Solar Panels

Modern caravans and motorhomes are increasingly using solar electric panels mounted on the roof to help keep the batteries charged. For many motorhome owners, freedom is not being restricted to a power hook-up.

Solar pv modules are either installed flat onto the roof structure using small brackets, or fitted onto a tilting frame.

The power from the solar panels normally feeds into a large Leisure battery. A solar charge controller or regulator is used between the panels and the batteries to prevent battery overcharging.

What are the different types of Solar Panel / Solar Cell and how will these affect my Caravan, Motorhome or Narrowboat?
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. 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.

Will a solar panel produce electricity on a cloudy day?

Yes, a solar panel does produce electricity even when it is not placed in bright sunlight. However, the production of electricity is not as high as when the panels are placed in bright sunlight.

Will solar panels work in the winter?

Yes, solar panels work on light not heat.

How can they help on my Caravan, Motorhome or Narrowboat?

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?

Batteries are rated in ampere hours, 45, 60, 75, 90, 150 amp hour etc, this describes the storage capacity of the battery. A 80 watt solar panel will produce up to 3-4 amps (A) per hour in bright sunny conditions. The solar panel needs to supply approximately 30% more than your needs to compensate for variables, such as cloudy days etc.

What is a blocking diode?

This is a component connected within the cable that prevents the solar panel discharging the battery when there is no sunlight.

Victron Energy Solar Panel
Click Here for the Datasheet					30W Solar Power
					50W Solar Panel
					100W Solar Panel
					130W Solar Panel
Type	Modules Size	Glass Size	Weight (KG)	Nominal Power (W)	Max Power (V)	Max Power Current (A)	Open-Circuit (V)	Short Circuit (A)
SPM30-12	450 x 540 x 250	445 x 535	2.5	30	18	1.67	22.5	2
SPM50-12	760 x 540 x 35	755 x 535	5.5	50	18	2.78	22.2	3.16
SPM100-12	963 x 805 x 35	958 x 800	10.5	100	18	5.56	22.4	6.53
SPM130-12	1220 x 808 x 35	1214 x 802	13	130	18	7.23	21.6	7.94

Single Core Solar Panel Cable with MC4 Connectors
	Cable Length: 1m Cable Thickness: 4mm
	Cable Length: 3m Cable Thickness: 4mm
	Cable Length: 5m Cable Thickness: 4mm