combining wind energy production and mussel farming. For this purpose we used a
cost distribution (Table 4.1), as elaborated by Miedema (2012), according to the
AMC approach (Stavenuiter 2002).
Figure 4.3 presents a summary of the three consecutive approaches of allocating
costs to the different operation and maintenance disciplines.
4.3 Potential for Synergy
To estimate the potential synergy through combining wind and mussel farming, the
following assumptions apply.
1
4.3.1 Operations and Life Cycle Management
For OWFs larger than 200 MW, it is common to have a control room ashore, 24 h
and 7 days a week staffed by two to four people. Here, the assumption is made that
with little extra effort this team can also manage the mussel farm, if it is integrated
in the wind farm environment.
4.3.2 Inspective, Preventive, Corrective Maintenance
and Improvement Maintenance
Previous studies and practical experiences (Thomsen 2012) have shown that in
general 50% of the charged maintenance labour are non-productive time because of
waiting for e.g. specific certified personnel, transport opportunities, acceptable
weather windows, adequate spares, tools and equipment. It is assumed that by
combining wind energy and mussel production these ‘lost hours’ can be reduced to
at least 25% of the charged maintenance labour. This means that, when the labour
cost is 60% of the total O&M cost of a wind farm, a cost reduction of 15% is
attainable.
To reduce the waiting time related to O&M of wind farms, and thus reduce
O&M costs, there are several logistical opportunities for synergy. For example,
when a multi-purpose ship sails out for a week to transport a maintenance crew to
and from the wind turbines, it can inspect the longline-installations and/or harvest
1
These assumptions were formulated and agreed on in an expert workshop, held in June 2010 at
the AMC Centre in Den Helder, Netherlands. Participants: Ramses Alma (AMC T&T), Nico
Bolleman (Blue-H), Henk Braam (ECN), Wim de Goede (HVA), Ko Hartog (HVA), Bertrand van
Leersum (ATO NH), Tom Obdam (ECN), Luc Rademakers (ECN), Hein Sabelis (Peterson), John
Stavenuiter (AMC Centre) and Frans Veenstra (IMARES).
4 Operation and Maintenance Costs of Offshore Wind Farms …
105
cost distribution (Table 4.1), as elaborated by Miedema (2012), according to the
AMC approach (Stavenuiter 2002).
Figure 4.3 presents a summary of the three consecutive approaches of allocating
costs to the different operation and maintenance disciplines.
4.3 Potential for Synergy
To estimate the potential synergy through combining wind and mussel farming, the
following assumptions apply.
1
4.3.1 Operations and Life Cycle Management
For OWFs larger than 200 MW, it is common to have a control room ashore, 24 h
and 7 days a week staffed by two to four people. Here, the assumption is made that
with little extra effort this team can also manage the mussel farm, if it is integrated
in the wind farm environment.
4.3.2 Inspective, Preventive, Corrective Maintenance
and Improvement Maintenance
Previous studies and practical experiences (Thomsen 2012) have shown that in
general 50% of the charged maintenance labour are non-productive time because of
waiting for e.g. specific certified personnel, transport opportunities, acceptable
weather windows, adequate spares, tools and equipment. It is assumed that by
combining wind energy and mussel production these ‘lost hours’ can be reduced to
at least 25% of the charged maintenance labour. This means that, when the labour
cost is 60% of the total O&M cost of a wind farm, a cost reduction of 15% is
attainable.
To reduce the waiting time related to O&M of wind farms, and thus reduce
O&M costs, there are several logistical opportunities for synergy. For example,
when a multi-purpose ship sails out for a week to transport a maintenance crew to
and from the wind turbines, it can inspect the longline-installations and/or harvest
1
These assumptions were formulated and agreed on in an expert workshop, held in June 2010 at
the AMC Centre in Den Helder, Netherlands. Participants: Ramses Alma (AMC T&T), Nico
Bolleman (Blue-H), Henk Braam (ECN), Wim de Goede (HVA), Ko Hartog (HVA), Bertrand van
Leersum (ATO NH), Tom Obdam (ECN), Luc Rademakers (ECN), Hein Sabelis (Peterson), John
Stavenuiter (AMC Centre) and Frans Veenstra (IMARES).
4 Operation and Maintenance Costs of Offshore Wind Farms …
105