The purpose of this deliverable is to take a closer look at the potential energy production, installation and OPEX costs for each configuration. The deliverable uses an installation (module of the EU FP7 LEANWIND Financial model) and O&M model (ORE Logistics tool) developed in UCC and further adapted for the LiftWEC project where needed. Programmed in Matlab using Excel input and output files, these operate running Monte Carlo simulations of a scenario against a time series of Metocean data. The models average results, determining the impact of uncertain weather conditions and failure rates on the installation and OPEX costs; installation time; and device power production.

When reviewing results, it is important to remember that these are estimates, without specific tested data and offshore experience for the LiftWEC device. Further information and testing are required to increase confidence in the figures. However, the deliverable is extremely useful as a comparison of the 4 baseline configurations and potential areas for improvement. Where relevant, sensitivity analysis is undertaken, identifying key bottlenecks that may be preventing these baseline designs from achieving their potential and economic targets.

The base case scenario examines the 4 configurations as part of a 20 x 1.25MW array at the Ifremer site considering the installation and O&M over a 25-year project lifetime. Extremely low availability figures indicated that the selected case study site is extremely challenging to access resulting in a) relatively long installation for 20 devices and high costs and b) low energy production during the project lifetime due to difficulties accessing devices to repair them. Sensitivity analysis verified the need to increase the weather windows available and other potential areas that could improve results including increasing the number of vessels available; reducing operation durations; and reducing failure rates.

Based on this analysis, optimised scenarios were developed for each configuration assuming the 25MW array was a first or second deployment, benefiting from learned and technical advances from previous pilot projects (single device). Results are summarised in the following table (see PDF for table), which highlights key results in grey from light to dark in order of preference to help illustrate which configuration proves most advantageous.

The Spar LiftWEC results in the lowest installation costs and time; the second lowest O&M and second highest power production; with the highest availability and capacity factor. This is due to the use of smaller, cheaper vessels to deploy and retrieve the device as well as having a simple connection/disconnection procedure that requires minimal time offshore and can be done at higher weather restrictions. Based on the scenarios run in this deliverable, the Spar LiftWEC configuration has the most advantages and likely to produce the lowest LCoE of the 4 configurations.