A Beginner's Guide to Solar Power
Welcome to a beginner’s guide on solar power, where we will walk through how a solar electric power system works.
What is Solar Power?
The core technology behind solar power systems (and solar panels) is Photovoltaic (PV) cells which converts light into usable electricity.
Types of Solar Power System
There are three main types of solar power systems namely off-grid, grid-tied, and hybrid. Each works a little differently depending on how it connects to the main power grid and how it stores energy.
Off-grid Solar System
An off-grid solar system is completely independent of the electricity grid. It uses solar panels to collect energy from the sun, which is then stored in batteries. You rely entirely on this stored energy to power your home or appliances. Because it’s not connected to any outside power source, it’s especially useful in remote areas where there’s no access to electricity. However, you need to make sure the system can store enough energy to last through nighttime or cloudy days, since you can’t fall back on the grid if the batteries run out.
Grid-tied Solar System
A grid-tied solar system, on the other hand, is connected to the local electricity grid. During the day, your solar panels may produce more electricity than you use. That extra energy is sent back to the grid and you get credited for it. At night or during cloudy days, you can draw power from the grid as needed. This type of system is not common in Kenya because it requires a power purchase agreement with the relevant power company.
Hybrid Solar System
A hybrid solar system combines the features of both off-grid and grid-tied systems. It uses solar panels and batteries like an off-grid system, but it’s also connected to the grid. This means you can store energy in batteries for backup and still draw from the grid when needed. Hybrid systems offer the most flexibility: they help reduce your electricity bills, provide power during outages, and ensure you always have energy available.
What is Needed to Build a Solar Power System?
A solar power system functions as an integrated unit, with each component playing a vital role in harnessing and delivering electricity. Here’s the key components that comprise a solar power system
Solar Panels – Capturing Sunlight: Solar panels absorb sunlight and convert it into direct current (DC) electricity using photovoltaic cells.
Inverter – Converting Power for Home Use: Since most household appliances run on alternating current (AC) electricity, the inverter converts the DC power from the panels (or battery) into AC power that can be used by your home.
Battery Storage – Storing Energy: The battery stores excess electricity generated by the solar panels for later use when sunlight is unavailable (e.g., nighttime or cloudy days).
Mounting Systems: Used to securely attach the solar panels to the roof or fabricated structure
Wiring and Connectors: These components are essential for connecting all the parts of the solar power system together to ensure safe and efficient transfer of energy power from generation to distribution.
These work together to ensure efficient energy capture, conversion, storage, and distribution as illustrated.
Solar Panels
There are currently 3 common types of solar panels.
Monocrystalline Solar Panels
The oldest and most energy efficient of the three technologies. As the name suggests, the solar cells are made with a single continuous crystal structure.
Polycrystalline Solar Panels
The slightly newer technology, where solar cells are made with a large block of many crystals instead of one continuous piece.
Amorphous Solar Panels
This is the youngest technology among the three, and it is basically a thin layer of silicon over metal or glass. Mainly used for light appliances such as portable chargers
The monocrystalline and polycrystalline panels are the ones used for home and commercial installations
When it comes to choosing solar panels, the considerations are:
- Which type of solar panel?
- What voltage?
- What wattage? (Measured in watts, the higher the number, the more power the solar panel produces)
- How many to get?
Inverters
The power we get from the solar setup is direct current (DC) while most home appliances use alternative current (AC). You therefore cannot simply plug your house appliances directly into a basic solar setup. Hence the need for an inverter to convert DC power to AC power.
Besides conversion, the inverter also synchronises grid and solar power. It also has safety features such as surge protection and some inverters have a monitoring and data reporting function.
The key considerations when choosing an inverter are the type of inverter (off-grid, hybrid and grid-tie), inverter capacity and manufacturer warranty and support
Batteries
Solar batteries are used to store excess energy generated by solar panels for later use—especially during the night, cloudy days, or power outages. Choosing the right battery depends on your energy needs, budget, and whether your system is off-grid, grid-tied with backup, or hybrid.
The most common types are:
Lead Acid Batteries
The most traditional type is the lead-acid battery. These have been around for a long time and are similar to the ones used in cars. They’re inexpensive and easy to find, which makes them attractive for people on a tight budget. While they all use the same basic technology—plates of lead and an electrolyte (usually sulfuric acid), they come in a few different types to suit different needs. Flooded batteries are tough and inexpensive but require regular maintenance. Sealed batteries don’t require you to top them off with water. There are two main types of sealed lead-acid batteries namely Absorbent Glass Mart (ABM) and GEL batteries. The most commonly used for solar power are GEL batteries.
Lithium-Ion Batteries
Next up are lithium-ion batteries, which are the most popular choice for solar energy storage today. They’re the same basic technology used in smartphones and laptops but on a larger scale. These batteries are much more efficient, lightweight, and longer-lasting compared to lead-acid. They also don’t need much (if any) maintenance, which makes them convenient. The downside is they tend to cost more upfront, but the long-term value often makes up for it. For most homeowners using solar panels, lithium-ion is usually the best balance of performance and convenience.
Choosing a battery (or batteries) is just like choosing a solar panel.
- Which type of battery?
- The voltage of the battery.
- The capacity of the battery. (Measured in ampere hour, the higher the number, the more power the battery can store)
- How many batteries?
- Manufacturer warranty and support?
In Conclusion
There are fears whenever it comes to solar power some of which are it is expensive and it does not produce enough power. The facts are:
- Solar panels will work as long as there is direct sunlight. Even on cloudy days, and when it is raining. Their efficiency has also improved greatly. Further, solar panels will last for over 25 years when maintained properly.
- Solar power equipment is getting cheaper over the years, due to mass production and better technology.
- The initial cost may be heavy but when you look at the Return on Investment (ROI), it is worth it! Most systems have an average payback period of 5 to 10 years. After that, you enjoy free electricity for as long as the system lasts.
This is quite informative. Thank you.