The first one coming to our mind was what activities could be done with solar cells because our school had the largest photovoltaic array in Hong Kong. One possibility was to study what factors affecting the output of a solar cell. The variables could be the light intensity, the incident angle or the colour of the light. Another possibility was to ask pupils to construct something, say a small car or a small boat, powered by solar cells. However, we found the cells were not cheap at all. A small sized 1 W peak value solar cell costs around HK$100 in Apliu Street in Shamshuipo. Finally, we gave up these ideas because of the limited budget.
2. The second possible activity was to make a solar energy reflector which was a curved reflecting surface focusing the sun rays at a small region. There are a lot of interesting and delicate designs at the Solar Cooker Review homepage. However, we decided not to choose this activity because we did not think our pupils could handle those tools to construct the reflector.
3. The activity we finally chose was the construction of a "greenhouse heater". An agricultural greenhouse is a house which has its roof and some or all of its walls made of transparent materials. The transparent roof and walls allow visible light into the greenhouse and the re-emitted heat radiation is partially "trapped" inside the greenhouse. This causes the inside warmer than the outside. Our atmosphere behaves similarly to trap solar energy and this is called the greenhouse effect. The theory of greenhouse effect can be found elsewhere, such as:
- "What's Green House Effect?" by Hong Kong Observatory:
http://www.hko.gov.hk/wxinfo/climat/greenhs/c_grnhse.htm?- "Global Warming Kids Site - Greenhouse Effect" by U.S. Environmental Protection Agency:
http://www.epa.gov/globalwarming/kids/greenhouse.htmlActually a greenhouse is not necessary really a house. Any transparent closed containers illuminated by sun rays would have its internal temperature increased. This principle has been used for many years in many rural areas to warm water (Cookers in Use Around the World). Any transparent vessels, such as a transparent plastic water bottle, can warm water under the Sun without any cost.
Another important reason that we chose the construction of greenhouse heater to be our pupils’ activity was a similar activity with worksheets already available on the web. It was an activity of the Young Scientists Award Scheme jointly organized by the Hong Kong Institute of Education, the Curriculum Development Institute and the Hong Kong Association of Science and Mathematics Education. And luckily, the project leader of the Young Scientists Award Scheme, Dr. NG Pun Hon, kindly agreed to give us advices in our preparation stage.
Copyright (C) 2005 HKIEd APFSLT. Volume 6, Issue 1, Article 7 (June, 2005). All Rights Reserved.
