Social and Techno-economic Impact of Rural Electrification in Isolated Places with Photovoltaic Systems: Evidence Gulf of Guayaquil

. The lack of electrification in isolated places is considered the main impediment to the economic development of the inhabitants, the use of new technologies such as solar photovoltaic is considered a viable solution to the problems of electrification however technical, economic and social factors limit the use of form, the work reviews the drivers of rural electrification with new types of renewable energy technologies in Latin America. especially in the Gulf of Guayaquil in Ecuador. For part of the research is taken as a case study an island that is populated by 17 homes where the economic technical study is carried out for the photovoltaic system of 405 Wp, the cost of the implementation is 1663.05 dollars, the cost of energy is 0.258 USD / kWh being a limitation for overcrowding in low-income homes even when they have no possibility of accessing a financial credits the inhabitants of communes. The electrified houses have a saving of USD$25 per month for fuel required for the operation of the generator used for 3 hours a day plus the purchase of candles for lighting at night and early morning. The survey conducted in the community reveals that the best benefit for the inhabitants is that children can receive virtual classes post-pandemic with the energy of the system can feed the antenna of the internet provider.


lntroduction
In 2015, during the United Nations assembly meeting, world leaders agreed a series of agreements to achieve a more just and equitable society, this new agenda was called Sustainable Development Goals (SDGs) that include 17 points with specific goals for 2030 [1] SDG number 7 It refers to guaranteeing access to safe, sustainable and modern energy available to everyone.Despite the encouraging numbers of rural electrification in poor countries there are still places without electrification for this reason the access and sustainability of projects to generate electricity from clean and renewable sources is required [2], [3].
One of the success stories is Ecuador where by 2020 99% of the population has electricity in their homes due to of the start-up of several hydroelectric generation plants, new distribution lines and electrification programs such as the Rural and Marginal Urban Electrification Fund (FERUM) that seeks to improve the living conditions of the inhabitants of popular sectors among others.However, the lack of electrification coverage in its entirety causes inequalities in society and abandonment of homes in search of better days in large cities, so in recent years the implementation of small domestic photovoltaic systems has grown significantly taking advantage of the sun's energy being a valid alternative to cover basic energy needs by displacing the use of generators that use fossil fuels.The use of non-renewable resources such as oil is not sustainable over time due to high costs, scarcity of the primary source, environmental pollution among others [4] The implementation of domestic photovoltaic systems seeks to provide electricity to families living in geographically isolated remote areas as is the main case of the islands, with this type of projects it is provided to improve the quality of life, safety, health and access to new information technologies, but many of the projects do not have the follow-up to work during the life of the system because they do not have a management plan Awareness among the population of the short-term needs of having this type of renewable system.Reference [5] discusses its advantages in replace the use of traditional fuels such as wood and diesel to avoid environmental pollution by reducing CO2 emissions improving the quality of life of residents, in addition to the growing use of photovoltaic systems in Latin American countries where there are very positive changes have been made by the residents to improve the quality of life of the residents, especially the physical health of the people.Data collected in 216 homes electrified with renewable sources in 9 communities show the reduction of CO2, firewood consumption by year is 2,123.39t and fossil fuel such as kerosene with 40.80 t / year.These data are encouraging, but in several LAC countries there are no laws and regulations on the use and integration of photovoltaic energy and the disposal of components at the end of life.Pulak et al. [6] indicate that the availability of electricity in remote areas provides progress and fosters economic activities through various livelihood pathways, in the work analyzes the experiences of two peoples in the state of Odisha in India for the adaptation of inhabitants to photovoltaic energy, it mixes a set of economic, demographic and social factors, also includes the approach of governments towards electrification in rural areas.The implementation of this type of system has improved the standard of living of households and especially of women that living in the place, noise in the community has decreased by not using internal combustion equipment along with the consumption of fossil fuels.But with the passage of time there is damage to the equipment with the lack of availability of the systems due to lack of maintenance and repair.

