SOLENERGI FÖR MILLENNIUM AVSALTNINGSANLÄGGNING : Undersökning av potentialen hos solceller i en off-grid lösning som energikälla inom projektet ''Water in a box''

Sammanfattning: This thesis aims first to investigate whether solar panels on the container can provide the process of desalination with energy at the desired location, as well as to dimension a photovoltaic system and battery storage that can run the facility off-grid. Then investigate whether solar cells can be an effective energy solution for Millennium Desalination Device (MDD). The results of this study show that the most annual solar production from containers is 11 510 kWh in Gobabeb, Namibia with a modular efficiency of 22,8 %, which corresponds to 8,2 % operating time per year and is the longest operating time that can be obtained from the all three scenarios. This means that with existing technology and only solar panels on the container, desalination plant is impossible to drive all year round off-grid. The installed power for driving 100 % operating time for one year is 141 kW in Gobabeb and 270 kW in Visby, the corresponding module surface will be lowest 618 m2 and 1184 m2 with modular efficiency of 22,8 %, but there are no additional spaces for all equipment like MDD, solar cells and battery in the container. If the operating time drops to 50 %, the installed power will be 71 kW in Gobabeb, the corresponding module surface will be lowest 415 m2 and battery storage capacity will be at least 160 kWh. Net volume with all equipment will be less than the volume of the container. The cost will be at least 0.2 Swedish kronor per liter of pure water produced with a life of 25 year for solar modules. Usage fee per liter of pure water is 0.03 Swedish kronor based on Gotland’s water and wastewater agency and it means MDD is not a cost-effective solution for Gotland at nowadays. But costs may fall in the future with the price reduction of solar cells and batteries. For water shortage areas, this can be a valuable way to solve the water crisis, but it also depends mostly on the area’s water price.