1999 saw the bicentenary of the first patent on a wave energy device by Girard (père et fils). However, work on wave energy began in earnest only in the early 1970s as a response to the oil crises. There were several Government sponsored programmes throughout the world, particularly in Japan, Norway and the UK. These programmes advanced the technology considerably and their achievements were impressive but they led to the installation of prototype devices (including one in the UK). The failure of these programmes to deliver economic supplies of electricity left the technology with a credibility problem that has been hard to overcome. Therefore, it is important to understand the reasons for this failure.
Size of Devices
The wave power resource around the UK is immense: approximately 120 GW or 2½ times the total electricity demand. Therefore, the early work on wave energy aimed at exploiting the maximum amount of resource possible, which led to a target design of 2,000 MW for the first wave energy schemes. Colossal schemes were required to achieve this target, examples of which are given in the table below. This entailed large construction costs, prolonged construction times and significant technical challenges. These factors led to high generating costs and large capital costs for the first prototype, which made all the technologies commercially unattractive.
Table: Example of devices from the first UK wave energy programme. Ref. T W Thorpe, "A review of wave energy", Report ETSU-R-72 for DTI, AEA Technology, 1992.
|
Name of Device |
Weight of each unit |
Number of units in scheme |
Capital costs |
Generating costs (Ref. 1) |
| NEL OWC | 22,500t | 606 | £ 6 billion | 19 p/kWh |
|
Bristol Cylinder |
20,000t | 276 | £ 5.6 billion | 19 p/kWh |
Technical Maturity
In the 1970's, wave energy was a novel technology. It faced many technical challenges, required the synthesis of many disciplines (e.g. oceanography, fluid mechanics, structural engineering, etc.) and needed the development of completely new fields. At the time, the nearest technology that it could draw on was coastal engineering (e.g. breakwaters and coastal defenses), an area where cost was not of primary importance. In the author's opinion, these early developments faced too many challenges to solve within the overall heading of wave energy.
Make Up of Research and Development
Most of the early R&D programmes were totally government funded (either in direct grants or through universities or research institutes) and many had a large academic component. At the time, these aspects were appropriate, because wave energy was an emerging technology, which needed the research skills of academia and which could not provide industry with the types of return that it required. However, industry-led development is generally required in order to achieve commerciality.
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Ref. 1: T W Thorpe, 'A review of wave energy', Report ETSU-R-72 for the DTI, AEA Technology, 1992.