Activities

The main activities of the project are:

  • Implementation of an electric microgrid powered by a hybrid renewable energy system capable of harnessing indigenous resources (biomass, wind and sun) and meeting the energy demand of the population.
  • Awareness and training of the people who will be linked to the project in the operation, maintenance and use of the hybrid plant.
  • Ensuring the replicability and sustainability of the system in its social, economic, environmental and geographical aspects.

Electric Microgrid

ELECTRIC MICROGRID
 
In the HIBRI2 project, the Guasasa case study was based on an existing installation, powered by a generator set; the necessary hybrid power generation systems has been designed. The design procedure described here deals only with some technical considerations of the design related to the consideration of wind technology; the development and management of a hybrid power system is a relatively long and complicated process, and involves other key aspects like for example social, environmental, management, contractual, quality assurance, training and some other aspects. These aspects obviously have to be taken into account through the project development, but are not described in this section. The design methodology includes basically the following stages: Data collection, Sizing study and Implementation project. These three stages will be briefly described.
 
I. DATA COLLECTION
 
The different aspects that influence the functioning of the system are listed below and are characterized in the following chapters. These are: characterization of the site (loads, topographical information, available resources, i.e., biomass, solar and wind); the components (biomass gasifier, generator set, PV generator, wind turbine, batteries and electronic converter); and the economic parameters
 
A. Load characterization
 
The population of Guasasa is made up of a total of 214 people, distributed among 85 dwellings, a health care, a pharmacy, a school, and some other collective use dependencies. As for its economy, the main activity of the population is based on fishing, which constitutes around 60% of the total economy. Apart from fishing, other activities carried out by the population are forestry and community work, accounting for 25% and 15% of the total economy, respectively.
 
In this context, it is proposed to increase the hours of supply (currently 12 hours) to reach a situation of 24 hours a day consumption. Even though some measuring campaigns of the existing situation (12 hours supplied from the genset) were undertaken, the design load profile (24 hours supplied from the microgrid) was estimated, as shown in the Figure.
 
Proposed Load Profile for Guasasa
 
Figure 1.  Proposed Load Profile for Guasasa
 
B. Characterization of the renewable resources
 
Only solar, wind and biomass resources have been considered and their characterisation is described below.
 
1) Solar Resource
 
In this case, various databases are studied, such as Meteonorm, NASA's meteorology and solar energy database, or the Global Solar Atlas, based on SolarGIS.
 
2) Wind Resource
 
Two databases consulted are presented here. The first is NASA's Solar Energy and Meteorology Database; the second is Global Wind Atlas. 
 
Global Wind Atlas is a database that can provide both wind roses, velocities, energy density, etc. (at heights of 50, 100 and 200 meters), as well as GIS layers to work with them in ArcGIS. However, they do not provide hourly mean values, so data from the NASA database are used for this purpose. 
 
3) Biomass Resource 
 
The characterisation of biomass as a renewable resource is based on the following parameters:
 
  • Available Biomass (tons/day): It is assumed that the biomass is fed to the gasifier to produce syngas, and the generators will consume this syngas to produce electricity. The existing biomass in Guasasa is mainly composed of yarúa, soplillo and ocuje. It is considered that the availability of this biomass is several times higher than what is required by the plant. Therefore, the biomass necessary to provide the electricity consumption calculated in the corresponding section has been estimated, using the following expression:
Biomass (kg/h) = Gas Consumption (kg/h) / Gasification Ratio (kg/kg)
 
The gas consumption is established from the electrical power delivered by the genset and the fuel consumption curve of the genset, while the value of 1.89 kg/kg has been taken for the gasification ratio; both of which will be analysed in later sections.
 
  • Average Price ($/t): 120 CUP/ton = 5 USD/ton; applied change: 1USD = 24 CUP 
  • Carbon Content (%): based on the analysis of samples carried out in the CIEMAT-CEDER laboratories in Soria, the value used for the Carbon Content is 48%, and it will be considered the same in both cases.
C. Characterization of components
 
The following is a brief description of some of the main characteristics of the components considered, starting with the gasifier, which is probably the most peculiar of the components of the configurations analysed.
 
