Solar PV panels: The quality conundrum
By Bevan Jones, Soltra Energy MD
Increasingly,
South Africans are becoming aware of the benefits of solar energy as a
renewable power resource. As a result, more solar photovoltaic (PV) panels are
entering the local marketplace. Some are high quality units, while others fall
short of reaching even the most basic of performance benchmarks.
Unfortunately,
instances of lower-grade solar PV modules being sold as premium quality
offerings have come to light, emphasising the need for buyers to be wary of
making costly investments without first ensuring the legitimacy and
authenticity of the products on offer.
Mirroring
these challenges are the vagaries of the terms and conditions of the warranties
and guarantees available from the solar PV industry. Limited understanding of
‘small print’ subtleties has resulted in buyer confusion.
As a
buyer, you need to be armed with the knowledge of how solar PV vendors back
their products before signing up for an often costly solar PV installation. Ideally you should shop around first to find the best solution with the most promising
warranty conditions.
Although
all solar panels sold in South Africa carry common law warranties against
latent defects, it’s important to carefully consider
the types and durations of the factory and in-service warranties offered by solar
system vendors and installers.
There are several different types of solar
PV system warranties available, covering the PV panels and other parts of a complete
installation.
As solar panels contain no moving
parts, they are usually very reliable and will have a long life. However, if
something does go wrong they are usually backed by a materials or product
warranty. It can be valid for between one and 10 years. It usually covers
components such as the panels’ glass, laminate backing and possibly the silicon
cells/wafers contained within.
Importantly, check whether the warranty is
underwritten by the panel manufacturer or the system installer. If it is the
manufacturer, will the panels have to be sent overseas to be repaired (at whose
cost?) or will they simply be replaced (swopped out) by the installer?
It’s also vital to understand the terms and
conditions of any regular maintenance contract which, if not followed
correctly, could void the factory or installer’s warranty.
What about the solar PV panels’ ability to
meet advertised performance benchmarks for the duration of their life – which could
exceed 20 years?
Performance output warranties are not as
common as materials warranties and you should check to see if they are included
- or omitted - before a purchase is made.
As all
solar PV panels degrade over time, performance
warranties should cover repairs to the silicon cells/wafers and/or panel
replacement in the event that their electricity production falls below a
predetermined percentage of the panels’ rated capacity during its lifetime
(usually 25 years). This performance drop should be due to a defect in the
cells themselves (not due to a fault of the rest of the system).
One of
the best industry warranties on the market is linked to a performance curve
which allows for a maximum of 3% degradation of the solar PV panel modules in
the first year and a 0.7% per annum degradation for the remaining 24 years.
Thus, by the end of a 25-year period, power output is warranted to be no less
than 80% of the modules’ labelled power output at purchase.
But what
happens if the vendor (or the installer) goes out or business at any point in
time during the 25-year warranty period? Who will resolve the issues? In this
event, it’s vital that the warranty be underwritten by one of more third party
guarantors, ideally reputable, independent finance institutions or insurance
underwriters.
This is key if the installation is
associated with a potential developer or investors in an industrial-scale solar
installation. They are looking for bankable technology in order to reduce risk
and support the long term economics of their projects, many of which are geared
to provide an annuity return.
A long-term,
non-cancellable warranty – meaning it remains in force even if the principals
are no longer in the solar power business - is central to the bankability of solar
farms and similar solar installations.
Other warranties which should be addressed
include those for the inverter – the device that changes direct
current to alternating current - which typically last for five to 10 years
– and the batteries, if a stand-alone or hybrid system is involved. Batteries
can be the most maintenance-intensive parts of a stand-alone power system, so
warranty fine-print should be studied carefully.
Finally, a balance-of-system (non-panel
components) warranty should be available from the installer or added to an
existing building insurance contract to cover the wiring and other
miscellaneous components.
