Case study: Hancock County Wind Farm

The Hancock County Onshore Wind Farm, in Iowa (USA), is a project owned by NextEra Energy, with wind turbines. Siemens Gamesa (SGRE) was awarded to implement the life-extension program of the wind farm and chose Endiprev USA’s team to perform the electrical retrofit and repowering service.

With the beginning of commercial operations in 2002, the Hancock County Wind Farm is one of the wind farms that makes Iowa one of the leading U.S. states in wind power generation. In February 2020, 42% of the state’s electricity produced came from wind, with more than 10GW of installed capacity.

The onshore wind farm has 148 V47/660 wind turbines, generating a total of 97.7 MW. That is enough electricity to power approximately 33 000 homes in the Iowa state. However, with almost 20 years since their commissioning, the wind turbines were starting to become outdated by the new technology currently in the market, able to produce much more energy.

Overhaul Retrofit

Siemens Gamesa was awarded the contract to conduct a life extension program in the 148 V47/660 wind turbines. This program seeks to increase the lifetime of the wind turbine in 10 years, while it improves its performance. Endiprev performed the complete electrical scope of the V47 Overhaul Retrofit in Hancock County Wind Farm. On this project, our team performed the following interventions:

• Top and Bottom Box Unwiring
• Top and Bottom Box Rewiring
• Commissioning
• Transformer Terminations
• Bottom Cabinet Stator Splicing

The Hancock County Wind Farm increased its capacity by almost 10%, now being able to produce 105.1 MW. This improvement represents enough electricity to power 2 000 more houses in the state.

Hancock County Wind Farm’s Commissioning

Endiprev’s team was also responsible for performing the commissioning of the now upgraded 148 V47/660 wind turbines. In fact, most of the technicians on the team had a lot of experience in commissioning. They did an excellent job by quickly identifying and solving any problem.

Field Technicians

Endiprev selected a team of 24 experienced technicians. The Hancock County Wind Farm project began in September 2019 and ended in February 2020, with a total effort of more than 16 000 hours worked. These technicians, who worked under very extreme weather conditions, were able to finish the project with zero recordable injuries, contributing to very satisfactory Health and Safety indicators.

In this team, Endiprev brought together several European and American technicians to boost the exchange of knowledge between them. Therefore, the Hancock County Wind Farm project was an ongoing training process, for the American technicians to gain more knowledge on the field and observe the experience from the other colleagues. This exchange allows Endiprev to keep the same high-quality standard in the service any of our teams perform.

Hancock County Wind Farm Challenges

Our team recognized from the beginning that the Hancock County Wind Farm was going to be a project with several challenges. One of the biggest ones was the very cold temperature, with a range between 0º and -30 ºC. That was something new to our team, and it made the execution of our work harder, even with the appropriate PPE, equipment, and materials provided. Additionally, the extreme weather conditions lead to another challenge: keeping the team’s motivation levels high. Nevertheless, our team did an excellent job by supporting and pushing each other to outstand their work to Endiprev values.

Without any doubt, this was a very important milestone for Endiprev USA not only because it was one of its major projects, but also because it strengthened the relationship between Endiprev and Siemens Gamesa in the USA.