Businesses and consumers alike are starting to embrace
renewable energy by installing solar panels to help
generate electricity and heat – but how do you ensure that
they always perform at their best? Dave Rogers, European
sales manager for Unger Europe, explains how correct
cleaning can increase the efficiency of solar panels

From political circles to public on-line
forums, renewable energy is a hot
topic for debate that shows no signs of
moving from the top of the agenda. With
high petrol prices highlighting our
dependency on oil, and the recent
discussions about drought status in various
parts of the UK, there always seems to be a
story that adds fuel to the fire.

Renewable energy sources provide a winwin
situation for businesses keen to achieve
two important aims. The most obvious is to
cut energy costs; the other is to demonstrate
a commitment to sustainability and lessen
the impact of a firm’s activities on the
environment.

The Renewable Energy Association (REA)
says that solar power is the fastest growing
energy technology in the world and that it
works exceptionally well, even in the UK’s
northern climate. The two main systems
currently in use are:
Photovoltaic (PV) panels – These convert
sunlight into electricity and are available
in a variety of formats including cladding,
roof tiles, and custom glazing.

Solar hot water systems – These absorb
energy from the sun and transfer it, using
heat exchangers, to heat water. A variety of
collectors are available, which are
commonly mounted on roofs in the same
way as PV panels.

Dirt reduces efficiency
Installing solar panels represents a big
investment in both time and money, so
businesses need to ensure that they are kept
in tip top condition to reap the expected
rewards. No matter where a building is sited,
solar panels are exposed to the weather and
environmental influences 24/7 and for 365
days a year. Dust, dirt and other deposits not
only look unsightly, they affect the
performance of the panels. Traffic fumes and
soot can build up quickly, especially on
systems that are located near roads, railway
stations or on industrial parks where there is
a constant stream of trucks, vans and cars.

The orientation of the panels is another
factor to consider. Because you are looking
to achieve maximum exposure to sunlight,
panels should ideally be oriented to the
south. When oriented in other directions, a
build-up of plants or moss on the surface can
result. The angle at which the panels are
placed can also have an impact. It’s widely
agreed that if the panels lay very flat, then
there will be more deposits to deal with. A
steeper angle will help to a certain extent, but
dirt may still have a tendency to collect in
lower corners. And although rain removes
some of the existing dirt, it also deposits new
dirt on the surface.

Keep it clean
Soiling left on the panels stops sunlight from
getting through, meaning less energy is
produced, in some cases resulting in a
decrease in efficiency of 30%. Clearly this is
not acceptable, so regular cleaning should be
put in place.

Water-fed poles have already established
themselves as a popular choice with many
professional window cleaners, because they
allow them to clean high buildings and
windows safely from the ground, alleviating
the need to work at height. These pole
systems also lend themselves to cleaning
solar panels, dispensing with the need for
ladders or cranes but still cleaning safely and
efficiently to help boost solar output.

Unger’s new HiFlo nLite system, for
example, features carbon fibre in its
manufacture. Although the poles are light,
making the job of the cleaning operative
easier and more comfortable, their lightness
doesn’t compromise the crucial need for
rigidity. Even when extensions are added to
increase the length and reach of the system,
the poles do not bend or become unwieldy.

Unger has also developed a larger brush with
soft bristles specifically to clean and prevent
damage to solar panels.

Cleaning with chemicals runs the risk of
leaving a film on the panels that can prevent
the sun’s rays from getting through, so
Unger’s HiFlo nLite system uses pure water –
processed to remove the minerals and
impurities that would otherwise dry and lead
to spots and streaks.

As more ways to create renewable energy
emerge, cleaning equipment will also
continue to evolve, ensuring that effective
maintenance produces maximum results.