Wave Energy Report On The Electrical Aspects Of The Edinburgh University Wave Energy Device

Abstract

In our offer of services there were no formalised Terms of Reference given, although the object of our participation was: - "To assist the ETSU Wave Power Programme by providing consultant services to Edinburgh University, the latter acting under an Agreement with the Secretary of State for Energy". By mutual agreement with ETSU and the Edinburgh Wave Power Team, the objectives of our investigations were: - a. To examine theoretical electrical concepts. b. To determine whether a.c. or d.c. electrical transmission is appropriate. c. To determine the specification of electrical generation equipment. d. To minimise the cost of generation and transmission plant. e. To make recommendations on transmission lines and cables. f. To produce an overall scheme for generation and transmission of electrical power, including an estimate of the cost thereof. The concept of installing generators, switchgear, transformers and cables out in the most exposed area of our coast line may be regarded as adventurous and perhaps this is the reason why SCOPA have been asked to work with the Edinburgh University Wave Energy Team on this project. We are proud that we are accepted as part of the team because it is refreshing to work with people anxious to overcome problems and reluctant to give up a promising concept when faced with apparent difficulty. At the same time we have come to respect the tenacious search for practical solutions to problems which is one of the main characteristics of the members of the team. It is with a sense of some surprise that we have found ourselves able to present a scheme for the generation and transmission of electrical energy from the Edinburgh 'Salter Duck' devices to the Scottish grid system which uses conventional ideas albeit in a manner not hitherto associated with the Wave Power Project. Of course there are a number of problems with the 'Duck' scheme, and, on our conventional assessment, it is relatively expensive; but we now believe it is possible, and promising. Certain problems common to wave power devices were identified during the investigations described in this report. We feel that this report would be incomplete without describing such problems, and accordingly have included these in the last Section (9) of this report. This report is confined to the technical and cost aspects of generating electrical power at sea on board the ducks, and delivering this power to the Scottish Transmission Grid System. The optimisation of hydraulic drives within the ducks, and the design of coupling arrangements between ducks is still proceeding. Arrangement of the electrical system has had to proceed on the basis of a specified duck design, which has a specific output. For reasons explained in the text of our report we consider the term "Wave Energy device" more appropriate than "Wave Power device". Henceforth the term "Energy" is used in preference to the term "Power" to describe the device.