Yeah me and my friend are doing a project and we neeed to know the disadvantages to photovoltaic solar energy… by dec the 8… kk thanks…
So you left it until the day before to ask this question? And then you start a sentence with ‘yeah’? Also, you mean ‘my friend and I’ not ‘me and my friend’. Anyway, enough criticism:
Photovoltaic solar energy isn’t very efficient. Although they recently developed solar cells that absorb a very broad-band of frequencies including all of the optical frequencies, they still suffer from reflection and internal heating. Also, they produce DC electricity. As most homes run off AC electricity this needs to be converted and that costs even more energy. Finally you need a good supply of sunlight to make this work. I have seen a building on the North-Wales coast coated in solar cells and I don’t think they are efficient enough to warrant that kind of expense.
The main problem with this renewable energy source is driving the cost and efficiency to a level that it can compete with others on an industrial scale.
Solar cells are a great way of augmenting existing energy systems, but to be truely efficient at an industrial scale they need to be very large and capture consistent energy (light). This is limited to certain parts of the world – and with the cost of such projects (the cells themselves are quite expensive to produce) – other systems can seem more attractive
References :
http://en.wikipedia.org/wiki/Photovoltaic
So you left it until the day before to ask this question? And then you start a sentence with ‘yeah’? Also, you mean ‘my friend and I’ not ‘me and my friend’. Anyway, enough criticism:
Photovoltaic solar energy isn’t very efficient. Although they recently developed solar cells that absorb a very broad-band of frequencies including all of the optical frequencies, they still suffer from reflection and internal heating. Also, they produce DC electricity. As most homes run off AC electricity this needs to be converted and that costs even more energy. Finally you need a good supply of sunlight to make this work. I have seen a building on the North-Wales coast coated in solar cells and I don’t think they are efficient enough to warrant that kind of expense.
References :
The main drawback with photovoltaic energy is that it requires light to work. Half of the time, the surface of the earth is in darkness.
Another could be the inherent inefficiency of PV cells. Conversion efficiencies of 10 to 20% are usual. The main effect of this is that a large area is required to generate useful amounts of energy. In densely populated areas this is a big drawback.
Another big drawback with PV cells is that they take a LOT of energy to actually make. A typical "payback" period (the period over which the cell has generated the same amount of energy taken to create it) is in the order of 5 years operation at maximum output. In practice, maximum output can only be achieved for part of this time thereby increasing the payback period.
There is a lot of work afoot to reduce the energy requirements in the production of PV cells and to increase their generation efficiency. This all goes towards reducing the payback period of PV technology.
Best regards.
References :
http://www.energybulletin.net/17219.html
http://www.csudh.edu/oliver/smt310-handouts/solarpan/pvpayback.htm
http://www.sta.com.au/webcontent4.htm