What is PV?
PV is the acronym used to represent the term photovoltaic. Photovoltaic was derived from the Greek word φώς phos meaning “light” and from the name of Allesandro Volta, the Italian physicist to which the electrical unit, volt was named in his honour. So, photovoltaic literally means light-electricity which is exactly what photovoltaic materials and equipment do-convert light energy to electricity.

How do we generate electricity from the sun?
In simple terms, just shine light onto a solar cell and you will get electricity.
In more detailed terms, PV works when a certain semiconducting material is exposed to sunlight, releasing small amounts of electricity known as the photoelectric effect.
The photoelectric effect is the conversion of electromagnetic radiation (photons) to electrical voltage by a material.
Sunlight is made up of photons and when it strikes a PV cell, they will either be absorbed, reflected or passed through the cell. The absorbed photons generate electricity and the energy of the photon is transferred to an electron in the atom of the PV cell which is made up of a semiconducting material.
The energized electron in the atom of the semiconducting material then escapes from its normal position and forms part of the current in an electrical circuit.  When the electron leaves its normal position, an empty spot forms. The voltage needed to push the current through external loads is provided by a built-in electrical field. This is a special electrical property of the PV solar cell.

What is a PV module?
A PV module is a made up of a group of solar cells assembled in a commercial unit, ready for installation.
Voltage for a solar cell is about 0.6 V and the maximum short circuit current is over 3 A. As the voltage is insufficient for many loads, the solar cells have to be connected in series.
One PV module has typically 36 cells and modules are connected in series as a string and  depending on the application also in parallel to the array. Thus a solar generator consists of several strings (modules in series) connected in parallel.
A PV module normally has a specified power rating and given a performance warranty by the manufacturer for 20 to 30 years.

What types of PV solar cells are there? There are two main types of solar cells available in the market today. Poly-crystalline solar cells have the highest market share, followed by the mono-crystalline technology and amorphous silicon. Copper Indium diSelenide (CIS) and Cadmium Telluride (CdTe) are new technologies.

BIPV
What is BIPV?
Building Integrated Photovoltaic (BIPV) is the buzz word used to describe multifunctional solar products that generate electricity while serving as construction materials. There is a large variety of BIPV products available in the market today. They are not only flexible in shape but can come in various colours and functions. BIPV can provide benefits and contribute to enhancing the attractiveness (or uniqueness) of a building’s design.

How are BIPV systems used?
BIPV systems can be aesthetically integrated into the building from the initial stages or retrofitted to an existing building. BIPV can be used as a:
Roof,
Façade,
Skylight
Atrium
Awning

What do the terms watt (W), kilowatt (kW), and kilowatt-hour (kWh) represent?
A watt (W) is a unit of power. A kilowatt (kW) is a thousand watts and a megawatt (MW) is a million watts. A watt-hour (Wh) is a unit of energy, or power multiplied by time. A kilowatt-hour (kWh) is a thousand watt-hours and a megawatt-hour is a million watt-hours (MWh). The electricity you purchase from the utility is measured in kilowatt-hours (kWh) and 1kWh is termed as 1 unit. Most single-family homes use 20 kWh or more per day. A refrigerator uses 1.2 kWh per day, and a computer uses 2.4 kWh per 8-hour workday.

What is the difference between AC and DC electricity?    
Alternating current (AC) electricity is the type of electricity used by lights, electrical appliances, and machines in Malaysia. The voltage of this electricity is constantly alternating. PV modules, however, produce direct current (DC) electricity, which has a constant voltage. This electricity has to be converted to AC by an electronic equipment called an inverter in order for it to be used by your electrical devices. The wires and inverter causes a slight loss of energy, so the AC output is about 90 to 95 % of the DC electricity.

Grid Connection
What is the difference between stand alone and grid-connected BIPV systems?
In a grid-connected BIPV system, batteries are not required for storage. The utility’s grid itself (TNB, SESCO or SESB) will act as storage and electricity from the utility will supplement the PV generated electricity.
For stand alone systems, batteries are required to store the energy generated by PV. This system is mostly used in remote or rural areas where the main electricity supply from the utility is not available.

What happens if a power cut occurs?
If a power cut occurs, the grid-connected BIPV system will automatically shut off. This is to ensure that electricity does not leak onto the national grid which may pose as a threat to the safety of those that may be working on the grid to restore power supply.

BIPV Systems
How much does a BIPV system cost?
Check out local BIPV systems pricing trend at http://www.ptm.org.my/bipv/database.htm

What is the capacity (kWp) required by my premise?
It depends on the household load consumption. For example, a 5 kWp system can save approximately up to RM150 on the monthly electricity bill (based on current TNB electricity rates with effect from 1 June 2006).

