A Feasibility Study - Aaltodoc - Aalto-yliopisto

With the nominal pump capacity of 0,09 m³/s, the RO system has 23 pressure vessels
and in total 161 RO membranes. The nominal production of 161 RO membranes is 4025
m³/day. The cost breakdown of Site 3 with a nominal pump capacity of 0,09 m³/s is
presented in Table 8.
9.7 Site 4
Table 8. Cost breakdown of Site 3.
Capital expenses (€) Operational expenses (€)
WEC 2 240 000 110 000
RO 680 000 80 000
Total 2 920 000 190 000
Annual 270 000 190 000
Site 4 has an excellent wave climate, with an average power of 38 kW/m. The
performance and retention curves of Site 4 have been given in the Appendix B. The
calculation presented in this Chapter follows the calculation method described in
Chapter 9.1. The average recovery rate in all the calculations on Site 4 has been 26,3 %
and the average permeate TDS is 96 mg/l, which is well below the limit of 500 mg/l.
The permeate production on Site 4 increases almost linearly with the nominal pump
capacity. The maximum permeate production of 3700 m³/day is achieved at the end of
the study area with a nominal pump capacity of 0,024 m³/s and a load factor of 0,95.
The fact that the load factor remains practically constant at 0,95, and the permeate
production increases rapidly and linearly with the nominal pump capacity, signifies that
Site 4 is an excellent area for the AaltoRO system. Figure 48 presents the permeate
production on Site 4.
Permeate production (m³/day)
4000
3500
3000
2500
2000
1500
1000
500
0
Permeate (m³/day)
Load factor (%)
0
0 0,05 0,1 0,15 0,2 0,25 0,3
WaveRoller nominal pump capacity (m³/s)
Figure 48. Permeate production (m³/day) and load factor on Site 4.
65
1,2
1
0,8
0,6
0,4
0,2
Load factor