An electricity supplier can complete only one of two projects. Each replacement resource would generate the same amount of electricity as the resource it replaces. The replacement resources would release no carbon dioxide while generating electricity.
| Project | Resource replaced | Replacement resource | Electricity generated each year in TWh | Carbon dioxide released by the resource replaced in tonnes per TWh |
|---|---|---|---|---|
| P | oil | the tides | 2.8 | 650 000 |
| Q | gas | hydro-electricity | 4.6 | 360 000 |
Calculate the annual carbon dioxide saving for each project, then determine the additional annual saving obtained by selecting the better project.
86 exam-style questions on AQA GCSE Physics 1.3 National and global energy resources, covering 1.3 National and global energy resources. Each one has a worked solution and a mark scheme showing where the marks go.