The expertise of Scotland's oil and gas industry could help reduce costs of offshore wind operations by at least 20 per cent, according to new research.  Scottish Enterprise has calculated that GBP330 million of savings could be made over the life of an average offshore wind farm by the oil and gas sector.  They have created a Guide to Offshore Wind and Oil and Gas Capability to highlight the opportunities for the oil and gas industry from getting involved in the offshore wind sector.  Potential crossovers highlighted in the guide include installation skills, maintenance activities and personnel.  The authors calculated that a 500-megawatt project over 20 years of operation would cost GBP1.558 billion to set up and GBP40m a year to run, without oil and gas expertise.  However, by using the expertise from the oil and gas sector these costs could reduce to GBP1.347bn set-up costs and GBP33.9m-a-year running costs.  Over the two decade life of the project, this would work out as a GBP330m saving.  The UK, Germany and China are currently the three largest offshore wind markets in the world and together over the next four years are expected to install 11GW of new offshore wind capacity - almost 83 per cent of the total global capacity.  The UK is forecast to be the largest market during 2011 to 2015 as the UK completes the first phase of projects