Solar Systems with and without Battery: A Comprehensive Guide

What is Solar PCU with MPPT5KVA Solar PCU with lithium Battery

Solar Systems with and without Battery: A Comprehensive Guide

Solar systems can be broadly categorized into two types: those with batteries and those without. The solar without-battery solution is called a grid-feed solar solution, and with a battery, there are two types of systems: solar PCU and solar hybrid system.

The terms “solar hybrid system” and “solar PCU system” are often used interchangeably, but their definitions differ slightly.

Solar Hybrid System

• Broad Definition: The solar Hybrid system can feed solar energy to the Grid and work as an independent power source in case of power outages. Generally, it refers to a system that combines solar power generation with a battery as a source in case of power failure. This is the most cost-effective solution where there are power deficit areas, and the power goes out for a small interval. Solar Systems with and without Battery: A Comprehensive Guide
• Key Components:
  
  • Solar panels
  • Hybrid solar inverter with grid feed and solar PCU built-in one.
  • Battery bank
• Functionality: When the grid is available, the system can operate as a Solar Grid feed system and charge the battery attached to it. Once the power outage happens, the battery system will be operational as a regular Inverter battery system.

Solar PCU System

• Specific Definition: PCU stands for “Power Control Unit.” This term typically refers to a system that manages the power flow from solar panels to the load (your appliances or devices).
• Key Components:
  
  • Solar panels
  • Inverter
  • Charge controller
  • Battery bank
• Functionality: The PCU ensures that the power from the solar panels is used efficiently and safely, and it may also include features for managing battery charging and discharging. The grid power is bypassed when the grid is available, and the battery is charged through the solar panels. The system automatically shifts to solar and battery mode once the battery is completely charged through the solar panels. There is a setting where the battery can be charged through the grid and solar panels, called grid and solar charge sharing.
• 

  Solar PCU system diagram

Key Differences

• Scope: While a solar hybrid system can include a PCU, the term “solar hybrid system” is broader and encompasses integrating multiple energy sources. A solar PCU system is more focused on managing power flow from solar panels.
• Generator Integration: A solar hybrid system often includes a generator for backup power, while a solar PCU system may or may not have this component.
• Control Features: Solar PCU systems typically have advanced control features for managing power flow and battery charging, while a solar hybrid system may have a more fundamental level of control.
• Solar hybrid inverter

Solar Systems Without Batteries

• How they work: These systems convert sunlight into electricity using solar panels. This electricity is then sent directly to the grid for immediate use.
• Benefits:
  
  • Lower upfront cost: These are typically less expensive and easy to maintain as no battery bank is installed with them. However, if power outages happen, this system stops functioning, and solar panels are useless at that particular time.
  • Simpler maintenance: Only solar panels need cleaning and maintenance.
• Drawbacks:
  
  • No backup power: If there’s a power outage, you’ll be without electricity.
  • Dependent on the grid: Solar panels rely on the grid for power generation. If the grid power stops, solar generation also stops.
  • Low Voltage and High Voltage shutdown: In case of a particular voltage that is well defined in solar grid feed, Inverters will shut down the system if the voltage range is below the set limit or higher than the set limit. Rural areas face this particular problem as the voltage from the grid is very low at times, so these systems become non-functional, and there is no power generation through the solar panels. In the Industrial areas, the grid voltage increases at night, and the solar system becomes non-functional at times as the system has a limited voltage range under which it performs. Most of the time, when grid-fed solar systems are non-functional, the user cannot find this problem as the monitoring application comes with 15 or 30-minute update data that cannot register these events.

Solar Systems with Batteries

• How they work: These systems convert sunlight into electricity but store excess energy in batteries for later use.
• So there are two types of Solar Storage Solutions 
• 1. Solar Hybrid PCU System
• 2. Hybrid Solar System 
• Benefits of Solar Hybrid System
• • Backup power: Provides electricity during power outages.
  • Energy independence: If one installs a good-sized battery bank, the user can be self-reliant in case of power cuts or when solar power is not available.
  • Potential for grid feed-in: The Hybrid Inverter can decide and can be set to store how much solar power to store and how much to feed into the grid, depending on the situation. It can also sell excess electricity back to the grid.
• Drawbacks:
  
  • Higher upfront cost: Batteries can significantly increase the initial investment.
  • Maintenance: If lead acid batteries are installed, regular maintenance is required as the life of the batteries is also limited. But if one installs Lithium LifePo4 baterries which has the longer life and no mainteance required at all and the power savings are enough to justify the cost of power stored. Where as the Lead Acid batteries are not able to give the value for money because of the maintenace and the shorten life span.

Key Points for Customers:

• Purpose: A system without batteries might suffice if your primary goal is to reduce your electricity bill. However, a system with batteries is essential if you need backup power during outages.
• Grid Dependence: Understand that systems without batteries depend on the grid for power generation and consumption. If the grid experiences issues, your system will be affected.
• Storage Capacity: If you choose a system with batteries, consider your energy needs and the frequency of power outages. Ensure the battery capacity is sufficient for your requirements.

Questions to Ask Before Installation:

• System type: Ask if the vendor recommends a system with or without batteries and why.
• Backup time: If you opt for a battery system, inquire about the estimated backup time during a power outage.
• Grid feed-inverter: Understand the rules and regulations regarding grid feed-in in your area.
• Maintenance: Ask about the frequency and cost of maintenance for solar panels and batteries.
• Inverters: Inquire about the type and efficiency of the inverters used in the system.

Explaining Grid Feed-in and Solar Storage Solutions:

• Grid feed-inverter: Explain that when your solar system generates more electricity than you need, it can send the excess back to the grid for credit. This credit can be used to offset your electricity bill.
• Solar storage: Emphasize that batteries store excess energy for later use, providing backup power during outages. This can be especially valuable in areas with frequent power interruptions or off-grid locations.