Today we reached a milestone. Our 810 watts of solar panels (that occupy most of the available roof area of our ProMaster Campvan) have delivered their First Megawatt-Hour of energy. This milestone occurred as we begin our fourth year of campervan travel but, more specifically, on our 589th day of campervan use. Thus our solar energy collection has only averaged 1.7 kwh/day - - maybe not surprising as we often use shore-power and have a second alternator - - both sources that contribute significantly to our energy needs. In addition, as noted below, one has to use or have a place to put (store) the energy - - otherwise the solar capacity is wasted.
A couple of interesting additional statistics. Our MidNite solar controller indicates that the noted 1004.2 kwhs of output equated to an output of 75,720 amp-hours - - which computes to an average battery charging voltage of 13.26 volts - - within the expected range for our lithium battery pack.
Lastly is the question of how much daily output should one expect from a flat-mounted solar panel. Until recently, the most we’d seen was 4.5 kwh/day. However, we’ve been camping in nearly perfect solar conditions recently . . . more southerly than normal (southern Utah and northern Arizona), getting close to the solstice, wondrous sunny weather, higher than normal altitude which translates into cooler temperatures and less atmospheric ‘debris’. We have now seen many days of solar collection exceeding 4.5 kwhs/day with the maximum, currently, having been 5.0 kwh/day - - and even on this day we had some shading and believe the theoretical maximum is higher yet. One of the difficulties in measuring this maximum is that we have to have a place to put this energey. As our lithium pack is 6.5 kwhs, either the pack has to be unusually discharged before we start the test (not the norm) or we have to ‘help things along’ during the day by using lots of energy.
And one final stat - - the most instantaneous power we have seen was 821 watts. This was achieved at a campground introduced to us by the Nomers (MsNomer), the Sugarloaf Campground, Medicine Bow National Forest, Wyoming at an elevation of 11,500' on July 22 (a month after the solstice).
Slightly lofty view of our solar panels taken from our perch at the Hamburger Rock BLM Campground just east of the east entrance to Canyonlands National Park, Utah.
Solar Milestone - One Megawatt
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