Alpha Services
Why Solar?
PV Cell or Solar Cell
Solar Panel
PV System?
Solar Inverter
Deep Cycle Battery
Inter Tie Meter
Racking System
Wiring System
On-Grid Solar System
Off-Grid Solar System
Step by Step Process

Will Solar Work
for my Home?


Frequently Asked Question (FAQ):

Q. What are the advantages of solar generated electricity?

A. Solar electricity generates energy without polluting the environment: no emissions, no noise and no waste. Solar panels require very little maintenance. The amount of electricity produced by a solar system varies depending on the amount of sunlight available yet it produces long-term, reliable electricity.

A solar system can be installed almost anywhere under direct sunlight, making it more versatile than other renewable energy sources. Sun Earth PV systems have been installed from small household rooftops to large utility scale power stations around the world.

Q. What is Vertical Integrated Production?

A. A PV module manufacturer achieves vertical integrated production when they oversee the entire production process of solar modules. It starts from silicon mining, ingot production, wafer cutting, to manufacturing solar cells and assembling modules. With this vertical integrated progress, the manufacturer controls the quality of every single aspect of the manufacturing process. Alpha manufactures solar modules using a vertical integrated production. This is how Alpha guarantees the highest quality of solar modules with a 25-year warranty.

Q. Will a PV system work in cold weather?

A. PV systems also work well in cold weather. In fact, PV generates electricity from light, not heat. It will perform even better in cooler areas than in a hot area with the same amount of sunlight. Alpha’s 500kW system in Italy has a very good performance with temperatures under zero degrees Celsius.

Q. How long will PV modules generate electricity?

A. The life cycle of a PV module depends on the quality of the solar cell. Top quality modules, such as the Sun Earth solar module with its own quality control in cell production, are designed to generate electricity for at least 30 years. With Alpha’s 20 years warranty, solar modules are warranted to produce 90% for first 10 years and 80% for the next 10 years of their original minimum power rating. In fact, most of the Alpha modules installed working perfectly , producing over 95% of their original performance.

Q. How to choose a PV module?

A. There are several important factors to consider when choosing a PV module. The first is verifying the quality of the module through their certifications. In Australia, the International Electro technical Commission’s Standards (IEC) is the authority for solar module certification. Solar modules must also comply with IEC61215 and IEC61730 (Class A) in order to apply for Australian government rebates. There are some other safety standards widely used around the world, like Underwriters’ Laboratories (UL) and CE. The next step is check construction of the module. It should feel solid when lifted. Check that the junction box is firmly attached. Pay attention to the length of the warranty and make sure the company who manufactured it has a good reputation.

Investigate whether the solar module company has total operational control of their products. Do they manufacture the module only with outsourcing the solar cell? Do they have an established business that will be operating into the foreseeable future? Have their products proven reliable in many years of operation? Finally, what are the price points of the module and how do they compare?

Q. What is the difference between mono-crystalline and poly-crystalline modules?

A. In general, the solar cell efficiency of mono-crystalline is slightly higher than the poly-crystalline. Alpha tests every single cell in our manufacturing process to ensure the power generated by mono-crystalline which is very high efficient modules is as indicated on the label. That means the power performance of a 200 Watt mono-crystalline module is the same as a 200Watt mono-crystalline module.

Q. What is the warranty on the solar modules?

A. The warranty on Alpha Solar modules first 10 years 90% power guarantee, and 25 years 80% power guarantee, and 5 years materials and workmanship warranty.

Q. How does a solar cell work?

A. Solar cells convert light into electricity. To convert sunlight into electricity light must be absorbed in the solar cell.

Collecting sunlight to make electric current at the junction of two substances, photovoltaic (or PV) technology is the most harmless method of power generation. PV is a direct current (DC) generator powered by the sun. When light photons hit the surface of a solar cell, electrons roam free in the silicon crystal structure forcing them through an external circuit (battery or direct DC load), and then returning them to the other side of the solar cell where the cycle recurs. The voltage output from a single solar cell is about 0.5V with an output that is directly proportional to cell's surface area (approximately 7A for a 6 inch square for a typical solar cell).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 with other solar modules.

