26 December 2009
- 02:1702:17, 26 December 2009 diff hist +21 m Small wind turbine →Disadvantages
- 02:1602:16, 26 December 2009 diff hist −2 m Small wind turbine →The Advantages
- 02:1202:12, 26 December 2009 diff hist +1 m Measuring DC electrical energy production from micro-renewables →Hugh Piggott wind turbine
- 01:4901:49, 26 December 2009 diff hist +10 m Thermosiphon →Pros & Cons
- 01:4301:43, 26 December 2009 diff hist −5 m Thermosiphon →Active
- 01:4101:41, 26 December 2009 diff hist +15 m Thermosiphon →Pros & Cons
- 01:3901:39, 26 December 2009 diff hist −12 m Thermosiphon →Gravity-feed System
- 01:3701:37, 26 December 2009 diff hist +18 m Thermosiphon →Pros & Cons
- 01:3401:34, 26 December 2009 diff hist −2 m Thermosiphon →Close-coupled System
- 01:3201:32, 26 December 2009 diff hist −1 m Thermosiphon →Passive
- 01:2401:24, 26 December 2009 diff hist 0 m Thermosiphon →Underlying Physics
- 01:2101:21, 26 December 2009 diff hist +7 m Thermosiphon →Underlying Physics