Renewable energy is abundant and available in various forms with the most popular being hydro, wind and of course, solar. Solar energy is the most abundant energy resource on Earth; 173,000 terawatts of solar energy strikes the Earth continuously at any given moment. That’s more than 10,000 times the world’s total energy use! As solar panel prices continue to fall, solar energy is increasingly becoming an economical energy choice for Nigerian homes and businesses yet many people are skeptical to adopt this energy source because they don’t fully understand it or because they have been exposed to negative reviews from others.

We would like to dispel some of the misconceptions and explain how renewable energy systems and their components work in the simplest terms.

Solar are by far the most popular commercially available renewable energy systems in Nigeria and are made up of three major components:

1. Solar panel array – used to harvest solar energy and convert light energy into DC electrical energy
2. Battery bank – used to store the energy collected by the solar panels for use when there is little or no sun
3. Inverter – used to convert the DC energy from the panels and battery bank into AC electricity which is usable by regular appliances

The inverter is the most interesting of the three so lets take a closer look. The inverter is usually permanently connected to a battery bank and converts or “inverts” the DC electricity stored in the battery bank into more commonly used AC electricity.

The most common type of inverter found in most homes/businesses across the country has an inbuilt rectifier which is used to charge the battery bank when the inverter receives input power from the grid or generator. Just like generators, inverters are rated in KVA which basically specifies the maximum load that the inverter can sustain, so the larger the KVA rating the more appliances can be powered at the same time.

Hybrid inverters are basically regular inverters with an inbuilt charge controller. These inverters can take an additional energy input directly from the solar panels and either channel this energy to charge the batteries or divert it through the inverter as AC electricity.

Understanding the flow of electrical energy will help us answer questions such as “what can it carry?” or “how long will it last?”. Electrical power is measured in Watts, lets say you have a light bulb (load) that is rated at 10W, this means you will need a power source that is 10W or more to power the light bulb. Lets say you have an inverter which is rated at 15W, this inverter will be able to power your light bulb comfortably, however it will not be able to power two light bulbs as that will require 20W (10W x 2). Thus the inverter rating is the maximum load the inverter can sustain.

Battery banks are rated in watt-hours (Wh). Lets say you have a battery bank that is 10Wh, this means it will be able to power your light bulb from example above for one hour (or two light bulbs for 30 minutes as long as you have an inverter that can sustain a 20W load). Thus the battery bank rating is how long in hours a battery bank will last for a specified load.

Finally lets talk about putting the energy into a battery bank from solar panels. Solar panels are also rated in watts, lets say you have a 10W solar panel, it would take one hour to fully charge your 10Wh battery bank, so if you had two solar panels (20W total), you would be able to charge that same battery bank in 30 minutes!

In Nigeria, inverters (also generators) are rated in KVA and globally batteries are rated in Ah, lets take a look at how we can convert these into the units of measure used above.

• Batteries: this is very easy and straightstraightforward, just multiply the voltage (V) of the battery by its Ah rating to get the Wh rating. For example, a 12V – 200Ah battery has a capacity of 2,400Wh or 2.4kWh.
• Inverters: these are a little less straight forward because it involves multiplying the KVA by the “power factor” or usable power, unlike in batteries where the values are fixed, the power factor varies from manufacturer to manufacturer and is not usually specified so we use 0.75 as anything below that would mean that the inverter is very inefficient. For example, a 1.5KVA will have a maximum load capacity of 1.125kW or 1,125W. Simple!

Unlike traditional backup generators, our energy systems are completely scalable which means the various components can be swapped for higher capacity ones or more components added on, for example you can always add more panels to reduce your charging time even in gloomy conditions or you can add mini wind turbines which work even at night or in the rain and so on. This amazing versatility makes renewable energy systems an excellent long term investment.

Renewable energy backup systems have numerous advantages over traditional fossil fuel generators:

• No Noise: Virtually silent, you no longer need to put up with thunderous racket of regular fuel powered backup generators, say goodbye to headaches and hello to better quality rest.
• No Pollution: Dramatically reduce the amount of poisonous fumes you and your loved ones are exposed to so you can enjoy better health and longer life.
• Minimal Maintenance: With the only moving parts being the cooling fan, maintenance is little to none, you’ll even forget that the backup supply system is there doing it’s job, no longer will you have to worry about oil filters and costly repairs and focus on more important things.
• Fuel Free: With the currently rising costs of fossil fuels what can be better than not having to worry about fueling your backup generator. Solar panels can harvest solar energy every day and store it in your battery banks ready for use whenever you need it.
• Instant Power Switching: Waiting in the dark while the backup generator comes on will seem like stone-age once you get used to our battery powered backup systems.