Production System
A solar mini grid’s overall capacity to provide electricity to end users is determined by the production system. Energy generation technologies, inverters, a management system and storage (batteries).
Energy Generation Technologies
Diesel generators, hydro power systems, solar photovoltaic (PV) modules, wind turbines, biomass-powered generators and geothermal-powered generators are included in a solar mini grid energy generation technology. It’s a mix of sources (hybrid) of renewable or nonrenewable.
Inverters
An inverter can convert electrical current from DC to AC. Based on end user’s requirement, power inverters are used in the system. Some energy generation technologies produce direct current (DC) while others produce alternating current (AC). For example, a Solar PV module can generate only DC. Almost all mainstream appliances of households need AC. So, in order to provide required AC to those appliances of households, a solar-powered mini-grid serving needs inverters as part of its production system. On the other hand, battery charging needs DC power.
The energy generation and storage systems each have their own inverter in an AC-coupled configuration with storage (a battery). These separate inverters connect to one another on the AC side of the system. In order to control charging and discharging, battery inverter can be used. The energy generation and energy storage systems are shared in an inverter in a DC-coupled PV configuration. DC coupling can provide better performance; battery charging is more efficient when there are fewer power conversion steps.
Management System
Management systems are included in a solar mini-grid system. It can measure, monitor and control electrical loads. For example, we can say about a charge controller. To prevent the battery from charging and over charging, it is connected between the solar panel and the battery or inverter/charger. In the same way, metering and monitoring equipment allow mini-grid managers to gather data about energy use across end users, which informs operational decisions. In order to optimize performance, management systems often couple computerized energy management tools with smart metering. Some management systems allow operators to control the system remotely, including shedding loads as per requirement.
Storage
Energy storage (such as batteries) are required in some mini-grid production systems. For example, solar and wind resources are non-dispatchable. This means they only produce power when the renewable resource is available, not according to user demand. If end users require power on demand, the mini-grid must be able to store energy and supply it when resources are not available. Energy storage adds stability to the system by storing energy for peak consumption. Large mini-grid systems that run diesel generators continuously do not require batteries, but nearly all other mini-grid systems require some type of energy storage.
In order to optimize system performance, longevity and cost, project developers need to identify the most appropriate energy storage technology for their mini-grid. Lead-acid batteries are the most common, but fuel cells and advanced battery technologies like lithium-ion and sodium-ion batteries are generally more efficient and last longer. Costs for these new technologies continue to decrease. Large battery banks can cause safety hazards. High concentrations of hydrogen gas can cause explosions, and leaks can cause electrolyte spills. Batteries should locate in well-ventilated locations such as outbuildings or utility rooms.
Distribution System
Generated electric power is delivered from the energy production system to end users by the electricity distribution system. Distribution and/or transmission lines, transformers and the infrastructure to support the lines, such as poles are key components of a distribution system. Lines can be overhead or underground. Overhead transmission is most common as it is comparatively cheaper.
A variety of voltages are used in the distribution system. It can be either AC or DC and either single- or three-phase power. AC voltage levels in a mini-grid network covering a large area can be changed by transformers. To transmit electricity more efficiently over a distance, AC output voltage can be increased by step-up transformers. On the other hand, step-down transformers decrease the voltage from high- or medium-voltage transmission lines to 120 V or 220 V for residential use. Distribution network costs and system losses in AC mini-grids can be minimized by transformers. Distributing electricity at medium voltage allows systems to use smaller conductors, minimizing cable costs. Higher voltage causes greater safety risks for operators and users. Therefore, special trainings are required for operators.
There are various efficiencies in various components. Therefore, the determining of voltage, current and transformers impact energy losses. Cost usually dictates which option project developers choose. DC is generally less expensive than AC, because AC requires power conditioning equipment. The availability of appliances for different currents should also be considered by developers.
End user System
End-user systems provide an interface for end users to access, use and monitor electricity from the mini-grid is provided by the end user system. It takes into account consumers’ needs and energy uses. For example, we can say about businesses require operating machinery for productive uses need different systems than households that use electricity for lighting and small appliances. The end-user system consists of connections to and from the mini-grid, systems to prevent electrical shocks and harm to both equipment and users and power consumption metering.
Energy consumption can be monitored in the end user system. It can estimate the cost of their consumption and understand the current status of the system. It can provide report on consumption rate and timing, like when and how much energy is used. Therefore, system operators can easily estimate and predict demand and consumption patterns. The data also allows regulators to establish tariffs that balance the needs of the operator and the consumer, while ensuring differing use cases are priced fairly and competitively. In order to ensure the safety of its users and protect valuable and expensive equipment, the system provides important electrical bond and grounding mechanisms.
Innovative metering and payment systems automate these otherwise complex tasks like making metering, billing and collection time consuming. The greatest degree of control over energy use can be provided by individual meters (one per end user). Meters can be pre- or post-paid; pre-paid meters typically are known as pay-as-you-go (PAYG) metering. Smart Meters are typically considered as newer generation meters. Although traditional meters or old generation meters are still in use. Smart meters do more than transmit payment and consumption data.
Utilizing mobile phone technology, smart meters gather data on energy consumption and facilitate two-way communication between the energy provider and end user. For example, a smart meter installed on the side of a residence communicates wirelessly with the utility systems. Some metering systems can log and report power quality and reliability data in real time, which helps to address the power quality issues before they become problems. Smart meters can even allow the grid operator to shut down troublesome loads before they jeopardize the entire system and cause problems for other consumers. Therefore, grid operators can ensure a higher quality of service to all customers by providing smart meters having these features.