Once a light generated carrier is collected, it can be either extracted from the device to give a current, or it can remain in the device and gives rise to a voltage. Generally, some of the light generated carriers are used to give a current, while others are used to create voltage. The combination of a current and voltage give rise to a power output from the solar cell.

Q. Is PV economical?

A. PV becomes increasingly economical as the size of the load becomes smaller and distant from grid power. If grid power is not available and the required energy is that of a typical household load, a PV system is usually the lowest cost option. For consumer appliances, PV can be up to 100 times cheaper than battery power.

For cases where reliable grid power is readily available, PV is usually not the lowest cost option, unless environmental impacts are factored in. Even in these cases, the economic viability of PV varies.

PV is not technically or economically suited to large base-load power for utilities, but may be suited to power production for individual houses in locations with high peak electricity prices occurring during the day. For grid-connected applications, the costing of a PV system for a particular location and application needs to be considered on a region-by-region basis.

Q. What are the advantages and disadvantages of PV?

A. In a number of applications, PV systems have several important technical advantages that make them the best choice for electricity generation. PV panels are extremely reliable and require low maintenance, they can operate for long periods and they are suitable for both large and small loads. These characteristics make PV an ideal choice for both remote power and remote residential electricity applications. For such remote applications, a PV-based system is usually the lowest cost choice. There are a number of other advantages, such as the distributed nature of PV power production and the low lead times to installation, which may be beneficial in grid connected installations. PV electricity generation is also environmentally friendly, with the lowest environmental impact of any of the electricity generating technologies.

The disadvantage of PV is its high cost compared to many other large-scale electricity generating sources. This applies to the use of PV for applications that are already tied to the electricity grid. Another concern is that the power density of sunlight is relatively low. This means PV tends to be less suited to applications that are physically small compared to the amount of power they require. Although solar cars, solar trains, solar planes and solar boats have all been made and used, in general these applications are difficult for PV or other solar-based systems.

Q. What are the components of a photovoltaic system?

A. The possible components of a PV system are a power conditioning sub-system, a storage mechanism, and other general components called “balance of system” (BOS) components. The power conditioning sub-system serves two functions.

One component of a power sub-system is often called a charge controller, which ensures that a battery in the system is charged from the pv array. The second component is an inverter, which converts the low DC voltage of the pv system into the same type of power (higher voltage AC) produced by a utility company Depending on the type of application, the inverter may also serve several other functions, such as battery charging or may disconnect the system from the utility when necessary. Another possible component of a PV system is the storage system. When included, this is usually battery storage, consisting of lead-acid batteries modified from those in cars in order to allow large amounts of energy to be drawn from them. Other system components are usually grouped under the term BOS and include the wiring of the array, the array mounting and battery housing.

The components of a PV system depend on what the system will be used to power. If the load is DC, then the inverter (which converts AC to DC) is not needed. Similarly, if the system is connected to the utility grid, the storage (and hence a charge controller) is not needed, while the inverter is.

Residential Solar FAQ

Q. How Does a Solar PV System Work?
A. Solar PV systems consist of modular panels made of silicon, which transform light energy into electricity. An inverter converts DC (direct current) generated by the panels into AC (alternating current), supplying power to your home or to utility.

Q. What Size System Do I Need?
A. Solar PV Installation Inc. tailors PV systems to the unique circumstances of each home or business. A detailed site survey is conducted to determine the appropriate system size. We provide these services at no cost.

Q. How Much Does A PV System Cost?
A. System cost depends on size, materials and labor. Most Solar PV Installation Inc. systems pay for themselves within 7 to 9 years. Every PV system is sized and designed to optimize performance and aesthetics.

Q. The 3 Main Types of PV Cells, which is best?
A. Monocrystalline: made from thin slices cut from a single crystal of silicon.
Polycrystalline: made from thin slices cut from a block of silicon crystals.
Thin Film: made from a very thin layer of a semiconductor deposited on a glass or metal base.
Monocrystaline PV solar is the most efficient solar sold around the world.

Q. Is there enough sunlight to make a contribution to the world’s energy needs?
A. Yes. The earth receives more energy from the sun in just one hour than the world uses in a whole year.

