While I love to cook when I love to cook, I'm not into it when I'm not. Batch cooking is a great solution and feels very satisfying to both the eco-entric and the time manager within.  This is especially true for people who prefer to eat wholesome and slow, ideally 100 mile, food.

Cold months are particularly well suited to bulk food prep.  Soups, stews, baked pasta dishes, muffins … can all be done 2, 3, 4 meals at a time.  If you're gonna turn on the oven to make a lasagne … make 2.  Freeze one.  Saves a trip to the grocery store to get the ingredients.  Saves cooking heat.  Saves time.  Once you're set up, it doesn't take twice the time to make 2 pans of lasagne.  

TIP: Use the heat again. Teach yourself to turn off the oven 10 - 30 minutes before the food is cooked.  Start gradually, with recipes that you know well.  The heat continues to cook the food without, necessarily, needing to remain at the peak temperature. 

Alternately, keep the oven on for the entire cooking time, but be sure to leave the oven door open, once you've removed the cooked food, thereby using the leftover heat to warm up the house.