Frequently Asked Questions on LEDs: (FAQs on Solar Products / Energy)

1. What are LEDs?
LED is an acronym for Light Emitting Diode. LEDs are Solid-State Components. They have

• No Moving Parts
• Are not fragile
• Last for decades

2. How is Light Produced in a LED?
Light Emitting Diode (LED) is a semiconductor Diode. LED consists of p-n (positive-negative) junction made of Semiconducting material. When connected to a power source, current flows from the p-side or anode to the n-side, or cathode, but not in the reverse direction. Charge-carriers i.e. electrons and electron holes flow into the junction from electrodes. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon (light).

3. What is the life time of LED?
LED has a longer lifespan that can stretch anywhere from 50,000 hours to 80,000 hours. Real lifetime of lamps are closely related to the device and operation, in addition, heat elimination, working temperature, working voltage and current and maximum junction are the important factors in lifetime and Rated lamp lifetime is valued when the lamps are 70% brighter than usual.

Based on how long a fixture is illuminated per day, here's what 50,000 works out to:
Hours of Operation: 50,000 hours is:
24 hours a day 5.7 years
18 hours per day 7.4 years
12 hours per day 11.4 years
8 hours per day 17.1 years

4. What type of Colors you can get in LEDs?
High-brightness LED could produce various colors covering in the whole visible light spectrum; NaBa Green uses either Warm White or Cool White.

5. What is the efficiency of LEDs?
The efficacy of LED changes along with the color and white color temperature. For example, the efficiency of 5000K white light is 15-20% higher than 3000K white light. We provide the maximum luminous efficiency up to 115 lm / w, achieving the maximum output in terms of performance per watt.

6. What is Watt?
Watt is a measure of power consumption. A 100 watt bulb incandescent bulb and 20 watt energy saving bulb give off about the same amount of light, but consume different amounts of power.

7. What is Lumen?
Lumen measures how much light a radiating light produces, but gives no information about energy consumption.

8. What is Candela and Lux?
Candela discloses how much light from a directed light source with a certain dispersion angle reaches a defined point. Lux is the most common measurement of light intensity and states the amount of luminous flux reaching a specific area from a light source.

9. What is Color Temperature?
Kelvin elates to the colour temperature of the light. For example a common bulb has a colour temperature of 2700° Kelvin.
Colour temperature: Hue:
2700 K Incandescent light
3000 K Warm white
4000 K Cold white
6000 K Daylight

10. How are Bulbs rated?
Energy efficiency rating for bulbs and fluorescent tubes
A = More efficient
G = Less efficient
Letter designations in text or figures indicate a bulb s energy efficiency rating on a scale from A to G

11. What will be your saving compared to other sources of Light with LEDs?

INCANDESCENT LAMP:
25W = 3W LEDs	40W = 7W LEDs	75W = 10W LEDs	100W = 15W LEDs
HALOGEN LAMP:
20W = 2-3W LEDs	35W = 4W LEDs	50W = 7W LEDs
HT-SODIUM LAMP:
75W = 30W LEDs	150W = 60W LEDs	250W = 120W LEDs	400W = 180W LEDs

Depending on the actual application, environment and design of LED Fixture, the values may change.

12. What is an Incandescent Bulb?
Incandescent bulbs create light by passing electricity through a metal filament until it becomes so hot that it glows. Incandescent bulbs release 90% of their energy as heat.

13. What is a Halogen Lamp?
Halogen lamps as opposed to common bulbs are filled with halogen. They give substantially more light, up to 100% more than a regular bulb. They also save 30% on electricity, reduce carbon dioxide emissions by 30% and have twice the operating life of a regular bulb.

14. What are CFL or compact fluorescents?
In a CFL, an electric current is driven through a tube containing gases. This reaction produces ultraviolet light that gets transformed into visible light by the fluorescent coating (called phosphor) on the inside of the tube. A CFL releases about 80% of its energy as heat. Energy saving bulbs and compact fluorescents use 80% less energy than a regular bulb and last up to 15 times longer. It remains eco-friendly throughout its entire lifecycle thanks to reduced energy consumption and waste production. Energy saving bulbs contain a small amount of mercury and should therefore be properly disposed of at a recycling.

15. What is a LED Lamp?
LED lighting products use light emitting diodes to produce light very efficiently. The movement of electrons through a semiconductor material illuminates the tiny light sources we call LEDs. A small amount of heat is released backwards, into a heat sink, in a well-designed product; LEDs are basically cool to the touch.

