COPENHAGEN - A giant wind turbine will whirr away outside the conference centre, powering the lights for the delegates holed up inside.

Top-level negotiators will get around on bicycles and television stations will have to adapt to the cool tones of low-energy LED lighting.

If United States President Barack Obama does attend he may tour the city in a limo which runs on algae diesel or electricity. Even the pens are made from recycled plastic bottles.

Welcome to the Copenhagen summit. It may not strike a deal to save the planet, but the conference is just about as green as can be.

Svend Olling, who is in charge of conference logistics for the Danish Government, says: "There are expectations that when we host a conference like this, we deliver it in a green, sustainable way."

The summit will be carbon-neutral - no mean feat for a two-week conference of more than 12,000 delegates.

Organisers have calculated the event's greenhouse gas emissions, most of which come from people flying to Denmark, and will offset them by funding energy-efficient brick factories in Bangladesh to replace 20 old, heavy-polluting ones.

The US$1 million ($1.38) million deal is being overseen by the World Bank.

Mr Olling says zero net emissions is the easy part. Organisers have also scrapped conference trimmings and reduced the carbon footprint of things the delegates can't do without.

So delegates won't get showbags containing frisbees, caps and USB devices when they arrive at the conference venue, the Bella Centre.

The gift budget of one million danish kroner ($275,660) has been spent on scholarships for 11 students to study climate change at Danish institutions.

Delegates will get a free pass for public transport and access to 300 bikes and helmets.

However, public transport can be bewildering in Copenhagen, with two train systems, the metro and the s-train. In the clean, shiny train stations there seem to be few maps and dutiful low-carbon delegates may need to plan their route in advance.

For the more high-brow participants, some 150 limos will run on bioethanol (from waste organic material), algae diesel or hydrogen, or they may be electric or hybrid models.

No water bottles either. "We have banned the use of plastic bottles in the conference centre ... this country is blessed with excellent drinking water coming out of every faucet, we will drink that please," Mr Olling said.

Delegates will fill their biodegradable corn starch cups from water fountains dotted around the Bella Centre.