Before the Blades Go Up
When the idea of the Green Leaf Inn first started we knew that wind turbine on site would be the perfect symbol for sustainability and a landmark from the road.
Before you just stick up a wind turbine, you need to see whether it makes sense and in WI, you have to have an assessment to qualify for state rebates.
Randy Faller with Kettle View Renewable Energy (certified by the MREA for commercial wind site assessment) came out to the Green Leaf Inn site, after discussing our goals and questions about the project over a pot of coffee. Critical items and questions included soil types (towers and turbines are heavy and awkward) for town stability, prevailing winds throughout the year, access for a crane for the installation, and tree height. We have a lot of trees over 70 feet high: to humans, these are beautiful, but to wind turbines, these are simply obstructions. With our tree height it looks like a 120 foot tall tower will be necessary.
Next, this machine came out and started to drill holes to check the soil for the structural engineers to precisely design the foundation for the wind turbine and buildings. Fairly critical since we don’t want the wind turbine bending in the wind. Gikes Engineering out of Waukesha did the soil borings and analysis.
Alliant Energy, our local electric utility bringing new service and 480 volt back to the 50kw Endurance Wind Turbine so we can complete the installation and start generating electricity.The first step was to drill under HWY 50 and through the woods that are along the roadway. Technically it was directional drilling- a technique often used in drilling for oil and natural gas. For this, a short string of warm days made the drilling go quickly and they were done in a half of a day. The county ordinances require electric service be underground to a wind turbine. But then again as an upscale boutique hotel project, underground power lines look nicer and are safer.
The next step will be done next week for trenching from the boring inside of our fence all the way back to the transformer. For this stage they like the ground nice and frozen so the ground doesn’t turn into mush. We already had that with the cement pouring and 2 ft. deep trenches that cost $2,000 to smooth out. Final stage is running the lines from the roadway underground and energizing the transformer, meter and interconnect panel.
Next, the wind turbine foundation was poured and it had to keeped at little warm for 28 days for curing to reach the over 4,500 psi strength. Anderson-Ashton did the foundation. The entire process was very interesting. Start out with soil borings so the geotechnical company, Giles Engineering Associates did their analysis of the soil types.
That report goes to the structural engineer for the turbine tower manufacturer to design the foundation. Spread footings were designed, a surveying company had to come out to locate the exact spot for the wind turbine. Then the plans go to the county and state to get permits and pay a fee.
It is critical to not disturb any more soil then what is being filled so you don’t get settling. The hole was dug, stone compacted in the bottom, and a few tons of rebar were carefully tied together by the Anderson-Ashton crew and the base foundation was poured with a bunch of rebar sticking up in the air from the base foundation for the second pouring so the two pieces are structurally tied together.
Then came the rain right when the cement trucks were coming to pour and after a half a dozen cement trucks pull in on our yard, we had two foot deep ruts. And then it all froze in place like a rock. There goes another $2,000 to get it leveled and smoothed out and we kept our fingers crossed that the cold weather (not a huge fan of cold weather normally) would stay and get the ground froze to support the weight of the crane and trucks with the turbine tower on it to be unloaded without sinking in to the ground.
The cold weather held out and we ploughed the yard so the snow that of course came would not insulate the ground like a blanket so the frost could freeze deeper. The day the turbine arrived started at 7am (logistics company forgot about an hour time zone difference), freezing cold, camera in hand (coffee in the other hand), and a huge smile on my face like a little kid on Christmas morning.
So far it looks like we will be a little over 10% over budget. That includes $29,000 to Alliant Energy to bring power back to a transformer by the turbine- nothing is ever easy- they will be directionally boring under Hwy 50 and then trenching underground to the transformer. Of course winter surcharges apply this time of year. Oh well, being green costs green.