Summary Build electric circuits with batteries to understand how electricity flows. Build circuits generating electricity with renewables: wind turbines and solar panels. Science content Physics: Electricity, Electromagnetism (7) Earth/Space: Sustainable practices, Interconnectedness (2, 5, 7) Activities in this lesson Electric circuits with home-made wires and bulbs Wind turbine Solar panel Materials Materials in the activities Procedure Use batteries as a source of electricity to build circuits. In the battery a chemical reaction happens that sets up a positive and negative end, which makes negatively charged electrons (which are free in a metal), to flow around the circuit. Other than storage in batteries, electricity can be made in many ways, including by burning fossil fuels and in sustainable ways (taking the energy of a natural resource and converting it to electrical energy). Brainstorm sustainable ways of making electricity (and maybe whether the energy source can be transported, another factor to be considered). Make electricity with a model wind turbine. The blades catch the motion energy of the wind and convert it to motion energy. The generator converts motion energy into electrical energy. Wind accounts for about 4% of B.C.’s electricity generation capacity. Could also turn a turbine like this with water for hydroelectric power. 87% of electricity in BC is hydro. In BC, we also still burn natural gas to make electricity. The hot combustion products drive a turbine. In places with a lot of sunlight, solar is a renewable way of making electricity. (Only 1% of BC electricity is solar.) Make a circuit with a solar panel, and use a flashlight, light bulb and if possible, the sun to produce electricity. Wire the solar panel and the wind turbine into a circuit, and use the wind turbine in reverse as a fan: Use an incandescent bulb or the sun on the solar panel, to make electricity to turn the fan blades. Table of ways of generating electricity (incomplete). Many methods turn a turbine which drives a generator. Several methods generate steam to turn the turbine. Energy source Energy transformations Mechanism Pros Cons Fossil fuels (coal, oil, natural gas/methane) chemical to thermal to motion to electricial burn fuel to heat water and make steam, which drives a turbine and generator releases CO2 and methane leaks, greenhouse gases Hydroelectric power motion (of water) to electrical water falls onto a turbine which drives a generator Need to dam rivers. Dams provide reservoirs for a water source. Water behind a dam is long term storage of energy. Wind energy and wind farms motion of wind to electrical wind turbine, including generator Offshore wind farms where there is space. Need a way to store the electricity generated. Solar power light to electrical (PV) or heat to electrical (CSP) photovoltaic cells (PV cells, solar cells) or concentrated solar power (CSP) Need sunlight. Need a way to store the electricity generated. Geothermal energy thermal energy only, or thermal to electrical geothermal heat pump (loop of pipe containing water underground), or steam (naturally occuring/injected water), to turbine then generator Always available. Iceland uses 90% geothermal heating Nuclear power nuclear to thermal to motion to electrical uranium atoms are split (fission) which makes heat, to make steam, to turbine to generator nuclear waste Biomass energy/Bioenergy chemical to thermal to motion to electrical burn biomass to make heat. biomass is crop waste, algae, compost, manure, methane waste (from animals) makes carbon dioxide, a greenhouse gas Tidal energy/Wave energy motion to electrical or gravitational potential to electrical turbine and generator. can add a dam above the turbine which fills at high tide Ocean salinity and temperature differences Grades taught Gr 6 Gr 7
