IS THE wind of public opinion blowing against renewable energy? Within the last fortnight, it has been denounced as a "white elephant" industry and been criticised for overstating the job numbers it can deliver for the Scottish economy.  Yet when alex Salmond stands up at the second Scottish Low Carbon Investment Conference (SLCIC) today, the chances of him being blown off his policy course are nil. John Swinney has put renewable energy and the wider low-carbon economy at the heart of the SNP government's growth strategy, and the latest number of jobs expected to be created in the sector has reached an eye-watering 130,000.  When the First Minister speaks at the SLCIC (which also has former US vice-president al Gore on the bill), he will continue to act as cheerleader-in-chief to the low-carbon community and pull more green rabbits out of green hats to deliver positive news for the sector. Since last year's inaugural event, there has been plenty of good news, with Gamesa, Mitsubishi and Doosan bringing renewable R&D operations to Scotland, and the establishment of the International Technology Renewable Energy Zone in Glasgow.  However, despite the underlying progress, the conference must address the economic elephant in the room - the lack of momentum in getting turbines turning in the North Sea. Offshore wind and its complex, job-heavy supply chain is the "big ticket" item for Scotland; it can deliver large amounts of energy and its success is crucial to employment and economic progress, as well as the government's 2020 carbon reduction targets.  Yet momentum towards delivering offshore wind projects since last year's conference has been slow. The "installed capacity" is only 190MW, against a target of 10GW, more than ten times higher, by 2020 - a date which once seemed far away but now looks relatively close in the lifetime of offshore wind.  The fundamental problem remains simple - money. Offshore wind is a new industry and too great a risk for many investors, who won't be comfortable until a number of large projects are up and running - proving the technology works and the returns are good. This means developers are funding early projects themselves, and, with significant risks and huge costs attached, only a limited number of companies are capable, or willing, to do this.  The other financial problem relates to the huge cost of offshore wind. at the moment, it is estimated that delivering one megawatt hour (MWH) of electricity from offshore wind will cost around GBP130-GBP140. This has enormous implications - for the cost of developing projects and for consumers. a taskforce in England has been asked to try to cut the cost to GBP100 per MWH, but Scotland's ambition is greater - to bring it down to around GBP80 per MWH.  This is a big ask, but there is talk of a knight on a white charger ready to ride to the rescue - in the shape of the oil and gas industry. Is this a realistic hope? It is a mantra repeated ad nauseum at conferences. as the oil and gas industry tails off, the narrative goes, offshore firms migrate into renewables, transferring knowledge, skills and expertise to help the new industry flourish.  There are encouraging signs. Oil and gas firms Technip and Subsea 7 have dipped their toe in renewables waters within the last year. There was also an event - described as "game-changing" - when oil and gas guru Sir Ian Wood and Ian Marchant, chief executive of Scottish and Southern Energy, a key developer of offshore wind, brought the two industries together.  a similar event will be held next month, but are oil and gas operators ready to jump from an established, buoyant industry into unpredictable new waters? Estimates suggest North Sea oil and gas could last three more decades, while many engineers earn six-figure salaries in the industry and there are opportunities in newer overseas markets.  against this backdrop, what of the claims that the oil and gas industry - not known for being cheap - can play a big part in driving down the costs of offshore wind? Some in oil and gas scoff at the idea. "You can pay hundreds of thousands of pounds to hire a suitable vessel to go far out into the North Sea," says one source. "Oil and gas companies won't blanche at that - the renewables lot fall off their chairs."  It seems an unlikely marriage anyway - one partner is much older, and more experienced in hostile offshore environments. The callow younger partner still gets pocket money from his parents, and needs to prove he can pay his own way.  It all comes back to money. Unless offshore wind can attract significant investment and drive down costs relatively soon, it could find itself in a vicious circle. Investors won't come in because they need to see a rising number of large, successful projects - but it will be difficult to develop such projects without the investment.  The same argument applies to the oil and gas industry - if big players are to make the move into renewables, they need to know the industry is economically sound, they need to see more momentum in offshore wind projects, and they need to be assured they can make money.  If the oil and gas industry can be persuaded to jump, Scottish Enterprise insists that this will drive down costs. Research published yesterday suggests oil and gas expertise could cut 20 per cent from the lifetime costs of an offshore wind project.  The oil and gas supply chain is so large, the argument goes, that a modest shift could have a big impact. Scottish Enterprise has produced a guide to offshore wind to share information with oil and gas businesses, explaining areas where they might have compatibility - from fabrication, installation and operations and maintenance through to health and safety and staff training and deployment. at the SLCIC today, Sir Ian Wood leads a session on Oil and Gas into renewables: Risk and cost reduction.  Marchant - whose company is set to pull out of a consortium bidding to build a nuclear power station at Sellafield, Cumbria - will also continue his efforts to form the partnerships needed to make the big breakthrough into offs