London has gone all-out to make the Olympics green — even supplying some of the energy for the Games with the help of environmentally-friendly treated poo.

When the city bid for the 2012 Olympics, political leaders declared they would be “the most sustainable Games ever”. That pledge has largely been met, and one way this has been achieved is by Thames Water installing the UK’s first commercial scale membrane bio-reactor, which, put simply, turns poo into fresh water. The water is used to feed the district heating system which provides heating and hot water to the buildings at London’s Olympic Park. It is also used to irrigate the wonderful green spaces and natural habitats in the Park.

That’s the Green Games for you!

The environmentalism of games organisers was motivated in part by the example of Sydney’s Green Games in 2000, and partly by the desire to use the Games to support sustainable regeneration of London’s poor East End district. To verify the claim that London 2012 would be “the most sustainable Games ever”, an independent commission was established. I have chaired that commission since 2005.

The Games are put on by the Olympic Delivery Authority (ODA), responsible for building the infrastructure, and the London Organising Committee for the Olympic and Paralympic Games (LOCOG), responsible for putting on the show.

The ODA has delivered exemplary low-carbon infrastructure, with 50% lower carbon compared to a “business as usual” case, assuming that the site was constructed in accordance with current regulations. All of the permanent venues were specified to deliver 15% greater energy efficiency and the now world-famous velodrome achieved double that — 30%. However, the jewels in the low-carbon crown are not the iconic buildings you see on TV but the un-glamorous energy centre, and a building housing a membrane bio-reactor.

The energy centre houses a gas engine which generates electricity from natural gas. The waste heat from the engine is used to supply a district heating system which heats the buildings on the Park and cools some of them using absorption cooling technology. The energy centre is currently running at 20% of its capacity. Additional bays are available for more engines in the future and there are more pipes under the ground to support new development for decades after the Games.

All this is great but it could be better. I argued in 2006 that sources of biogas from waste should be developed to help deal with London’s waste problem and provide renewable fuel for the energy centre. It did not happen, largely due to risk-averse energy and waste industries wanting to stick to tried and tested solutions. Plans for a wind turbine on the Park were cancelled.

Now the nation is gripped by Games fever and my team is spending a lot of time poking round behind the scenes to see how it is all working. LOCOG has a good way of working to manage energy consumption. Each venue and functional area has an energy conservation plan and a team of people examine detailed information every day to monitor performance. However, the big problem for me is the small things that give the wrong messages. LOCOG has a “no idling” policy for vehicles requiring them to switch off their engines when stationary. This message has clearly not got through to the bus drivers or their supervisors. Every transport hub we have visited has seen busses with engines running constantly.

This is bad for carbon emissions and cost, but more importantly it contributes to London’s poor air quality that sees 4,600 people each year die prematurely. Surely a sticker on the dashboard is not beyond the wit or budget of LOCOG. There are also too many examples of lights being left on in broad daylight. This includes the huge temporary building in the media centre for journalists’ recreation and shopping. I was told the building has only one light switch, and if you need the lights on inside the building you have to have them on outside as well. So, the most sustainable Games ever appear unable to specify a building with the correct light switches.

I am in no doubt that London will deliver the most sustainable Games ever because the big things have been done very well. However, the small things are giving the wrong messages to the world.