Success stories of rural electrification with solar PVs in Latin America
The light at the end of the tunnel for several inhabitants of remote places in electrification is the implementation of photovoltaic systems, some of the projects developed in Latin America are mentioned below: In Colombia, the Ministry of Government implements 5 projects to electrify with solar panels 174 families in seven villages in the municipality of San Onofre.The project, which had an investment of $3.541 billion pesos, was financed with resources from the Allocation for Peace of the General System of Royalties.Precisely, through OCAD PAZ, this sector and the Ministry of Energy have been able to finance, since 2018 and until today, 70 electric energy projects to benefit about 27 thousand families (specifically, 26,870) with investments close to 516 billion pesos.In addition, 363 families in Sucre have benefited from the installation of solar panels in their homes.
While in the Dominican Republic the National Energy Commission (CNE) has donated isolated photovoltaic energy systems in the schools of La Laguna and Rosa La Piedra, in the province of Elías Piña, on the border with Haiti as shown in figure 1.
The project, which benefits a total of 270 students (164 from La Laguna school and 106 from Rosa La Piedra school) in the first school, 12 photovoltaic modules, of 445 Wp each, were implanted on the roofs for a total of 5.3 kWp, an inverter with a capacity of 3 kW; and a storage system with a battery bank, consisting of 16 batteries at 12 V, Gel, maintenancefree of 800 Ah.On the other hand, in the Rosa la Piedra school, they were installed with 8 photovoltaic modules with a capacity of 445 Wp, with an installed power of 3.5 kWp, an inverter with a capacity of 3 kW and storage system consisting of 12 batteries at 12 V, GEL, maintenance-free of 600 Ah.The investment in these two projects was almost 33 thousand dollars [7]. According to data from the World Bank in Mexico there are around 3.5 million people who still did not have access, 60% of whom belong to indigenous communities.The Government recognizes that, because of population growth in the next 10 years, the number of people who do not have access to conventional electricity would increase.by 20%, making it a matter of state priority, so the PSIE is created to support the rural electrification strategies and measures established by the Ministry of Energy (SENER) with the support of the experience of the World Bank.The short-term results are encouraging with a total of 2235 homes in 40 rural communities electrified with the installation of 2357 kilowatts of photovoltaic capacity, reducing the emission of 139 000 tons of carbon dioxide equivalent (CO2e) per year by displacing polluting energy sources.Another important point is social and educational improvement such as access to basic and health education infrastructure in several remote locations (Banco Mundial, n.d.).
Some Latin American governments have called for companies to tender the implementation of solar systems, Chile launches the solar house program through the Chilean Ministry of Energy and the Energy Sustainability Agency (AgenciaSE) where it calls for the application for the aggregate purchase and implementation of residential photovoltaic systems connected to the grid for a total of 654 projects in twenty communes of the country distributed in the communes of Arica, Linares, la Unión, Puerto Montt, among other towns throughout the Chilean region.
While Peru puts out to tender 21 rural electrification projects, with photovoltaic mini-grids representing an investment of 355 million soles (87.8 million dollars) and will benefit more than 91 thousand people from 977 localities in the country.The projects are part of the National Rural Electrification Plan that aims to serve low-income villages in the regions of Ancash, Cusco, La Libertad, Huánuco, Piura, Cajamarca, Junin and Ucayali, it is expected to contribute to achieving the goal of reaching a rural electricity is around of 96% in 2023 and that to year 2026 the universal access to electricity in rural areas of the country will be realized, which is one of the better Sustainable Development Goals (SDGs) assumed by Peru.
3 Photovoltaic solution for electrification.

