Electrical basics for solar systems - What you need to know

Electrical Basics for Solar Enthusiasts: Understanding the Fundamentals

Introduction

Switching to solar power is an exciting step toward sustainability, but for many, the electrical principles behind it can feel overwhelming. Understanding electrical basics such as Ohm’s Law, volts, amps, resistance, watts, and the interplay of AC and DC power is essential for a successful solar installation. Fortunately, Australis Solar has expert electricians who carry out solar installations across Perth daily. Our team has a wide range of experience in electrical work and is equipped for any scenario that they might come across.

This guide on solar electrical works and principles, we’ll explore topics like PV strings, wiring configurations, grounding, and surge protection, all tailored to help you understand and make the most of your solar investment.

Ohm’s Law: The Key to Circuit Design

Ohm’s Law is the cornerstone of electrical science. It defines the relationship between voltage ( $V$ ), current ( $I$ ), and resistance ( $R$ ):

$\times R$

In practical terms, Ohm’s Law helps predict how much current will flow through your solar circuit based on the voltage of your panels and the resistance of your wiring. Proper understanding ensures safe and efficient designs, avoiding issues like overheating or system inefficiencies. Fortunately, Australis Solar is an expert in solar panel installation and energy efficiency, ensuring your system is optimised for safety and performance. Our Clean Energy Council accredited designers and Solar Accreditation Australia (SAA) members understand solar energy and the intricacies of working with electricity.

Volts, Amps, Resistance, and Watts Explained

These four units are the building blocks of electricity:

Volts (V): Measure the potential energy or “push” in a circuit. Solar panels are often rated at 12V, 24V, or 48V.
Amps (A): Represent the flow of electricity. Higher amperage requires thicker wires to handle the load safely.
Resistance (Ω): Indicates how much a material opposes electrical flow. Using low-resistance materials like copper in solar installations ensures minimal energy loss.
Watts (W): Total power output. Calculated by multiplying volts and amps: $\times A$

Example:
If a 24V solar panel produces 5A, it generates: $24 \times 5 = 120W$

Understanding these basics is critical for accurately sizing your system and selecting the right components to ensure maximum efficiency and safety. At Australis Solar, we’ve taken the complexity out of designing solar systems and ensuring compatibility between components. Our expert team creates tailor-made solar solutions that align with your energy needs, property layout, and budget. From optimising PV string configurations to choosing the best inverters and ensuring proper cable sizing, our designs are engineered for peak performance, reliability, and long-term energy savings. Let us handle the technicalities while you enjoy the benefits of sustainable solar energy.

Parallel vs. Series Circuits

Solar panels are connected in parallel, series, or a combination of both, affecting system voltage, current, and performance:

Series Wiring: Panels are connected end-to-end. Voltage adds up while current stays constant.
Pro: Great for inverters that require high input voltage.
Con: Shading on one panel affects the entire string.
Parallel Wiring: Panels are connected side-by-side. Current adds up while voltage remains constant.
Pro: Shading on one panel doesn’t impact others.
Con: Requires thicker wires to handle higher current.

Series and parallel circuits. In series are connected along a single path, so the same current flows through all of the components. Components connected in parallel are connected so the same voltage is applied to each component.

Hybrid Example:

A solar array might combine series and parallel wiring to balance voltage and current, optimising the system for specific inverter requirements. In a series configuration, the voltage of each panel adds together, making it ideal for systems that require higher voltage to meet the operating range of the inverter. On the other hand, a parallel configuration increases current while maintaining a constant voltage, which is often necessary for lower-voltage inverters or systems with shading concerns.

Combining the two configurations allows solar arrays to maximise efficiency and compatibility with various types of solar inverters, such as string inverters, microinverters, or hybrid inverters. This approach ensures the solar system operates effectively under different conditions while minimising energy loss. At Australis Solar, we specialise in designing customised solar arrays that use the optimal wiring configuration to suit your energy requirements and ensure seamless solar panel installation for Australian homes saving money.

PV Strings and How They Work

A PV string is a group of solar panels connected in series. Strings are key components of larger solar arrays, and their design affects:

System voltage and current.
Shading tolerance and efficiency.
Inverter compatibility.

Proper string design is essential for ensuring your inverter operates within its optimal range, which is critical for maximising energy harvest and overall system efficiency. By carefully configuring the number of solar panels in each string, installers can achieve the ideal voltage and current levels required for the inverter to perform at its peak. This prevents issues like under-voltage, which can reduce energy output, or over-voltage, which can damage the inverter or other components.

For example, if your inverter operates best within a voltage range of 200V to 500V, designing a string with the right number of panels connected in series ensures the array consistently falls within this range, even during varying sunlight conditions. Additionally, a well-designed string accounts for factors such as shading, temperature changes, and the specific characteristics of your solar panels.

At Australis Solar, we take the guesswork out of string design by using advanced tools and expertise to create tailored systems that maximise your energy production. Our approach ensures that your inverter and entire solar setup are not only compatible but also optimised for Perth conditions, delivering reliable and sustainable energy for years to come.

