Offshore energy sources and climate challenge – Part 4– LFP & VLFP - Risk Factor
As per Offshore energy sources and climate challenge – Part 1 – Destruction Factor and Availability Factor
1. The Destruction Factor (DF) is availability of offshore energy harvesting structures to sustain to severe weather conditions and challenges of climate change.
DF= H (max) X S (max)
Where H (max) is maximum height of waves in (m) before destruction
S (max) is maximum speed of wind in (m/s) before destruction.
2. The Availability factor (AF) is the boundary where production of offshore energy cuts.
AF= H (cut) X S (cut)
Where H (cut) is maximum height of waves before production cuts
S (cut) is maximum speed of wind before production cuts.
Data sheets of large and very large floating platforms (LFP & VLFP) carrying wind turbines contain some information on optimal and critical issues concerning operation and survival modes of constructions.
In regard of trend to install these platforms deeper and deeper in the ocean the prognosis on extreme events become not quite reliable i.e. higher winds and waves than expected may appear.
Underwater waves due to geological anomalies at the seabed are also unpredictable.
Examples for large civil floating platforms are:
Hexicon, Sweden – www.hexicon.eu – platform expected to carry 6 large wind turbines
Shimizu Corporation, Japan – http://windeng.t.u-tokyo.ac.jp/ishihara/e/ - floating platform supposed to carry 3 large wind turbines
HIPR Wind, Germany – www.hyperwind.eu – platform expected to carry 20 MW turbines.
In case of enough information available on optimal and critical waves and winds the relation DF/AF=RF may provide estimation on technical and financial factor of risk (RF) integrated into concerned structures.
In case of underwater anomalies RF is not applicable till LFP and VLFP are anchored.
Large and very large free floating platforms (LFFP & VLFFP) may fully apply to RF.
I would like to thanks to Mr A. Bossler for his report as per the link below.
P.S. - 20.08.12 - The size of Hexicon is similar to a size of conventional 1 GW TPP.
Shall Hexicon reach such a power output?