Are some trees better for energy conservation than others?

It depends on which part of the country you live in.

In northern latitudes with cold winters, dense evergreens planted to block chilling winds are important for conserving heat energy. Likewise, deciduous shade trees with a sparse branching habit are desirable for keeping a northern home cool in summer when they have leaves while allowing sunlight through in winter after the leaves drop to provide passive heating.

In the South, where summers are hot and winters are mild, keeping cool in summer often outweighs passive winter heating. In that case, year-round shade from evergreens may be desired. If passive heating is desired, lower branches can be pruned from the base of the crown to allow light in from the low declination of the winter sun. Elevating the crown also improves airflow, which creates comforting breezes during the heat of summer.