Low Carbon Ferries Feasibility Study
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LOW CARBON FERRIES FEASIBILITY STUDY Part 2 Analysis Report to Orkney Islands Council Issued by Aquatera Ltd P732 – April 2016 Funded by: Acknowledgements: (Captain) Willie Mackay This study was completed for: Orkney Islands Council Marine Services Harbour Authority Building Scapa Orkney KW15 1SD Contact: David Hibbert Technical Superintendent, Development & Infrastructure Tel: 01856 873636 Ext 3623 Email: [email protected] This study was completed by: Aquatera Ltd Old Academy Business Centre Stromness Orkney KW16 3AW Contact: Ian Johnstone Tel: 01856 850 088 Email: [email protected] Issue record The version number is indicated on the front cover. Version Date Details V1 16 Feb Part 1 draft 2016 V2 04 Apr 2016 Part 2 analysis draft Members of: Executive Summary The scope of the report was to investigate how the current inter-island routes could be serviced by ferries powered from alternative fuels. Within the report: The possible fuel alternatives were to be determined; The routes have been assessed on their applicability to the possible fuels; An understanding was gained on the possible impact upon the local grid; and The details of what changes would be required to the current service were discussed and evaluated, in relation to alternative fuel options. Due to the age of the current vessels operating the routes, retrofitting was not considered as a viable option and any alternatives to the current fleet would be new vessels. The work included the compilation of case studies of vessels deriving power from alternative fuels which includes LNG, CNG, hydrogen, full-electric, liquid nitrogen, bio- fuels, compressed air, ammonia, nuclear, wind and wave. The report also considers hybrid propulsion systems using a mix of fuel sources. The possible scenarios of continuing to use diesel were also considered for comparative purposes. The compiled case studies have been dispersed throughout the report to provide real world examples in the discussion of possible alternatives to the current fleet. Following the investigation into real world examples was the characterisation of the current fleet and onshore infrastructure. This was completed in order to understand the requirements that alternative fuels would need to meet in order to match service expectations. A discussion into the fuel options and the methods of utilising them in comparison with the current route services fed into the first screening process. An initial screening process was conducted in order to remove the technologies that were not currently feasible. The method used for the initial screening was to rate the previously mentioned fuels against five categories: Time to market; Overall cost; Regulatory compliance; Suitability of technology; and Availability of infrastructure. Through this screening each of the five categories were deemed to have equal importance and thus no weighting was added to any of them. The figure below illustrates the results of this screening process; the columns in red on the left corresponding to the fuels and technologies deemed to be unsuitable for investigating further, and the remaining green columns on the right indicating the fuel and technologies that were put forward to secondary screening. Figure 1 Initial Screening Results For the remaining ten propulsion methods, further screening provided a means of prioritising their implementation within the Orkney Ferries fleet. Unlike the initial screening process, weightings were agreed upon, during a workshop with OIC stakeholders, and applied in order to provide an indication of the importance of particular categories in comparison to others. The weighting ranged from one for little/no importance to five for very important. The categories in which they were ranked against, and their agreed weightings were: Table 1 Secondary Screening Weightings Scoring Category Weighting Risk 5 Ability to deliver energy requirement for route(s) 5 Infrastructure requirements 3 Operational cost 3 Required energy input relative to propulsion output (efficiency) 2 Robustness and flexibility of the service 2 Impact on curtailed energy 1 Local content – opportunities for local business and employment 1 Impact on emissions 1 The scorings were made per route level to avoid dropping technologies which may suit short distances rather than long ones. (level 1 being short routes – Graemsay and Papa Westray, level 2 medium routes – Shapinsay, Rousay and Houton, and level 3 long routes – North Isles). Using the weights described previously for each criterion, the results were as shown in Figure 2 („alternative fuel electric hybrids‟ correspond to all electric hybrids but diesel). Figure 2 Weighted scores for the secondary screening per technology and route levels. The grey line indicates the minimal threshold required for the fuel system to go through analysis. Based on the results from the second screening, the fuels taken for further analysis were the ones with a score over 15, i.e. natural gas (LNG and CNG1), electricity (Li-Ion battery), hydrogen (fuel cell and direct combustion) and