An algorithm for comparative analysis of power and storage systems for maritime applications

This paper presents an innovative algorithm to compare traditional and innovative energy systems onboard for maritime applications. The solutions are compared adopting a multi-criteria method, considering four parameters (weight, volume, cost, emissions) and their relevance according to the kind of ship and navigation route. The algorithm, which includes a large and updated database of market solutions, leads to the implementation of HELM (Helper for Energy Layouts in Maritime applications) tool. HELM was conceived to support the design of maritime systems: it chooses the best technology comparing traditional marine diesel engines, propulsion systems with alternative fuels (methanol, ammonia, LNG) and innovative low-emission technologies (fuel cell and batteries). Two case studies are investigated: (i) a small passenger ship for short routes (ii) and a large size ro-ro cargo ship. For case (i), fuel cells represent a competitive solution, in particular considering navigation in emission control areas. For case study (ii) Internal Combustion Engines shows are the best solution. The evaluation of alternative fuels is performed, considering a sensitivity analysis on emissions’ importance: methanol, LNG, and ammonia are promising solutions. For case (i), the installation of electrical batteries is also evaluated to analyse potential advantages to reduce the amount of H2 stored onboard.

Comparison of the most likely low-emission electricity production systems in Estonia

To meet targets for reducing greenhouse gas emissions, many countries, including Estonia, must transition to low-emission electricity sources. Based on current circumstances, the most likely options in Estonia are renewables with energy storage, oil shale power plants with carbon capture and storage (CCS), or the combination of renewables and either oil shale or nuclear power plants. Here we compare these different scenarios to help determine which would be the most promising based on current information. For the comparison we performed simulations to assess how various systems meet the electricity demand in Estonia and at what cost. Based on our simulation results and literature data, combining wind turbines with thermal power plants would provide grid stability at a more affordable cost. Using nuclear power to compliment wind turbines would lead to an overall levelized cost of electricity (LCOE) in the range of 68 to 150 EUR/MWh (median of 103 EUR/MWh). Using oil shale power plants with CCS would give a cost between 91 and 163 EUR/MWh (median of 118 EUR/MWh). By comparison, using only renewables and energy storage would have an LCOE of 106 to 241 EUR/MWh (median of 153 EUR/MWh).