Solar panels, when combined with a battery, can provide a reliable source of power...  If you are worried about the cost/benefit of installing panels in the UK, there are specific panels produced for northern and temperate locations that are more suited to poor light conditions.

Boat owners have few choices when it comes to charging batteries while away from mains power.  The two most common choices for charging a boat battery whilst cruising is either to have a generator on board or use engine driven alternators.  However there are alternatives to burning fuel, and this month the Green Blue looks into how solar power and panels can be used as one such alterative.  It generates electricity without producing emissions of greenhouse or any other gases, and its operation is virtually silent.

What is a Solar Panel?

A solar panel is defined as ‘a device that collects and converts solar energy into electricity or heat.’  It can however sometimes seem confusing as there are also a variety of alternative names that all basically refer to solar panels such as - Photovoltaic Cells, PV Modules and Solar PV panels.   

The word ‘photovoltaic’ means ‘electricity from light’ and the beauty of the the photovoltaic (PV) process is that it converts the free solar energy from the sun (the most abundant energy source on the planet) directly into electricity.

How does a solar panel work?

• A PV cell consists of two or more thin layers of semi-conducting material, such as silicon.
• When the silicon is exposed to light, electrical charges are generated
• This electrical charge is then conducted away by metal contacts as direct current (DC).
• The electrical output from a single cell is small, so it is necessary to have multiple cells connected together and usually enclosed behind glass to form a module or panel!
• The nominal output voltage of a solar panel is usually 12 Volts, and they may be used singly or wired together into an array according to how much energy you need to convert to power your appliances on board or in your home.

Do the panels need direct sun light?

The electrical output of a solar panel is dependent on the intensity of the light it is exposed to. As a result a solar panel will tend to generate more electricity on a bright day than when the skies are overcast and grey. However, photovoltaic cells do not need to be in direct sunlight to work, so even on grey British days a PV cell will be generating electricity.

Are solar panels used in the UK?

Solar panels have been used for many years in the UK in systems such as monitoring stations, radio repeater stations, telephone kiosks and street lighting to name just a few examples. However the use is not just land based and there is also a substantial market for solar panels in the sailing world, with battery chargers for boat being further developed all the time.   

Can this technology be easily used on boats?

Solar charging kits for boast are widely available and have now been developed to suit the needs of recreational boaters whether it be inland or coastal users.  Specific panels now been designed to survive in the marine environment, and withstand harsh salty and wet conditions. They are also especially tough yet allow for flexible mounting options which are useful when space is of a premium.  A popular suggestion from long distance cruisers is to build a goalpost arch across the stern and mount two PV solar panels on it.  This provides optimum exposure to the sun and does not mean you have to be moving the panels around the deck chasing the sun all day. 

How long will a system last on my boat?

The average lifetime of a solar panel can be in excess of 20 years, crystalline silicon modules in particular have a very long life span. In addition to this, they require very little maintenance. Other components that are needed in the systems, such as batteries, have a varied lifespan and can last between 2 and 15 years depending on type so it is worth doing your research.

Where can I find out more?

Select Solar - http://www.selectsolar.co.uk/

The Electric Boat Association - www.electric-boat-association.org.uk

Electric Boat website - http://www.electricboats.co.uk/

Marine Store - http://marinestore.co.uk/page/mrst/CTGY/solar-panels/