Battery
The page lets you define your battery strategy by choosing between self-consumption and backup use cases, and automatically calculates the appropriate battery size for the project.
Purpose of This Page
This page is used to add and configure a battery system within a PV project.
It allows you to define the battery’s role in the system, either to increase self-consumption or to provide backup power during grid outages.
Based on the selected use case and preference inputs, solarVis automatically calculates the required battery capacity and proposes suitable battery systems.
The results are based on an hourly simulation that compares solar production and site consumption and determines when the battery should charge or discharge.
Battery calculations express state of charge limits, efficiency losses, and charging/discharging power constraints to reflect realistic system behavior.
All inputs on this page directly affect:
Required battery capacity (kWh)
Self-consumption and grid dependency
Backup performance during outages
Energy flow outputs and system behavior simulations
Electricity cost savings and bill reduction
Long-term financial metrics such as return on investment
Recommended battery products and system configuration
What You Can Do Here
On this page, you can:
Enable or disable a battery system for the design
Select the battery use case: Self Consumption, Backup, Autonomy
Adjust your target values, such as self-consumption rate, backup duration, and autonomy level
Let solarVis automatically size the required battery capacity or choose the battery manually
By comparing different battery capacities, you can clearly see their impact on the system performance and easily choose the most suitable solution for your project.
Review the recommended battery system and select a matching product
Battery Preferences
Battery sizing and behavior are defined through a set of preferences that depend on the selected use case.
Use Case Selection
You should select one of the following battery design modes:
Self Consumption (On-grid projects)
Backup (On-grid and Zero injection projects)
Autonomy (Zero injection projects)
In off-grid projects, calculations are based on autonomy by default. The use case selection is hidden because there is no other option for off-grid systems.
The selected use case determines:
Which input fields are shown
How battery capacity is calculated
How the battery is operated in simulations
1. Self Consumption Mode
This mode focuses on increasing the share of generated solar energy that is consumed directly at the facility.
In this mode, the battery stores excess PV production during the day. It discharges the stored energy later when on-site consumption exceeds solar generation.
It will be seen on On-grid projects.
The battery is operated within a usable capacity range of 10% to 90%.
Targeted Self-Consumption Rate (%)
Set the percentage of self-consumption you want to achieve with a battery system.
The panel displays:
Current self-consumption rate without a battery
A slider to define the desired target
SolarVis calculates the battery capacity required to store surplus production and reach the selected target.
This mode is commonly used for:
Reducing electricity bills
Increasing solar utilization
Improving energy independence without full backup requirements
2. Backup Mode
Backup mode is intended to provide power continuity during grid outages by supplying energy to essential loads.
In this mode, the battery is sized to support critical consumption for a defined duration while maintaining a reserved charge level.
It will be seen on On-grid and Zero injection projects
Minimum Backup Time (hours)
Define how many hours the battery system should supply power to critical loads during an outage.
This value represents the minimum guaranteed backup duration.
Critical Load Percentage (%)
Specifies what percentage of the total site's total consumption is considered essential during a power outage.
Examples of critical loads include:
Lighting
Refrigeration
Communication systems
Security and safety equipment
SolarVis uses this percentage together with the consumption profile to calculate expected energy demand during backup operation.
Minimum Backup Time and Critical Load Percentage are considered when generating battery suggestions; however, they do not affect the calculation when a battery is selected manually.
Backup Reserve Rate (%)
Set the minimum percentage of battery charge that should remain reserved for backup.
This ensures that the battery is not fully discharged during normal operation and remains ready in case of a grid failure.
Consumption in backup mode is calculated automatically based on the selected consumption profile.
The reserve rate influences:
Battery dispatch strategy
Usable capacity for self-consumption
Overall battery sizing
The Backup Reserve Rate applies to both automatic and manual battery selection, allowing maximum self-consumption while preserving the defined backup capacity.
3. Autonomy Mode
This mode is designed to increase the level of energy independence by maximizing how much of the total consumption is covered by solar production and battery storage.
It will be seen on Zero injection projects.
The battery is also operated within a usable capacity range of 10% to 90% in this mode.
Targeted Autonomy Rate (%)
Set the desired autonomy level for the project.
The panel displays:
Current autonomy rate without a battery
A slider to define the target autonomy rate
Autonomy represents the percentage of total electricity demand that can be supplied by the PV system and battery without drawing energy from the grid.
