Resumen de Towards the exploitation and commercialization of tidal current energy conversion systems: an economic approach
The vertiginous increase in the global demand for energy, together with the imbalance between the period of fossil resource formation and the rhythm of its consumption, makes it necessary to promote renewable energies in order for energy consumption to coexist with sustainable development. One of the most important challenges as regards renewable energy generation is to be able to move to a new low carbon economy in which energy demands can be met while the levels of CO2 emitted are reduced. In order to meet this challenge, it will be necessary to exploit other forms of renewable energy that are currently less developed but which have a high potential, such as ocean energy. This has led to an incipient interest in the successful development of these technologies and in bringing them onto the market. Of the various types of ocean energy, this paper is focused on marine current harnessing which, although it is still in its infancy, and despite the fact that only some marine current energy conversion systems are being implemented at the prototype and pre-commercial demonstration stage at sea, has a high predictability and an enormous potential for electricity production. In spite of these advantages, there are numerous areas of uncertainty which need to be explored related to technical development (knowledge of resource mapping, device design, array deployment), economic aspects (high LCOE, difficult prediction as regards long-term cost reductions, high technology risks), socio-environmental concerns (complex administrative issues, effects of ocean technologies on the environment, social acceptance) and infrastructure (grid access, supply chain, maintenance tasks) if the future of the industry is to be insured.
The aforementioned problems and requirements are the reasons why we were motivated to develop this research work. The objective of this thesis is to develop different economic research studies in an attempt to mitigate some of the risks identified that may affect the development of these technologies as regards becoming marketable. The principal features outlined in this thesis are described below:
- First, we have presented a description of the basic concepts of tidal energy and an assessment of resources. We have also described the main challenges that must be met in order to achieve robust, feasible and cost-effective tidal technologies while simultaneously helping the acceleration and sustainability of these energy systems.
- Second, we have proposed a strategic analysis of the ocean energy industry as a whole, and with a more particular focus on tidal current energy so as to assess the current state of the tidal industry in the EU. PESTEL stands for political, economic, social, technological, environmental and legal analysis for this industry/market and the framework also identifies the principal stakeholders involved in each of these disciplines.
- Third, we have developed an economic-financial model for marine current harnessing projects that will provide a detailed description, thus aiding the discovery of the profitability and feasibility of these renewable energy projects. The methodology developed considers the following aspects: (i) a definition of the fundamental variables of the economic model; (ii) a definition of the financing structure of the model based on the common stockholder equity of the industry that the partners must provide and the estimation of the bank financing needs; (iii) a definition of the main components required to define the forecast balance, the forecast income statement and the forecast sources and application of funds for the entire service life of the project; (iv) a determination of the cost-benefit analysis using the information provided in the cash-flows of the project and the forecast sources and application of funds; (v) an analysis of the most important economic-financial ratios of the model and; (vi) the realization of a sensitivity analysis, with the aim of detecting business risks when fundamental variables of the model, such as investment, the annual energy production, the price of energy, the interest rate, the percentage of loan requested or the tax rate, oscillate.
- Fourth, we have proposed general details of installation and maintenance maneuvers for first generation TECs. A detailed description of the procedures required to carry out installation and maintenance maneuvers for first generation TECs in a manual and automated manner is also provided in order to find new approaches with which to increase the competitiveness of this source of renewable energy in the near future.
- Fifth, the effectiveness of the proposed economic-financial model and the definition of the installation and maintenance maneuvers in a manual and automated fashion has been used to analyze a numerical case study of a tidal current energy farm of 50 MW in the Alderney Race.
