Solar · Wind · Nuclear · Hydro · Fossil Fuels · Compare & Contrast
Photovoltaic (PV) cells convert photons from sunlight into electrons using the photoelectric effect. Silicon atoms absorb photons and release electrons, creating a direct current (DC), which is converted to AC by an inverter.
Wind turns large blades connected to a rotor. The rotor spins a generator inside the nacelle at the top of the tower, producing electricity. Offshore turbines can be 200m+ tall and produce 15 MW.
A neutron strikes a uranium-235 nucleus, splitting it into smaller atoms (krypton + barium) and releasing 2–3 more neutrons plus enormous energy (200 MeV per fission). Those neutrons split more U-235 — a chain reaction. Control rods absorb neutrons to regulate the reaction.
1 kg of uranium-235 releases the same energy as 3,000,000 kg of coal. This is why nuclear plants use so little fuel and produce so little waste by mass.
The opposite of fission — light nuclei (deuterium + tritium) fuse into helium, releasing vast energy. Powers the Sun. Commercial fusion reactors (ITER) are being built but not yet operational.
Ancient plants and marine organisms died and were buried under sediment millions of years ago. Over millions of years, heat and pressure transformed organic matter into coal (land plants → coal), oil and gas (marine organisms → petroleum). Burning fossil fuels releases carbon that was sequestered from the atmosphere over millions of years — all within a few centuries.
Solar electricity cost $400/MWh. Coal still cheapest. Renewables = 3% of electricity.
Solar at $50/MWh. Wind cheapest new electricity. Renewables = 29% of electricity.
Solar at $30/MWh. Renewables = 33% of global electricity. EVs 18% of new cars sold.
IEA: 60% renewable electricity, triple renewable capacity, 50% EVs in new car sales.
Net-zero CO₂ emissions. Nearly 90% clean electricity. Hydrogen replacing gas in industry.
The ratio of actual output over a period to the maximum possible output. A 1 GW solar plant with 20% capacity factor produces 200 MW on average. Nuclear at 90% = nearly always running.
As solar grows, it produces excess power at midday but demand peaks in the evening. The resulting demand shape looks like a duck. Battery storage is the key solution — charge during the day, discharge at night.
Nuclear power produces almost zero CO₂ per kWh, yet it generates less than 10% of global electricity. What are the trade-offs that make countries hesitate to build more nuclear plants? Explore the data and form your own view.