The following energy sources, in a various combinations were assessed to provide potable water using seawater reverse osmosis (SWRO) for around 50,000 people in Eritrea: wind power and solar power. Various types of SWRO technology were employed and the cost of scenarios that were able to meet the users’ water needs was compared with the costs of the equivalent diesel generator powered scenario over 25 years. The most financially-attractive scenario, a hybridised power plant using solar and wind power was compared with the equivalent conventionally (diesel generator) powered scenario using present and net present value (NPV) methodology. The discount rate used for NPV calculations was found to be pivotal for this comparison, so the logic of the appropriate discount rate was investigated and a discount rate of 3.6% was considered the most appropriate. This resulted in the renewable powered solution for this scenario being financially attractive when compared to the diesel generator powered scenario. This conclusion was mainly due to recent changes in the prices of diesel fuel in Eritrea and solar power generally. Research conducted on this scenario previously, and published in 2014 based on 2010 prices, concluded that this scenario was not financially attractive in comparison to diesel power.
Part of the book: Desalination and Water Treatment