Been following this topic since it started and it has evolved into a rather interesting discussion on electric utility generation and distribution. There seem to be those who are certain that the power they get is green because there is wind and solar farms in their State or surrounding area. Wind and solar are only possible of supplementing a portion of any utilities system. When there is no wind or a heavy cloud day your power will come from coal, natural gas, nuclear, or hydroelectric generation and it doesn't matter what you utility produces. There are many power pools throughout North America and power is a commodity that is traded daily, even hourly. It is quite normal for a utility whose main source of power is water - hydroelectric to purchase cheap overnight coal and nuclear power from producers in the pool as it is not possible to start/stop these generators when power generation is not required in the local grid. This allows these hydro utilities to save water for peak loads during the day and sell any surplus at a rate generally higher then what they paid overnight. One other problem is transmission bottlenecks which is why some areas are subject to brownouts or even rolling blackouts as a worst case. The ability to increase the import or export of power relies new transmission facilities and new transmission line right of ways are subject to opposition and blockades in some areas.
Just a comment on baseboard heaters, they are close to 100% efficient as they are noting but a resistor. Cost of operation is totally dependent on the cost of other heating options relative to electricity.
Then again maybe I don't know what I'm talking about