1) Gasifier
 
The main parameters that will characterise the gasifier are:
 
  • Gasification ratio (kg/kg): understood as the ratio between the syngas generated and the biomass consumed in the gasifier. The value obtained is 1.87 kg/kg. The plant technology is from the Indian company Ankur. This type of gasifier accepts various types of firewood, wood chips, chopped bamboo, etc., as long as they have a moisture content of less than 20%.
  • Lower Calorific Value of syngas (LCV), in (MJ/kg): According to the manufacturer's data the LCV of the gas is approximately 1050 kcal/Nm3 (1468,89 kcal/kg) or 6.15 MJ/kg.
2) Generator Set
 
In Guasasa, in addition to the genset associated with the gasifier, the existing genset prior to the project (80 kWe, DENYO brand, model DCA-100ESI) was considered. 
 
3) Solar PV Generator
 
The PV generator will be installed on a fixed structure on the ground, and will be connected on the AC side through an inverter, or on the DC side through a charge regulator.
For the design, a module belonging to Canadian Solar has been selected, model "SuperPower CS6K-295MS". As for the size of the solar part, it is set at 40kWp. A cost of 1,750 $/kWp is considered. 
 
4) Wind Generator
 
In this case, the wind turbine to be included is from the manufacturer Bornay, a participant in the project, and the model is the 3000W, so its characteristics will be used (power curve; useful life of 20 years, hub height of 17m, cost of 3500 $/kW). 
 
5) Battery Storage
 
Electrochemical storage based on Lead-Acid batteries has been proposed for the storage system. Initially, the "BAE Secura PVS BLOCK Solar Battery" model has been selected, with a nominal capacity of 2.17 kWh/element and a cost of about 200 $/kWh. 
 
6) Power Converter 
 
It is necessary to incorporate a bidirectional electronic converter into the system that allows the change from direct current to alternating current and vice versa. A cost of 300 $/kW is considered. 
 
D. Economic Parameters
 
As for the inflation rate, the value taken is 2.8%; for the discount rate, a value of 8.9% stands out, a figure that has been estimated to increase in the period 2016-2033, so that for the cases studied an assumption of 10% has been selected as the value for this parameter; on the other hand, the project life time is estimated at 15 years.
 
II. SIZING STUDY
 
The output of this stage in the design is a detailed behaviour of the selected configuration in terms of stability and performance. The software used in both initiatives was HOMER, an international reference for the design of hybrid and microgrid systems, with the HOMER Pro version being used in the HIBRI2 project.
 
The sizing study has been: establishing the Base Case as a reference, which is the existing system (a 80 kWe genset in Guasasa), and then design the optimal configuration according to the particular conditions in each site. 
 
Results show that the inclusion of renewable generation in the microgrid is always favourable, both from an environmental and an economical point of view. The following table shows, for example, the results for Guasasa’s sizing study, in terms of configuration.
 
TABLE I.  CONFIGURATIONS FOR THE BASE AND PROPOSED CASES, IN GUASASA
 
Base case Proposed design
Genset (80kW) Genset (80kW)
  Gasifier (10kW)
  PV Generator (40kW)
  Wind Turbine (3kW)
  Battery(50kWh)

 

Both from an environmental point of view (fuel consumption, genset share, renewable fraction) and from an economic point of view (LCOE), the Proposed system results much more favourable; the only known obstacle for this installation is the high initial investment, which may be softened with projects like this one in order to encourage the market of microgrids through the appropriate financing mechanisms.
 
III. IMPLEMENTATION PROJECT
 
The HIBRI2 Project does contemplate the implementation phase but, due to the different conditions experienced during the Project, even though a part of the implementation stage had already been started in Guasasa, the implementation project that will finally be carried out is that of a microgrid for training and research in the CUBAENERGÍA facilities. So, this will be discussed briefly in this section.
 
Single Line Diagram of the microgrid to be implemented in CUBAENERGÍA’s facilities
 
Figure 2.  Single Line Diagram of the microgrid to be implemented in CUBAENERGÍA’s facilities
 
In Figure 2, a single line diagram for the layout of the final microgrid is shown. It can be seen that it is composed of a 20kWp solar PV generator, 10 kWp of which are connected to the AC bus through two solar inverters, and the other 10 kWp are connected to the DC bus through the respective two charge regulators; there is one 5 kW wind turbine, a 10 kW gasifier, 50kWh Li-Ion battery (the evolution of this technology through these years has made it possible to enter in the final configuration); there are three bidirectional converters 10 kW each, one for the gasifier and two for the microgrid; the role of the genset is performed by the grid, which is a particular bi-phase one; and includes also all the necessary equipment for the implementation of the microgrid. 
 
