The Lakota wind turbine does seem to be a promising turbine capable of handling windspeeds and not reduce its power after it goes beyond its rated speed. We've been very happy with it here at the Alternative Energy Store and offer it our customers. However, I would refrane from assuming that it would produce at least 70% of an average size home.
To start off, in our experience, there really is no true "average" home value for the amount of power (kilowatt hours) consumed. This varies wildly from state to state, country to country and neighbor to neighbor. For instance, in my home we consume approximately 300kWHr per month. However, typical customers we speak with (US, Canada and other countries) consume anywhere from 500kWHrs to 3500kWhrs(!). Clearly that's a wide range, and people on the higher end of the usage spectrum need to look for ways to be more energy efficient. Look at your current electric bill to see how much you currently consume.
Next, you simply can't make any assumption of how much power a wind turbine is going to produce until you know how much wind is your location. The Lakota, as an example, will produce about 250kWHrs per month in average wind speed of around 12mph. In my personal situation, if I had that relatively strong average wind speed the Lakota would produce about 80% of power requirements. However, again, our home tends to be on the very low side of the consumption spectrum compared to folks in the US and Canada.
Rich, to answer your questions specifically:
You ask: Is there a transformer with a disconnect that will take power from a wind generator and pump it directly to grid?
Response: All of the grid tie inverter systems (solar or wind) inherently and to be electric code compliant will automatically disconnect the power generated by your system from the electric utility line should the grid go down.
You Ask: If someone hit a utility pole, how do would I stop power from the wind generator from back feeding through the breaker panel and frying the line worker? Can this be done with out having to manually hit a disconnect? ( at work, out of the house)
Response: Again, the same as above. The inverter would take care of that automagically and the excess energy would be diverted to a "dump" load (see below).
You Ask: Can I divert the load so the wind generator does not �free wheel� out of control?
Response: Excellent question! Most folks don't usually think about this particular situation (you're clearly thinking of all the possibilities, as you should). Typically the wind turbine systems have a "dump load" (usually a high wattage heating coil/element) where they can dump their excess energy to, should the utility grid be unavailable.
For the Lakota wind turbine, to use that as an example again, we usually recommend:
* An SW series inverter (e.g. the SW4024: http://www.AltEnergyStore.com/cart/2.html )
* The Grid Tie Interface unit to go with the SW4024 and allow you to do grid intertie (http://www.AltEnergyStore.com/cart/951.html)
* Appropriate disconnects and fuses and cables
* A minimal battery bank of ~250A-Hrs (unless you want to have more of a backup power supply)
* A Trace C40 used in diversion control mode in conjunction with a high amperage DC relay to through excess power to a high wattage heating coil (e.g. a electric dryer element - you can get these for $25-$40).
* You're overall cost on the components for such a system would be around $7-$8k.
Going with a Trace SW series Power Panel (e.g.: http://www.AltEnergyStore.com/cart/51.html) will greatly reduce your wiring, time for installation and worries for being code compliant. It combines the inverter, disconnects and much of the wire nicely on a single metal backplane.
At this time, there are no grid tie inverters on the market that we're aware of that are UL approved and allow you to hook up any 'ol electric wind turbine (like the Lakota) to the grid. There are, however, systems that we sell (such as the Excel from Bergey or the Jacobs wind trubine) that do come with a grid tie inverter specially designed for use with those turbines and do not use a battery bank. However, these systems cost around $20k-$30k including the towers. This may not be where you wanted to start at, price-wise.
