OES Annual Report 2012 - Ocean Energy Systems

124
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Foundations / Moorings – In offshore wind, foundations make up approximately 20% of the total Capex,
uninstalled. This is likely to be similar for tidal farms, with fixed foundation requirements, but potentially less
for wave farms, with mooring system requirements.
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Electrical Connection – In offshore wind, electrical components make up 15% of the total Capex,
uninstalled. This is expected to be similar for wave farms, due to similar distances from shore, but perhaps
less for tidal farms, which can be close to shore.
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Installation – In offshore wind, the installation of foundations, electrical cables and turbines makes up
approximately 20-25% of the total Capex. This is expected to be similar for tidal farms but perhaps less for
wave farms depending on WEC installation strategy.
There is still a large variety of wave and tidal energy converter concepts, more so in wave energy. It is
therefore difficult to put a fixed breakdown of Capex for both that will be universally accurate. A prospective
breakdown of costs for wave and tidal energy arrays is Shown in Figure 2. These cost breakdowns are for
Phase 3 projects only. Phase 1 and 2 projects are expected to have a different cost breakdown.
WAVE
TIDAL
16%
4%
Development
Converter
Mooring
Electrical Export
Installation
20%
4%
Development
Converter
Foundation
Electrical Export
Installation
15%
50%
11%
45%
15%
20%
FIGURE 2: Prospective Capex Breakdown for Phase 3 Wave and Tidal farms
Although the target costs for Ocean energy projects are circa €4m/MW to be comparable to offshore
wind (Table 3), this would equate to a target costs of circa €2m/MW for the wave energy converters and
€1.8m/MW for tidal energy converters themselves. This is the ‘dry’ cost to deliver the hardware to the
quayside before installation. It is possible to assess metrics, such as structural tonnes/MW of particular
solutions to see if the material costs are likely to be consistent with these long-term requirements. Cost
requirements are similar to the current cost/MW of offshore wind energy converters. Given that the input
energy resource for both wave and tidal energy can be denser than for wind energy (see Table 8), ESB
see no fundamental reason why these alternative offshore energy converters cannot achieve competitive
structural costs. However, in order to realise this, technology developers must ensure that their solutions
have the potential to be as structurally efficient as offshore wind energy converters in order to meet the
longer term phase 3 cost requirements.
Cost Indicators and Risks
Presently, evaluating the economic potential for technology can prove difficult as only a small number of
wave and tidal technology developers have progressed past TRL7, at which stage there is credible visibility
of final commercial costs. In terms of performance there are only a small number of technology developers
that have completed meaningful levels of generation and running hours and can therefore give credible
capacity factor projections. As such, the evaluation of economic competitiveness at this stage is, for the
ANNUAL
REPORT 2012