Frequent Questions – FAQ


What is a PV Solar system?

A Photovoltaic Solar System is essentially a group of components that can convert sunshine into electricity on a daily basis. A typical standalone system consists of a solar array (a collection of solar panels), a charge controller, a storage battery and an inverter that changes the electricity stored in the battery into normal household  power.

Picture1How many solar panels do I need? What size should they be?

The required size and number of panels will depend on the total amount of electricity (kWh or units) that you require on a daily basis. The more electricity you require, the more panels you need. Once our system designers know what your daily energy demand is, they can calculate the number of panels required to produce this energy for your specific location.

How do I know how much electricity I use every day?

If you have a prepaid meter, take a reading every 24 hours and subtract the figures from each other. The answer will be the total number of units (kWh) that you consume in a 24 hour day. Doing this over a period of time will give a very good indication of your average daily energy consumption.

If you get a monthly electricity bill, you need to divide the total monthly energy consumption (in kWh) by the number of days between readings.

It is also possible to calculate your total daily electricity requirement. Download our ‘Energy Analysis Calculator’ for this purpose. Please feel free to contact any ALLSOLAR for assistance or further information. Also see how much energy do I use?

What type of battery must I use in a solar system?

Use only deep cycle batteries. These are very different from car batteries and specifically designed to be charged and discharged every day over a long period of time. Depending on the application, different types and sizes are used. Our trained system engineers will advise you on the best options for your purpose.

What is an inverter?

An inverter is an electronic device that changes Direct Current (DC) Power that is stored in the battery bank, into Alternating Current (230 Volt AC) power that is required by common household appliances. Various sizes and types are available. The correct choice of inverter will depend on a number of factors relating to your power requirements and application. Once again, our specialists will advise you on the best options.

What’s the difference between a ‘Modified Sine Wave’ inverter and a ‘Pure Sine Wave’ inverter?

A Modified Sine Wave inverter is a cost-effective way to produce AC power. They however have some major limitations. The output is not suitable for all electrical devices. Some equipment will work erratically, might overheat and could create additional noise. Electrical motors will also use 20% more power from the inverter due to lower efficiency.

These types of inverters are normally used for small and simple loads, such as camping sites where one would power a few lights, TV and other light loads for a short time. We do not recommend modified sine wave inverters for permanent installations or domestic applications.

Picture2Pure Sine Wave inverters offers the best output waveform you can get from an inverter and all appliances are able to run off them without interference or overheating. The power they deliver can be of better quality than that of Eskom! Sinewave inverters are far more complex structures and include many sophisticated protection circuits (depending on model and brand name). This type of inverter is more expensive than modified sine wave but has a much better performance and it is far more reliable. Many inverters are designed for very specific applications. Please ask our Technical Consultants to assist you to choose the right model and power level for your application.

Why do I need a solar charge controller? What does it do?

If you connect a solar panel directly to a battery, it will charge the battery. But the solar panel will never know when the battery is full. Eventually the battery will start overheating and might even explode! A charge controller or regulator is an essential part of any power system that charges batteries. Its basic function is quite simple – to  prevent the battery from overcharging. Good controllers also prevent the battery from being discharged too much and display the battery’s status and other electrical data.

What will it cost to replace Eskom in my house with a Solar PV system?

This will firstly depend on the amount of energy (the number of units or kWh) that is required in a 24 hour period. Since different people have different electricity requirements, this total daily energy requirement can vary widely. A number of other factors will influence the initial investment amount, such as location, quality of components, reserve capacity, specific application etc.

To give you a rough but realistic indication, a fully installed, turnkey stand-alone system starts at around R12 000 per kWh per day. This is the cost to produce 1 kWh of energy every single day for many years to come. Solar panels are typically warranted to produce their given output for 25 years, while battery life can vary between 1 and 15 years depending on the type used and the care they receive.

My friend said that a “Solar company” can install a system to power his house for less than R 25 000?

Best to ask your friend whether he has been quoted by a reputable company that can provide good references. Has he been given a comprehensive quotation, stating exactly how much power will be produced by the system? Have realistic loss factors been explained? Has a complete list of components been provided and are all the hardware, cabling and installation fees included? Also ask him to check on the quality of the panels, batteries and product warranties. A lot of cheap and unreliable products are being offered that can fail after only a few months! Finally ask him if installation standards has been specified.

I have a limited budget. Can you still help me?

Of course! Our expandable design approach means your system could grow as your budget allows. We can also adapt system components to meet a smaller budget within reason.

Why choose ALLSOLAR over other similar companies?

ALLSOLAR is the largest and fastest growing group of solar specialists in South Africa. With so many branches country wide, you know that you will be dealing with a reputable company backed by nationwide technical and product support. This fact alone should give you peace of mind!

ALLSOLAR adds value to people and companies by arming them with the right knowledge and products to make informed decisions.

The ALLSOLAR team represents a multitude of skilled consultants that shares their knowledge amongst our nationwide branches.

In addition, we have a number of product specialists who act in an advisory capacity. Over the years we have also developed good relationships with product manufacturers who will assist with any support related issues.