Community mass 2
The implementation project was carried out in the Gulf of Guayaquil in the community of Masa 2, which is 40 minutes from the Caraguay pier by river transport at coordinates -2.36, -79.85.The place is made up of 17 houses with the same number of families, the houses are mostly built of wood and on pillars because they are next to the Guayas River and when the tide rises or in the rainy season they suffer from flooding as shown in figure 2.
The inhabitants lack basic services such as electricity and piped and potable water, 4 of the 17 houses have fuel generators that work from 6:00 p.m. until 9:00 p.m., the other houses provide energy at a cost of one dollar a day, the place being away from the city has complications in the acquisition of fuel.Through visits to the sector and the gathering of information carried out on the houses in the Masa 2 commune, the following consumption data and devices used by families were obtained.The community had serious telephone communication problems, it only received a signal at a certain point, this is increased by not having an internet signal and not being able to use communication applications such as whatsapp, messenger, telegram, etc.The community receives about 12 hours of sunshine per day, so the energy potential from the sun is high at the place of implementation with a monthly average of 135.71 kWh/m2/ month, in figure 3 the meteorological data in the locality is shown, the wind speed has an average of 2 m/s for this reason it is not viable to install wind turbines as it needs a speed of 12m/s to reach rated power.In the coming years, technology is expected to improve, especially vertical type wind turbines to generate energy in locations with little potential.

Photovoltaic generator
The model of the solar panel to be used is monocrystalline type JKM405M-72H, it is commercially available, the technical characteristics are the following: maximum power of 405 W in tested in standard conditions; efficiency is 20.13 per cent; the open circuit voltage (Voc) is 4 9.4 V, the maximum voltage is 40.42V; the short-circuit current (Isc) is 10.69 A, while the maximum current reaches 10.02 A; Panel size is (mm) are 2008×1002×30mm; the cost of capital is US$ 187.64/405Wp; the replacement cost is the same; A cost of $ 10 is proposed for operation and maintenance is low because it has no moving parts, the manufacturer determines a useful life is around 25 years.
The estimation of the hourly energy production of  the solar panel can be calculated by equation 1, in kWh [9]   () = (  ×   () ×   () × )/1000 (1) Where,   ,   ,   are the number, voltage and current of the photovoltaic solar panel.

Charge controller
The energy generated by the solar panel has to be treated to store in batteries or used directly in the charge, the device commissioned or deliver the modify the voltage values and control the status of the battery is the charge controller, currently there are components with novel technology that intelligently manages the generation of the solar panel to reach the maximum charge in the battery in a shorter time.The equipment to be used is from the manufacturer Victron type MPPT 75/15, a photovoltaic power of up to 440 W can be connected in 24VDC.

Battery banks
Being an isolated system, the battery bankis the device that stores the backup energy for certain hours of the day or when the charge requires it.It has two charging and discharging processes, the first occurs when the generation generated by the solar panel is greater than the demand for electrical energy per hour needed by the user, the state of the charge can be calculated by equation, 2 while for the discharge state equation 3 is used [10].
In the equation is considered for a given time the state of the charge of the equipment, the energy of the battery (kWh), the performance of the equipment, at the time of charging and discharging the power of the battery.In the case of lithium batteries, the state of charge is different, however the implementation in isolated places is complicated by the initial cost of the element despite achieving a lower cost of energy and a longer operating lifetime.
The elements that are distributed locally with the manufacturer Ritar power with a capacity of 100 Ah at 12 V, the battery type is maintenance-free AGM.Due to the characteristics of this type of battery, it is defined as a rechargeable accumulator, it is sealed and belongs to the lead acid family, due to its manufacture it does not require maintenance or ventilation.

Inverse without network connection.
Most of the appliances that the house owns work in alternating current, for this reason it is necessary to convert the direct current of the battery bank into alternating current, the component in charge is the inverter without connection to the network for this purpose is used from the manufacturer Victron energy 24/250, 120V, the peak power is 400W with an efficiency of 88%.
To calculate the power generated by the photovoltaic panel, it is done using equation 4, where the power of the battery intervenes in reverse plus the power of the solar panel to the inverter and the performance of the equipment.