Inverters: Converting DC to AC

Solar panels generate direct current (DC), while most homes use alternating current (AC). The inverter converts DC into AC for household use.
Key inverter types include:

String Inverters: Economical and widely used; ideal for systems with minimal shading.
Microinverters: Attached to each panel, allowing independent operation. Best for shaded or complex roofs.
Hybrid Inverters: Compatible with batteries, enabling energy storage for night use or power outages.

Example: A solar array producing 400V DC needs an inverter to convert it into 230V AC for household appliances.

Grounding and Safety in Solar Installations

Grounding is a critical aspect of any electrical system, protecting people and equipment from electrical faults. In solar systems, grounding ensures:

Fault currents safely dissipate into the earth.
Protection from lightning strikes and power surges.
Compliance with safety standards.

At Australis Solar, we prioritise safety in every solar installation by using high-quality grounding rods and conductors. Proper grounding is essential to protect your system from electrical hazards, such as faults or lightning strikes, by safely dissipating excess electrical current into the earth. Our expert team ensures that all grounding components meet Australian standards, providing a secure and reliable solar setup that safeguards your home and enhances system longevity. Trust Australis Solar to deliver a solar installation that’s not only efficient but also designed with your safety in mind.

Surge Protection for Solar Systems

Solar arrays are vulnerable to power surges from lightning or grid disturbances. Installing surge protection devices (SPDs) safeguards:

The solar panels.
Inverters and other system components.

For optimal protection, it’s crucial to install Surge Protection Devices (SPDs) at both the DC and AC ends of your solar system. This dual-layer protection safeguards your equipment from power surges caused by lightning strikes, grid fluctuations, or other electrical disturbances. By covering both sides of the system, you ensure comprehensive defence for your solar panels, inverter, and other components, enhancing the reliability and longevity of your installation. At Australis Solar, we ensure every system is equipped with the best surge protection solutions tailored to Australian conditions.

Battery Basics for Solar Systems

Adding battery storage to your solar setup allows energy use during cloudy days or at night. Key considerations include:

Battery Types: Lithium-ion batteries are most common due to their long lifespan and efficiency.
Battery Voltage: Must match your system (e.g., 12V, 24V, or 48V).
Charge Controllers: Regulate energy flow into the battery, preventing overcharging.

At Australis Solar, we offer a range of high-quality solar battery solutions to meet diverse energy storage needs. Our selection includes:

BYD Battery Box: Recognized for safety and efficiency, BYD batteries feature a modular design, allowing for customizable and expandable capacity to suit various applications.
Tesla Powerwall: Known for its compact design and built-in battery inverter, the Tesla Powerwall offers high energy density and ease of installation, enabling homeowners to quickly benefit from reliable, clean power.
Sigenergy – SigenStor: Released in 2024, this versatile all-in-one solar energy system offers high scalability, a 10-year warranty, stylish design, and advanced safety features, including a built-in fire extinguisher. Capacities range from 5 to 48 kWh, with AI capabilities for smart communications.

Read more here: Australis Solar- Home Battery Storage

Our expert team is dedicated to designing and installing solar battery systems tailored to your specific energy requirements, ensuring optimal performance and long-term reliability.

Cable Sizing and Efficiency

Choosing the correct cable size minimizes energy loss and overheating. Factors for our installers and designers to consider:

Voltage Drop: The loss of voltage as electricity travels through cables.
Tip: Use thicker cables for longer distances to reduce voltage drop.
Material: Copper cables are preferred for their excellent conductivity and durability.

Example: For a 20A system running 30 meters, a 4mm² cable is more efficient than a 2.5mm² cable.

Monitoring and Maintenance

At Australis Solar, we offer cutting-edge solar monitoring tools like smart energy meters to help you keep track of your system’s performance in real-time. These tools enable you to monitor energy production, consumption and may help identify potential issues, and optimise efficiency—all from the convenience of your smartphone or computer.

Regular maintenance is crucial for keeping your solar system running smoothly and efficiently. Our expert team recommends:

Cleaning Solar Panels: Dust, dirt, and debris can reduce your panels’ ability to absorb sunlight, lowering energy output. Australis Solar provides professional cleaning services to ensure your system stays in top condition. Discover more about maintaining peak panel efficiency here.
Inspecting Connections: Connections can corrode or wear over time, impacting performance and safety. We offer thorough inspections to identify and resolve any issues before they become significant problems.
Checking Inverter Status: The inverter is the heart of your solar system, converting DC electricity from your panels into usable AC power. Regularly checking its status ensures optimal energy conversion. Australis Solar’s team ensures your inverter operates efficiently with every inspection. Explore inverter services here.

By partnering with Australis Solar for your system’s maintenance and monitoring, you ensure your investment continues to deliver maximum energy savings and long-term reliability. Contact us here to schedule your service or learn more about our tailored solutions.

Conclusion

Understanding electrical basics empowers you to design, maintain, and optimize your solar energy system effectively. From wiring configurations to inverters and surge protection, every detail matters in ensuring efficiency, safety, and long-term performance.

At Australis Solar, we simplify the technicalities of solar energy. Whether you’re starting small or planning a large installation, our experts will look after you and ensure a seamless transition to renewable energy. Contact us today to bring the power of the sun into your home!

For more information on switchboards and how they work watch this M. E. N video explanation