Onshore Power Supply

OPS calculation tool

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This website offers a simple calculation tool that helps develop a feeling for the costs and benefits of OPS. The tool is filled out with characteristic data, but can be readily adapted to the local situation by changing the cost figures and data on the number of ships and their fuel consumption.

Main goals

The tool can be used for two main specific goals: - to calculate the annual costs and benefits of OPS - to calculate the annual emission reduction.

In addition, the tool permits estimation of the effects of different parameters on costs and emissions, thus providing insight into cost effectiveness.

In the cost effectiveness calculation, costs are balanced against the total amount of air pollutants prevented. Figures for the relative harmfulness of air pollutants have been taken from a study by AEA technology, for which click here. Because of their more damaging nature, SO2 and PM have been assigned a higher weighting factor. The calculation algorithm is as follows: pollution units (tonnes) = 1* NOx (tonne) + 2,2 * SO2 (tonne) + 12.8 * PM (tonne). The cost effectiveness is expressed in € per pollution unit).

Click here for the tool.

Manual for OPS calculation model

The tool can be used to calculate emission reductions, financial costs and benefits and emission benefits on an annual basis. The tool calculates the additional annual costs for the integral OPS project, not for individual parties such as vessel and terminal/port operators. Benefits are expressed as negative costs.

The tool can be used:


The tool contains three sheets with calculations for different vessel types and one sheet with basic data. The former sheets contain input data (operational and cost data) and formulae for calculating annual costs and emissions reductions. Further down, general data, investment costs and operational costs can be filled in. For comparison, OPS and use of auxiliary engines are listed in parallel. Input data can be filled out in the white-coloured cells. All these cells can be changed according to your particular preferences and used to estimate the effect of certain choices.


Below, a stepwise manual for working with the tool is provided. The capital letters indicated can be found in the left-hand side of the tool.

A Under “General information”, data can be entered on how frequently ships are berthed and for how long. These data are needed to calculate operational costs and emission changes.
B Depreciation period and interest rate affect annual costs, with higher interest rates and shorter depreciation periods leading to higher annual costs.
C Here the investments costs at the terminal can be filled in. The tool distinguishes various cost categories, which are summed to yield the total investment costs. Annual costs are calculated using the interest rate and depreciation period. Investment costs are not relevant for the auxiliary engines, as these are vital outside the ports.
D In this section the shipside investments costs are filled in. A range of cost categories are listed, which are summed to yield the total investment costs. Annual costs are calculated using the interest rate and depreciation period.
E The operational costs depend on fuel and electricity consumption levels, fuel and electricity prices and electricity taxes. From these data, annual costs are calculated. Savings on auxiliary engine maintenance costs can be filled in here, with negative costs standing for benefits. The total benefits are calculated from the number of hours at berth, as input to the General information section. There is an option to calculate with a CO2 price in advance. This option enables simulation of the influence of inclusion of the Maritime industry in the EU ETS on the cost effectiveness of OPS.
F The total annual costs are calculated by summing the various cost categories under B to F. The costs or benefits accruing from using OPS can be calculated by comparing the ‘auxiliary engine costs’ with the ‘OPS costs’ (row 65), the outcome of which is presented in Box I.
G The emission benefits are calculated by using emission factors from the data section and total annual consumption figures. Total annual consumption is calculated on the basis of the ships’ consumption and the number and duration of port calls. The emission benefits can be found by comparing the figures in rows 76-80. The type of fuel can be changed from diesel to HFO here, as well as the energy source used for power generation (by clicking on a pull-down menu)
H The total annual costs can be calculated by subtracting the ‘auxiliary engine costs’ from the ‘OPS costs’. Negative costs mean that OPS yields a financial benefit. The cost effectiveness is expressed in Euro per unit of pollution. Pollution units are used to sum the various air pollutants, with SO2 and PM being judged to be 2.2 and 12.8 times more harmful on the basis of a study by AEA Technology (2005).
I For each pollutant the relative emission reduction is calculated using the figures in rows 76-80.

Note: the basic data can be changed in the ‘data' sheet. These basic data include emission factors for fuel burning and power consumption.

Click here for the tool.