Future greenhouse ambitions

I don't have the land to do it yet, but my dream is to build a year-round greenhouse in a back yard, so that I can have green all throughout the monochromatic bleakness of a New York winter. This is pretty much a daydream at this point, but I'd like to get some feedback from folks in the know.

The feature wish-list is as follows:

• a dug-out trench, shaped like a V with a flat bottom. Thinking something like 12' (or go metric and make it 4m) wide in the middle, with sides at a 60° angle going to ground level (total depth of around 10' or 2.5m)
• a double-paned glass or plexiglass roof, for insulation and lighting
• heating elements in the outer layer of roof, for snow and ice removal
• a space heater, to regulate temperature during the cold months
• an aquaponics tank (probably using goldfish, but possibly tilapia)
• aquaponics grow beds lining the angled sides
• compost-activated biochar beds on the flat part

The idea would be to run the aquaponic outflow to the top of the sloping sides, supporting herbs, leafy greens, and flowers. The runoff collects at the bottom of the slope, where it is returned to the fish tank. The flat surface would be used for root vegetables and bulbs like onions and garlic.

I realize that this is a tad ambitious (and that I may just be throwing the biochar bit because I think its cool), but part of why I'm posting this is to get the benefit of collective experience. Any thoughts?