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Wind Energy FAQ

1. What is a wind turbine?

2. How much energy can a wind turbine produce?

3. What is an off-grid system and an on-grid system?

4. What are the components of an off-grid wind turbine system?

5. What is the cost of the system?

6. Do I have to pay the full cost of the system up front?

7. Can I buy the wind turbine system in installments?

8. What is the cost of the electricity produced by the wind turbine?

9. How soon can I recover my investment?

10. What is the annual maintenance cost for wind turbines?

11. Diesel and petrol generators are very cheap in comparison to wind turbines (maybe one-fifteenth the cost). Why should we consider buying a wind turbnie system?

12. Home UPS systems are very cheap in comparsion to wind turbines (maybe one-sixth the cost). Why should we consider buying a wind turbine system?

13. What is the area needed to install a wind turbine?

14. In what parts of Pakistan do we have good wind speed?

15. Can wind turbines be installed in flats, homes, and commercial sites?

16. How does a wind-solar energy hybrid system work?

17. What is the warranty of the wind turbines?

18. Would birds get hurt by the wind turbines?

19. What are safety measures in case of strong winds or a storm?

20. What is a unit of electrical consumption?

21. What is 'rated capacity'?

22. What is 'peak load'?

23. What is 'average load'?

 

1. What is a wind turbine?

A wind turbine is a fan that is operated by wind. The fan turns the shaft of a generator to produce electricity. It is essentially the conversion of kinetic energy electricity.

2. How much energy can a wind turbine produce?

Depending on the size of the turbine, a wind turbine can have a peak capacity from 100 W to 5 MW. 

3. What is an off-grid system and an on-grid system?

An OFF-GRID system is a stand alone system which is not connected to the grid of the utility company. The electricity produced is stored in batteries on the site and consumed within the same facility.
An ON-GRID (also known as GRID-TIE) system feeds the electricity produced by the wind turbine directly into the grid of the utility company via transmission lines.  Thus, there is no need to store the electrical power through batteries.

4. What are the components of an off-grid wind turbine system?

Every stand alone wind turbine system consists of four parts:

1. Wind Turbine in an open area mounted on top of a pole or a tower.
2. Charge Controller which controls the voltage and charges the battery bank
3. Battery bank for storing the generated electricity.
4. Inverter, which converts the DC output from the battery bank to standard AC mains voltage as well as monitoring the mains supply and performing yield optimisation functions.

5. What is the cost of the system?

There is only a one time initial cost to put up a wind turbine system.  There is no fuel or operations cost. The turbine just keeps on producing electricity on its own and storing it in the battery bank for your use. Wind is for free.

6. Do I have to pay the full cost of the system up front?

You can buy the turbine by paying 100% up front and then rest in peace.  However, if you prefer to have an installment plan, there are several leasing companies, modaraba companies and banks who are willing to finance the purchase of the wind turbine.  They would require a down payment of between 10-25% of the cost of the turbine, and the balance would be paid to them over a period of 3-5 years. The actual terms must be negotiated between the financing agency and the customer.

7. Can I buy the wind turbine system in installments?

Yes, there are several finance agencies / banks / leasing companies that are willing to finance the purchase of wind turbines. Please consult our sales department.

8. What is the cost of the electricity produced by the wind turbine?

Since the cost effectively is the initial investment cost (with negligible running or maintenance cost), one can compute the cost of electricity produced by dividing the total investment over the life of the turbine. Our turbines have a life of over 20 years. And there are 8,760 hours in one year. Thus, ideally, a 1KWp turbine should produce 8,760 KWh (units) of electricity per year.  However, due to variances in the speed of wind, we can estimate an average of around 40-50% (world average) of the electricity produced. 

Based on this, we will see that the cost of the electricity will be between Rs. 3-4 per KWh (unit) over a period of 20 years. In comparison, the current cost of electricity is above Rs. 14 per KWh (unit).  It should be noted that the cost of electricity is around Rs. 13-15 per KWh (unit) in case you are generating your own power through a diesel or petrol generator.