A solar mini grid’s overall capacity to provide electricity to end users is determined by the production system. Energy generation technologies, inverters, a management system and storage (batteries).
Energy Generation Technologies
Diesel generators, hydro power systems, solar photovoltaic (PV) modules, wind turbines, biomass-powered generators and geothermal-powered generators are included in a solar mini grid energy generation technology. It’s a mix of sources (hybrid) of renewable or nonrenewable.
Inverters
An inverter can convert electrical current from DC to AC. Based on end user’s requirement, power inverters are used in the system. Some energy generation technologies produce direct current (DC) while others produce alternating current (AC). For example, a Solar PV module can generate only DC. Almost all mainstream appliances of households need AC. So, in order to provide required AC to those appliances of households, a solar-powered mini-grid serving needs inverters as part of its production system. On the other hand, battery charging needs DC power.
The energy generation and storage systems each have their own inverter in an AC-coupled configuration with storage (a battery). These separate inverters connect to one another on the AC side of the system. In order to control charging and discharging, battery inverter can be used. The energy generation and energy storage systems are shared in an inverter in a DC-coupled PV configuration. DC coupling can provide better performance; battery charging is more efficient when there are fewer power conversion steps.
Management System
Management systems are included in a solar mini-grid system. It can measure, monitor and control electrical loads. For example, we can say about a charge controller. To prevent the battery from charging and over charging, it is connected between the solar panel and the battery or inverter/charger. In the same way, metering and monitoring equipment allow mini-grid managers to gather data about energy use across end users, which informs operational decisions. In order to optimize performance, management systems often couple computerized energy management tools with smart metering. Some management systems allow operators to control the system remotely, including shedding loads as per requirement.
Storage
Energy storage (such as batteries) are required in some mini-grid production systems. For example, solar and wind resources are non-dispatchable. This means they only produce power when the renewable resource is available, not according to user demand. If end users require power on demand, the mini-grid must be able to store energy and supply it when resources are not available. Energy storage adds stability to the system by storing energy for peak consumption. Large mini-grid systems that run diesel generators continuously do not require batteries, but nearly all other mini-grid systems require some type of energy storage.
In order to optimize system performance, longevity and cost, project developers need to identify the most appropriate energy storage technology for their mini-grid. Lead-acid batteries are the most common, but fuel cells and advanced battery technologies like lithium-ion and sodium-ion batteries are generally more efficient and last longer. Costs for these new technologies continue to decrease. Large battery banks can cause safety hazards. High concentrations of hydrogen gas can cause explosions, and leaks can cause electrolyte spills. Batteries should locate in well-ventilated locations such as outbuildings or utility rooms.
Distribution System
Generated electric power is delivered from the energy production system to end users by the electricity distribution system. Distribution and/or transmission lines, transformers and the infrastructure to support the lines, such as poles are key components of a distribution system. Lines can be overhead or underground. Overhead transmission is most common as it is comparatively cheaper.
A variety of voltages are used in the distribution system. It can be either AC or DC and either single- or three-phase power. AC voltage levels in a mini-grid network covering a large area can be changed by transformers. To transmit electricity more efficiently over a distance, AC output voltage can be increased by step-up transformers. On the other hand, step-down transformers decrease the voltage from high- or medium-voltage transmission lines to 120 V or 220 V for residential use. Distribution network costs and system losses in AC mini-grids can be minimized by transformers. Distributing electricity at medium voltage allows systems to use smaller conductors, minimizing cable costs. Higher voltage causes greater safety risks for operators and users. Therefore, special trainings are required for operators.
There are various efficiencies in various components. Therefore, the determining of voltage, current and transformers impact energy losses. Cost usually dictates which option project developers choose. DC is generally less expensive than AC, because AC requires power conditioning equipment. The availability of appliances for different currents should also be considered by developers.
End user System
End-user systems provide an interface for end users to access, use and monitor electricity from the mini-grid is provided by the end user system. It takes into account consumers’ needs and energy uses. For example, we can say about businesses require operating machinery for productive uses need different systems than households that use electricity for lighting and small appliances. The end-user system consists of connections to and from the mini-grid, systems to prevent electrical shocks and harm to both equipment and users and power consumption metering.
Energy consumption can be monitored in the end user system. It can estimate the cost of their consumption and understand the current status of the system. It can provide report on consumption rate and timing, like when and how much energy is used. Therefore, system operators can easily estimate and predict demand and consumption patterns. The data also allows regulators to establish tariffs that balance the needs of the operator and the consumer, while ensuring differing use cases are priced fairly and competitively. In order to ensure the safety of its users and protect valuable and expensive equipment, the system provides important electrical bond and grounding mechanisms.
Innovative metering and payment systems automate these otherwise complex tasks like making metering, billing and collection time consuming. The greatest degree of control over energy use can be provided by individual meters (one per end user). Meters can be pre- or post-paid; pre-paid meters typically are known as pay-as-you-go (PAYG) metering. Smart Meters are typically considered as newer generation meters. Although traditional meters or old generation meters are still in use. Smart meters do more than transmit payment and consumption data.
Utilizing mobile phone technology, smart meters gather data on energy consumption and facilitate two-way communication between the energy provider and end user. For example, a smart meter installed on the side of a residence communicates wirelessly with the utility systems. Some metering systems can log and report power quality and reliability data in real time, which helps to address the power quality issues before they become problems. Smart meters can even allow the grid operator to shut down troublesome loads before they jeopardize the entire system and cause problems for other consumers. Therefore, grid operators can ensure a higher quality of service to all customers by providing smart meters having these features.