How to calculate how much solar panels I need to support my equipment?

  • First calculate the total watts required for your equipment. Let’s assume 50W.

    Let’s assume your equipment will run 24hrs per day.

    50W x 24hrs = 1200Wh ; so each day you are consuming 1200W

    Figure out your worst case winter sun in your area;   let’s assume it’s 3hrs peak sun per day.

    So with 3hrs of sun you need to generate 1200W of power

    1200W per day equipment load / 3hrs sun per day = 400W of solar panels

    *** This is the absolute minimum amount of solar you would require. With solar it’s always a good rule of thumb to add at least 20% additional capacity, so the recommended would be 500W minimum of solar panel capacity to support 50W equipment load with 3hrs of sun per day.

How long will my battery backup power my equipment?

  • To figure out how long a battery backup system will keep your equipment powered there is a fairly simple calculation you can do:

    ((Battery Capacity (Ah) x Battery Voltage (12V)) x Percent Discharge (50%)) / Your Equipment Load (W)

    So let’s say your 12V battery capacity is 100Ah and your equipment load is 50W

    We use 50% discharge because you really don’t want to discharge batteries much more than 50% if you want them to have a long life.

    100Ah x 12V = 1200Wh

    1200Wh * 0.5 (50% discharge) = 600Wh (adjusted battery capacity)

    600Wh / 50W = 12hrs backup time

Can I use automotive batteries for solar systems?

  • Automobile batteries are designed as high current starting batteries and are not designed for low current applications such as solar systems. The life of automobile batteries will be very short. We recommend using quality AGM or GEL batteries which are designed for solar applications for best results.

Where can I find my Peak Sun Hours?

  • Go to resources à calculators. Follow the “Lookup” link next to “Average Hours of Peak Sunlight per Day” field. Enter your zip code or city state to look up average peak sun hours each month. Alternatively, NREL (National Renewable Energy Lab) provides a free tool called “pvwatts” (http://pvwatts.nrel.gov/ ) for more specific data in more locations and more detailed information.

I have my system hooked up but I’m not getting the correct voltage out of the controller, what’s wrong with it?

  • Most often this might be caused by loose or incorrect connections, or the product is designed for a different application. First check the installation manual to be sure all connections are correct and that the device is designed to supply the voltage for your application. If all connections are correct, check the power supplies. Are the batteries charged sufficiently for the load? If it is a solar charge controller, are the solar modules connected correctly and are they receiving good sunlight to operate? Always best to review each components manual to ensure a safe and successful installation.

What is a Peak Sun-Hour?

  • 1 Peak Sun-hour = 1000 Wh/m2= 1kWh/m2The Sun provides approximately 1000 Watts ofPowerper square meter of area at Earth’s radial distance from the Sun. For every 1 hour the Sun provides that power, the Energy applied to that square meter is equal to 1000Wh. (Energy = Power x Time) Due to the Earth’s curvature and rotation, 1 square meter of the Earth’s surface does not always get the full 1000W of power the Sun is providing. For simplicity of calculations specifically for solar system performance, we add up all of the Solar Energy provided to 1 square meter in a specific location over the course of a day, or average day of a year, and divide it by the standardized power of 1000W/m2This provides an easy to deal with unit of Average Solar Energy Irradiance per day in a location… or Peak Sun Hour. So, even though sunrise to sunset may be 12 or more hours… the Sun at 5 to 6 PM is not nearly as strong as the sun from 11AM to 12PM. Peak Sun-Hours allows us to mesh all of those bits of energy together to 1 average unit for easier calculations for energy production.

How much sun does my RemotePro need?

  • The RemotePro® is designed to fully recharge the supplied batteries in a 24 hour period with 6 hours of peak Sun. One hour of Peak sun is equal to 1000W per square meter of sunlight.  Fewer peak sun-hours means a longer time to fully recharge the battery bank.  The amount of peak sun varies for any location. It is recommended to check with a data base tool like PV watts provided by NREL to determine the sun hours you can expect in your area.  Pay close attention to the winter months, as they will generally have fewer available Peak Sun Hours. Adjusting the solar modules to a steeper tilt can help mitigate the shorter days.  

What information do you need to help me size a system?

  • We need to know the load in watts for each piece of equipment you plan to use. We also need to know the operational voltage for each piece of equipment and if it is powered thru wires or PoE. A good way is to send us a spec sheet for the equipment that you plan to power and we can analyze the given information to size out the best system for you. 
  • For solar systems it's important to know Peak Sun Hours at the site so we need to know where you plan to deploy the system. Provide us with zip code or city/state/country.