A Feasibility Study - Aaltodoc - Aalto-yliopisto

9 Case study
A case study will be performed in order to determine the feasibility of AaltoRO. Four
different areas will be studied, each with unique wave power characteristics. From all
four areas a performance curve of the WEC WaveRoller will be supplied by AW-
Energy, which will serve as the basis for all further calculations. With the supplied data,
a performance calculation of the entire system will be carried out. Lastly, the price of
the produced water will be estimated, thus giving an estimation of the feasibility of
AaltoRO.
First, the general description of the calculation method will be given. Second, the
presumptions and simplifications that have been made will be presented as well as some
details that will be common to all four cases, e.g. the membrane type. Third, the
optimum pressure level for the operation of AaltoRO will be determined. Fourth,
calculations will be performed separately for each case area in order to determine the
optimum configuration, the permeate production and the cost of the produced water in
€/m³.
9.1 Calculation method
This Chapter presents the general calculation method used in determining the feasibility
of AaltoRO. The calculation begins with the wave resources available on the location.
The developer of WaveRoller, AW-Energy has provided performance curves of
WaveRoller for each of the chosen sites. These performance curves represent the
capability of WaveRoller as a pump pressurizing seawater to 65 bar pressure.
From each Site there are two curves. The first gives the ratio between the nominal pump
capacity of the “wave-pump” and the annual production, represented by the upper
picture in Figure 34. For instance the star represents the nominal pump capacity of 0,02
m³/s and the annual production of 350 000 m³ of feed water in 65 bar pressure.
The second curve one is a retention curve and represents the probability of each nominal
pump capacity (the lower picture of Figure 34). The annual production of 350 000 m³
with a nominal pump capacity of 0,02 m³/s (the star) in the upper picture has been
calculated as the area marked with grey in the lower picture. It has been presumed that
with wave powers lower than the nominal pump capacity, the WaveRoller can operate
without problems, but with wave powers greater than the nominal pump capacity, it will
operate only with its nominal capacity (the black line in the lower picture).
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