Explore how light carries energy and powers solar cells via the photoelectric effect, and learn how semiconductors and band structure enable silicon-based photovoltaic energy conversion.

Trace the shift from particle and wave theories to wave-particle duality, explain refraction, diffraction, and color spectrum, and introduce the photoelectric effect as the basis of quantum mechanics.

Explore how doping silicon with group five and group three elements creates n-type and p-type semiconductors, forming a p-n junction for solar energy under light.

Explain how the bandgap determines the figure of merit for solar cells using Planck’s law and the sun’s spectral radiance, and why single‑junction cells cap near 33% efficiency.

Explore alternative geometries for solar cells by stacking multi-junction designs that vary bandgaps from high to low, boosting efficiency beyond 33% and enabling compact, high-performance PV.

Explore photovoltaic energy concepts, including the photoelectric effect, silicon semiconductors, band gaps, and the P junction, and learn to derive solar-cell efficiency and estimate its size for daily energy needs.

Explore the kinetic energy of wind and how power depends on density, area, and velocity, especially velocity cubed, to explain turbine placement and wind-resource potential.

Estimate 3 MW per 10,000 m^2 using 0.4–0.5 efficiency and 600 W/m^2 wind density, implying millions of turbines are needed and design choices to increase effective area and manage fluctuations.

Show how wind speeds follow a Rayleigh distribution and how power output scales with V^3, causing fluctuations that require storage and grid management, with turbine rotation to cap output.

Explore marine power through wave, ocean thermal, and tidal energy, driven by moon gravity and ocean temperature gradients, with osmotic and current options as additional marine energy sources.

Explore geothermal energy from earth's hot core and mantle, powered by radioactive decay, and learn how geothermal power plants transfer heat; compare to heat pumps that move heat using electricity.

Geothermal heat pumps tap near surface ground temperatures to heat and cool buildings with minimal electricity, storing seasonal energy and achieving a stable interior climate.

Explore how an ideal gas model explains engine and heat pump cycles on a P-V diagram, where cycle area yields work and heat drives the process.

Discover how a heat pump uses work to move heat from cold to hot, define heating and cooling efficiencies with Q high and Q low, and compare Carnot cycles.

Derive that a heat pump’s heating efficiency equals the cooling efficiency plus one, using the second-law thermodynamics and kelvin-based calculations, and assess ideal versus real performance and price thresholds.

Trace how coal, oil, and natural gas form under heat and pressure, and reveal their carbon emissions and climate impact, then preview biogas as a renewable methane source.

Convert bio waste into biogas with a digester, producing methane for cooking or power. Explain co2 neutral energy by recycling carbon and compare waste versus crops, safety and digestate impacts.

Hydrogen offers a carbon-free energy source for combustion engines and fuel cells, with potential as a biofuel, in future nuclear fusion, and for energy storage via power to gas.

Examine hydrogen generation from water electrolysis, the role of methane, and the rise of green hydrogen with power to gas as energy storage.

Electrolysis splits water into hydrogen and oxygen using electricity from surplus solar energy. Hydrogen stores energy as chemical energy for later use, akin to a battery.

Completing this section on biochemical energy, learners explore photosynthesis, biofuels, and the potential to harvest and generate energy while storing energy in biofuels, molecules, or polymers through chemical bonds.

Explore nuclear energy, including fission and fusion, and compare renewability, CO2 emissions, and risks. Learn how fission powers today while fusion promises a near-pure, sun-like energy future, yet remains experimental.

Revisit nuclear decay and its role in geothermal energy, focusing on uranium-238 and thorium-232 decay chains, while introducing fission and fusion as other nuclear energy forms.

Explore energy storage options for solar power, including mechanical, electromagnetic, electrochemical, and thermal methods, with practical examples like pumped hydro, heat storage, and cavern storage.