Analysis of CO2 savings through the installation of a solar application on sailing yachts in the mediterranean sea

Abstract

The recreational craft industry in Europe was first regulated in 1998 in the Recreational Craft Directive (RCD) with the purpose to tighten legislation for engine exhaust emissions. However, still today, mainly diesel engines are used for propulsion (as alternative or complementing propulsion from sails) and for charging batteries onblue water Sailing Yachts (charter and owner yachts at Sea) which lead to exhaust emissions. The purpose of this thesis was to assess the current average usage and dimensioning of solar applications onboard of Sailing Yachts (SY) in the Mediterranean Sea. The core question was to find out to which extent photovoltaic (PV) applications allow for a reduction of the usage of the diesel engine and consequently for a decrease of CO2 emissions. Based on literature research and a proprietary survey conducted among 47 SY owners with PV installation in the Mediterranean Sea, it was found that the average SY has a size of 12 – 14m and a weight of 10 -13 tons. A “traditional” average SY without any RE installation onboard, being at Sea 100-140 days per year, 8 hours a day, with 45% of engine time (3,6 hours per day) may consume between 500 – 1080l diesel per year. With an output of 2,66 kg CO2 per liter of marine diesel used, yearly CO2 emissions may be in a range from 1,3 tons up to 2,9 tons CO2. Based on the average daily solar output in the Mediterranean Sea, which was calculated with an average of 3,82 Wh for 1W horizontally c-Si, and an average installation size of 1,77 m2, the average capacity of a PV application onboard a SY results to be 286 Wp. The average daily output for 286 Wp would be 1.086 Wh (1,09kWh). Comparing this final energy yield with the calculated average daily energy demand of 207 Ah (resulting in 2.484 Wh @ 12V), a larger than average dimensioning to cover the energy demand at least from March until October is needed.It was found that diesel consumption and diesel savings resulting from a PV installation onboard depend greatly not only on dimensioning of the system in terms of - engine, battery, PV panels, battery charger etc. – but also on the behavior of the SY owner/charterer respectively the crew. The total amount of energy consumed onboard and the resulting need of recharging batteries, will be as important as the willingness to sail more and use the engine only if necessary. The result of the proprietary survey showed that some participants were able to save a lot of diesel while others indicated to have hardly any savings at all. The average percent age resulted in nearly 30% of possible diesel and consequently CO2 savings on a yearly basis by the installation of a PV application.