electric hybrids (Li-Ion battery + diesel/LNG/CNG/hydrogen fuel cell/hydrogen direct combustion). The analysis carried out looked at: the opportunity to produce the fuel locally (electricity and hydrogen) or the need to import it (natural gas and diesel); the different storage options; and the finance associated for both onshore and on-board storage systems. Assessing the capital cost marine diesel comes out the cheapest due to the infrastructure already being in place but this has the highest carbon content. LNG would be the cheapest lower carbon option. Greener energy such as electricity and hydrogen were found to be the most expensive options, however their costs are very likely to drop in the future with improvements in these technologies and growth in their markets. The cheapest fuel per kWh is electricity, which makes its operational cost 1 LNG and CNG were looked at separately for simplification purposes, even though the most likely scenario would be to import LNG and gasify it for storage. low; LNG2 and diesel also have low OPEX; hydrogen is the most expensive one with higher OPEX.3 An assessment of the carbon savings for each technology analysed compared to the current baseline (diesel) was also carried out and showed that the biggest reduction in carbon emissions would occur for the full electric option (Figure 3). Figure 3 Annual amount of carbon released per technology and reduction compared to gas oil The impact on renewable energy curtailment in Orkney was also studied. Fossil fuels do not have any effect on this as they are not produced locally. However, the electricity and hydrogen options have the potential to use significant amount of curtailed energy and even to allow for more renewable installations if the grid was to be upgraded. The possibilities of modular energy storage have also deemed to be technologically feasible. This could reduce barriers currently limiting the use of some technologies, such as full-electric; which would suffer from high capital costs, long charging times and the need for grid upgrades. The alternative of changing the batteries during stops will significantly reduce the strain on the local grid by avoiding the requirement of rapid charging. The weightings for the scoring of the secondary screening were decided at a workshop including Orkney Marine Services, Local Energy Scotland, Orkney Island Council‟s 2 CNG has a higher OPEX due to the high cost of import. 3 Operational costs are still unknown as the technologies are not well developed in the marine sector, but they were estimated considering a percentage of the assessed capital costs. However, by doing so, the full electric system has an overestimated OPEX (it should be the lowest) due to its high Capex. Transport Manager and Aquatera. Depending on the priority of the council, these weightings can be changed which would result in a different overall ranking. To demonstrate this point, increasing the weights on the priority of carbon emissions was also explored. In this analysis „Low carbon concern‟ represents the weighting of 1, „Medium carbon concern‟ describes the effect of increasing this weighting to 3 and „High carbon concern‟ gives a maximum weighting of 5. The effects of this investigation are illustrated in the graphs below for CAPEX and OPEX, across the different route levels. Figure 4 Secondary screening for level 1 routes with varying weightings on the importance of carbon savings, and associated CAPEX and OPEX Figure 5 Secondary screening for level 2 routes with varying weightings on the importance of carbon savings, and associated CAPEX and OPEX Figure 6 Secondary screening for level 3 routes with varying weightings on the importance of carbon savings, and associated CAPEX and OPEX The above figures show that the scores are highly sensitive on carbon savings. With selecting technologies with a score over 15, increasing the weight on carbon emissions would screen diesel out and bring full electric and hydrogen technologies joint first for short routes and second and third for medium routes. For medium and longer routes, the best scored technology would be alternative fuel electric hybrid, instead of LNG. From the cost analysis, diesel appears to be the cheapest option. However, from the carbon analysis, it has the biggest impact. On the opposite, technologies using energies which can be produced locally (hydrogen and electricity) are the most expensive but the most environmental friendly. Electric hybrids may be a compromise between these two criteria. Figure 7 shows the ratio between the amount of CO2 released and the capital expenditure for each technology. Figure 7 Amount of CO2 released per £ of Capex Through the process of screening possible propulsion technologies and prioritising the remaining viable methods, it became clear it was not possible to support one particular technology for the Orkney routes. But instead the report highlights how differing technologies fit differing needs and priorities, and the consequences of these choices. However, one conclusion across all alternatives is that deviating from the marine diesel will be the need to accept impact of cost.