Learn How Electricity Works
21 plain language explainers on how electricity is generated, measured, traded and counted, written for readers with no background in energy. Each one answers its question in the first paragraph and links to the country, grid and carbon pages that hold the figures behind it.
Electricity Basics · Grids and Operations · Markets and Prices · Carbon and Emissions · Data and Measurement
Electricity Basics
3 explainersHow electricity is generated, measured and delivered.
- How a Power Grid Works A plain guide to how electricity is generated, moved and delivered, and why supply and demand must match every second of the day.
- Capacity Factor Explained What capacity factor measures, the typical range for each generating technology, and why installed capacity is not the same as generation.
- Baseload Power and Why the Term Is Disputed Baseload once meant the plants that ran flat out around the clock, but in a grid full of wind and solar the word now causes more arguments than it settles.
Grids and Operations
8 explainersHow operators keep supply and demand in balance.
- What Is a Balancing Authority? What balancing authorities do in North America, how their hourly data is collected, and how they differ from ISOs and RTOs.
- Interconnectors Explained Interconnectors are the cables that link neighbouring power grids, letting electricity flow across borders to cut costs and keep the lights on.
- Curtailment Explained Curtailment is when a grid operator turns down wind or solar output on purpose, and it happens for congestion, oversupply and system security reasons.
- The Duck Curve, Explained The duck curve is the daily shape of demand left over after solar output, with a deep midday belly and a steep climb into the evening peak.
- Dunkelflaute: Dark, Windless Weeks Dunkelflaute is a cold, still, overcast spell when wind and solar produce almost nothing, and it sets how much backup a renewable grid needs.
- Ancillary Services and Frequency Response How grids hold frequency at 50 or 60 Hz using inertia and reserves, and how batteries and demand response now help.
- Grid Scale Energy Storage Explained What batteries and pumped hydro actually do on a power grid, how long they last, and the jobs storage cannot do.
- Transmission Constraints and Congestion Why cheap electricity cannot always reach the places that want it, and what redispatch and congestion costs really are.
Markets and Prices
7 explainersHow wholesale power is traded and what sets the price.
- What Is a Bidding Zone? Why European electricity markets are divided into bidding zones, why some countries are split into several, and what a zone price means.
- How Day-Ahead Electricity Markets Work How the auction for tomorrow's electricity works: bids, offers, a clearing price for every hour, and how zones are coupled together.
- Merit Order and Marginal Pricing How power plants are stacked by running cost, why the last one needed sets the price for everyone, and why gas so often ends up setting it.
- Why Electricity Prices Go Negative How wholesale electricity can trade below zero, and why inflexible plants, per-unit subsidies and sunny windy weekends cause it.
- Capacity Markets Explained A capacity market pays power plants to be available rather than for the electricity they produce, and it exists to make sure enough capacity is built.
- Wholesale Price vs Retail Electricity Bill What is actually in a household electricity bill, and why the wholesale price is only one part of what you pay.
- Why Are Electricity Prices High? Gas costs, carbon prices, grid investment and scarcity: the real reasons electricity prices rise, explained simply.
Carbon and Emissions
1 explainerHow the emissions of electricity are counted and compared.
- What Is Carbon Intensity? Carbon intensity is the CO2 released per kilowatt hour of electricity, and it explains why two grids of the same size can pollute very differently.
Data and Measurement
2 explainersWhere the figures come from and what they can and cannot tell you.
- How Electricity Statistics Are Collected Where electricity figures come from, why gross and net generation differ, and why two sources rarely agree exactly.
- How to Read a Generation Mix Chart TWh or share, stacked areas, annual or hourly: how to read an electricity generation chart without being misled.