Cost of components used in the system.
The modeling and technical characteristics of every components used in the installation have been explained in the document, table 2 indicates the acquisition values in US dollars, the sizing of the system for the home was carried out in the PvSyst software that is a specialist to indicate the elements to be used, the system is composed of a 405 W monocrystalline photovoltaic panel, two 12 V 100 Ah batteries that are connected in series to achieve a 24 V system, a 75 V and 15 A MPPT charge controller , a 250 VA at 24V inverter, additional all the consumables for the internal installation of the home.

Economic technical sizing
At present there are several software for the dimensioning and optimization of hybrid renewable energy systems, among the main ones is HOMER [8], [11]9], [12]each one offers advantages with respect to its competitors, because it will take advantage of a single source of generation, the dimensioning and economic study is done in PVsyst [13] [14] To meet the energy needs of the house the renewable energy system consists of a solar panel of 405 W, a charge controller of 15A, 75V to 24VDC, 2 batteries of 12 V, 100Ah and an isolated inverter of 24VDC / 120VAC of 250VA, the operating scheme is shown in figure 4, where the only component that is generator and storage is the battery bank made up of two units.The photovoltaic panel will generate 535 kWh / year of which 296 kWh / year will be used, to take advantage of the excess energy the use of the load must be analyzed, the cost of the installation is 1663.05dollars, the maintenance cost is 10 dollars annual because the system has no moving parts.The levelized cost of energy is 0.258 USD / kWh, in the next 25 years it is not possible to recover the investment, however, the purpose of the project is not the economic but the social part for the development of the community.
The main energy results of the system are a production of 1320 kWh/kWp/yr, the performance ratio is 0.467, the normalized production reaches 2 kWh/kWp/day, the panel losses are 2.06 kWh/kWp/day while the system losses are 0.21 kWh/kWp/day.Figure 5 shows the losses of the system, the largest percentage is due to the energy stored in the battery and that is not used reaching 40.4%.

Contribution to local development
In the literature it refers that electrification is the fundamental pillar for the development of isolated communities with the generation of income to be able to work in hours where artificial light is needed, to know and understand the scope of the benefits of the implementation of system solar photovoltaic energy for homes the Lowing Coe method is used.
All users of the mass 2 community are requested to describe in order of priority the benefits they have obtained with the implementation of the photovoltaic system on a scale of 1 to 5, where 1 is the most important, the information has been obtained based on surveys after 6 months of implementation and operation of the photovoltaic solar system.The benefits established in the survey were based on a meeting with the community board and then socialized with 68 people from 17 families who were benefited, the calculated weighted average score is shown in Figure 6.According to the average score ranking presented, the best benefit is access to virtual classes post pandemic, once the photovoltaic systems have been implemented, 3 of the 17 families contracted the internet service and share the signal to the neighbors, the equipment is powered 24 hours a day, with them students can receive virtual classes and be able to investigate on the web to complete academic training.
The second benefit in importance for the inhabitants of the isolated community is access to entertainment, in the design of the load the operation of the television is 5 hours with which they can watch the news in the three editions, football matches, novels etc, while those who have access to the internet can be connected to social networks and communicate without worrying about cell phone discharge due to battery backup. of the system, in this locality they do not have mobile phone coverage.
The third benefit in order of priority is fuel savings and payment for energy.In the community two gasoline generators were turned on from 6:30 p.m. to 9:30 p.m., each family was charged a value of $ 25 per month for three hours a day of energy at night, with the implementation of the system each family does not make the payment of the aforementioned value equivalent to a non-negligible contribution to the household economy, noise pollution from the operation of the generator set is also avoided.The environmental issue stops polluting by not emitting greenhouse gases by consuming two gallons of gasoline a day.
The fourth benefit in order of priority for users is the lighting in the early morning hours to prepare to go out to work in fishing tasks at 5 am and travel the approximate path of 50 m from the houses to the canoes, in this journey they have found snakes that put the safety of fishermen at risk.The fifth benefit is the lighting at night, the dimensioning of the system considers the use of 5 LED spotlights of 9 W for 6 hours therefore during night hours students can reinforce academic activities.As the last benefit in order of priority for users is to charge the cell phone and radio, however, this point is interesting because visits to other communities the requirement most requested by the inhabitants is to be able to charge the cell phones to communicate.

