This is often done with tapped resistors, variable rheostats, or electonic voltage regulators. The losses occur because all of these methods usually use equipment or controls adapted from AC powered rectifier systems. Solutions For a brief explanation of how we minimize these losses and reduce system cost, see the right side column on this page. Better components are a pretty obvious solution, but defining WHAT is better is not so easy. Better does not always mean more expensive - better is primarily matching the components to the application.
Safety factors are much less obvious.
Another factor not usually allowed for is system deterioration. Using batteries with the minimum internal resistance possible to reduce I R losses. Both of these have very heavy plates and heavy duty internal connections. Typical lifespan on our batteries using our system design is 10 to 12 years. We hope this has shed some light on the subject of solar electric systems for cathodic protection.