Truth in Rated Capacity and Power Curve of Turbines

Among the challenges in piecing together a wind project is the selection of a wind turbine. Several factors are used to determine the appropriate wind turbine for each project. Primary among these is using the manufacturer's rated capacity to estimate energy production.

Some turbine manufacturers claim higher turbine name-plate capacity and therefore higher energy production than what a customer will realize. We have observed this most frequently in smaller vertical axis wind turbines (VAWT) and less frequently in horizontal axis wind turbines (HAWT). This is a particular problem if power ratings and power curves are not certified by an independent agency. I have written a whitepaper that will describe a quick method to verify, at a theoretical level, if a turbine's actual production will ever measure up to the claim. The analysis in the whitepaper and rules of thumb can be easily applied to assist you in evaluating a wind turbine for your project. A 'back-of-the-envelope' check, of both the rated capacity as stated by the manufacturer and the power curve supplied by the manufacturer, can prevent you from choosing a turbine that will not perform as advertised because, after all, the energy production cannot defy the laws of physics.

Article written by Dr. Pramod Jain

Email Pramod at pramod@frombeginningtowind.com

Visit Wind Energy Consulting and Contracting Inc.

A few common questions about wind projects, from the Technical Side

In this blog I will list common questions that we have encountered from organizations that are considering adding wind energy to their portfolio of energy resources. In subsequent blogs I will answer the questions in some detail and point you to resources that will help you to answer the question. As with any endeavor like this, answers are not always crisp and precise; the answer usually starts with “It depends.” In my answers I will help you to understand: A) What the answer depends on? B) Why does the answer depend on it? and C) Any other the issues related to the answer.

1. What are the economics of a wind project? How much does it cost to install a wind project? How much of the total install cost is turbine cost? What is the cost of producing energy using wind? How does this cost compare with other sources like coal, natural gas, solar and others?
   
2. Which country leads the world in wind energy production? Which country has the highest penetration of wind energy in electricity generation? Is there a limit to the maximum penetration of wind?
   
3. Wind 101. How is wind generated? How much wind speed do I need for a viable wind project? What is shear? What is turbulence? How do I measure wind speed?
   
4. Turbine 101. What are the major components of a turbine? What are the major types of turbines? Who certifies turbines?
   
5. Project Siting 101. What are the main considerations when siting a wind project? What are the impacts on the environment from a wind project? How serious is the issue about killing of birds and bats? Which agencies will I need approval from? What are the other studies and analyses that I need to perform?
   
6. Wind Resource Assessment 101. How do I find out wind speed at my location? What are the limitations of high level wind resource maps? What kind of wind resource analysis is required to get a project funded?
   

My focus will be on projects of the size of 50KW to 10MW. This is not a hard and fast range, but a range that the industry refers to as small wind, distributed wind and community wind. WECC’s niche market consist of school districts, colleges/universities, municipalities, factories, hotels, and a variety of other facilities.

Find more details at http://www.frombeginningtowind.com

Article written by Dr. Pramod Jain

Email Pramod at pramod@frombeginningtowind.com

Visit Wind Energy Consulting and Contracting Inc.