Monthly Archives: May 2014

Quaid-e-Azam Solar Park - ROI

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The government of Pakistan has recently launched the Quaid-e-Azam Solar Park in the Cholistan desert near Bahawalpur. The project aims to produce 100 MW of electrical energy by end of 2014 and 1000 MW by end of 2016. This is a small step in the right direction. Countries like India, China and Germany are much ahead in the game with installed solar projects of 2600 MW, 20000 MW and 36000 MW respectively. Let us take a closer look at the price that we will have to pay for the energy produced.

The cost of the 100 MW project is around $131 million, that is the price per Watt is $1.31. That seems to be quite good, lets look closely. We know that 400,000 panels are to be installed in the first phase to produce 100 MW of electrical energy. This means that each Solar Panel would produce 250 W and the cost of each panel would be $327.5 or Rs.32750.

Assuming that there is peak solar energy available for six hours daily, each solar panel would produce 1.5 kWhr of energy each day or 547.5 kWhr of energy per year. This amounts to 13687.5 kWhr of energy over a 25 year period (assuming that the performance of the Solar Panels does not degrade over the 25 year period). Now assuming that each unit of energy (kWhr) is sold at Rs.15 the total energy produced by the Solar Panel over its life period amounts to Rs.205312.5 i.e the revenue earned from selling electricity is 6.27 times the investment (205312.5/32750=6.27).

Solar Park Bahawalpur

Solar Park Bahawalpur

In other words the investment is recovered in 4 years and you have free electricity for the remaining 21 years. Please note that the above calculations do not include the operational costs, if any. Also, the above analysis assumes that the performance of the Solar Panels does not degrade over its life time.

Final Comment: The location of the proposed project does not seem to be optimum as Bahawalpur is receiving 2000 kWhr per squared meter per year as opposed to vast expanses of Balochistan that receive 2200 kWhr per squared meter per year.

Solar Payback Time in Pakistan

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It is quite well known fact that installing a solar system at your home requires a large initial investment. But it is also known that solar panels have a typical life period of 25 years. Other equipment used in a solar system such as batteries, charge controllers and inverters have a shorter life span and may need to be replaced every 2-4 years. In this article we try to calculate the payback time of a simple solar system that uses all its energy in real time converting DC voltage produced by the solar panel to AC voltage through an inverter.

Let us assume that our load requirement is 500 W and we have 5 solar panels of 100 W each. We next assume that we have an inverter also rated at 500 W. Let us further assume that the solar panels receives peak sunshine for 6 hours daily (this is called Peak Sun Hours and is quite complicated to explain in this brief article). Therefore the total energy produced during a 24 hour period is

500 W x 6 hr = 3000 Whr = 3 kWhr

In one month the solar panel would produce

3 kWhr x 30 = 90 kWhr or 90 units of energy

Now assuming that a unit of energy is sold to you at Rs. 15 (including all the taxes and surcharges) the total savings per month are

90 units x Rs. 15/unit = Rs. 1350

Now let us look at the investment we made in the solar system. Solar panels are widely available in the local market for Rs.100/watt. This results in Rs. 50,000 investment in solar panels. An additional Rs. 10,000 are spent in the inverter. So the total cost of the solar system is Rs. 60,000.

So the payback time of this solar system is

60,000 / 1350 = 45 months or 3.75 years

This is highly encouraging because all your investment is recovered in less than 4 years and you have 21 years of free energy from your solar system.

Solar Payback Time in Pakistan is about 4 Years

Solar Payback Time in Pakistan is about 4 Years

Note:

1. The above analysis is also valid for grid tied systems where the energy is sold to the grid during the off peak hours (day time) and  bought from the grid during peak hours (evening, night time).

2. A real system would also need some batteries to provide backup when there is a power shut down and solar energy is also not available.

3. Although solar system is expected to have 25 years of life, it will not operate at 100% throughout this life period e.g. it might be operating at only 80% after 20 years.