One of the first issues is the orientation of the house. Solar panels do better on the south side. You should research whether your roof needs to support more weight. You will also do well to consider all aspects of solar building --- you can find books available in e-format for this. Go to Amazon and read reviews carefully. Things like roof overhang, kinds of windows, etc, can make a big difference in cooling your house (I'm assuming in India, heating isn't a big issue). For the solar panels, what's available where you are is a starting point. I will note that in sunny countries, like Turkey and Tunisia, I see a lot of solar hot water on roofs, but not so many solar panels.

How do you decorate your place, what kind of style, colors, and feelings? That will greatly influence the type of door you might want. Also, think of your budget, and whether you want to install it yourself or hire a professional (you don't need to tell us, just keep that in mind). Then look around Houzz, in the products page, they have lots of interior sliding doors and hinged ones, from elegant frosted glass in a dark wood frame, to rustic reclaimed wood planks. You may not want to purchase that exact model, but it might give you a better idea of what would fulfill your airflow needs without sacrificing style.

The energy efficient bulbs shown in the above photo suck the light is awful and they butn out quite often, if you want real energy savings go with LEDs they come in warm or cool light and you probably never have to chang a bulb as long as you live. They come in all kinds of wattages and can be retrofitted in almost any fixture.

Did a search, and it looks like "Geyser" is a brand of instant water heater: http://www.snapdeal.com/products/appliances-geysers-immersion-rods Can you build a box around it? If it needs ventilation, put a screen or vented box over it? Of course, if I'm wrong and this is a water shooting up in the air kind of geyser, then I'd suggest selling tickets and offering it up as a tourist attraction.