Southwest Windpower’s Skystream can be used to charge batteries but a circuit must be present that will shut the turbine down as the batteries reach a full state of charge or a circuit to dump the extra power.
If you could hire someone inexpensively to shut the breaker off as the batteries “top off” that would work. The better alternative is to add a relay that is opened and closed by a relay driver.
SKYSTREAM DISCONNECTION OPTION #1
The above system uses the AUX OUTPUT from a charge controller to open the circuit between the Skystream and the inverter output using two AC solid state relays (SSRs). As soon the batteries reach a full state of charge, the AUX OUTPUT will command the SSRs to open the circuit. As the Skystream no longer has a “grid” to push power into, it will shut down and apply the brake. When the voltage drops, the SSRs will reconnect the turbine and the current will flow again.
This system will work flawlessly and is fairly inexpensive to setup. It is probably preferable to use a diversion load instead of wasting the excess electricity but this system (disconnection) is much easier to install and costs less.
SKYSTREAM DISCONNECTION OPTION #2
This second option is the same as OPTION #1 except it uses a 3 pole (3 phase) SSR instead of two separate units. The reason we use a 3 pole and not a 2 pole is that a 3 pole is usually less expensive and easier to locate..
If you have access to a 2 pole AC SSR then by all means use it!
Tips when disconnecting the Skystream to prevent battery overcharge:
- Always use a heat sink under the SSRs as they make a lot of heat and will burn out.
- Program the on and off voltages with at least a couple of volts difference (hysteresis). This will prevent the turbine from cycling too often.
- You can also use a Morningstar RD-1 or other voltage controlled switch to operate the SSRs.
- A standard double pole relay can be used instead of an SSR.
Don’t ever allow any other model of wind turbine to open circuit or free wheel. The Skystream is designed to apply a brake when open circuited. Other turbines will likely be damaged by over voltage or over speed.
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