IGCSE 0625 / Section 1.7 / Core

Where our energy comes from.

Every kilowatt we use is drawn from somewhere: ancient sunlight locked in coal, the pull of the Moon on the seas, or heat rising from deep inside the Earth. Sorting these into what runs out and what renews, and tracing them back to their source, is the heart of this topic.

The key idea

Energy resources are either non-renewable (fossil fuels and nuclear fuel, which run out) or renewable (replenished as fast as they are used). Most of our energy can be traced back to the Sun, with a few exceptions.

Definition · learn the exact words

A renewable resource is replenished as fast as it is used; a non-renewable resource is used far faster than it forms and will run out.

most resources trace back to → the Sun

The exceptions are geothermal (heat inside the Earth), tidal (mainly the Moon) and nuclear (the fuel itself).

Section 01

Trace it to the source.

Explore each resource and follow its energy back to where it began. Most threads lead to the Sun, a few to the Moon or to the Earth interior.

Stage 1 · Learn

Check renewable and non-renewable

Four quick checks on the two categories and where the energy comes from. Each correct answer earns XP and lights this skill on your star map.

Quick check+10 XP

A renewable energy resource is one that...

Quick check+10 XP

Which of these is a non-renewable resource?

Quick check+10 XP

Most of the energy resources we use can be traced back to...

Quick check+10 XP

Which resource does NOT originate from the Sun?

Section 02

Two kinds of resource.

The dividing line is simple: does the resource refill as quickly as we draw on it? Fossil fuels and nuclear fuel do not, so they will eventually run out. Renewables are topped up by nature.

Non-renewableRenewable
Coal, oil, natural gas (fossil fuels)Solar, wind, hydroelectric
Nuclear fuel (uranium)Tidal, wave, geothermal
Run out: used far faster than they formReplenished as fast as they are used
Fossil fuels release carbon dioxideLittle or no carbon dioxide in use
Examiner trap

Most resources trace back to the Sun: it drives the weather (wind and waves), the water cycle (hydroelectric), and plant growth (biofuels and fossil fuels). The clear exceptions are geothermal (heat from inside the Earth), tidal (mainly the Moon gravity) and nuclear (energy stored in the fuel). Learn those three exceptions and you can reason out the rest.

Stage 2 · Exam

Exam-style questions

Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.

Finish the four checks above to unlock the exam questions
Exam style+20 XP

Which list contains only renewable resources?

Exam style+20 XP

The energy carried by wind originally came from the Sun because the Sun...

Exam style+20 XP

A major advantage of renewable resources over fossil fuels is that they...

Skill unlocked

Energy resources, mastered.

This skill is now lit gold on your star map. Keep the chain going.

-Rank -Level -Score -Topics
Go deeper · practice
Six original Cambridge-style questions
Classifying resources as renewable or non-renewable, tracing energy back to the Sun, the exceptions, and the trade-offs between resource types. Attempt each, then reveal the worked solution.
Stage 3 · master the unit
Motion, forces and energy challenge
Mixed questions across the whole unit, each one worth XP. Start this only when you feel confident across every topic in the unit, not just energy resources.
Start the unit challenge →