It has been proven that hands-on learning helps students develop a deeper understanding of new topics. GREENBMG’s Dual Axis Solar Tracker was created to provide a hands-on learning tool for students learning about renewable energy. The Dual Axis Solar Tracker can be used to teach all grades from grade 1 to grade 10, depending on which parts the lesson focuses on.
The worksheets below can help teachers plan lessons in an age-appropriate way. The grade 1 worksheets focus on energy and the sun, with two easy-to-follow diagrams that will illustrate the conversion of energy.
As the grades get higher, teachers can begin to focus on more complex ideas of solar energy.
Take a look below at the teaching tools GREENBMG has created for the Dual-Axis Solar Tracker that can be used in a lesson plan.
If you want to see how it works, click below:
The sun produces most of the energy found on Earth. Energy is what makes cars move and engines work. It makes sailboats sail. Without the sun, there would be no life.
A magnifying glass can be used to concentrate the sunlight and burn wood or paper (Figure 1)
A concave mirror is used to focus the sun's energy on our engine.
The engine makes electricity from the heat. Electricity turns the LED lamp on.(Figure 2)
Light is a form of energy that is around us that reaches us from the sun. When sunlight reaches the mirror, it is reflected and concentrated at the focal point to heat our engine. Light travels in straight lines from the sun and it travels in straight lines from the mirror to the engine.
The heat in the Stirling Engine rotates the yellow flywheel and turns a generator. The electricity from the generator turns the LED light on.
Everyday, millions of tons of fossil fuels are burned to provide energy for people’s need. Consequently, the thermal energy of the earth increases. When we use the heat from the sun no extra heat is produced and no gases or pollutants are released.
Solar, geothermal, hydroelectric, wind, and biomass are renewable sources of energy.
To be able to use solar energy we need to use PV panels or solar thermal devices like a solar concentrating dish. In this setup, the sun’s radiation energy is reflected and concentrated through the use of a concave mirror. The concentrated heat is then absorbed by an engine and changed into rotational energy (kinetic energy) in the yellow flywheel. The flywheel then rotates a generator to produce electrical energy.
Conservation of energy for the dual-axis sun tracker with Stirling engine:
Sun energy received by the dish = Heat released at the engine + Energy of the flywheel
Identify the forms of energy involved when the dual-axis tracker works with dish and Stirling engine.
Identify the forms of energy involved when the dual axis tracker works with PV panels.
Energy comes from two main sources, renewable and non-renewable. Sun and geothermal are renewable sources while gas and coal are non-renewable sources of energy. Heat is a form of energy that is transferred from one object at a higher temperature to another one at a lower temperature.
In other words, heat is transferred when there is a temperature difference. Radiation is an important method of heat transfer. The sun’s energy is transferred to the earth by radiation. The sun’s energy is dilute and it must be concentrated to be used in a practical way. A reflecting dish or a concave mirror can be used to reflect this energy and concentrate it. This concentrated energy can be used in many ways.
A Stirling engine is a device that converts heat into work. It absorbs part of this concentrated energy. The absorbed radiant energy heats the cylinder and runs the engine. Heat conduction is another method of heat transfer. The heat from the cylinder is transferred to the body of the engine by conduction. Heat convection is the transfer of heat through the movement of heated fluid. The heat from the engine body is transferred to the air by convection. In other words, the body is cooled down by the ambient air and the air is heated up.
Question: In the flame experiment, when the Stirling engine is operated by the flame from the alcohol, what is the main heat transfer from the flame to the engine?
What are the advantages and disadvantages of applying flame compared to solar dish?
Solar thermal technology and solar PV technology are two main types of capturing and using the sun’s energy. When we use the heat or concentrated heat of the sun, the technology is called solar thermal. While when we use photo-voltaic cells to generate direct current electricity, the technology is called solar PV.
GREENBMG's off-grid demonstration setup shows the fundamentals of solar PV and solar thermal energy in the same setup. It is composed of:
A PV panel charge controller
12 V battery
Automatic sun tracker that operates a Stirling engine.
How It Works
Sunlight first is received by the panel and a DC current of 12-17 volts is generated The current is sent to a charge controller. The charge controller charges a 12-V battery and it prevents the battery from overcharging. An inverter changes the DC current from the battery to 110V AC electricity. The tracker motors use this electricity to track the sun. The sun rays are concentrated by an off-center dish. The Stirling engine changes the concentrated heat into mechanical work and rotates a flywheel. The flywheel rotates a generator to generate electricity.
Downloadable PDF science worksheets: Dual Axis Solar Tracker