IV. THE FUTURE
 
The HIBRI2 project is currently in the stage of acquisition of the materials for the microgrid. The microgrid includes the main technical characteristics of the case studies analysed, such as incorporating wind generation, solar PV, biomass gasification, and storage in the form of batteries with control by electronic converters, all for the scale of tens of kWs, considered to be the most replicable in Cuba. It is hoped that this installation will overcome the obstacles for microgrids acceptance in Cuba by providing experience, familiarity and knowledge of these systems, and may also serve to train the technicians in charge of designing, installing and operating these installations in the future. 
 
The collaboration in the field of microgrids in Cuba continues, with new initiatives that include other stakeholders that might come up with new options for the implementation of these technical solutions in the island and allowing to analyses issues such as replicability and sustainability.  

Capacity Building

Training is a fundamental component in HIBRI2. One of the main objectives of this project is the technological appropriation of fully renewable and sustainable energy generation processes, the production of electrical energy from solar photovoltaic and wind energy, and electrical and thermal cogeneration through the gasification of biomes, by of the final beneficiary population and of the agents involved in the action, to ensure sustainability over time and the replicability of the experience to other populations.

The scientific-technical training of the local agents involved in the project and specialists and professionals from the energy sector of the Island of Cuba has been carried out through a cycle of scientific-technical workshops: "Fundamentals of Micro-Electrical Networks as Renewable Energy Sources for Isolated Communities”, addressing the different topics covered by the project: hybrid generation plants with renewable energies (photovoltaic, wind, biomass), gasification, design and operation of electrical microgrids, sustainability of energy systems, efficiency and saving of energy, geographic information systems and rural electrification of isolated communities, delivered by experts from CIEMAT and CUBAENERGIA, and specialists and teachers from other organizations, including the BORNAY Company and the University of Las Tunas.

These activities are also intended to be a space for the exchange of experiences and debate. In addition, they seek to know the reality of the current state of the projects that are being developed in this line at the local and regional level, and promote the exchange of experiences between decision-makers and those responsible for energy planning and the promotion of renewable energies, as well as to consolidate existing relationships between the different groups interested in the subject.

These actions also intended to give continuity to the training carried out during the previous phase of the project, Hybridus, strengthening the professional technical work force at local, sectoral and national levels, with the incorporation of innovative solutions for power generation through hybrid systems and with renewable sources. This preparation of specialists aims to contribute to promoting electrification and energy supply projects in isolated communities in Cuba.

First workshop “Technological status of renewable sources. Hybridization of systems for rural electrification. Biomass and wind energy”.

The first workshop was held between February 25 and 28, 2020 in Playa Girón, Cuba, and was attended by experts from CIEMAT, CUBAENERGÍA and the company BORNAY, as well as professionals and technicians from the electricity and Cuban electrification.
This workshop on the “Technological status of renewable sources. Hybridization of systems for rural electrification. Biomass and wind energy”, aimed to place students in the technological state and national and international context of renewable energies, their real potential for available sources and technologies and electrification through the hybridization of systems. Also, the design of hybrid systems based on renewable sources for micro-grids was addressed.

The program had a practical part focused on the design and simulation necessary to determine the technical-economic feasibility of a hybrid project or a Microgrid. This was carried out by using the trial version of the software HOMER, Legacy, Hybrid Optimization of Multiple Energy Resources, which allows the design of renewable energy projects, oriented to hybrid systems. The program facilitates the simulation of systems with multiple generation and storage technologies in a simple way. In addition, a technical visit was made to the community of Guasasa, a location where the electrical microgrid powered by a hybrid system capable of taking advantage of indigenous resources and satisfying the energy demand of the population is to be installed.

Second and third workshop

A second workshop on the on the “Design and implementation of hybrid systems. Solar resource measurement and photovoltaic technology. Geographic Information Systems”, would address the availability and measurement of the solar resource, as well as the current state of photovoltaic solar energy and the design of photovoltaic plants for rural electrification. Mini-hydraulic energy and its potential for energy cogeneration through hybrid systems would be introduced. Geographic Information Systems would be incorporated for energy planning and the integration of renewable energies, with special emphasis on projects linked to the analysis of the regional potential of renewable resources and rural electrification with these sources.

The third workshop on “Sustainability and replicability of hybrid systems for rural electrification. Electrical and thermal cogeneration from biomass gasification”, would address the tools that contribute to the evaluation of the technical-economic feasibility and sustainability of the designed energy systems. Key aspects would be incorporated for the evaluation of the social and environmental impact and the reduction of gender gaps, associated with the expansion of the electricity service. The biomass gasification process for electrical and thermal cogeneration through hybrid systems would be studied. And energy efficiency would be introduced in the rural electrification of isolated communities.

