Global warming or the phenomenon that the temperature of the surface of the earth is increase; leading to climate change and severe natural disasters. There are many “natural” causes of this global warming such as volcano eruption, wildfire etc. and from some scientific conclusions suggesting that one of the causes is from human. There are also some evidences proving that after the year 1980 (The industrial revolution period), the average world temperature has been significantly increasing compared to the previous decade.
And with more than half of the electricity generated for the usage in Thailand uses natural gas as the fuel which is deplete-able and has to be imported. So the fuel and electricity prices are continually rising and very sensitive to the political and economic situation.
There are, hence, supporting and promoting program from the government every year to decrease the use of deplete-able resource, leading to the cut of global warming cause and electrical independence of the country.
The Department of Alternative Energy Development and Efficiency (DEDE) predicts that from the year 2010 to 2011, the investment in sustainable energy business will rapidly and continually increase. And the DEDE will cooperate with government sector, private sector, and finance loan sector to help promoting and pushing the investment. The Board of Investment (BOI) also considers the investment in alternative energy as one of the most important section. Because the investment cost is high and pay-back term is long, which means a single project cannot be successful without government support.
Solar cell is a device that receives and uses the energy in sunlight to help pushing its inner electrons through the circuit. The movement of the inner electrons here is then called the electricity generating. These free electrons move in one-direction, so it is defined as “Direct Current”.
- Purified the semiconductor compound (mostly Silicon)
- Cool and slice the substance into wafer
- Dope the wafer with other compounds to make electrical poles
- Assemble the wafers into Panel
Layers of the module are different between manufacturer, depending on cost structure and technology but mainly a Photovoltaic module consists of:
- Cover glass: tempered glass helps protecting the module
- Anti-reflecting coating: the coating helps catching the sunlight as much as possible
- Doped wafers to act as electrical poles (positive and negative pole)
- Front and back contact grid: the grids lets electron runs a complete circuit
PV power plant is one of the most eco-friendly projects. During both the construction and operation period, there are no pollutions e.g. sight, air, sound pollution emitted to the surrounding area. So this is the factory which can safely be located near a community.
All two main equipments in the PV power plant i.e. solar modules and inverter are electronic devices so there are no moving parts in the electricity generating process which means the machine wearing out is not an issue here.
The electricity generating process starts when the modules harvest the energy in sunlight to excite its free electron to move through circuit line, making a direct current which is transferred into alternating current by inverter. After that the alternating current will be fed through power transformer so its voltage is here adjusted to the level that can be connected to the public grid line. The generated electricity from PV power plant is very clean and has a good quality as it contains only limited number of distortion signal because of the sophisticated inverter and its supporting international standard.
No heavy machines are needed during the construction phase and most of the work is related to leveling the land and piling the poles for mounting structures. Time used for connecting solar modules together is very short because almost every device is designed into modules and package.
To be designed in complete set, the transportation and installation of equipments is very easy and not time-consuming. There are no high-building in the plant as the highest mounting structure in general is only 1.5 meter tall and one-storey control building which is the only building inside.