A multidisciplinary approach for an effective and rational energy transition in Crete Island, Greece.

This article proposes a mixture of actions for the development of an effective and rational energy transition plan for all sectors and for all types of onshore final energy use in Crete. Energy transition is initiated with an appropriate capacity building campaign. The plan is based on the introduction of energy saving measures and the exploitation of all the locally available energy resources (wind, solar, geothermal potential, biomass), integrated in a cluster of centralized and decentralized power plants and smart grids to produce electricity and heat and for the transition to e-mobility. The core of the energy transition in Crete will be a set of 14 wind parks and Pumped Hydro Storage systems (PHS) for electricity generation and 12 Combined Heat and Power plants, properly designed and dispersed in the insular territory. Economic analysis is executed for the proposed essential power plants on the island. Biomass, solar and geothermal potential can cover the heating demand in Crete several times. Heat can be produced with a specific cost of 0.05 EUR/kWhth from cogeneration plants fired with solid biomass and biogas. The wind parks-PHS systems exhibit payback periods of approximately 10 years with a final electricity selling price at 0.12 EUR/kWhel. The article shows that 100% energy transition in Crete constitutes a feasible target

A mixed-method approach for the assessment of local community perception towards wind farms

The implementation of wind power projects can have significant impacts on local communities. If on one hand the project can bring important economic benefits, on the other hand it can represent a source of conflicts and discontentment. This paper aims to revisit this topic, addressing impacts and their perceptions from the local community point of view. A mixed method approach was proposed and implemented in a Portuguese region (municipality) used as case study. Semi-structured interviews directed towards local stakeholders were conducted to evaluate the acceptance of these wind power projects and the perceived impacts. The qualitative study was subsequently complemented and validated by a quantitative approach, through a questionnaire targeting local population. In general, the collected opinions seem mainly driven by the perceived socio-economic benefits resulting from wind farm deployment, with generally positive attitude towards wind farms. Identified local positive impacts include "community funds", "benefits in kind" and "indirect local employment". The key role of benefit sharing mechanisms on ensuring public acceptance and effective local development is confirmed.- This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia (Portugal) within the Project Scope: UID/CEC/00319/2019

Cost-reliability analysis of hybrid pumped-battery storage for solar and wind energy integration in an island community

This paper presents a mathematical model for estimating the optimal sizing and assessing a standalone hybrid power system's performance entirely based on variable renewable energy sources and coupled with a hybrid energy storage system. This study evaluates how different levels of the main components' capital cost and the loss of power supply probability would affect the cost of energy and the power system's optimal sizing. The case study selected for this study was Ometepe Island in Nicaragua, where the crater lake of an extinct volcano was considered a feasible upper reservoir of a pumped storage hydropower plant, reducing the investments associated with this component. The mathematical formulation considers energy storage losses and gains, and the Pareto efficient solutions of the multi-objective optimization model simultaneously increase reliability, reduce the cost of energy, and minimize curtailment energy. By employing time-series with an hourly resolution, the model allows assessing the impact of the interannual variability of renewable energy sources on the system's performance. As for the case study, the cost of energy obtained from the model results ranges between €0.047/kWh and €0.095/kWh, based on international reference values, and these values match the information available in the literature and other databases

Improving understanding of energy autonomy: a systematic review

Autonomy is often cited as a key aspect of energy systems. Previous academic literature on energy autonomy has predominantly approached it from a technological perspective, and conceptualized it as self-sufficiency of energy production. In addition to self-sufficiency, autonomous energy users and communities often aim to create energy systems that treat different stakeholders as equals, with a balanced distribution of costs and benefits. This paper has two aims. First, it aims to clarify the concept of ‘energy autonomy’. Second, it aims to provide an overview of existing literature addressing energy autonomy, identifying relevant publications and publication outlets, as well as main research themes and activities. The results, based on a systematic review of 71 peer-reviewed academic articles, show that energy autonomy research has increased in the last twenty years. The results also show how existing literature has understood, and used, the concept of energy autonomy in varying ways. Furthermore, the paper reveals how motivations, technologies, and scales differ in energy autonomy projects. While the aim of reaching energy autonomy is often motivated by economic and/or social reasons, these aspects are nevertheless rarely discussed in academic literature as the predominant focus tends to be on technological issues and self-sufficiency. The paper concludes with energy policy implications and avenues for future research

Improving understanding of energy autonomy: a systematic review

Autonomy is often cited as a key aspect of energy systems. Previous academic literature on energy autonomy has predominantly approached it from a technological perspective, and conceptualized it as self-sufficiency of energy production. In addition to self-sufficiency, autonomous energy users and communities often aim to create energy systems that treat different stakeholders as equals, with a balanced distribution of costs and benefits. This paper has two aims. First, it aims to clarify the concept of ‘energy autonomy’. Second, it aims to provide an overview of existing literature addressing energy autonomy, identifying relevant publications and publication outlets, as well as main research themes and activities. The results, based on a systematic review of 71 peer-reviewed academic articles, show that energy autonomy research has increased in the last twenty years. The results also show how existing literature has understood, and used, the concept of energy autonomy in varying ways. Furthermore, the paper reveals how motivations, technologies, and scales differ in energy autonomy projects. While the aim of reaching energy autonomy is often motivated by economic and/or social reasons, these aspects are nevertheless rarely discussed in academic literature as the predominant focus tends to be on technological issues and self-sufficiency. The paper concludes with energy policy implications and avenues for future research

