9 January 2010
The 1kw wind generator has been up and running for +- 6 weeks and only once did we loose 2 hours of power. We had 4 people staying in the house with 35 Watt fans that ran all night. Also 6 low energy globes of 11 W and an oldish upright fridge that is not very energy efficient. During the building process the wind energy was used to operate a 400w saw, a 450w drill, a 900w grinder and a 450w power planer.
The system consists out of a 1kw wind generator, 4 x 102 amp hour batteries that gives 48 Volt and an inverter.
Most days have been windy from about 10am onwards and the wind tends to drop again around 10pm. (late November to early January)
During a high storm with strong wind, the generator was charging at 50% above its rated capacity, that is it was charging at 1.5kw.
The generator makes a noise when it is charging and when it brakes. It brakes when it is charging over 480 W and when the batteries are full. It brakes by shorting the output of the generator which increases the torque and causes the generator to turn out of the wind. The noise is a low hum like a fog horn in the distance.
When you look at the inverter it gives the battery voltage and the charging amps of the generator. The battery voltage gives the state of charge. If the wind generator is not charging, 52V represents a fully charged battery. If the voltage drops to 40W the inverter will cut out to protect the batteries against over discharge.
When a battery is discharged too much the battery life decreases. The batteries we are using are deep cycle batteries which should have a life of about 2000 charge cycles. A charge cycle is a when a battery is run down to 40 Volts and recharged to full.
3 Feb 2010
I was away for about 2 weeks, during which time the system cut out because the voltage dropped below 40V. We now know that the system does not kick in again when the batteries have re-charge. The content of the fridge/freezerwas rotten with goo all over the floor. School fees I suppose.