NTK 40 KW and 65 KW Wind Turbines

Nordtank 65 Nordtank 65 Nordtank 65

Technical Overview

EMI offers two options for its smaller wind turbines – the "NTK 40" and the "NTK 65." The electricity outputs are determined by the generator used. Both turbines are refurbished Nordtank 65s utilizing modern day controls and systems to create a like-new, reliable wind turbine with a projected 30+ year life.

The originally designed NTK 65 has a 1,200 RPM generator and is capable of producing in excess of 65KW of electricity in strong wind conditions. The NTK 40 version offered by EMI is a de-rated version of the NTK 65, utilizing an 8-pole, 900 RPM generator.

Advantages of De-Rated NTK 40:

  1. Slower Rotation Speeds - increases reliability and life of the wind turbine by reducing speed and operating forces.
  2. Produces more electricity in light wind conditions.
  3. Lowers the cut in speed for making electricity to approximately 6 mph.
  4. Reliable operation in wind conditions in excess of 50 mph.
  5. Meets utility "Distributed Generation (DG)" requirements for renewable systems that are often required to be less than 40 or 50 KW in size. 

Both the NTK 40 and NTK 65 are equipped with the EMI-WTC (Wind Turbine Controller) that allows for monitoring and control from a Windows PC, Android App or IPad/IPhone App. The controller has two customizable options - Fixed and Variable.

Controller Options: Fixed and Variable Speed

EMI offers two variations of controllers – Fixed and Variable. With the Fixed Speed solution, the turbine speed is controlled by the grid and is fixed at either 900 RPM or 1,200 RPM. Whereas with the Variable Speed solution, the rotation speed is optimized against the wind speed to maximize output in both light and strong wind conditions.

Fixed Speed Controller

The Fixed Speed Controller provides a fixed operating speed on the high speed shaft of either 900 RPM (de-rated version) or 1200 RPM. The Fixed Speed Controller requires direct grid connection and grid reactive power for operation. Three phase operation only. See EMI-WTC data sheet for controller details.

Variable Speed Controller

The Variable Speed Controller uses elaborate control systems to generate power, using Self Excitation Induction Generator technology (SEIG) to produce electricity and manage speed. The Variable Speed Controller functions autonomously from the grid and can operate in both grid tie or off grid (Micro-Grid) environments. Furthermore, the controller manages power output (voltage) through speed control. The controlled speed varies between 800 RPM and 1,100 RPM depending on wind speed, electricity needs and power regulation. The controller allows the turbine to operate at reduced speeds in strong wind environments (in excess of 50mph) without the need to shut down. It also utilizes dynamic braking which complements the mechanical brake. Can operate on three phase OR single phase.

In Micro Grid environments the controller is further controlled be a Master Micro Grid Controller (MMGC), which limits the automated controls in a process of managing micro grid voltage and excess power production. Typical MMGC environments are where multiple wind turbines are operating in an off grid environment and are part of a larger overall SCADA network. Contact EMI for custom SCADA solutions.

The Variable Speed Controller will be available Q3, 2016.

Automation Tie In

Whether a turbine operates with fixed or variable speed, the controller integrates into an overall energy management system with EMI's Automation Tie In. Users manage the wind turbine and automate certain processes to run or stop, based upon electrical output levels. Automation Tie In adds little cost to the controller but produces significant cost savings by using locally produced electricity first vs. buying retail. Automation also manages expensive electricity demand charges. Depending upon the application, the Automation Tie In feature can double one’s net value received from each wind turbine.

Each EMI turbine includes refurbished blades which are overhauled to an "as new" condition. Cracks and other defects are repaired, not patched. The blades have a proven track record and by slowing the turbine from a constant speed (1200 RPM) to maximum 900 RPM (De-rated) and 1,100 RPM (Variable Speed) it significantly increases the life between blade overhauls (beyond 25 years).

Pricing NTK 40/65 Turbine

NTK 65 - 1200 RPM Fixed Speed
NTK 40 - 900 RPM Fixed Speed
NTK 40 - 900 RPM Variable Speed

Pricing does not include shipping or installation. Both can be provided and are subject to project scope and logistics. Freight on board Texas.



  • 40 KW, 900 RPM or
  • 65 KW, 1,200 RPM
  • 3 Phase, 480VAC, 60Hz

Controller: EMI-WTC

  • EMI-WTC: Customized Controller for energy optimization
  • I-Phone/I-Pad App HMI
  • Automation & Energy Management
  • Near Zero Power Consumption
  • Integrated Meter for Fault Monitoring


  • 3 Section Hot-dip galvanized Tubular steel
  • Top and Bottom access doors
  • Height – Hub 80' (with base)
  • Interior tower ladder with nacelle access


  • 3 fixed pitch
  • 54' diameter
  • Upwind orientation


  • Fiberglass reinforced polyester
  • Swept area: 2,290'

Operational Data:

  • Cut in wind speed: 7mph (40KW) & 8mph (65KW)
  • Cut-off wind speed: None – stall regulated


  • Tower (3 sections total) 14,100 lbs
  • Nacelle, Blade, Rotor and Bedplate total 9,300 lbs