Solar Energy MCQ Quiz in मल्याळम - Objective Question with Answer for Solar Energy - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Concept:

Power delivered by the solar cells is given by:

Pmax = (F.F) × VOC. ISC

VOC = Open Circuit Voltage

ISC = Short Circuit Current and f

F.F. = Fill Factor

Calculation:

The fill factor of solar cells is:

\(\rm{ F. F = \frac{ maximum \ power \ obtained}{V_{oc} × I_{sc}}}\)

\(0.65 = \frac{65 × 10^{-3}}{V_{oc} × I_{sc}}\)

\(V_{oc} × I_{sc} = \frac{65 × 10^{-3}}{0.65} = 100 \ mW\)

∴ option 1 and 3 satisfy the result

i.e.

V_oc × I_sc = 40 mA × 2.5 V = 100 mV

Voc × Isc = 50 mA × 2 V = 100 mV

Explanation:

Pyranometers:

• A type of actinometer (an instrument for measuring the intensity of radiation, especially ultraviolet radiation) used to measure irradiance of solar energy or the total hemispherical solar radiation within the preferred location as well as the flux density of solar radiation.
• The range of solar radiation extends between 300 & 2800 nm.
• The SI units of irradiance are W/m² (watts /square meter).
• Usually, these are used in the fields of research like climatological & weather monitoring, but current attention is showing interest in pyranometers for solar energy worldwide.

Pyranometer Working Principle:

• The working principle of the pyranometer mainly depends on the difference in temperature measurement between two surfaces like dark and clear.
• The solar radiation can be absorbed by the black surface on the thermopile whereas the clear surface reproduces it, so less heat can be absorbed.
• The thermopile plays a key role in measuring the difference in temperature.
• The potential difference formed within the thermopile is due to the gradient of temperature between the two surfaces.
• These are used to measure the sum of solar radiation.
• But, the voltage which is generated from the thermopile is calculated with the help of a potentiometer. The information of radiation needs to be included through planimetry or an electronic integrator.

Pyranometer Design/Construction:

The pyrometer design or construction can be done using the following three components:

Thermopile:

• As the name implies, it uses a thermocouple used to notice dissimilarity in temperature between two surfaces. These are hot (labelled active) and cold (reference) accordingly. The labeled active surface is a black surface in a flat shape and it is exposed to the atmosphere. The reference surface depends on the difficulty of the pyranometer because it changes from a second control thermopile to the covering of the pyranometer itself.

Glass Dome:

• The glass dome in the pyrometer limits the response of spectral from 300 nm to 2800 nm from 180 degrees of view. It also protects the thermopile sensor from rain, wind, etc. This construction of the second dome gives extra radiation protection among the inner dome & sensor compared to a single dome because a second dome will reduce the instrument offset.

Occultation Disc:

• The occultation disc is mainly used to measure the radiation of the blocking beam & diffuse radiation from the panel surface.

Pyrheliometer:

• The pyrheliometer is one type of instrument, used to measure the direct beam of solar radiation at regular occurrence.
• It collimates the radiation to determine the beam intensity as a function of the incident angle.
• This instrument is used with a tracking mechanism to follow the sun continuously.
• It is responsive to wavelength bands that range from 280 nm to 3000 nm. These instruments are specially used for weather monitoring & climatological research purposes.

Pyrheliometer Construction & Working Principle:

• The external structure of the Pyrheliometer instrument looks like a telescope because it is a lengthy tube.
• By using this tube, we can spot the lens toward the sun to calculate the radiance.
• Here the lens can be pointed in the direction of the sun & the solar radiation will flow throughout the lens, after that tube & finally at the last part where the last part includes a black object at the bottom.
• The irradiance of solar enters into this device through a crystal quartz window and directly reaches a thermopile. So this energy can be changed from heat to an electrical signal that can be recorded.
• A calibration factor can be applied once changing the mV signal to a corresponding radiant energy flux, and it is calculated in W/m² (watts per square meter).
• This kind of information can be used to increase Insolation maps. It is a solar energy measurement, that is received on a specified surface region in a specified time to change around the Globe.
• The isolation factor for a specific area is very useful once setting up solar panels.

