I am very fortunate in that I live in a house that has a large south facing window in my living area. Each day in the afternoon we tear open the curtains to let the sun shine in. You would be surprised how much it heats up the house.
Once the sun goes down the curtains get closed. We also use the sun as our light source. Our lights remain off all day until evening and only if we absolutely need to, do we turn them on.
The sun is a frugal and easy way to heat and light your home.
This is part of the Frugal Tuesday Tip blog hop.