The Marine Farm Accelerator (MFA) has the aim of quantifying and reducing the uncertainties associated with energy yield predictions of marine energy projects. The process of determining uncertainty predictions on energy yield is reasonably well developed in the wind industry but is relatively immature in the wave and tidal energy sectors. As these industries develop, potential investors will need to know not only the most likely revenue that the project may deliver but also the uncertainty on that revenue. Consequently, there is a requirement to assess methods of quantifying uncertainty and to standardise the process of reporting uncertainty within the wave and tidal energy industries. The MFA has taken an important first step in this process with the development of a Taxonomy Document which lists the losses and uncertainties that should be considered as part of an Energy Production Estimate (EPE). This current Reference Document has been developed to provide guidance for determining the uncertainties highlighted in this taxonomy document. It is the result of an industry-wide research study involving two main components:
- Literature Review of relevant industry standards, technical guides as well as academic papers, conference proceedings and books;
- Stakeholder Engagement involving interviews with industry practitioners including consultants, device and project developers, surveyors and modellers, and academics.
Together these two activities have provided a consolidated view of the state-of-the-art of uncertainty assessment within the wave and tidal energy sectors and this information has been used to provide best practice guidance on the assessment of the individual uncertainty categories and how they should be combined to inform an overall project uncertainty.
This guidance has been applied to a series of example projects to demonstrate the variation in approaches that can be undertaken. Much of this variation arises from the process by which the EPE is calculated in the first place. This document provides a summary of the different approaches for determining the EPE and the uncertainties which are relevant to these approaches. Although the wave and tidal uncertainty categories in the taxonomy document are the same, the ways in which they should be addressed and the current levels of understanding differ significantly. Tidal energy is essentially deterministic (driven by the position of the sun and moon relative to the earth), whilst wave energy is stochastic (driven by the weather). The tidal energy industry is also more mature and this is reflected in the greater variety of modelling options available. As a result, wave and tidal energy are largely considered separately in this document.
The final aspect of this project has been the development of an Interactive Uncertainty Tool which provides a standardised method for the uncertainty assessment. This tool has been applied to the example projects to record and present the results.