For those who love an extended get away, maintaining power to all the essential accessories can sometimes be one of the biggest hurdles of the trip. Aside from taking a large, bulky generator on your travels, utilising the sun as a free energy source via the use of solar is a reliable and sustainable alternative. Not only does Australia have plenty of sun to go around (well, except for when I go camping!), but, modern advances in solar power technology means that solar is now a very efficient, effective and portable off-road means of generating power.
What you need:
- A solar panel
- A solar regulator/ charge controller
- Deep cycle battery
- 12v socket or power inverter (if you intend on running 240v appliances)
Types of Solar Panel:
- Mono-Crystalline
Most efficient of the rigid panels, fragile and also most expensive. Suffer from slight power loss in high temperatures.
- Poly-crystalline
Cost effective, but not as efficient for the surface area and still fragile. Suffer from slight power loss in high temperatures.
- Amorphous Panels
Least efficient, very portable and robust, able to be folded & rolled. Minimum power loss from high temperatures.
How big of a solar system will you need?
To determine what size system you’ll require to keep up with power demands, it’s recommended to first do some rough calculations on expected power usage. Keep in mind these figures may vary greatly from campsite to campsite and the final numbers are estimates only.
To calculate your daily power requirements, add together all of the appliances you intend on running. These may include lights, fridges, air compressors, fans, chargers, etc. This figure needs to be in amps to aid in adding all the usages together. Most appliances will give you the amp figure in its specifications, which can be multiplied by the number of hours you intend on using it to get an approximate daily power usage.
Amps
x
hours of usage per day
=
Total power usage for that appliance, per day
If there is no amp value on the specifications, you can roughly work it out by dividing the wattage by the volts. Keep in mind this figure will not take into consideration losses in the system, inefficiency’s and imperfect conditions.
Watts
/
volts
=
amps (for 1 hour)
Then use the first formula to calculate approximate total power usage. Once this has been done for all appliances, add the totals together to get the total power usage for your entire campsite for 1 day. This figure will determine how much solar power you will need to generate per day to maintain this daily output, or it will dictate how long you will be able to stay powering your appliances before your storage battery starts to drop below the recommended discharge levels during the night.
Some approximate solar panel figures for power generation (based on 8hrs of sunlight):
- 80W solar panel – 4-5amps p/h, 35Ah total daily production
- 100w solar panel – 5-6amps p/h, 45Ah total daily production
- 120w solar panel – 6-7.5amps p/h, 55Ah total daily production
- 160w solar panel – 9-10amps p/h, 75Ah total daily production
- 200W solar panel – 11-12amps p/h, 90Ah total daily production
- 240W solar panel – 13-14amps p/h, 110Ah total daily production
- 100Ah
- 120Ah
- High ambient temperatures
- Overcast / rainy conditions, shaded areas
- Solar panels not clean
- Panels not positioned at correct angles
- Panels in fixed locations
- Unplanned power usages
- Power losses throughout the system
- Faulty panels
- Damaged storage batteries
- LED Campsite lights @ 0.4amps x 4 hrs = 1.6amps (night time usage)
- Fridge @ 2.5amps x 24 hrs = 60amps (40amps for 16hrs running from battery)
- Phone charger @ 1amp x 1 hr = 1amp (night time usage)
General battery sizes
Keep in mind it’s recommended to never discharge a deep cycle battery more that 50-70% of its capacity to avoid permanent damage. This will have to be factored into any calculations to ensure they are not based on taking the battery down to 0% charge. Always fully charge batteries before a trip.
Factors to consider
Other factors which may affect power usage and production:
Example:
Comes to a daily total of 62.6Ah per day, 42.6Ah of which will be used whilst the solar system is not gathering power.