We ordered the van with the maximum number of solar panels that Jayco could fit on the roof, namely three (3) panels of 120 kilowatts each. Unfortunately the other things on the roof (e.g. antenna, air conditioner) mean that there are fewer panels possible than you might expect. Also fitted was a 100 amp-hour deep cycle battery, a Topray TPS-555 1230 Solar Change Regulator and a battery monitor (as part of the SETEC Drifter).
We added a Projecta 600W inverter. This is a “modified sine wave” (i.e. not a pure sine wave) inverter with which we run limited mains powered appliances when they are needed off the grid, specifically electric blankets and a small washing machine. We do not attempt to run anything with more current draw than them from the inverter, and certainly not electronic equipment.
In the summer and autumn, the battery recharged by 11am on most days and never fell under voltage. However in winter with limited sunlight hours, the battery did not fully recharge every day, and with cold nights off the grid using electric blankets, the battery did sometimes drop under voltage overnight.
Aside from the obvious inconvenience of not having lights etc. until the sun had done its work, driving the battery under voltage uncovered an undesirable feature of the TPS-555 1230 solar charge regulator. When the battery voltage falls below a set threshold, an alarm sounds. Initially we thought there was a cricket loose in the van, such was the chirp…chirp…chirp sound of this alarm. Once the cause was identified we then discovered that this alarm could only be reset by either returning the battery to sufficient voltage, requiring sunlight, or by disconnecting the battery altogether from the controller, requiring a screw driver. There was no other way to silence the cricket that was keeping us awake.
We have addressed these various limitations with some modifications:
- an LPG heater to avoid use of the inverter on cold nights (see blog post),
- a replacement solar charge controller (the Victron BlueSolar MPPT 100/30) that includes an alarm reset function amongst many other features and has Maximum Power Point Tracking (MPPT) to squeeze some additional charge from the available sunlight,
- provision made for a second battery when rewiring for the replacement solar charge controller, which we will add if battery capacity rather than sunlight hours proves to be a limitation (and if not, we will avoid its weight and space).
We gave these modifications, along with the LPG heater and the waste water replumbing, a shake down on a short trip to the Grampians. For updates on the effectiveness of the solar system, watch this space …