LED stands for Light Emitting Diode. A LED is a semiconductor which produces light within a narrow spectrum. LEDs have very low energy consumption, emit little heat and have an average lifetime of up to 50,000 hours. A LED can unlike other light sources, change color.

Frequently Asked Questions on Solar Products / Energy: (FAQs on LEDs)

1. What is Photovoltaic (PV)
Photovoltaic means electricity from light. The photovoltaic (PV) process converts free solar energy directly into electricity.

2. What are solar cells?
Solar cells are basic building blocks for PV modules. They are usually made of thin wafers of Silicon. The basic function of a solar cell is to convert sunlight energy into electric current.

3. What is a PV module?
A group of Solar cells connected either in series or parallel encapsulated in a laminate. PV modules deliver direct current (DC).

4. What are Solar Home Systems?
A Solar Home system (SHS) is a system that converts solar energy into electric energy for domestic purposes.

5. What are the components of a Solar Home System?
The system consists of Power pack and Loads. Power pack consists of PV module, inverter, charge controller and battery. Loads consist of appliances such as lights, fans, TV, etc

6. What are the different types of Solar Home Lighting Systems?
Direct System (DC) System and Alternating Current (AC) system. DC System: A system that generates DC power and runs only DC appliances. These systems can be used for basic lighting, DC fans, TVs etc. AC System: A system that converts the DC power generated to AC power using an Inverter. This system can generate 230V AC power which can be used to power all AC appliances such as colour televisions, ceiling fans, music systems, refrigerators, electric blenders (mixers), lights, etc.

7. What are solar inverters?
PV modules deliver DC current. An inverter is therefore required to convert the DC power to AC power that is used in conventional utility powered appliances like color TVs, fans , refrigerators etc.

8. How should a PV module be mounted? What are Tilt angles?
In order to optimally receive solar irradiation, PV modules must always face the equator. They are mounted at a certain Tilt angle, which is approximately the latitude of the location.

9. How do I estimate the energy requirement for my home?
Our trained sales personnel would help you arrive at the optimum energy consumption. However you could use this formula for arriving at the load consumption Daily energy demand = No. of loads X Power consumption of load X Daily usage( hours) Load - TV, fridge, Tube lights, CFLs, Incandescent bulbs etc.

10. How do I arrive at a SPV system configuration for my daily energy consumption?
Based on your daily energy consumption, a SPV system is “sized” and a solution arrived at. We at Environ Energy specialize in system sizing and installation. Contact us at info@nabagreen.com

11. Do you provide energy solutions to institutions and industrial enterprises also?
We are proud of our attempts to cater to the unique needs of each customer, and we are heartened by the trend of people buying bigger systems. Our solar solutions range upto MW catering to a wide section of clientele.

12. What is Solar Thermal? Is it the same as Solar PV?
Solar Thermal systems produce heat from Sun’s radiation whereas Solar PV systems convert light directly into electricity using semi-conductor technology.

13. What is the maximum temperature of hot water that can be attained by using a solar water heater (SWH)?
Temperature of hot water depends on ambient temperature. However during summer temperature attained can be greater than 600C

14. How does a Solar Water Heater work? What are the different types of SWH?
There are 2 types of SWH - Flat Plate Collector (FPC) and FPC SWH - The solar radiation is absorbed by flat plate collectors which consists of a metal box covered on top with a glass sheet. Selectively coated blackened metallic absorbers form the bottom part of the box. The sides and bottom are insulated to minimize heat loss. The absorber consists of riser tubes to carry water. The absorber plate absorbs the solar radiation and transfers the heat to the flowing water through the riser tubes to the insulated storage tank Evacuated Tube Collector ( ETC) water heaters. ETC SWH - The collector is made of double layer borosilicate glass tubes evacuated for providing insulation. The outer wall of the inner tube is coated with selective absorbing material. This helps absorption of solar radiation and transfers the heat to the water which flows through the inner tube. The vacuum within the evacuated tubes reduce conducted heat losses. This system is suitable for hard water areas (hardness up to 800 PPM)

15. What are the commonly used SWH capacities for domestic application?
Solar water heaters of 100-500 litres capacity are suited for domestic application. Larger systems in excess of 1000 litres can be used in restaurants, canteens, hotels, hospitals, process industries etc.

16. What is the payback period of a 100 LPD SWH system?
A 100 LPD system pays back in less than 4 years. A 100 litres capacity solar water heater can replace an electric geyser for residential use and saves 1500 units of electricity annually.

17. What are the environmental benefits of using a Solar Water heater?
A Solar water heater of 100 litres capacity can prevent emission of 1.5 tonnes of carbon-dioxide per year.