The Camper Trailer Book – Chapter 17: Lighting explains that affordable Light Emitting Diode (LED) lighting became a reality around 2010. LEDs now draw little energy. Powering them by a small solar panel and battery is feasible.
Most LEDs provide tightly focused beams over a range of 15º to 150º. They are efficient and effective for lighting working surfaces, for cooking on campfires, and for reading etc. The wider beam LEDs light up wide areas.
It is primarily the LED’s ability to illuminate defined areas that enables higher light levels using lower wattage. They are ideal for camping and camper trailer use.
This 5-watt LED fits the standard (MR16) globe holder. It has about the same light output as a 50/60 watt incandescent globe.
Light ‘colour’ is usually specified in ‘colour temperature’, (in the kelvin scale). Warm white is around 3100º k, daylight white is 5000º k upwards. Anything below 3100º k will have a yellowish tinge.
There is a wide range of 12-volt versions in both warm white and daylight white. Be wary of the ‘white light’ versions. Some people like them, but the light has a harsh blueish tint. Many people find it too ‘cold’.
Older trailers are likely to have 12 volt MR 11 or MR 16 halogen light fittings. The MR 11 is 35 mm in diameter with pins 4.0 mm apart. The MR 16 is 51 mm in diameter, with pins 5.3 mm apart.
Standard LED globe assemblies of the right size will often fit directly into these MR sockets. The heavier LEDs are liable to work free and fall out over rough roads. It may pay to replace the whole fittings by those that secure the LED in place.
There are also grid voltage LEDs that look like the 12 volt versions but have far larger locking pins. Some are physically larger, and have Edison screw or bayonet type fittings.
Most LEDs run from 12 volts. Those sold for 230 volt use have a tiny in-built inverter (or a close-by external inverter) that drops the grid voltage to 12 volts. Some, but not all LEDs, run from either AC or DC.
The light output of the previously common incandescent globes was generally thought of in terms of their wattage, and people chose them much on that basis. That wattage, however, is a measure of the energy drawn – not of the light produced. As all such globes were of much the same efficiency this did not matter. LEDs however vary considerably in efficiency.
An LED’s light output is shown in the actual unit of light output (i.e. lumen). Because of this a high quality LED may have twice or more the lumens per watt of many an eBay special. As a very rough guide a top quality LED (in 2018) has about ten times the light (lumens) output of its earlier incandescent globe equivalent. A five watt LED will be like a 40-60 watt incandescent.
A lot of solar energy is there to be used. Right now we use only 1/7000th of it. It is feasible to use solar almost anywhere during daylight hours but is most practicable in those areas on the map that are shown as brown or browny-yellow.