Transformers 3 part 03

In the rush to cash-in on wind energy, developers are often trading low first costs for higher total costs of ownership to be shouldered later by the wind farm owners and operators.

Converting wind energy to electrical power is the fastest growing segment of the US energy sector. Today, wind energy represents less than 5% of the US electrical generation and is targeted to reach 20% in the foreseeable future. For this to happen, new sites need to be developed in spite of a down turning economy.

Bolstered by available federal stimulus dollars, we are seeing a virtual modern day 'land-rush'. In the words of one industry leader, 'if there is a site that has a viable wind profile, access to network connections, and access for delivery of materials, and we don't develop it, some one else will.'

This head long rush to install more and more wind turbines has outstripped the usual developmental learning curve, where new technologies mature by a process of trial and error, resulting in defining equipment suited for the job at hand.

The added economic pressure of today's market has made an already competitive market even more demanding. This has, in the view of many industry insiders, resulted in purchasing decisions for equipment based largely on the lowest initial cost solutions and not solutions that will provide the best choice in terms of total cost of ownership, network stability, less down time and lost revenue from high maintenance issues. This is nowhere as apparent as in the case of Wind Turbine Generator (WTG) transformers.

Historically this WTG transformer function has been handled by conventional, 'off the shelf' distribution transformers, but the relatively large numbers of recent failures would strongly suggest that WTG transformer designs need to be made substantially more robust. The practice of using conventional 'off the shelf' distribution transformers as a low cost solution is folly. In some cases site operators are maintaining a quantity of spare transformers to combat the frequent outages caused by standard distribution transformers being used where they are not suitable.

The role of the Wind Turbine Generator (WTG) transformer in this process is critical and, as such, its design needs to be carefully and thoughtfully analyzed and reevaluated.