As a consequence of the COVID-19 Pandemic, both workshops, scheduled between 2020 and 2021, had to be postponed until the COVID-19 conditions allowed their implementation. Its realization has finally not been possible because the appropriate conditions have not been reached within the execution time of the project.

Participants in the 1st Workshop, “Technological status of renewable sources. Hybridization of systems for rural electrification. The energy of biomass and wind”, held in Playa Girón between February 25 and 28, 2020

Participants in the 1st Workshop, “Technological status of renewable sources. Hybridization of systems for rural electrification. The energy of biomass and wind”, held in Playa Girón between February 25 and 28, 2020

Internal training action among project experts:

In the month of December 2021, a training was carried out by the Bornay Company to train experts participating in the Project, on the installation of the selected equipment.

The training covered:

  • Wind turbines: installation, wiring and functionalities.
  • Victron Energy converters: products, wiring, functionalities and configuration.
  • Pylontech batteries: connection and configuration.

This training was carried out via videoconference and was attended by five experts, three as speakers and two as students.

Screenshot of the virtual training session given by the company Bornay. December 1, 2021


Screenshot of the virtual training session given by the company Bornay. December 1, 2021

 

 

 

Sustainability

Replicability and sustainability. System's socioeconomic, environmental and geographical aspects

Expected results

Sustainability and replicability of the system

It consists, on the one hand, in carrying out a sustainability analysis on three fronts: environmental evaluation, socio-economic analysis (based on the costs of investment and operation and maintenance of the project and the Input-Output table of Cuba) and socio-impact assessment -institutional and, on the other, of a replicability study, based on geographic information systems, that takes into account the conditions of other similar sites detected (availability and characteristics of residual biomass, availability of the solar resource and population conditions).

 

Activities

Environmental Sustainability Analysis

The evaluation of environmental sustainability will be carried out through the Life Cycle Analysis (LCA) methodology. LCA is a methodology that evaluates the environmental impacts of a product or service during all stages of its life cycle from the extraction of all resources, through the stages of production, distribution and use and end of life (reuse, recycling, recovery and disposal). Based on technical data and emissions from the different activities that take place in the project life cycle and using databases, the environmental impact will be quantified. Finally, the stages and processes responsible for the greatest environmental burdens will be identified and reduction strategies will be evaluated.

 

Esquema general de las etapas del ciclo de vida de un producto

Life cycle Analysis steps

 

Social and institutional impact Analysis.

 A diagnosis of the institutional structure of the project and the impact of its development on the different relevant actors will be made. The proposed task aims to analyze the institutional structure of the project throughout the different phases that make up its life cycle. For this, the different actors involved in each phase will be identified as well as the relationship between them as a result of the implementation of the project. This analysis allows an institutional diagnosis as well as the identification of weaknesses and measures that could strengthen the institutional structure of the project studied.

 

Esquema general de las etapas del ciclo de vida socio-institucional del proyecto

Stages of the socio-institutional life cycle of the project

 

Socioeconomic impact Analysis for the Cuban economy

Based on a large-scale technology development scenario, which takes into account the country's resource and energy needs, the impact of such development in terms of job creation and economic stimulation will be analyzed. The input-output analysis is a tool based on the classic model developed by Leontief, which allows knowing in depth an economy by analyzing the interdependence between sectors through the description of the economic flows or transactions that take place in the production process.

 

Flujos o transacciones económicas en un proceso productivo

Economic flows or transactions in a productive process

 

Based on data on investment and operation and maintenance costs throughout the different stages of the project life cycle and the Cuban Input-Output table, the impact on employment and the economy in Cuba would be estimated.

Taking into account a future scenario of large-scale penetration, the results will allow estimating the direct, indirect and induced impact on the generation of employment and increase in the production of goods and services in the different economic sectors of the Cuban economy.

 

Spatial and technological replicability

The development of this activity is carried out with geographic information systems, and takes into account the conditions of other similar sites (according with the results of HYBRIDUS project – Phase I). The study will be extended to other areas and will have the collaboration of the University of Las Tunas for its development. It will also take into consideration the technological characteristics of the micro network as determinants of its replicability.

 

Replicabilidad espacial y tecnológica

Spatial and technological replicability