# Battery ## 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 {% hint style="info" %} 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. {% endhint %} * Review the recommended battery system and select a matching product {% embed url="" %} ## 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) {% hint style="info" %} 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. {% endhint %} 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.** {% hint style="info" %} The battery is operated within a usable capacity range of 10% to 90%. {% endhint %} **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. {% hint style="info" %} This mode is commonly used for: * Reducing electricity bills * Increasing solar utilization * Improving energy independence without full backup requirements {% endhint %} #### 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. {% hint style="info" %} **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. {% endhint %} **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 {% hint style="info" %} **The Backup Reserve Rate** applies to both automatic and manual battery selection, allowing maximum self-consumption while preserving the defined backup capacity. {% endhint %} #### 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.** {% hint style="info" %} The battery is also operated within a usable capacity range of 10% to 90% in this mode. {% endhint %} **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 {% hint style="info" %} This mode is commonly used for projects aiming to minimize grid dependency rather than focusing only on backup scenarios. {% endhint %} ## 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 {% hint style="info" %} Once applied, all energy, financial, and performance calculations update automatically. {% endhint %} ## 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 {% hint style="info" %} The battery’s contribution to the financial performance may vary depending on local regulations. {% endhint %} ### 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 {% hint style="info" %} **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. {% endhint %} *** ## Related Pages * [Project Details Page](/project-design/create-a-project/project-details.md) * [Consumption Page](/project-design/create-a-project/consumption.md) For more assistance, don’t hesitate to [get in touch.](https://www.solarvis.co/en/company/contact) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.solarvis.co/project-design/create-a-project/battery.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.