The US-made stator is wound tighter and should be more efficient, but we don’t have any hard data to prove that yet. The (old) Trinidad stators were hand wound, and ended up with additional wire around the outside of the turns, which increases the over-all resistance (longer wires). The new stators are wound on a machine that winds them tighter, and we end up with about 0.3 ohms, compared to the 0.5 ohms of the old stators. So, with 40 percent less resistance, there will be more current flow. We just don’t know how much (yet). The stator is now clamped into the housing using longer #10 screws, which extend from the front about 2 inches into the housing with SS nuts inserted into “divots” in the housing. This is much stronger and easier to work with than the old system of embedded nuts in the fiberglass. The new screws have 3/8 castle nuts on the ends, which replace the flat head screws.
The old control box had a 30 amp rectifier. We have changed to a 50 amp rectifier and are in the process of changing to a new electronic rectifier. In testing, it showed a 20 percent increase in amps at low wind speeds, with a lower start up speed, and a very slight increase at higher wind speeds. We are looking at “active rectification” that could offer even greater efficiency improvements. The new control box is anodized.
The US made blades are stronger and smoother, and we put helicopter tape on the leading edge to protect against wear. Blades are now painted with two part polyurethane. We also write the gram weight of each blade at the base so that, if one blade gets damaged, you can save money by ordering one with a similar gram weight rather than a matching set of 3. Fiberglass production recently moved to our facility and is ramping up.
The US made rotors are much more accurately machined, and so should be smoother running.
We are changing to a vinylester resin for the housing that has a 250 degree rating, compared to the old 170 degree. This means we can increase the temperature at which the generator operates, and increase the wind speed at which it goes into freewheel, the most common complaint on the old KISS. The new stators have 311 degree insulation. The housings are bing molded in a new mold that is significantly straighter, with fewer comsmetic imperfections. The housings will have a thermal additive that increases the heat transfer through the housing.
We have added a “nosecone” for cosmetic reasons.
We have replaced the old plastic pole cap and graphite bushing with a “yaw bearing” consisting of two stainless needle bearings and a deldrin thrust washer, so the generator will turn more easily into the wind. This also changed the mounting system so that it is easier to install and remove, and more logically intuitive.
All generators are now serial numbered, so that we can determine what parts have gone into each unit. We will also be able to tell if a generator is still within the warranty (which is transferable).
Improvements will continue.