[solarguy]

As noted by metro, your 36 watt figure is for ideal circumstances. That means:

1. oriented at 90 degrees to the sun at all times
2. cells are not hot. heat causes output to drop
3. no shading whatsoever
4. perfect soldering job/wiring/load/controller, with no or minimal losses

In reality, none of those conditions will apply to your installation. My biggest concern is with shading. For many panels, if you significantly shade even one cell, output can drop by 50-75%. Unless the cells are virtually in contact with the glass, you may shade some of the cells on the edge by the frame.

So, one of the consequences is that you may not need any charge controller at all if your battery is decent sized. Especially if it's flooded lead acid, as opposed to AGM (absorbed glass mat) or gell cells. FLA's appreciate a little controlled overcharge occasionally.

None of these issues should be a deal breaker.

HTH,

troy