Craig Mayhew’s Blog

These factors can be used to show the environmental and financial impact of inefficient HTML.

1. A core 2 duo e6600 uses ~30 watts more when under single core heavy load than when it is idle. 30 watts = 0.03 kWh.
2. Assuming 10p/kWh then 1 computer second costs 0.00008333 pence.
3. Assuming 0.54055 Kg of CO₂ emissions per kWh for the average UK grid electricity then 1 second of additional computer processing time creates 0.0045g of CO₂
4. 3600 seconds in an hour

Financial Cost = (pencePerkWh/3600) * 0.03 * renderSecondsPerPageView * pageViews

Examples: (using 1 million page views, each taking 0.25 seconds)

Financial Cost = (10/3600) * 0.03 * 0.25 * 1000000 = 20 pence
CO₂ Emmissions = (0.54055/3600) * 0.03 * 0.25 * 1000000 = 1.12Kg of CO₂