Feasibility of investment in Blue Growth multiple-use of space and multi-use platform projects; results of a novel assessment approach and case studies

Highlights• A comprehensive history of multiple use of space blue growth.• New metrics for comparing salmon to megawatts are presented.• Method and criteria for ranking potential investments in blue growth business models.• Profitable case studies described involving electricity, water, mussels and fish.Blue Growth is the creation of economic activity and jobs at sea, while multiple use of space makes efficient use of the available sea area by combining industries. Clearly there are many combinations and many value propositions. However, most technologies to date are considered blue sky concepts, with little robust techno-economic analysis demonstrating profitability.AbstractThe paper begins by providing a comprehensive review of Blue Growth and multi-use in Blue Growth; both in policy as well as the wide range of current technologies, including ocean energy, offshore wind energy, offshore aquaculture and desalination.The Maribe H2020 project provides the vehicle for the research element of the paper. The major contribution is a new methodology for selecting, filtering, developing and ranking business propositions for multiple-use of space (MUS) and multi-use platforms (MUP). Application of the method for the first time identified three case studies where Blue Growth combination projects can be economically viable, with attractive internal rate of return (IRRs). Results presented for the case studies report standard investment metrics and show the relative contribution of each product (energy, food, water) to the system profitability, as well as socio-economic impact. Existing companies were fully engaged in the process. Co-creation between sector experts and industry led to both improved business value propositions and robust assessment of investment readiness. In contrast to the presumption that large scale platforms are commercially attractive, the highest ranking case study companies required smaller capital expenditure (CAPEX) and operated in niche subsectors.In conclusion, the positive economic performance of the case studies should provide confidence for the EC as well as investors that MUS and MUP have viable economic futures leading towards commercialisation. The macro and micro assessment methods will be particularly useful in other Blue Economy contexts and in other multiple product contexts

Integration of the environmental management aspect in the optimization of the design and planning of energy systems

The increasing concerns regarding the environmental pollution derived from anthropogenic activities, such as the use of fossil fuels for power generation, has driven many interested parties to seek different alternatives, e.g. use of renewable energy sources, use of “cleaner” fuels and use of more effective technologies, in order to minimize and control the quantity of emissions that are produced during the life cycle of conventional energy sources. In addition to these alternatives, the use of an integrated procedure in which the environmental aspect will be taken into account during the design and planning of energy systems could provide a basis on which emissions reduction will be dealt with a life cycle approach. The work presented in this paper focuses on the examination of the possibilities of integrating the environmental aspects in the preliminary phase of the conventional design and planning of energy systems in conjunction with other parameters, such as financial cost, availability, capacity, location, etc. The integration of the environmental parameter to the design is carried out within a context where Eco-design concepts are applied. Due to the multi-parameter nature of the design procedure, the tools that are used are Life Cycle Analysis and Multi-criteria Analysis. The proposed optimization model examines and identifies optimum available options of the use of different energy sources and technologies for the production of electricity and/or heat by minimizing both the financial cost and the environmental impacts, with regard to a multiple objective optimization subject to a set of specific constraints. Implementation of the proposed model in the form of a case study for the island of Rhodes in Greece revealed that an optimized solution both cost and environmental-wise, would be an almost balanced participation of renewables and non-renewable energy sources in the energy mix

Computational Simulation and Dimensioning of Solar-Combi Systems for Large-Size Sports Facilities: A Case Study for the Pancretan Stadium, Crete, Greece

The article examines the introduction of solar-combi systems in large-size sports facilities. The examined solar-combi systems consist of solar collectors, a biomass heater and thermal storage tanks. In a sense, they constitute hybrid thermal power plants. The full mathematical background is presented on the operation of such systems, along with a proposed operation algorithm, aiming at the maximization of the captured solar radiation. A case study is implemented for the coverage of the thermal energy needs for hot water production and swimming pools heating, met in the Pancretan Stadium, Crete, Greece. In this way, the article aims to indicate the technical and economic prerequisites that can guarantee the feasibility of the examined systems, highlighting the significant potential contribution of such systems towards the realization of energy transition plans from fossil fuels to renewables. The economic feasibility of the introduced system is based on the avoiding diesel oil and electricity procurement cost, consumed for the coverage of the thermal energy demands under consideration. The optimum dimensioning of the examined case study results to an annual thermal energy demand coverage balance of 55% by the solar collectors and 45% by the biomass heater, giving a payback period of 5–6 years