Alkoomie Station - Cooktown
Alkoomie Station - Cooktown
Alkoomie is an incredibly rugged 18,400ha. cattle station, around 40 km to the west Cooktown. It runs from the valley of the South Branch of the Endeavour River, up over the towering escarpments of the 480m high Dickson Plateau. Alkoomie station has never been connected to the electricity grid and for numerous years has relied on a diesel generator to provide its electricity. It was calculated that the generator used approximately 1.5 litres of disel an hour, which adds up to about 80,000 litres per year. When you factor in other running cost such as services, repairs and break downs, it was a costly exercise. FNQ Solar Solutions , was contacted last year to design an off-grid power system, using solar and batteries to power the homestead.
The homestead generally is only occupied by two people, but in different parts of the year it can house up to 12 people. The homestead is on the top of a mount range and has beautiful views, a golf course and some nice big trees. We liaised with the station owners, and agreed to install the solar panels on the second storey roof of the homestead. This way we werent required to trim any trees, and the solar panels received maximum sunlight. To protect this system, the system we installed lightening protection on both the DC & AC sides of the inverters. This system also has remote monitoring. This allows simple software updates or programming changes to be done via internet without being on site.
This system was AC COUPLED. This means the power from the solar panels, feeds directly to a standard grid-connect inverter. The energy from the solar panels is then converted to 230 volts AC, this feeds any appliances that are turned on in the homestead first, for example the fridges, tv's and any loads turned on during the day. Any excess power is then transferred to the battery/inverter charger, which converts this 230volts AC into 24 Volts DC, to charge the batteries. The battery inverter/charger, will provide any extra power that may be required during the day, and will also power the house overnight, using the energy stored in the batteries.
The generator is still utilized and we installed an automatic generator starter on the generator. The generator will start if the state of charge in the batteries fall bellow 65 percent. This ensures long life on the batteries. The generator will also start automatically if the loads on the battery inverter/charger are too high, to stop the inverter going into overload, it will then stop automatically if the loads decrease or are turned off. The whole system is automated, and the hot water system automatically turns on during the day to heat off the solar power. The automation saves the customer time and makes things easier for the customer.
Appliances the customer was running:
- 2 x Fridges/Freezers
- 1 x Chest Freezer
- 1 x Kitchen Appliances
- bread maker
- 1 x TV
- 1 x Washing Machine
- 8 x Ceiling fans
- - Lighting
- 1 x Vaccum
- 2 x engel frdiges
- 1 x water pump
- - general pwr tools
- 1 x 300l Hot water systems
1 x Clothes Dryrer
So we installed
- 22 x ET Solar 250watt Poly solar Panels 5.5 KW
- 1 x Schnider Electric 3kw grid-connect inverter
- 1 x Schnider Electric Battery/ Inverter Charger 3.5kw
- 12 x 2v BAE Batteries (24 volt battery bank 1500 Amp-Hour Batteries 36 Kw of batteries)
- 1 x Schnider Electric Battery Monitor & Data logger
- 1 x Schnider Electric Combox (remote monioting)
B.A.E batteries are manufactured in Germany
Schnider Electric is a French company who own Clipsal Australia.
The solar array installed was 250 percent over sized, to ensure even in overcast conditions the batteries will remain highly charged.
The expected battery life is 12 years, as the daily discharge amount was around 29 percent, and the batteries will run for 2.5 days with out the generator starting if there was completely no solar. The over-sizing the of the solar array ensures there is enough solar power to charge the batteries, even in overcast weather.
Warranties on the products
Batteries, 3 Years Full replacement warranty
3-5 Years Prorata (meaning in between 3-5 years you may have to pay the difference, of what they expect the battery life to be during this period, this is where the battery monitor will help to notate and prove no damage has been done)
ALL Schneider electric products.
ET Solar Panels, General workmanship
ET Solar Panels Output to be no less than 90 percent at 12 years
ET Solar Panels Output to be no less than 80 Percent at 25 years.