Technical paper from Analog Devices about wide range energy meter LTC2947 that eliminates the need for unique and expensive sense resistor values. Link here (PDF)

Monitoring energy has similar benefits in many applications, not just solar. Handheld, rack-mounted and in-line energy meters are widely available and can be used by people such as facility managers to track and allocate energy used by equipment or departments among many things. This may also include load profiling, where expected energy consumption patterns are compared to present usage and areas of concern are flagged based on deviations from modeled energy patterns. By sizing loads, people can determine how many widgets, including lights, computers, batteries, can be connected to a system at any time. Electric bikes and vehicles can report their energy use per mile and quantify the energy being extracted from or returned to a battery.