During a utility outage, how will you cook without gas? A gas range can cover this, as long as the natural gas line isn’t turned off (often done during natural disasters to avoid fires) or you don’t run out of propane. You’ll have to light burners with a match, and most modern gas ovens won’t work without electricity, because of the glow-bar. Efficient wood cookstoves (and even cooking atop a wood space heater) are other options, though during the summer, adding that heat to the house is a problem. Outdoor grilling during the summer avoids overheating the house.
I have a small BioLite camp stove that uses wood (small twigs) and includes a small fan powered by thermo-electric technology (heat-to-electricity); this stove includes a USB port for charging a cellphone while cooking. Solar ovens are a backup option, especially for summertime power outages, but cooking is limited to daytime and full sun is usually required.