Small Scale DC Output On Grid Solar Panel Kits With Battery Storage

Product Specification

Small-Scale Electricity Generators And Possibly Energy Storage Systems

Mini-grids can serve a wide range of customers. These include private households, commercial businesses such as shops, ice makers and mobile phone chargers, agricultural loads such as irrigation pumping and cold storage, productive loads such as grind mills and wood or metal working shops, and semi-industrials such as telecom towers, processing plants or flower farms.

Applications include:

• Village power supplies
• Island power supplies
• Hotels & mountain resorts
• Remote farms
• Lodges & Cabins
• Hospitals & Schools
• Telecommunication and radio stations
• Mobile applications

A mini-grid’s production system consists of energy generation technologies, inverters, a management system and sometimes storage (batteries). The production system determines the mini-grid’s overall capacity to provide electricity to end users.

Energy Generation Technologies

Mini-grid energy generation technologies can include diesel generators, hydropower systems, solar photovoltaic (PV) modules, wind turbines, biomass-powered generators and geothermal-powered generators. A mini-grid may use a single energy source or mix of sources (hybrid) that are either renewable or nonrenewable.

Inverters

Mini-grid production systems use power inverters when end users need a different type of electrical current than what the energy production technology generates. Some energy generation technologies produce direct current (DC) while others produce alternating current (AC). Solar power, for example, generates DC, whereas nearly all mainstream appliances require AC. So a solar-powered mini-grid serving households would need an inverter as part of its production system. Battery charging, on the other hand, requires DC power. An inverter would convert electrical current from AC to DC if the current were coming from a grid-tied (utility) system or from a diesel generator.

In an AC-coupled configuration with storage (a battery), the energy generation and storage systems each have their own inverter. These separate inverters connect to one another on the AC side of the system. Operators can use the battery inverter to control charging and discharging.

In a DC-coupled PV configuration, the energy generation and energy storage systems share an inverter. DC coupling can provide better performance; battery charging is more efficient when there are fewer power conversion steps.

Management System

Mini-grid production systems include management systems, which measure, monitor and control electrical loads. A charge controller, for example, connects between the solar panel and the battery or inverter/charger to prevent over-charging of the battery. Likewise, metering and monitoring equipment allow mini-grid managers to gather data about energy use across end users, which informs operational decisions. Management systems often couple computerized energy management tools with smart metering to optimize performance. Some management systems allow operators to control the system remotely, including shedding loads as needed.

Storage

Some mini-grid production systems require energy storage (such as batteries). Solar and wind resources, for example, 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.

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, nickel metal hydride and sodium-ion batteries—are generally more efficient and last longer. Costs for these new technologies continue to decrease.