9. How soon can I recover my investment?

Based on the computation method described above, you should be able to recover the total cost of the wind turbine within 3-5 years (in comparison to the diesel generator or utility company rates).

10. What is the annual maintenance cost for wind turbines?

nternationally, annual maintenance costs for wind turbines are in the range of approximately 2% of the installed cost. 

11. Diesel and petrol generators are very cheap in comparison to wind turbines (maybe one-fifteenth the cost). Why should we consider buying a wind turbnie system?

There are many reasons to consider using wind turbines in comparison to diesel or petrol generators as follows:

12. Home UPS systems are very cheap in comparsion to wind turbines (maybe one-sixth the cost). Why should we consider buying a wind turbine system?

A wind generator cannot be compared with a home UPS system for the following reasons:

13. What is the area needed to install a wind turbine?

A guy mast tower needs its guy wires to be anchored in the ground at a distance of approximately 50% of the height of the tower. So if the tower is 6m high, the guys would be pegged 3m away approximately. If the tower is 12m high, the guys would be anchored approximately 6m away from the base of the tower.

14. In what parts of Pakistan do we have good wind speed?

According to the study conducted by the National Renewable Energy Laboratories (NREL) of the USA Government Department of Energy, and funded by USAID, there is good wind in around 9% of the total land mass of Pakistan. Areas where the wind is usable are as follows:

To view windmaps for Pakistan, or for other countries around the world, click here.

15. Can wind turbines be installed in flats, homes, and commercial sites?

Wind turbines can be installed on roof tops and in your lawn if the required area is available for installation. Please ensure that you own the roof of the building before you attempt to install one there.

16. How does a wind-solar energy hybrid system work?

n areas where there is insufficient wind, it is advisable to use a wind-solar energy hybrid solution.  In this system, the charge controller, batteries, inverter and cables are common. A wind turbine and a solar panel array are connected to the same system. This provides greater reliability for the system at a nominal incremental cost.

17. What is the warranty of the wind turbines?

We provide a standard warranty against manufacturing defects for 24 months. This is extendable up to 5 years at an additional cost. The life of our turbines is in excess of 20 years. Our Duramp batteries have a standard warranty of 20 months although the life of these batteries would be between 5-8 years. After sales services is also available from the company.

18. Would birds get hurt by the wind turbines?

Studies conducted worldwide show that instances of birds getting in the way of wind turbines are very rare. And this is negligible in the case of small wind turbines. The span of the blades of a small wind turbine are relatively small and the turning speed is not as high (unlike the rotors of an aircraft).  Thus, birds do not get sucked in.

19. What are safety measures in case of strong winds or a storm?

The small turbines (up to 2KW) have an inbuilt mechanism in its yaw system, which will turn the blades parallel to the wind in case of strong winds or a storm. Thus, the blades will not turn and the turbine will come to a standstill.
For turbines larger than 2KW, we also provide an electrically operated braking system, as a double protection. 

20. What is a unit of electrical consumption?

When you receive the bill / invoice from your utility company, it shows the no. of units of electricity that have been consumed, the rates and the total amount.

A unit on the bill is a kilowatt-hour (KWh).  It is 1000 watts of power consumed by you in one hour. So if you consume 1KW of power in 3 hours, you will be charged for 3 KWh (i.e. 3 units).

You need to distinguish between a KW and a KWh.  You appliances will indicate the no. of watts or KW that are used.  For example, if you have an hair dryer that is rated at 1400W (i.e. 1.4KW), it means that if you use it for one hour, it will consume 1.4 KWh.  If you use it for 2 hours, it will consume 2.8 KWh.

21. What is 'rated capacity'?

Rated Capacity is the power that can be generated by a wind turbine or a solar system at its peak. This is also shown as Wp, i.e. Peak Watts.

22. What is 'peak load'?

This is the amount of power that can be consumed by your home, office, etc in case you have all your lights, appliances, machines, etc turned ON.

23. What is 'average load'?

This is the average of the wattage used by you during the day, month, year or any period.

For further questions regarding wind energy, please e-mail us at info@ees-energy.com