Q: I want to use solar panels at home to lower my electricity bills. I don't know my daily electricity consumption. Where should I start?
A: You can find your monthly consumption from your electricity bill. Due to the seasonal usage, it is better to see the bills in different seasons and find the average usage per month. Then divide it by 30 in order to get your daily usage.

Q: I know my daily electricity consumption but I don't know which system to choose?
A: There are three types of photovoltaic system. Grid-Tie Systems, Grid-tie Systems with Battery Backup and Off-Grid Systems. For the details check our educational page.

Q: What factors should I take into account in order to choose the solar panel?
A: Usually the panels are selected by their power and their output voltage.

Q: The maximum panel I found on the internet was 250 watts while I need 1kW (1000 Watts) power. How do I know the number of the panels?
A: 1000W divided by 250W is 4 panels, but in reality you should overshoot your power requirements because the 250W rating is the maximum power, not the power for normal usage.

Q: The solar panels produce direct current (DC) but I want to use it for my house lighting and the lights need AC current. What should I do?
A: You need an inverter to get the same type of electricity as the utility.

Q: What is an inverter?
A: An inverter is a device which converts the Direct Current (DC) into Alternative Current (AC). If you want a photovoltaic system for your house or office, you need an inverter. For more information about the inverter, please visit the inverter page.

Q: Some inverters have 110V/60Hz output and some 220/50Hz. How can I make sure that I have chosen the right one?
A: In fact the voltage and frequency varies in different regions. For example, most of the countries in American continent use 110 Volt/60Hz electricity while in Europe and Asia the Voltage and frequency is 220V/50Hz and when you want to choose an inverter, you have to make sure the its output is compatible to your region standard.

Q: What is the difference between panels in parallel and panels in series?
A: Panels in parallel add their current ratings while their voltage remains the same. Series connections add the voltage while keeping the current the same (the exact opposite of parallel connections).

Q: At the back of the panel, I see the Voc (open circuit voltage) and the Isc (short circuit current), what is this information for?
A: Normally, you should know the voltage of the panel in order to choose your inverter or battery bank or even if you want to connect it directly to the consuming device. Isc represents the maximum current produced by the panel; the current cannot reach this value once in a circuit.

Q: I turn my system on but after couple of seconds, the inverter turns itself off. What is the problem?
A: The load is too much and the inverter can't supply enough current. You should disconnect or turn off some consuming devices.

Q: I have had my system for a while but it has stopped working. How can I find the defected components?
A: The easiest test is starting from your panels. We assume that you have a Multi-meter and you know how it works. Otherwise we recommend you to find a local technician to do that because it is dangerous to touch the components if you don't have any basic knowledge of circuits/electricity.

Q: How should I install the panels in order to keep them in good condition?
A: It is recommended to put some space between the panel and the roof in order to let fresh air pass under the panel. Since some of the sunlight heats the panel, it will get hot if air is not allowed to flow. The higher temperature can also affect the efficiency.

Q: How can I test a panel?
A: First disconnect the panel from the system, then measure the output voltage by a regular multi-meter and compare it to the voltage written on the back of the panel. Normally under the direct sun, the rated voltage is a bit higher. Make sure that the multi-meter is on DC.

Q: The panel looks in good condition but the output voltage from the panel is too low, how can I fix it?
A: Open the junction box at the back of the panel. If the terminals are corroded or burned, you should change the junction box.

Q: I have opened the junction box and everything is in good condition but the output voltage is too low. What is the problem?
A: The diodes are defected or they are in wrong direction.

Q: How can I test the diodes?
A: For testing a diode, you should take it out. Put your Multi-meter on diode test. Connect the red wire of multi-meter to the cathode of diode and the black wire to the anode. The cathode of the diode is always marked by a dash or a line on the diode. If you hear a beep or see a number on your digital Multi-meter, it means that the diode is defected and you should change it. If not, flip the diode and test it in other direction, you should see a number or hear a beep. Otherwise the diode is defected and you should change it. Make sure that you have performed the test in both directions.


Home | About Us | Services |FAQ | Contact Us | Copyrights © Alpha Solar Energy 2010