Two types of fir trees from the mainland — the Douglas and Noble — make up the vast majority of Christmas trees that will move into Hawaii living rooms in the coming days.

If you’ve wondered why that is, so has the state Department of Land and Natural Resources, which in 2013 had a study done on the potential for a Hawaii-grown tree market.

There are a few tropic-tolerant types being tried that are pretty, but according to the study, looks might not count for everything. Success may hinge on how the plant smells. Not Christmas-y enough? The customer base will turn up its nose.

Regarding solar energy’s big picture, think small

Hawaii’s solar energy industry has depended on a number of life preservers to stay afloat — tax credits, net energy metering, environmentally concerned citizens — but the newest one may be the most significant yet. Interest in “self-supply” solar system is growing among Hawaii homeowners, albeit slowly — the cost of battery storage is still stubbornly high.

But as costs come down and more people have their own power plant, there may be less need for giant utility-sized projects hulking over the landscape — windmills, offshore wave machines, fields of solar panels and the like. That would be another good reason for environmentally concerned citizens to invest in the technology.