Electric chainsaws are cheaper, safer, less noisy and easier to use and to maintain than gas units; and also less polluting.
Gas And Electric Chainsaw Energy-Efficiency
Electric chainsaws vibrate less and are safer than gas units; but you should not use them outdoors, in wet weather.
Unless for very light tasks, corded electric chainsaws are a better choice. They are quiet, lightweight and flexible. Cordless units lack horsepower and their only significant advantage over corded chainsaws is not to be dependent on an electrical outlet.
Gas chainsaws are more powerful; they cut faster and are the best suited for heavy outdoor tasks. But they are noisy, high-maintenance and, typically, energy-inefficient and polluting.
If you do need a gas chainsaw look for a CARB and EPA 50-state emissions standards compliant chainsaw (USA and Canada) for lower emissions and higher energy-efficiency.
Gas Or Corded and Cordless Electric Chainsaws
Corded electric chainsaws are typically more powerful than cordless units; they are the best alternative to gas chainsaws for heavier tasks.
Look for Underwriters' Laboratories (UL) rated chainsaws for anti-kickback and other standard safety and energy-efficiency features.
Corded electric chainsaws are excellent for workshop projects, or for firewood cutting. They can be a lot more powerful than cordless chainsaws; typical units must be within 50 feet of the electrical outlet.
Cordless electric chainsaws are very flexible, and the quietest and lightest type of chainsaws. They are great for light pruning and for trimming tree branches, but they aren't meant for heavy tasks… Unfortunately, they have a relatively short runtime (30 minutes, often) and a limited power output.
Gas And Electric chainsaws prices
Prices vary within each category of chainsaws. You can find premium electric saws with prices below $100, but high-rated gas chainsaws (Husqvarna, Poulan...) are priced above $200 (see: Electric Chainsaw Reviews at Amazon.com).