It is claimed to be the most advanced warship in the world, and its performance would thrill the most avid boy-racer.

Yet HMS Daring - back at its berth in Scotstoun shipyard last night after a month of sea trials - is also the greenest ship in the Navy.

The 4500 miles it has covered up and down the west coast of Scotland were achieved on an average of 35 cubic metres of fuel a day - a rate of consumption that could take it to the Falkland Islands, or to New York and back, without refuelling.

Its exhaust emissions are a fraction of its predecessors', and even the shell casings from its 4.5in gun can be recycled.

But a public demonstration of its handling yesterday by builders BAE Systems showed that eco-friendly firepower hasn't been achieved at the expense of manoeuvrability or speed.

The Daring, first in a class of six Type 45 destroyers at various stages of construction on the Clyde, has already exceeded its key contractual performance requirements.

The electric propulsion system - generators powered by gas-turbine engines - can take it to its target top speed of 29 knots in 70 seconds, but it still has enough left to get to 31.5 knots in another 50 seconds.

The gas turbines produce 47 MW, enough to power every house in Dundee. Its stopping power is equally impressive - from 30 knots to zero in 5.5 ship lengths, against a contractual requirement of 8.5 lengths. It can spin on a nautical sixpence - its turning circle is less than 3.5 times its own length, albeit at a heel angle which could test the most experienced sea-legs.

Each Daring class will cost the government £1bn, including capital charges (if they paid cash it would be £650m).

Jim Imrie, managing director of the Type 45 project, said: "It is recognised as being much more environmentally friendly than any of its predecessors or anything else that's coming out.

"Propulsion is all electric, the first in the world, and has no gearbox to go wrong."

The customers also seemed impressed. Commander David Shutts, the ship's senior Royal Navy officer, said: "It is early days in her life, but Daring has already lived up to the high standards that we have set for her.

"We have had fantastic co-operation in the early-stage design. Those of us who will be using the ship have been able to offer common-sense advice on what will work.

The galley, for example, was designed by naval chefs."

The Daring will have a crew of 181, housed in standards of accommodation that are already being acclaimed, with 39% more crew space.

In the interests of stealth the flush-panelled upper deck gives the Daring a featureless appearance compared with a traditional warship. The bits that normally stick out on radar - anchor chains, bollards and other deck equipment - are under cover in the shrouded quarter deck and fo'csle.

The result is that the 7350-tonne Daring has the radar cross-section of a biggish fishing boat.

Its own Sampson multi-function radar system is the best tactical air support and defensive system in the world, with a range of hundreds of kilometres.

It is said to be able to pick up a cricket ball travelling at three times the speed of sound, and at the same time train on multiple targets.

Lieutenant-Commander Phil Harper, the ship's navigator, said its predecessor, the Type 42, could only fire at two targets simultaneously. But the Daring's PAAMS anti-missile system can deal with dozens of threats, prioritising targets and changing priority if an incoming missile alters speed or direction.

There are 48 missiles, each 20 times more manoeuvrable than a Formula One car. They are housed in silos, which have to be reloaded in port.

"It doesn't sound much, but by the time you have used them up most air forces are dead," said Lt-Cdr Harper.

Armed Forces Minister Bob Ainsworth was impressed by what he saw, but non-committal on the possibility of a further two being ordered.

"Daring's success at sea is an excellent start to the intensive trials phase that will now begin as we bring her world-leading missile defence system into full operation," he said.

"I have spoken to her crew and they are delighted with the capability of the ship.

"Our planning assumption is for eight. We have bought six and there is no need for a decision yet on the other two. That will have to be assessed, but the yards are full - there is enough going on for now."