There are many similarities between a solar installation in an RV and a regular single-family home. OK, some differences are quite fundamental, like the total number of available PV panels and their orientation, yet with respect to the system wiring, differences are less apparent.
The RV and the Marine environment have accumulated heaps of solar technical knowhow, that is directly applicable to home construction. And the major increases in efficiency of Photovoltaic panels in recent years, have had a dramatic impact on the cost of these systems, which has enabled a whole new group of homeowners to go off-grid. New battery storage technologies from companies like Tesla are the new frontier for the homeowner, but for this new technology to become a standard, home wiring has to go low voltage.
As RV’ers, we have experienced the complications of dual voltage (12V DC/120V AC) systems and have responded to conversion losses (going from 120V to 12V and vice versa) by largely converting to 12V. It makes sense, to avoid up-converting the 12V-48V that is produced by your solar panels to 120V followed by a down-conversion to 5V or 12V used in many electronics. Each conversion creates a 10% energy loss that is unacceptable with Photovoltaics. The fact is that the majority of home appliances don’t need 120V AC and that the few that do, can be grouped together for a simpler installation.
Many powered devices in the home today are in fact internally already low voltage. In addition to most interior lighting, good examples are TV’s, computers, fans, speakers, phones and fire alarms. And some of the heavy users like refrigerators, have been proven to work well on 12V, while at the same time being much more efficient than the standard home fridge (p.e. a condenser fridge with Danfoss compressor).
For it to happen in the home environment, a major change has to take place to enable low voltage appliances to be used in a low voltage framework, as well as major changes in the distribution of electricity through the power gird. And with the emergence of the lithium battery technology, ultimately even the home air-conditioner could be part of such a design.
My upcoming van conversion will be a good example of how to apply low voltage to your home setting; but that’s what your RV is supposed to be: your home from home!