Solar cell

• A solar cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.
• The output of the solar cell is of the order of 1 W.
• A solar cell is a sandwich of n-type silicon and p-type silicon. It generates electricity by using sunlight to make electrons hop across the junction between the different layers of silicon.
• When sunlight shines on the cell, photons (light particles) bombard the upper surface.
• The photons (yellow blobs) carry their energy down through the cell.
• The photons give up their energy to electrons (green blobs) in the lower, p-type layer.
• The electrons use this energy to jump across the barrier into the upper, n-type layer and escape out into the circuit.
• Flowing around the circuit, the electrons make the lamp light up.

String inverters handle groups of solar panels (strings) individually. If one string is affected by shading, dirt, or mismatch (like different panel orientations or aging), it only impacts that specific string, not the entire system.

In contrast, central inverters connect many strings together, and a problem in one string (like shading or a faulty panel) can drag down the performance of the whole system.

Thus, string inverters reduce power loss from partial shading or panel mismatch, increasing overall system efficiency and performance.

String Inverter Technology

• A string inverter connects a “string” of solar panels (typically 8–30 panels) to a single inverter. Each string is treated as an independent unit.
• DC power from each string is sent to a dedicated string inverter, which converts it to AC power. Multiple string inverters are used across a large system.

Central Inverter Technology

• A central inverter collects DC power from many strings (hundreds of panels), combined through DC combiner boxes, and converts all the power to AC in one large unit.
• DC strings feed into combiner boxes. Combiner boxes route the power to a single large inverter (hundreds of kW to MW). AC power is sent to the grid or a distribution system.

Concept:

LCD Modes:

1.) Reflective type cell:

If the one glass sheet used to sandwich the thin layer of a liquid crystal is deposited with transparent electrodes and the other with a reflective coating on their inside faces in a liquid crystal cell then it is known as a reflective type cell.

2.) Transmittive type cell:

If the two glass sheets used to sandwich the thin layer of a liquid crystal are deposited with a transparent electrode on their inside faces in a liquid crystal cell then it is known as a transmittive type cell.

3.) Transreflective type cell:

Transflective LCD displays have both transmissive and reflective characteristics. They contain an integrated backlight unit and a semi-transparent reflector or a reflector with a hole for each pixel.

The image shows a large collection of interconnected solar panels arranged in a grid to form a solar array.

Important terms related to Solar Plant:

• Solar Cell: The smallest unit that converts sunlight into electricity. Many solar cells make up a solar module.
• Solar Module (Panel): A single panel consisting of multiple solar cells connected.
• Solar Array: A group of multiple solar modules connected to generate higher power output. This is what is shown in the image.
• Battery Bank: A storage system for energy, but the image does not show batteries.

The correct answer is 6 to 7.

Key Points

• Rajasthan has a lot of solar energy potential.
• Rajasthan has a semi-arid climate, and the Thar Desert covers 66.66% of the state's total land area.
• With these climatic characteristics, it may receive 6-6.4 kwh/m² of solar radiation per day.
• This is the second-highest amount in the globe and around 300–325 sunny days annually.
• The western cities of Rajasthan often experience temperatures between 35 and 40 degrees, with summertime highs of above 45 degrees.
• Rajasthan has a solar energy availability of 6 to 7 kw/km².
• It has the capacity to produce 100000 MW of power year, albeit only 442.25 MW is currently being produced.

Additional Information

• Solar radiation intensity:
  • It is the density of solar radiation coming per unit area of the photoelectric module. 
  • Above the earth's atmosphere, solar radiation has an intensity of approximately 1380 watts per square meter (W/m²).