Is solar panel cost effective?

I hold the view that photovoltaic panels are not cost effective at this moment (solar energy to electric energy conversion efficiency is only up to 20%; to power a TV, you need over 1 sqm of panels and one 175W panel costs A$1100, see: http://www.solazone.com.au/PVpanels.htm ).

Now go to that link and look at some real numbers!

175W panel cost A$1100.

Now, look at the tariff rates here:
http://www.ipart.nsw.gov.au/documents/EA_Residential_and_business_price_list_2009.pdf

Now, if I assume the buy back rate of : 60 cents/kWh

The solar panel needs to generate : $1100 / 0.60 kWh of electricity to pay for itself. This is 1833 kWh.

For this panel to generate 1833 kWh of electricty, it takes 1833 / 0.175 = 10476 hours of full capacity generation.

The solar annual solar availability is about 2,000 to 2,500 hours pa. (Note that there are 8760 hours per year.) So it takes 10476 / 2250 = 4.7 years to break even the cost. This assumes you don't use electricity and the full PV generated energy goes into the grid.

So unless you are really keen to "show" your committment to ESD, solar panels (photovoltaic panels) are not cost effective if you already have connection to the power grid.

P.S. The story would be somehow different with remote areas where generators or power lines are required to supply electricty. By that time, the comparison will be the installation and running costs of generators and power lines. PV panels will be attractive for those applications.