How to use angled louvres to allow winter sun and block summer sun

Gudday!
  We are building a solar passive modular home with wheat-straw panels for insulation, which has a fair bit of glass on the Northern side. (Southern Hemi.) We will be in the Southern Highlands which can get quite cold (for Australia!) with decent frosts and the occasional snowstorm. Summers however can be quite hot.
 The house is approx 12m x 4.6m and will be angled just a little east of true north.  We will build a 3m wide verandah along the north wall, and run a wood heater/oven/stove for winter. As soon as possible I will be building a cob surround with benches either side to absorb the heat in winter and coolth in summer.
 My question is regarding allowing the winter sun in to the northern windows with a 3m verandah shading them. I was planning to put clear panels over the windows and large sliding glass door, and then build angled wooden louvres under to allow the winter sun and block the summer. Is that feasible? I'm a little stumped on how wide the clear panels should be. As wide as the windows or wider, and by how much?
Adrienne
I've attached a plan of the house without the verandah, which will be on what is the bottom wall in the plan.

Great idea.
I'm a little confused though. Covering the windows with clear sheets ....why?

I'm sorry I wasn't clear - I mean put clear panels in the verandah roof over where the windows are.

If you like that symmetrical look then yes same size as the windows(or twice the size, or half), wider panels will be stronger but more expensive or need extra supporting. Smaller and maybe you make more louvres, extra work.  Here we have snow load to think about too.
I have these by the back door of my house. They're 5 foot 1x6 cedar fence boards and pretty flimsy at that size. Small aluminum angles attached, single screw in the center from the opposite side as a pivot. Have to move each one separately though. If you made the brackets somewhat like the added part of the pic and joined them with a rod they could all move together.

In the summer I can turn them flat and block most sun.  This is winter so they're angled to let the most light in.  If it snows I have to tip them vertical.

If you completely enclose the veranda you might want to put these on the outside to better reduce heat gain.