Compare solar PV installers: Ask the right questions.

Compare solar PV installers: Ask the right questions.

By Jack Ward, CEO of Soltra Energy

If you are considering a solar photovoltaic (PV) installation, you’ll probably be asking for quotes from a number of installers. Before you do, here are a few pointers to help you ask the right questions of the potential installers before comparing their costings and making a choice.

As you might expect, understanding the pricing structure of the installation as quoted will be a priority. An easy way to compare competing quotes is to ask the suppliers for their price per Watt (PPW). This is how professional contractors price out solar systems.

The PPW is the price for each Watt of solar energy you’ll be purchasing and it should be based on the completed system’s price, including VAT and other additional items. The ‘Watts’ element is calculated according to the installed DC Watts, which can be arrived at by adding the wattage of all solar panels to be fitted.

Don’t be confused by the fact that solar systems’ output is generally measured in kilowatts (kW) – simply multiply by 1000!

Some points to ponder:

  • Make sure you compare ‘apples with apples’ by using the gross price of the installation including labour, materials, financial costs (if appropriate) and other overheads.
  • Ensure that sure the specification meets your requirements. For example, do you need a domestic, grid-tied hybrid system without battery storage; or an off-grid system with batteries or something in-between. If you are running a business, you might opt for a solar/diesel hybrid system which should include a generator and an intelligent management system to automatically prioritise the power source as necessary.
  • Are the Watts used in the calculation DC Watts? (Some quotes may detail AC Watts.)
  • Bear in mind that some solar panels are better than others. Opt for Tier One, branded panels with warranty back-up but expect them to be more expensive than Tier Two panels or unbranded items from a fly-by-night supplier.
  • The type of string or micro inverter selected can vary in price by as much as R4.00 per Watt.

Note that the biggest variance in price should be system size. However, as a system gets larger, not all costs increase proportionally.

Nevertheless, as a rule of thumb, your solar PV installation in South Africa should cost between R 20.00 per Watt for a grid-tied installation and R 40.00 per Watt for a hybrid alternative. Any price under or over this range should be closely examined for accuracy and supplier dependability.