The chief economist for the Centre for Global Energy Studies (CGES), Leo Drollas, said discoveries are continuing apace, including giant fields such as Kashagan in Kazakhstan, and the Tupi field offshore Brazil.

"The world has not had net depletion of reserves for decades. We should not be worrying about depletion, but about getting the oil out of the ground," Drollas said.

What would bring prices down would be the effects of a shrinking economy, Barroso said.

The CGES was far more bearish than the International Energy Agency, he said, but the IEA last month lowered its world oil demand growth estimate for this year from 2.2 million b/d to 800,000 b/d, just higher than the CGES' estimate, from last year, of 600,000 b/d, which it produced during the US mortgage crisis.

"And we see even worse in 2009," Drollas said.

Production cuts or stagnation since January 2006 in OPEC producers such as Nigeria, Iran, the UAE, Venezuela and Indonesia was offset by a rise in Saudi production.

But output from the OPEC "10" - which excludes Iraq and newer members Angola and Ecuador - is still less than it was in January 2006, Drollas said.

And with declining output, stocks draws have been growing for six successive quarters.

But Drollas said with weakening demand, stocks will build again, and the combination could help push down the price of a barrel of oil to between $60 to $80 in the next few years.

His bearish view was shared by the Finnish-owned consultancy Poyry.

David Cox, head of Poyry's energy consultancy, envisaged four scenarios in which oil prices fell and none in which it rose in the near future, either because new technology reduced the need for energy, or because of either catastrophic or gradual economic decline arising from the cost of energy. "I can see oil below $100/b in six or nine months," Cox said.

UK could shrink as efficiency grows

The UK is the biggest gas market in Europe, but it is shrinking, for a number of reasons that have little to do with milder winters over the past few years.

Chief among them is price. But several speakers at the conference referred to domestic demand for gas falling owing to building regulations, better insulation and more efficient heat generation. But there could still be another dash for gas. (See map: Gas price snapshot: Jun 25 2008).

Microgeneration, by producing power as well as heat at times of the highest wholesale prices, would save households money after a period, although so far the take-up has been limited.

Centrica estimates there are still about 4 million open-flue boilers that are "incredibly wasteful" and, being made of pigiron, will never break.

It has set up a New Energy division within British Gas, under Gearoid Lane, to engage not just with the industrial and commercial end of the market to cut their costs and share some of the savings, but also with households.

But it is very difficult to part householders from their money, for green energy, Lane told the conference.

Small, local energy networks would allow more efficient use of energy, if Britain moved away from its centrally-planned network with heavy transmission losses.

National Grid (NG) and regulator Ofgem are working now on a long-term energy network scenarios projects, which looks at five possible ways the onshore gas and power grids might develop between now and 2050, progressively moving away from today's landscape of big plants and pylons towards microgeneration. (Listen to a related podcast: Consequences of rising European gas prices.)

As it is, distributed energy schemes account already for 12 GW, installed in factories, schools and elsewhere.

And much of the red tape that has held local generation schemes up in the UK could be slashed in an initiative announced June 18.

If the proposals, devised by Ofgem and government, survive, customers will find it easy to switch supplier from a national to a local generator.

Between combustion in a power plant and delivery at the home, 65% of the energy in gas is lost, compared with 10% from microgeneration, meaning less gas will be needed.

And by generating electricity at times of peak demand, and hence high wholesale prices, this system would take demand off the national electricity network and allow the deferral of peaking plant investment.

But NG's networks operations director Chris Train said that there was a "strong indication" of another dash for gas to fill the gap between the decommissioning of old coal and nuclear plants and the building of new ones - a time when the UK could have "intermittency" problems with renewable energy.