Anyone who walked through Stratford's Olympic Park would have invariably noticed organisers' efforts to ensure London hosted the greenest Olympic and Paralympics Games to date.
A square mile of contaminated or derelict land in East London was transformed into a leafy urban park containing thousands of trees and wetlands to attract wildlife.
Seven small wind turbines, a biomass boiler and solar panels ensured that 10.8 percent of the energy supplied to the Games was renewable. Electric car charge points were also installed to reduce transport emissions and recycling bins were dotted around the park helped to improve waste management.
However, much other green innovation happened behind the scenes, with sponsors and suppliers stepping up their efforts to help the London Organising Committee of the Olympic and Paralympic Games (Locog) and the London Organising Committee deliver the London 2012 sustainability plan.
London 2012 was the first summer Olympic and Paralympic Games to embed sustainability into its planning from the start. The summer marked the first time an organising committee had measured the Games' carbon footprint over the entire project term, from winning the bid in 2005 to the dissolution of the Games in Autumn 2012.
An independent consultancy, Best Foot Forward (BFF) worked with Locog from the offset to identify what would be the event's emission hotspots, such as IT services and transport, to minimise emissions during the preparation and staging of the Games.
Games sponsor Coca-Cola also adopted BFF's software and methodology to map the carbon footprint of its own activities during the Games and has pledged to continue to use the formula when measuring and reducing its carbon footprint in future Olympic Games.
David Stubbs, Locog head of sustainability, explained that its green technology approach included asset re-use and recovery, sustainable procurement, and redeployment of skilled technology management into the UK workforce.
However Stubbs suggested a lot of the green initiatives and technology had been invisible to most of the public.
"The Games were all about the experience, so we weren't preaching messages about saving energy because people were there for the sport. So that means that you never even saw a lot of the clever technologies, even though they were really impressive," he told V3.
In 2010, the focus on the need to conserve energy during the Games intensified with the roll out of a series of energy-saving technologies.
This was because it had become clear that plans for a 2 Megawatt wind turbine on the Olympic Park site were unviable and Locog would therefore fail to meet its original target to source 20 percent of its energy from renewables. Instead, a new target was introduced to reduce energy consumption by 20 percent over Games time.