Barriers to the implementation of the photovoltaic system
The main technical factors are the little knowledge and expertise of renewable energy system providers in Latin America, limiting the ability to implement photovoltaic systems; the slow growth of the market does not allow for a reduction in installation and component costs.On the economic side, several of us have high tariffs for the import of components without fiscal aid and credit from financial companies.Among the social political factors, it is mentioned that some countries have not yet approved energy efficiency policies and regulations, with a deficit in the labeling of high-efficiency appliances without mentioning construction standards.
While in the local part it has been shown that the use of photovoltaic systems for rural electrification is a valid option with a few advantages however there are a number of factors that limit the implementation on a medium scale, among the technical, economic, political and social factors [15] One of the cases that has prevented the implementation is Puerto Roma, in 2010 the National Electricity Council (Conelec), began the plan to install solar panels in several towns in the Gulf of Guayaquil, with an approximate cost of USD 1.5 million.In the year 2016 as part of linking to society the place was visited, of 150 photovoltaic systems worked only 2 to 10% of their capacity the reason for the lack of maintenance in the battery bank that required completing the electrolyte and cleaning of the terminals as it is a saline environment, figure 7 shows the status of the batteries.In this specific case, the photovoltaic storage battery broke down, the user, not having the purchasing power and knowledge, bought an automotive battery, it does not have connection terminals, it has a false contact.
The bad experience of the inhabitants is spread inhabitants of other islands that limit the implementation of new individual systems to this is added the use or replacement by poor quality or counterfeit equipment experienced failures in the photovoltaic solar system, damage to luminaires and other equipment mainly batteries [16].Another limitation is the economic barrier, users are people with limited economic resources and photovoltaic components are extremely expensive compared to other countries due to tariff issues, so users buy poor quality elements and have short-term problems, suppliers of regulated products encourage to apply for bank loans for the purchase of systems but only a small percentage of users are creditors to loans from the banking due to low purchasing power being another limitation for implementation.
The global price of solar panels has decreased significantly in recent years, but the battery remains the component with the highest cost and shorter lifespan.The cost for a 420 Wp system is approximately 1400 dollars.The after-sales, technical and training service is null according to the surveys carried out, when the systems were delivered the operation of this was explained, but they did not return to give the maintenance or explain the type of maintenance required to operate the planned lifetime.

Conclusions
The present work analyses the social and technical-economic impact of the implementation of photovoltaic systems in the Gulf of Guayaquil is taken as a case study the community of mass 2, the finding found is the decrease in the implementation of solar systems since 2010 in the Gulf Guayaquil due to premature damage of equipment by not having a management model for maintenance and repair.The other side of the coin are the communities that do not have constant electrification, use fuel generators for three hours during the night, through a survey the importance of access to electricity is listed, the most important is to receive virtual classes of college and school, followed by entertainment in television series, Access to satellite internet, the third important benefit is the saving of $ 25 per month in fuel.With electrification there is a before and after in the lives of the inhabitants.
The installed systems of 405 Wp have an implementation cost of 1663.05 dollars, the cost of energy is 0.258 USD / kWh, the initial cost is a barrier to new individual projects due to the poverty levels of the inhabitants of the sector this increases with the difficulty of accessing the national financial system.An important measure to maintain the proper functioning of the solar system is to have a management plan, form a directive that receives a monthly fee for the operation, maintenance, and technical training to a group of inhabitants.

Fig. 2 .
Fig. 2. Community of masa 2 on the banks of the Guayas River

Fig. 3 .
Fig. 3. Meteorological data at the place of implementation

Fig. 5 .
Fig. 5. Diagram of losses of the photovoltaic system

Table 1 .
Equipment they own in their homes.

Table 2 .
List of components used in the system.