How do solar cells generate electricity?
Photovoltaics (PV) can be thought of as a direct current (DC) generator powered by the sun. When light photons of sufficient energy strike a solar cell, they knock electrons free in the silicon crystal structure forcing them through an external circuit (battery or direct DC load), and returning them to the other side of the solar cell to start the process all over again.
The voltage output from a single crystalline solar cell is about 0.5V with an amperage output that is directly proportional to cell’s surface area (approximately 7A for a 6 inch square multicrystalline solar cell). Typically 30-36 cells are wired in series (+ to -) in each solar module. This produces a solar module with a 12V nominal output (~17V at peak power) that can then be wired in series and/or parallel with other solar modules to form a complete solar array to charge a 12, 24 or 48 volt battery bank.
Solar Systems Philippines also offers pre-assembled Grid-Tie kits. This kit comes with all of the equipment that you will need including product/installation manuals, mounting rails, and clamps for your panels.
What components do I need for a grid-tie system?
Grid-tie systems are inherently simpler than either grid-tie with battery back-up or stand-alone solar systems. Mounting structures and wiring a grid-tie system is just solar modules and a grid-tie inverter!
The sophisticated grid-tie inverters incorporate most of the components needed to: (1) convert the direct current from the modules to alternating current, (2) track the maximum power point of the modules to operate the system at peak efficiencies, and (3) terminate the grid connection if grid power is interrupted form the utility.
What components do I need for a grid-tie system with battery back-up or OFF-grid?
There are many components that make up a complete solar system with the 4 main items as: (1) solar modules, (2) charge controller(s), (3) batteries and (4) inverter(s).
The solar modules are physically mounted on a mount structure (refer to Q7) and the DC power they produce is wired through a charge controller before it goes on to the battery bank where it is stored.
The two main functions of a charge controller are: (1) to prevent the battery from being overcharged and (2) eliminate any reverse current flow from the batteries back to the solar modules at night.
The battery bank stores the energy produced by the solar array during the day for use at anytime of day or night. Batteries come in many sizes and grades.
The inverter takes the DC energy stored in the battery bank and inverts it to 120 VAC to run your AC appliances.
Will solar work in my location?
Solar is Universal and will practically work anywhere — yet, some locations are better than others. (1) Irradiance is a measure of the sun’s power available at the surface of the earth and it averages about 1000 watts per square meter. It is expected to generate about 140-160W per square meter of solar cells placed in full sun with typical crystalline solar cell efficiencies around 14-16%. (2) Insolation is a measure of the available energy from the sun and is expressed in terms of “full sun hours” (example: 4 full sun hours = 4 hours of sunlight at an irradiance level of 1000 watts per square meter).
Apparently, for those parts of the world that receive more sunlight from others, they will have more “full sun hours” per day.
Please refer to the Residential Solar Guide, Solar Insolation Zone Map to give you a general idea of the “full sun hours per day” in your location.
How can I find out the average sunlight hours I get where I live?
Usually, the average sunlight hours are quite consistent from where you live. For your convenience, we have a Solar Map of the Philippines that can help estimate the size of the solar system that you will need based on your information. Click here to view the System Sizing Estimator.
How much will a system cost per square foot for my home?
There is no average per square foot since the cost of a system depends on:
- your daily energy usage
- the daily full sun hours received in your location
- other sources of electricity
To accurately size a system that will meet your requirements, we need to know:
- how much energy you use
- electricity usage costs
- the average peak sun hours in your location
The cost of the system will depend on the percentage of electricity you hope to gain for your energy needs.
If your home is connected to the utility grid, simply look at your monthly electric bill, then call us. We will try our best to help you design a system that will suit your needs!