Would an earth sheltered greenhouse work as winter enclosure?

[ulkal]

I came across the idea of an earth sheltered greenhouse that makes it possible to grow veggies and fruits in colder climates, year round. Here is the article:

http://www.treehugger.com/green-architecture/build-underground-greenhouse-garden-year-round.html

For some reason, I have always been intrigued by earth sheltered homes (probably because of my Sci-Fi enthusiasm ). Now I wonder, if this would be an option to accommodate tortoises in the winter/on colder days? According to the video, the environment is also humid, which is a plus. How would it be possible to regulate temperature? Could you use a small solar panel to power devices?

To me, it seems a reasonable idea to house tortoises. I am sure it takes a lot of work and some investment, but it might pay off. And offer more space than a bedroom.

This is purely hypothetical, as I do not own a plot of land where I would be allowed to make such extensive changes. But I hope to do so one day.
Opinions?

 

[Tom]

Only a thermometer can answer this.

I will share that the earth is a huge heat sucker. In areas with frozen winters sinking something down into the earth will help keep temps warmer than the outside air, but getting those temps up to tropical levels and holding them there will not be so easy. My little 4x4' underground boxes suck up a fair amount of electricity in the winter. The ground stays around 50 all winter long, even on freezing nights, but I have to burn some electricity to keep the temps up to 80 in those boxes. The ground just soaks up all the heat and transfers it away.

So something like this will keep the air warmer than the surrounding air, but getting it warm enough for a tropical tortoise will be a challenge.