Going Solar for Homes - 3

Gulp, still not keeping to the “Post a blog on every Friday” resolution. Not giving up! Soon, I ‘ll be this diligent blog-a-writer….Ahem......

I just came back from visiting one of my “in-progress” projects at Chennai. I’m really excited as the fab. owners are really keen on the sustainability aspect and asking for more. I was sort of not pushing too many ideas on them for fear of being bullish. But delightfully, they’ve been asking for more sustainable features in their home designs. We are even thinking of pushing back grey water into water closet cisterns, this is kinda new for Indian homes though quite popular in the west.

Last time, we talked on the economics behind going solar in an Indian home. According to the United States Green Building Council (USGBC), building construction and operation represents 70 percent of electricity consumption, 39 percent of energy use, 39 percent of carbon dioxide emissions, 40 percent of raw materials used, 30 percent of waste generated, and 12 percent of potable water consumption here.

This is in tandem with what, someone said (not sure where I picked it from),

The “true” cost of a home is not only the purchase price, but the amount that it cost to also operate and maintain every month."

So though the initial costs seem high for an average home owner, the monthly savings on electricity bill would be on an average of 1000Rs/month, working out to Rs12000/yr (savings will increase every year due to spiking electricity fares).

Let me get you in onto the latest solar news. I am hearing that the Indian government is going real serious with solar and intends to use every home roof top in future to generate electricity to meet commercial requirements during the day. Electricity will be purchased from the owners during daylight hours and returned subsidized in the nights. I am hearing that from March 2011 all apartment builders are mandated to use solar to generate current to meet a fair percentage of the demand.
While the commercial building industry has taken great strides towards streamlining the construction process and producing greener buildings, residential construction has a long way to go.

Now coming back to – “How and where does one install the Solar panels and it’s accessories?”

THE PANELS
The panels take up quite a bit of space. For an average home with substantial solar dependency, we are looking at a roof space of about 200 SFT. There are 2 ways of installing the panels depending on the roof type:

Flat Roofs: The panels would have to be raised and inclined on a framework so as to have an incline sloping down southwards for maximum exposure to the sun.



Pitched Roofs: The panels to be laid flat on the roof incline sloping down southwards for maximum exposure to the sun. The is the best possible method as the panels can gain benefit from the existing slope and form an indigenous part of the roof design.



NOTE: Care to be taken that no shadows fall on the panels.

THE BATTERY
The battery to be placed in close proximity to the panels and housed in a 5’ X 6’ shelter that could be in masonary or plastic/wooden casing with plenty of air circulation to prevent overheating. Interestingly for the the prudent and DIY lovers there is plenty material available on the net to help with making a home made solar battery. One video here