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Solis Seminar Episode 42: Off-Grid Energy Storage With Solis


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For areas without power grids or frequent power outages, such as remote rural areas, edge of grid locations, ocean island arcs, mountain areas, etc., off-grid energy storage systems bring great benefits. Some homeowners are now also choosing to go “off-grid” in order to be less reliant on their local power grids.  Power cuts due to extreme weather conditions and the rising global cost of energy are prompting consumers to rethink how they power their homes.  

Solis provides complete solar power solutions for this type of demand and different application scenarios. From small pure off-grid systems and self-consumption energy storage systems to oil generator compatible systems, users can choose the corresponding solution to meet their specific needs.

This Solis seminar will demonstrate the off-grid energy storage system using Solis Off-Grid products.

About Solis Off-gridInverters (EO series)

The Solis EO series off-grid inverter is integrated with a 1 MPPT solar charge controller with a wide voltage range (90~480V) to adapt to many system design needs and maximise generation. It can support the connection of mains and diesel generators, and for larger systems, up to 10 inverters can be connected together in parallel.

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Exquisite design appearance and compact structure make installation more convenient for system owners. Featuring multiple integrated safety features and protection measures as well as online system monitoring.  This online monitoring ensures the safety of batteries and all other connected equipment by enabling fast, efficient identification of any faults. Ongoing operation and maintenance of a Solis off-grid system is simple, convenient and efficient. 

Key Product Features


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Strong load-support capacity

Solis EO series off-grid inverters can carry various non-linear loads, up to 5KW, which can basically satisfy all kinds of household appliances.

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Designing Energy Storage Systems with Solis Off-Grid EO Series Inverters

Below we take a simple household based in Plymouth, the UK as an example to describe the design of an off-grid system.

Step1:Determine the load and energy consumption of the house


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This data is what will determine if your system is sound and economical.  Understanding the energy consumption is critical when designing any solar + storage system – off-grid or on-grid.

Step2:Calculate the number of solar panels needed for your location and average weather conditions.

Taking the UK as an example, AVERAGE PEAK SUN HOURS in Plymouth is 3.0 hours

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Calculate energy generation requirement:

11175Wh/day ÷ 3.0 sun hours/day = 32725W

32725W ÷ 0.8 (system losses) =4656.25W per day

4656.25W x 30 days Wh = 139,687.5 Watt-hours (139.6875 kWh/month)

This project will be dealing with lower voltage devices therefore a 48V system issue table.


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Calculate Wattage and number of solar panels required:

11175Wh/day ÷ 3 sun hours/day = 32725W

32725W ÷ 0.8 (system losses) =4656.25W

4656.25/500 = 9.3125(3 Solar panels 500watts)

For this project we woulduse10solarpanels@500 Watts each.

Step3:Selectthe most appropriate Solis Off Grid Inverter Model


According to the calculated value, the photovoltaic panel capacity is 4656.25W, so the4kW (S5-EO1P4K-48)inverter is the correct model to select.

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Step4:Selectcompatible batteries for the system according to load and energy consumption

The average daily energy consumption of the project is 11,175 (Wh/day) as previously shown in Table 1 above. If the DOA (the Days of Autonomy) is 1 day, the inverter efficiency is 95%, the selected battery isa48V lithium battery, and the Maximum Depth of Discharge is 80%;

Battery Capacity (Ah)

= (11175/ (0.95×0.80×48)) x 1


306.35Ah Battery Capacity required for the system

Step5:Balancethe System

Select the appropriate cables, circuit breakers and protection devicesusing the above configuration to connect the entire system.

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Off Grid systems can provide independence from the power grid and energy security for those in areas where there is no power grid.  Critical to a successful and efficient system is to design and configure every element correctly.  The energy consumed at the property is the starting point when designing a new off grid solar system.

The Solis off grid inverter series is adaptable to the needs of many usage scenarios – with storage, integrated with a generator etc.

For more information contact your local Solis team and visit

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