Urja Khabar
Kathmandu : As part of our weekly series on ‘Urja Gyan’, published every Friday, this week (11 Asoj) topic we have made an effort to provide information about solar energy and its advantages and disadvantages. In the previous week, we had mentioned the benefits and drawbacks of hydropower.
1. What is Solar Energy?
Answer : The sun is the rich energy planet with 23 thousends terawatts (TW) each year . It is an alternative source of energy. Solar energy is the power we get from the sun. It is that energy which plant get from the sun. The thing which is used to capture sunlight and change it into electricity it known as the solar panel. It will then turn into electricity to light up lights, TVs and even your entire house. This is endless, source of pollution-free renewable energy that does not pollute and most definitely does not harm our environment.
2. What are the advantages and disadvantages of solar energy?
Answer: In Nepalese Context, which is the better option: solar power or hydropower ? There are many advantages and disadvantages of solar power which must be considred before making a conclusion.
Advantages:
Pollution Free : Since no smoke, gas, etc. is released, it is pollution-free and also renewable.
Easy to install : it can be installed quickly in fields, rooftop.
Noise free : Like other power plant, it does not make any noise.
Cost-effective resource : There is no payment needed for sunlight, and this source of energy is highly available in quantity.
No wear and tear : There are no moving parts so the level of wear and tear is basically zero.
Highly useful for Low-power Consumption : It is not difficult, and can be applied in any device that uses a little electricity–like calculators,clocks and many more.
Affordable : A lot of research is being conducted for reducing the cost and increasing the effectiveness of solar panels, so its price will decrease in upcoming days and more people will be able to afford.
Disadvantage:
Irregular electricity production : Electricity can hardly be produced during cloudy or rainy days, and it cannot be produced at night.
Battery required for nighttime use : Electricity generated in daytime must be stored to operate i.e. lighting or anything else needed during the night hours.
Risk of damage : Solar panels are thin and breakable, so they need to be handled with care to prevent damage.
Inverter needed for AC power : Electricity produced by solar panels is DC so we need an inverter to change it into AC which is the kind of power used in our homes and factory.
Less efficient : Solar panels have a lower efficiency of around 20–25%, where as hydropower is capable of achieving up to 90–95% efficiency.
Needs more space : It requires more coverage area for solar panels to be established. For instance, a 150-watt solar panel requires about 1 square meter of space (assuming approximately 15% efficiency). Required a lot of space for tools to install, maintain and so on if produced it commercially. For example, 1 megawatt of power plant will require around 250 thousand square meters (84 bighas) of land to generate solar electricity.
Conclusion: In cases where hydropower cannot be produced for some reason, solar power plants can partially provide electricity. Therefore, it is beneficial to develop electricity through an energy mix.
Multiple Choice Question Answer
1. What power does a photo Voltaic cell convert solar energy into ?
(A) Electrical power
(B) Thermal power
(C) Electricity and heat
(D) None of the above
Answer: Electrical power
2. On which day does a solar panel gets the least sun hours?
(A) December 1
(B) November 20
(C) December 22
(D) October 20
Answer: December 22
3. What does an inverter do?
(A) AC to DC
(B) DC to AC
(C) Increase AC voltage
(D) Decrease DC voltage
Answer: DC to AC
4. When using a battery charged by a solar system, which connection is best for efficiency?
(A) 12V DC bulb, TV
(B) 230V AC bulb, TV
(C) Both (A) and (B) are the same
(D) None of the above
Answer: 12V DC bulb, TV
5. What day of the year does a solar panel gets most sun hours?
(A) June 1
(B) June 21
(C) July 15
(D) July 1
Answer: June 21
6. Which of the following is the best type of solar charge controller?
(A) Simple type
(B) PWP type
(C) MPPT type
(D) None of the above
Answer: MPPT type
7. What does a solar charge controller do?
(A) Charges the battery from solar power
(B) Can charge the battery from both solar power and grid power (NEA)
(C) Charges the battery only from grid power (NEA)
(D) None of the above
Answer: None of the above