What is the BIPV system lifetime?
The performance of the PV modules is guaranteed between 15 to 30 years (manufacturer specific). The PV having no moving mechanisms is meant to last for a long time. However, the performance may deteriorate between 10 to 20% over a 20 year period. For inverters, the warranty given by the manufacture is normally between 5 to 10 years (as stated by three leading inverter manufacturers in the world).

Do I need to maintain my BIPV system?
A BIPV system has no moving parts, is silent in operation and requires no maintenance. As Malaysia is located close to the equator, there is abundant rainfall and therefore, the PV modules do not require regular cleaning. Nonetheless, it is a good practice to ask your PV service provider to conduct periodic checks (every 2 years) on the inverter, cable tightness, system connections, and mounting structure.

Will a BIPV system cause my roof to leak?
Most flat roof installations do not require penetrations therefore do not increase the chances of leaks happening. Instead a BIPV system can actually protect a flat roof beneath it from ultraviolet rays and leaks. The general rule to ensure that roof leaks do not happen is to never puncture a hole on the roof tile!

What about location of the BIPV systems? What must I know to ensure the BIPV systems are installed to give the best performance for my house/building?
There are a few things to look out for. First of all, ensure that the PV modules are not shaded. Shading is highly critical as it can cause significant loss of energy. Shading may happen if your building is surrounded by other buildings or by tall trees around the area.
The second point to remember is to choose the best location when installing the BIPV systems such as at the highest part of the house/building. Lastly, ensure that the tilt angle for the PV modules are at the recommended angle that is, less than 30 degrees. Since Malaysia is located close to the equator, installations with more than 30% tilt will have a lower energy yield.

What is the required area to install PV modules?     
Basically an 8 to 10m2 area is needed for a 1 kWp PV modules for monocrystalline or poly crystalline technology. These two are the most common technologies. The other technology would be the amorphous silicon type and the area required is about 16 to 20 m2 per kWp capacity.

Can I add on more PV modules and increase the size of my BIPV system in future?
Yes, you definitely can. The only limiting factor would be the availability of roof space as well as your budget!  Also, do not forget to ensure that your inverter matches your PV modules

Are BIPV systems only meant for new buildings? Can I retrofit to existing buildings?
BIPV systems are not only meant for new buildings but can be retrofitted to existing buildings as well.

Why should I consider installing a BIPV system?    
A BIPV system reduces or eliminates the amount of electricity you purchase from the utility (TNB, SESCO or SESB).  A BIPV system also reduces your monthly electricity bill and acts as a hedge against future electricity price increase. The electricity generated is clean, renewable and reliable.
By installing a BIPV system, you are helping the community reduce the peak load on the utility’s grid (TNB, SESCO or SESB) and you can also provide additional electricity for the grid when you generate more than you use during the day.

Do I have to select certain appliances to be powered by the PV system?
No, the solar electricity is fed through your main electrical distribution system via an inverter and can be used by any lights and appliances just like utility electricity.

What is Grid-Connected BIPV?
Grid Connected BIPV means that the BIPV system is connected to the utility electricity grid, so that the electricity generated by the BIPV system feeds the local load and sends the surplus electricity into the electricity grid when the user demand is low. There are no batteries in this system to store the PV generated electricity as the grid acts as your ‘store’. During the day when there is less electricity consumption, the excess electricity is fed-back into the grid. During the evening when the electricity consumption increases, electricity would be drawn from the grid.

How do I know if my Grid-connection is safe?       
Your PV service provider will install the BIPV system in accordance with the installation guidelines as detailed in the Malaysian Standard MS 1837:2005 Installation of Grid-Connected Photovoltaic (PV) System. Before the system is interconnected to the utility grid, it will be tested and commissioned by the service provider and witnessed by he utility’s representative. The service provider will also have to send a test and commissioning report to PTM (MBIPV).
It is thus essential to engage a PV service provider to carry out the competent installation of the PV systems.
(Note: PV service providers will have a competency certificate awarded by UniKL-BMI. Training will commence in Q2 2007.)

How do I know if my system is working well?
Your BIPV system installation includes a PV meter, which records the total electricity generated by the BIPV system. You can see the PV meter, which will be installed close to the TNB meter for residential consumers, and you can monitor the increasing amount of electricity generated and sent to the utility grid.  In addition to the above, your system will be monitored by a PV Monitoring Centre, being established under the MBIPV Project. The PV Monitoring Centre will monitor the performance of the BIPV installations under the MBIPV project, and prepare statistical monitoring reports of the BIPV Installations and oversee responses to all faults reported if problems are encountered.