Bringing Power to the People

Author : Sammi Jackson, RS PRO

05 September 2023

Figure 1: A large-scale solar generation implementation - featuring solar panels, inverter hardware, energy storage banks and grid connectivity

Solar power is seeing widespread uptake - from professional maintainers and renewable energy enthusiasts alike. Large-scale deployments are being joined by an increasing prevalence of micro-generation sites and domestic installations. This article looks at how building a solar solution from a single source supplier can simplify the part selection process while also maximising system performance, reliability and durability.

Adoption of renewable energy is an essential element of the fight against climate change, and the flexibility and efficiency of solar generation has seen it emerge as one of the most popular and appealing options. These days, solar solutions represent a trusted source of electrical power across various sectors. In industrial settings, for example, solar provides a highly adaptable means of powering sensors and other installed infrastructure in off-grid, hard-to-reach locations. Many utility companies deploy this equipment as part of Internet of Things (IoT) networks, with significant costs and operational time savings being derived through the use of solar power.

For leisure users, meanwhile, solar is widely employed in mobile applications, acting as an effective means of topping up batteries for boating, camping and caravanning trips. It can also be used in public transport to support lighting and signage at rail and bus stations, plus other hubs.

Creating a solar system

As the popularity of solar continues to grow, well-informed decisions must be taken on how to build generator hardware capable of delivering optimal performance. In many cases, that is best done by performing a backwards study of the system based on several key points.

Starting with energy storage, it’s vital to understand how much energy the associated battery can store - enabling the specification of a solar panel that can adequately replenish the energy stock required. For example, a 20Ah-12V battery (240Wh) could supply 240W for a 1 hour period, 120W for 2 hours or even 2W for 120 hours. In tandem with this, appliance usage must be considered - how much energy will end-point devices use, and how long will they be in operation for?

Considering these factors, energy generation must be approached by selecting the right solar panel and evaluating how much energy it can generate. The generated energy is given from the power generation (in W) multiplied by the sun-exposure time, which can vary depending on the season, weather, position and orientation of the solar system. Also, there is an evaluation required of crucial associated equipment, including charge controllers that stabilise the current and make it usable for appliances, plus the cabling and connectors, which must guarantee safe and dependable operation over many years.

These considerations represent the early-stage preparation before subsequent system specification. Once performed, it puts the solar adopter in a good position to choose the right components for the task at hand. But not all products, such as solar panels, inverters, cables and connectors, are the same. It’s therefore critical to assess factors like quality and interoperability to ensure that the solar system is efficient and long-term reliability is maintained.

Choosing the right panels

The general rule of thumb for selecting solar panels is that 5-45W panels are optimally suited for battery maintenance and small off-grid projects. The 60-200W panels keep leisure batteries topped up in building, mobile and marine applications with 12VDC equipment. Plus, 120-240VAC appliances can be used with an inverter.

Figure 2: A multifaceted RS PRO solar solution

Typically, there are 2 primary types of solar panels - namely monocrystalline and polycrystalline. The main differences between them are in their manufacturing processes, appearance, efficiency and cost. Monocrystalline panels are produced from a single crystal structure. They have higher efficiency and perform more effectively in low-light conditions, though are usually more expensive. Conversely, polycrystalline panels are made from multiple crystals. They have slightly lower efficiency, but are generally more affordable. Both types have advantages and are commonly used in various solar energy applications.

There are ways for solar adopters to establish whether monocrystalline or polycrystalline panels will be likely to perform well at the point of use. For instance, it’s best to select panels that have been 100% tested from an electrical and mechanical standpoint - following TUV Rhineland and IEC 61215 standards. In addition, some suppliers will perform electroluminescence tests on their panels to ensure there are no life-shortening micro-cracks in the cell circuit.

Solar panels also come in different grades - with A-grade cells delivering maximum power in all light spectra, but with the smallest overall physical dimensions. This results in a more compact, robust and lightweight solar panel. The panel layout is essential too - with increased spacing between the cells and frame edge resulting in yield improvements of up to 2.5%.

Reliability is also critical. Some solar panel providers ensure that all crystalline panels can deliver a 20-year cell output. They are tested in state-of-the-art environmental chambers to check they will withstand the effects of saltwater spray, frost, hail stones, ammonia, dust and sand in the harshest settings and across temperatures spanning from -40°C to +80°C.

Connectors and cables matter

As noted, solar panels are a critical part of a broader solar solution - but there are many other products and components that are worthy of detailed consideration at the point of selection. Ultimately, all solar systems rely on the seamless integration of multiple pieces of equipment - and are therefore only as good as the sum of their parts.

Indeed, it’s easy to overlook the role played by interconnects, such as plugs, sockets and adapters, in a solar system - even though they are vital to overall performance. These components connect the panels to other panels, batteries, charge controllers and junction boxes. The most common type of solar connector is the MC4 connector, which is a standardised single-pole component with built-in strain relief and interlocks. These interlocks ensure secure mating and protection against accidental release between plugs and sockets. As they are often deployed outside, MC4 connectors are weather-proof and paired with double-insulated and UV-resistant cables. Such cables can operate over a wide range of ambient temperatures (usually from -40°C up to 100°C), making them resilient to weather extremes.

Easing the selection/sourcing process

These are just some factors that need to be considered when specifying a solar system. And sometimes, those implementing such systems face a bewildering array of options when it comes to the component elements. Fortunately, there are providers that can present a one-stop-shop, offering the flexibility and scalability to create solar systems for any application. This approach also makes it simpler for the supplier to perform an end-to-end evaluation of all requisite parts, with rigorous in-house quality control and testing significantly influencing performance factors such as efficiency and reliability.

RS PRO embodies a comprehensive approach to solar power, providing everything needed from a single source. Its range covers 1.5-150W solar panels, charge controllers, batteries, inverters, connectors, cables and even toolkits. Structural systems, hardware, engineering materials, testing equipment and power monitors are also included. By seamlessly integrating these components, complexity and doubt are eliminated - thus empowering users to build their solar solutions confidently. The portfolio is also modular and scalable, allowing end users to futureproof systems so they can be quickly expanded and adapted when required.