A solar system is available separately for $195 including GST. The system consists of four components.
A 4 watt solar panel
A special regulator charger that will even charge the batteries when there is less than 12v coming from the panel
and two 12v 7amp hour gel cells.
No guarantee can be given that this will power the bog at all times as sunlight naturally varies from place to place and installation to installation. The panel produces around 4 watts in sun and the bog can have a low drain fan installed that draws not much more than half a watt. The batteries are 12 volt 7 amp hour and two are supplied. Battery storage is therefore 12 *14 watt hours = 168 watt hours and the fan uses about 0.5 watts meaning that supply with no sun should continue for 168 * 2 = 336 hours divided by 24 = 14 days. In the event that the batteries do go flat, the power plug at the back of the bog should be removed until the panel has recharged the batteries. 42 hours of sunlight may be needed to fully restore the batteries to full charge. The regulator is specially designed to continue charging even when the panel voltage drops below the battery voltage. This means that even cloudy, dark winter days will contribute something.
In the event that the system runs flat in winter. Remove the plug from the back of your bog. Seal the faeces bag to stop the smell or begin your outside compost now. Once there has been enough sunlight to recharge your batteries you can reconnect your bog fan. If you have a multi-meter available you can detect full charge if the battery voltage measures over 13v when the sun is shining or around 12.6 volts when the sun is not shining.
You must remove your batteries from the charging circuit if you wish to use an external battery charger. Your warranty will void if you use an external charger with the batteries in circuit or if the external charger is not suited to the battery type. 12volt gel cells.
While we can't give a performance guarantee we none the less will give all the practical assistance and advice we can.
Please note that we have tried to save money to bring you the solar system as cheaply as possible. Unfortunately this means that you need to arrange your own materials to mount the solar panel. We may offer more alternatives so that a larger system with all the extras is available in the near future. To date (May 2004) we have had no reports of these solar systems being insufficient to power a bog installation.
A new super solar kit is available with at least 8 watts of solar panel and 28amp hours of battery storage. See the price list. These kits will give greater security of supply for more southerly customers or during bad winters or summers.