Somerville is expanding its electronics recycling program to include computers and networking equipment in a move that city officials said could save about $75,000 a year in disposal fees. Starting this week, the city began accepting laptops, desktop computers, printers, cartridges, servers, and other equipment at the public works yard for free. Such items previously could only be disposed of during periodic hazardous-waste recycling events. The program is offered through a contract with Protek Recycling, which sorts through the materials for either repair and donation to nonprofits, or disassembly to salvage reusable parts and safely dispose of the remainder. In a statement, Mayor Joseph Curtatone said the program will help lift the burden from residents of disposing of old electronics. “Electronic waste recycling questions continue to be among the most frequent calls to our 311 constituent service center, and we hope this change will serve residents well,” he said.