12 Volt Solar Questions

QUESTIONS ANSWERS
I have a garage with a workshop and I'm interested in a 12V solar power system. What size kit would I need to operate a roller door, one or two lights and operate some power tools? The size depends on how much power you use. A roller door uses about 500 watts, power tools use from 500 watts to 1500 watts.
First work out how much power you would be using each day.
let's look at some examples: Let's say you use solar power to operate a 500 watt roller door motor for 10 minutes a day (4 to 5 open/closes). You would need a 30Ah battery and 60 watt solar panel If you want to use a 1500 watt drill for 10 minutes a day that would require three times as much power, a 90Ah battery and a 180 watt solar panel.
Also, when you run AC appliances like the roller door and a drill that plugs into a wall socket then you also need an AC to DC power inverter, it connects to the battery and has one or two sockets on it that you use to plug in the roller door power lead and power tools with AC plugs.
Make an estimate of how much power you will use in a day or a week then ask us to quote for a system that will be able to supply that amount of power. When making an estimate of power consumption look at the power tag information on the power tools, look for WATTS or tell us the brand/model and how often it is used - how many hours or minutes they are used each day or if not used daily then per week. What type of lights do you have or need? How many hours usage per day/week? we recommend using LEDs that run off 12V ad use very little power.
   
Can I add to the solar lighting system I have now to produce more power to run extra lights? Yes, you can add another battery and solar panel and connect them in parallel for 12 volts or you can even connect them in series to  make a 24V system, which is better for minimising power losses in long runs of electric cables. Our lighting controller and LED lights will run on both 12 and 24 volt systems.
   
Can I use a timer to switch on the lights automatically at sunset? Yes the solar lighting controller has 2 timers - timer 1 for sunset and timer 2 for sunrise. You can enable both timers or disable any one timer, for example disable timer 1 and set timer 2 to switch on the lights 3 hours before sunrise. Timer operation is triggered by the light falling on the solar panel, timer 2 learns when to come on by remembering the sunrise time from the previous day.
   
What type of solar lighting can you suggest for a shipping container used for storage. All solar light systems require a solar panel to generate electrical power, a battery to store that power, and a solar regulator to ensure proper battery charging, and of course, lights.
We make up lengths of electrical cable to connect up the components and include a light switch, light timer or motion sensor, depending on your preference. Our 4 watt dome style LED lights will illuminate an area about 2x2 meters, therefore in a short 3 meter long container we would recommend two lights. For a 6m container 3 lights, and 6 lights for the longest,12 meter, containers. The size of the battery and solar panel depends on how long the lights are used.
   
I want to buy a simple hassle free reliable solar regulator for my two 80 watt solar panels. What do you recommend? There are two types of solar regulator; the basic PWM solar regulator and the more expensive MPPT types that have more complex electronics to extract the most current from solar panels. PWM are suitable for small PV systems.
Your 80 watt solar panels are 12 volt modules so you need a 12V solar regulator.
The two panels will generate a combined current of around 8 amps so the solar regulator must be rated for 10 amps continuous use.
The most basic one have four connections, two connect to the solar panel and the other two go to the battery terminal. Others have another set of connections for the load (Load is the technical term for anything that uses power) to control power usage so the battery will not be completely drained, instead it automatically disconnects the load when the battery level runs low and later reconnects when the battery has been recharged.
   

Can you show some of the technical requirements I should consider to make up a solar lighting system to light a 4x4 metre stable for 4 to 5 hours a night during the winter months. We are after general overhead lighting with enough light to be able to read.

 

To provide enough illumination for a 4x4 metre shed requires a minimum of four 4.2 watt LED lights. When used for 5 hours per night they will consume (4 lights x 4.2W x 5 hrs = ) 84 watt-hours. Now convert watt-hours (Wh) to amp-hours (Ah) to calculate the battery size. This is a 12 volt solar power system with power stored in a 12V battery so divide the watts by 12 to find amps.
The four lights have a combined Ah consumption of (84 Wh รท 12V = ) 7 Ah.
The battery should have capacity to store three times the daily power usage to allow for two cloudy days per week. It's also important that battery level be kept above 50% depth of discharge (DOD) to maintain maximum services life. Therefore the battery must hold six times normal daily usage = 42Ah.
The solar panel must be large enough to make up the daily usage plus 50% per day to make up for extra usage during cloudy days.
So it must provide ( 7Ah + 50% =) 10.5 Ah per day.
Based on four equivalent peak sun hours per day, it takes 5 watts of solar power to provide 1 Ah per day. Therefore this system requires a minimum of 55 watts of solar power.
Therefore I would recommend a 42 Ah battery and a 60 watt solar panel as the power source.