Solar Energy Systems commonly used in Pakistan are Solar PV systems, Solar Water Heating systems, Solar Lighting Systems and Solar Pumping Systems. Generally the users do not appear to be satisfied with the solar system in use. Here we discuss what are the myths and realities causing dissatisfaction to users in Pakistan.
Myths and Realities of Solar Photovoltaic Systems in Pakistan
Faiz Mohammad Bhutta | Izhar Energy Services (PVT) Ltd.
MYTH: If you install solar photovoltaic system, you will have free energy round the clock.
REALITY: This is not true. Off-Grid solar Photovoltaic systems are designed on the basis of three factors. First is how much load in Watts you want to run through solar, second is for how hours ( operational hours) in whole day ( 24 hours) you want the run the specified load and how much the system will run on batteries continuously if there is no sun or rainy season. Generally customers tell to the vendors the total watts load only and they do not tell the operational hours and autonomy (system operating without sun). The price of the system varies as per watts load, number of operational hours and days (hours) of autonomy. The price of 1000W system for six hours operation will be different from price of system for 12 hours operation.
Remember – Customer is buying not watts but units (Watt-hours or Kilo Watt Hours) from the vendor so he/she has to define watt-hours/KWatt-hours (units) per day and autonomy days. After the system is installed, ask the vendor to show the watt-hours generated from the system at Energy Meter as committed by him as per design.
MYTH: Any Battery can be used in solar system and that lasts forever.
REALITY: It is not true. Only and only for solar DEEP CYCLE GEL BATTERIES are allowed which are different from normal car batteries in its construction and functioning. Normal car battery is lead acid battery with liquid acid as electrolyte solution and it quickly discharges to run your engine and then slowly charges. Contrary to this, DEEP CYCLE GEL batteries have thick lead terminals with electrolyte in the form of GEL which does not leak out even if your turn the battery up and down. These are maintenance free batteries and they discharge slowly and charge quickly. Battery life is in the hand of user as its life depends upon the temperature in which it is placed, charge and discharge cycles and depth of charge which means that how much battery will be discharged. If the battery is allowed to discharge to the dead stage every time, its life will decrease quickly. The battery life depends upon the quality of charge controller also which is responsible for controlling the battery current and charge. These charge controllers has one feature of low voltage disconnect which means when the battery reaches to low voltage, it automatically disconnects. So battery life is dependent on its environment, charge and discharge cycles, depth of discharge and quality of the charge controller also.
MYTH: There is no need of battery in the day as sun is available in the day.
REALITY: This is not true. Solar radiations do not remain constant throughout the day. In the start radiation are lower, then starts rising and at 12 Noon solar radiations have high power and then starts decreasing and at 4 p.m the radiations are poor but this cycle changes with the season. It is different in winter and summer. When in the morning solar radiations are low, the load draws some current from solar and remaining current from batteries and at 12 Noon, the load draws the whole current form solar and zero current form battery. So no solar system can work without back up. Question here arises, then why ON-GRID system work without battery. In case of ON-GRID system Grid (means Wapda supply) is its battery backup because ON-Grid solar is always sync with Grid supply and when Grid is off, solar system goes off. So in ON-GRID system works with GRID supply and this supply also works as battery backup. So solar systems always need back up for its continuous operation.
MYTH: Solar System can be installed anywhere.
REALITY: Solar System cannot be installed anywhere. The solar panels responsible of arresting energy occupy certain space as per its design. As standard 10 MSQ (Meter Square) space is required to generate 1 KW of power. So if you want to generate 10KW of power, you must have space of 100 SQM space to install the solar panels.
MYTH: Solar is free energy from the sun, the solar system should be cheap.
REALITY: No doubt solar is free energy but the technology which converters solar energy into usable electrical energy is very expensive. Solar cells are made from Silika which is type of sand. To convert the sand into solar cells and then solar cells into solar modules requires very complex, sophisticated and stringent processes which are very expensive. If we produce solar cells here in Pakistan, then solar systems can be made cheaper and affordable.
MYTH: Solar Panels lasts forever and have unlimited life.
REALITY: Solar Panels have certain life dependent upon its quality and design. Solar panels are of different types, some last for five years, some for 10 years and some for 25 years. It all depends upon the design and quality of the solar panels. Form user point of view all solar panels look same. So it depends upon the user from whom and what quality of solar panels he/she purchased and used. Solar panels having TUVE certifications of IEC 61215 and 61730 from Rheinland and SUD are usually considered having life of 25 years. Usually 25 years limited warranty is written at manufacturer’s technical specifications. It means that panel will give performance of 75 to 80% at the end of 25 years as solar panels lose its yield of 1% every year.
MYTH: Solar system is very expensive and un-affordable product.
REALITY: it is not true. Solar system is affordable now. Actually you are buying solar system for 25 years of life ( if it is high quality system from high quality company). So if you have bought solar solution of 1000W in Rs.500,000 for 12 hours operation a day, it means that you have paid this amount for 25 years which means Rs.1666 per month and you are getting daily 12 Units per day whose value is Rs.240 per day if you get from WAPDA this electricity. Now for each month you will pay to WAPDA Rs.7200 per month and per year Rs.86,400 without taking into accounts the continuous inflations of 30 to 40% per year. Now your investment of Rs.500,000 is being recovered in Five and Half years and if you take into account the inflation of electricity, then you investment will be recovered in four years or so. So in case solar system, it is always taken as payback not up-front cost. So solar system is now affordable.
MYTH: Solar system does not require any maintenance.
REALITY; Solar system only requires maintenance in the form of cleaning of panels in a month on regular basis or replacement of batteries after its expiry which may be two or three years in case of high quality battery. In more dusty areas, weekly cleaning of panels is recommended also. Care and wise use of solar system is more important than the maintenance. If you have purchased system for six hours operation per day, then use it for six hours a day. If you have purchased system for 12 hours operation a day, then you can use it with 12 hours a day. Wise use means that you should not increase the load from the designed limit and should not increase its use from designed operational hours. Wise use can enhance the life of the system. If you have purchases system of 1000W for six hours, then do not increase load more than 1000W and its use more than six hours a day. We have seen the batteries swollen up and charge controllers and inverters burnt down and it only happens that if you misuse the system beyond it designed limits.
We conclude that solar system is affordable and sustainable if you purchase is rightly, use it rightly and maintain it rightly. Concentrate on realities rather to believe in myths.
BREIF INTRODUCTION OF ENGR. FAIZ MOHAMMAD BHUTTA
Faiz Mohammad Bhutta is an engineer plus MBA. He has 30 years of experience of serving at technical and managerial posts in national and multinational companies; He is currently serving as General Manager Izhar Energy Services, Izhar Group of Companies. Apart from his professional career, he has served as visiting teacher on engineering and management subjects in Air University, COMSATS University and UMT.
He has also contributed as PEC Task force member on Building Energy Code 2011.
He is chairman of Renewable and Alternate Energy Association of Pakistan Lahore Chapter. He is member of organizations namely International Solar Society Germany; ASHRAE USA, Executive Member REAP, Life member of PEC , Life Member of HVACR Society, Life Member of IEP and Life member of IEEEP.
He is a writer & Trainer also and his articles are published in EIR, HVACR Journal, TechnoBiz, Engineering Horizon, Energy Magazine, HVACR Journal etc.
He has attended lot of national and international EXPO and Conferences on Alternate Energy in China and Germany.
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