SolarVis calculates the required battery capacity to reach the selected autonomy target, considering:
PV production profile
Consumption profile
Daily and seasonal energy balance
This mode is commonly used for projects aiming to minimize grid dependency rather than focusing only on backup scenarios.
Selected System
After defining battery preferences, solarVis calculates the required battery capacity and displays suggested battery systems.
For each suggested option, you can review:
Total battery capacity
Expected self-consumption rate
Expected autonomy
Backup duration with solar energy support
You can:
Accept the suggested battery system
Manually select a different battery model
Compare alternatives before applying the system
Once applied, all energy, financial, and performance calculations update automatically.
Battery Impact Overview & Performance Visualization
After a battery is selected, the platform provides a visual performance summary to illustrate how integrating a battery system affects energy usage, backup capability, and electricity costs when compared across different system configurations.
The project connection type can be set to on-grid, and zero injection to see these charts.
Key Performance Indicators
At the top of the page, summary indicators provide a quick overview of system performance based on the selected battery strategy.
Yearly Average Self-Consumption
This indicator shows the proportion of solar energy that is consumed directly on-site over the course of a year.
It reflects how effectively the system minimizes electricity exported to the grid.
The value increases as battery storage allows excess solar energy to be used later.
It is influenced by load behavior, PV production, and battery operation strategy.
Backup Time (With Solar Energy Contribution)
This metric represents the estimated duration during which the system can supply power to critical loads during a grid outage while solar generation is available.
The value is derived from battery capacity, critical load definition, and expected solar energy contribution.
Backup Capacity
This indicator reflects the usable portion of the battery that is allocated for backup operation.
It accounts for reserve settings and system constraints.
It ensures that sufficient energy remains available when an outage occurs.
Annual Energy Estimation Chart
This visualization highlights how battery storage enhances both self-consumption and cost efficiency.
The visual chart comparison of electricity cost behavior across the year. Each month is displayed with three comparative values:
Cost without solar energy
Cost with solar energy only
Cost of both solar energy and battery
This view allows users to understand how energy generation and storage influence grid dependency and financial outcomes over time.
Monthly Utility Bill Comparison
For each month, a detailed breakdown is shown for the different system configurations.
Before Solar
This scenario represents full reliance on the grid, with no on-site generation or storage.
All electricity is purchased from the utility
No surplus energy is produced
With Solar
This scenario shows the effect of adding PV generation.
Grid consumption is reduced
Excess energy may be exported
Costs change depending on seasonal production
With Solar + Battery
This scenario demonstrates the added value of energy storage.
A larger share of solar energy is consumed on-site
Grid usage is minimized both outside solar production hours and by storing solar surplus in the battery instead of exporting it to the grid.
Financial performance becomes more stable across the year
The battery’s contribution to the financial performance may vary depending on local regulations.
Daily Energy Usage Chart
This section visualizes how energy is produced, consumed, stored, and supplied throughout a typical day.
The chart is based on an hourly simulation and shows how the PV system and battery interact with site consumption over a typical day in the selected month.
The chart combines multiple energy indicators to illustrate system behavior at each hour:
Production
Represents the solar energy generated during the day.
Consumption
Shows the site’s electricity demand throughout the day, reflecting typical usage patterns such as daytime activity and evening demand.
Autonomy
Indicates whether the site is being supplied by on-site energy sources (solar and battery) rather than the grid. Higher autonomy means lower grid dependency at that hour.
State of Charge
Displays how full the battery is over time. It increases when excess solar energy is stored and decreases when the battery supplies energy to the site.
Monthly Selection
The month selector allows you to view how daily energy behavior changes across different seasons.
This helps illustrate:
Seasonal variation in solar production
Changes in battery usage patterns
Key Insights from the Charts
Shows when solar energy is consumed directly, stored in the battery, or supplied back to the system on an hourly basis
Illustrates how grid dependency increases or decreases throughout the day and across the year
All values are based on the same hourly simulation used for system sizing, savings calculations, and performance analysis
Makes backup readiness and system resilience clearly visible
Shows how energy storage improves both operational performance and financial outcomes
Off-Grid Connection Type + Battery
When an off-grid connection type is selected, the Battery page reflects a fully independent system without grid support.
In this mode:
All consumption must be covered by solar production and battery storage
Energy deficits indicate periods where usable production is insufficient
The visualizations emphasize usable production, consumption balance, and energy deficit, helping evaluate whether the system can operate reliably without a grid connection.
Related Pages
For more assistance, don’t hesitate to get in touch.
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