Reducing Arduino Power Consumption
Contributors:
Alex the Giant
Alex the Giant 
Resources and Going Further
More information on low-power modes and options can be found in the datasheet for the 328P.
For more power-related fun, check out the following SparkFun tutorials.
Electric Power
An overview of electric power, the rate of energy transfer. We'll talk definition of power, watts, equations, and power ratings. 1.21 gigawatts of tutorial fun!
Sunny Buddy Solar Charger V13 Hookup Guide
How to hookup the Sunny Buddy: a solar-powered, MPPT (peak-power tracking), LiPo battery charger.
SparkFun Qwiic Dual Solid State Relay Hookup Guide
A Hookup Guide to get you started with the SparkFun Qwiic Dual Solid State Relay.
MicroMod Ethernet Function Board - W5500 Hookup Guide
Add Ethernet and PoE capabilities to your MicroMod project using the Ethernet Function Board - W5500.