Week 11 Assignment
Seoul Global High School
Suyeon Lee
Assignment
1. What are the advantages of solar energy over other forms of renewable energy options?
2. How much solar energy can be extracted and used for your country as a fraction of the total
energy needs of your country.
3. What method of solar energy harvesting would you use for energy extraction form sun and
why.
1.
Solar vs. Wind

Wind turbines can take a lot of space and be noisy, so they’re better suited for rural rather
than urban locations.

Wind energy works best in windy places, not surprisingly. Solar power is versatile–
Germany is currently the largest market for solar panels, even though it’s not known as a
particularly sunny place. In other words: it’s more important to live in a windy place if you
want to use wind turbines than it is to live in a sunny place if you want to use solar
panels.
Solar vs. Hydropower

Hydropower is typically done in large-scale dams rather than for homeowners (although
someone with a rushing stream or river on their property might be able to use small scale
“micro-hydro”); solar can be used almost anywhere.

Large dams are extremely expensive to build.

Flooding large areas of land destroys habitat and can force human relocation; solar panels
can be installed on existing unused space like rooftops.
Solar vs. Biomass

Crops like sugar cane and other sources for biomass require land that could otherwise be
used for growing food. Algae help avoid this problem somewhat because it can grow in
water. Solar doesn’t necessarily need to use land space, since it can go on existing roofs.

Burning biomass creates CO2 emissions, though less than fossil fuels like coal. Solar
energy doesn’t create emissions as it produces power.
- Source: http://1bog.org/blog/the-advantages-of-solar-power-vs-other-renewable-energy-sources/
2.
According to the Electric Power Statistics Information System of KPX, as of September 26, 2011,
Korea saw the total generation capacity of 918MW (382MW of wind energy and 536MW of solar
energy). If it will include the generation facilities for private cars or those which have yet to
exchange electric power, the capacity of solar energy has already reached 655MW last year and
highly exceeded 1GW, said electric industry’s experts. - Electric Power Statistics Information System
http://epsis.kpx.or.kr/epsis/servlet/epsis/EECU/EECUController_BBS?cmd=view&cd_upper=&cd_bbs
=004001&leftPos=&no_index=2455
에너지원 별로는 화석연료가 32만2954GWh로 전체 생산량의 67.2%를 차지했고 다음으로 원자력
이
14만8596GWh(30.9%)를
기록했다.
신재생에너지원은
수소가
6472GWh로
1.3%,
태양열
1073GWh(0.2%), 기타(지열, 조력, 풍력 등) 985GWh, 바이오연료/폐기물 750GWh 순이었다.
-Kosca Journal (Aug 29, 2011) http://www.koscaj.com/news/articleView.html?idxno=56187
Solar energy was recorded to take only 0.2% of Korean energy production. This is only one-tenth
of the world average of OECD members.
3.
Two kinds of solar energy harvesting system are widely used. They both have their own
advantages and disadvantages.
Solar Thermal Power Plants
Solar energy can be used to generate electricity. Some solar power plants use curved mirrors that
can direct solar radiation on specially designed pipes. The focused solar radiation heats up the
water that flows through the pipes, turning it into steam. This steam is afterwards being used to
run turbines and generate electricity, a process much like one would expect to see in a traditional
coal power plant.
The main problem with the solar power plants is that they only work while the sun shines. On
cloudy days, or during the night, the solar plants cannot produce electricity. Therefore, the
solution is to use hybrid technology. There are plants equipped with combined systems for energy
production. This means - during the sunny periods they use solar energy, whereas the remaining
time steam is produced from fossil fuels. This hybrid technology enables constant operation of
this type of power plants.
Photovoltaic
When we speak about photovoltaic we refer to solar cells. Solar cells are specially designed panels
made out of semiconductor materials. Semiconductors enable to convert solar radiation into
electricity most directly. Unlike the solar thermal power usage, where the electricity is obtained
indirectly, here we have a direct conversion.
Solar cells are also called photovoltaic cells (abbreviated: PV), and are often used for low power
consumption. Such applications are, for instance, when we need to recharge the batteries of our
Laptop or to power our Pocket PC. There are very affordable commercial home PV systems for
such purposes. The first PV cells were developed in the 50's of the last century for the purpose of
space exploration. This is why when we mention the use of PV cells, most people think of space
satellites.
In the majority of cases they are made out of silicone - amorphous or crystalline, but also other
materials are investigated and can be used as potentially better solar cell materials.
When solar radiation illuminates a PV cell, part of this energy is being delivered to the electrons
from the semiconducting material. The electrons are being released and can move to surface of
the solar cell, and the created potential difference can be turned into electric current.
When solar cells are connected by a conducting material, current will flow through the wires.
Individual cells are connected in photovoltaic panels of certain power. By combining a number of
such panels we can build solar panel fields. Some fields are placed on devices that monitor the
movement of the Sun. Such devices can adjust the angle of the incident solar radiation for
maximum efficiency. Electricity from the PV cells can be used for lighting, home appliances, or it
can be stored in batteries. There is a huge potential and we can expect PV cells to be able to run
cars in the future.
- Source: http://www.squidoo.com/solar-energy-usage-conversion-methods
Table comparing the two methods
Source: http://www.construction21.eu/articles/h/efficiency-of-solar-energy-harvesting.html
From the two different methods, I would like to use photovoltaic (PV) method of harvesting solar
energy. Countries with large areas of land available may be able to utilize the solar thermal
method but countries that do not have a lot of available land, Korea for instance, need to use a
method that does not require large fields. Buildings and facilities that receive solar energy are
close in distance with solar panels, which is also a factor that makes photovoltaic method possible.
Although the current photovoltaic method can only produce low power, it is comparatively cheap,
and greater numbers of panels can be installed with same expenses compared to the solar
thermal method. Since Photovoltaic method has a bright future for development we can expect to
see more efficient versions of this energy harvesting method.