This project aims to show how, and at what cost the start of new life in arid or deserted coastal areas can be originated by the introduction of a simple bio-energy scheme. The main objective was to implement a techno-economic evaluation of a full bioenergy project for the reconstruction of an artificial good quality soil in a deserted coastal area of Tenerife, for the production in sequence of biomass (herbaceous crops), electricity/heat and desalinated water by reverse osmosis (RO), needed for irrigation and other uses. Biomass productivity in these extreme conditions has also been estimated, including the possibility of Carbon Dioxide (CO2) injection and the use of high water retention crystal grains in the artificial soil. Finally, the electricity and desalinated water cost were evaluated, as well as the total investment cost.
A techno-economic assessment of the entire system and cost of the products was finally performed for the chosen configuration. The energy surplus was estimated to be in the range of 18-28 %, which could be seen either in terms of biomass, or energy, or water. The manufacturers of the main components (biomass generator, desalination system, irrigation system) provided formal offers for their products and a techno-economic assessment for the complete system was performed. The production costs of biomass, electricity and water (therefore, irrigation costs) were assessed.
The economics of the whole system were restricted, mainly due to the current high cost of the biomass power generator, resulting in a high production cost for the biomass (from 1500 to 3500 ECU/tDM depending on the economic calculation mode). The cost for biomass irrigation by desalination plants powered by fossil fuel in a standard diesel engine was also evaluated. These results showed considerably less, but still significant costs (550 ECU/tDM).
In conclusion, the system can be regarded as energetically balanced, but requires more economic improvement. Possible methods for improving the economics of the whole system were identified. The land rescuing potential ( the main goal of the project) of the proposed 10 hectares (ha) bioenergy scheme, as well as a scale-up of the system were described.
The most relevant result of the project are probably represented by the fact that the proposed scheme is energetically balanced and feasible using commercially available technologies.