Do Solar Panels Work?   Yes they do......these are some of the most successful examples where they provide power away from a mains supply, communications satellites in space, illuminated navigation buoys, irrigation pumps in remote areas, radio and monitoring equipment in remote areas.

How can they help on my Caravan or Motorhome?   Quite simply by charging the battery(s) during daylight hours. They work at their best in bright clear sunshine, most high quality solar panels will still produce a useful charging current even in cloudy conditions.

What size solar panel is required on a Caravan or Motorhome?   To some degree this is the "How long is a piece of string" question. As a general guide, most owners would want to try to balance the power produced by a solar panel with their average daily 12 volt power consumption. Average consumption is also a wide question, generally it is in the region of 10 - 20 ampere hours (Ah) per day from the leisure battery. (Batteries are rated in ampere hours, 45, 60, 75, 90 amp hour, this describes the storage capacity of the battery).  A 50 watt solar panel will produce up to 3 amps (A) per hour in bright sunny conditions. On a good sunny day, allowing for the changing position of the sun in the sky, low in the morning and evening, overhead in the middle of the day, you might expect this 50 watt panel to produce 14 to 18 Ah of battery power. As previously stated, most solar panels will still produce power in less than ideal conditions.

The following illustration shows how much difference a solar panel would make even if it were only able to produce half of it's rated maximum output.

To help increase your understanding of the flow of power from a solar panel the next illustration shows an approximate guide to current produced by a 50 watt solar panel during a bright summer day, from 4:00am to 9:00pm.

WHAT DIFFERENT TYPES OF SOLAR PANELS ARE AVAILABLE? There are two basic types of cells used in the manufacture of most modern general purpose solar panels, these are crystalline (monocrystalline / polycrystalline) or thin film. Both produce similar outputs in sunny conditions, although thin film cells generally perform better in overcast weather. The only down side of thin film solar panels is their size and weight, a much greater area is required to equal outputs of crystalline panels.

The total range of different types of construction, shapes, sizes and outputs could become very confusing for the inexperienced. Solar panels from Germany, Spain, Japan, Croatia, Australia, America, Mexico and yes even Britain.

Many of these have been tested by Solar Solutions and selected for the caravanner and motorcaravanner. As previously suggested the required output of your solar panel(s) would mainly be determined by your average 12V power consumption. There are often occasions when size and weight are important considerations, these can be accommodated from our range. 

WHAT OTHER EQUIPMENT IS REQUIRED IN A SOLAR PANEL SYSTEM?  Most solar panel systems will require a voltage regulator (controller) to protect the battery(s) from overcharging.  Solar panels can produce up to 18 volts, this would damage a 12V battery if allowed to continue unchecked for a long period.A regulator will allow the battery to charge at a maximum of around 13.5 to 14.0 volts, sufficient to achieve a good level of charge within the battery without causing damage.  We have regulators available to cope with solar panel power outputs up to 60 amps, the smallest model is suitable for panels up to 4.5 amps, followed by 6.5A, 10A, 12A, 16A, 20A, 25A etc., on to 60A.

The battery is a vital part of any system, as with the correct selection of a solar panel, it is also wise to try to match the battery storage capacity to your average 12V power consumption and production of power from your solar panel.  It’s unlikely that much 12V power will be consumed during daylight hours, therefore it is important to have enough battery capacity to store the power produced by your solar panel.  This capacity should be balanced to cope with power needs in the evenings and at times of poor cloudy and overcast conditions when the solar panel output is reduced.  Most caravans/motorhomes have only one batter of around 70-90Ah, to make the best of solar panel system it is a good idea to increase the battery storage capacity to a minimum of around 150Ah.

This can normally be achieved by doubling up two 75Ah batteries and wiring them in parallel (positive to positive and negative to negative). If the battery compartment is not big enough for two batteries the second one can be placed in any convenient position, e.g. under a seat, in the bottom of a cupboard, safely mounted in a plastic battery box. Monitoring equipment is entirely optional in a solar panel system, although it is helpful to be aware of the charging current flowing from the solar panel(s) and voltage of the battery. Our most popular ammeter and voltmeter is a combined instrument with a large liquid crystal display (LCD), a push button changes the reading from current flowing to battery voltage. Some of the regulators of 12 Amps and above are available with built-in LCD ammeter/voltmeters.

It is worth noting that when using a low output solar panel, not permanently fitted to a caravan or motorhome (left outside only when on-site), a regulator would not be necessary.You are the regulator, as you will only use the panel when you feel you need it and put it away when you do not.The time to be concerned about a solar panel causing damage to a battery, by overcharging, is when the caravan or motorhome is left parked with no 12V power being consumed, this is when a regulator must be fitted.

YOU CAN SAVE HUNDREDS OF POUNDS WITH SOLAR PANELS! If that has caught your attention, read on. Some of us will often choose a campsite for the convenience of using the hook-up facility. During colder months this may well be necessary, during the warmer times of the year a site with less facilities, or even a peaceful farm site may see more attractive. This is where the major savings can be made, in dramatically reduced site fees and no electricity charge, but only if your vehicle is equipped to provide you with sufficient 12V power, without hook-up. The solar panel systems referred to in this brochure, along with adequate battery storage capacity, would relieve the need for hook-up for most of us.