If you have ever been to Kanyakumari, you’d have noticed the huge array of windmills that greet you on the way. It’s a spectacular scene with so many windmills lined up on either side of the national highway.
Windmills like that are huge and they produce electricity in large quantities. Of course, they are uber-expensive and take a lot of space. These factors make them inviable to be installed within cities. But, there is another category of windmills called micro wind turbines or micro-generation wind turbines.
Wind has a lot of kinetic energy stored in it. This kinetic energy/wind energy can be harnessed to our advantage (think: wind powered sail boats). With the advent of motors and generators, we now have windmills that can generate electricity as their blades rotate. Micro wind turbines are small windmills that can be installed on roof tops using small towers, open-spaces like parks, etc. It seems they should be installed at least 6 m higher than surrounding obstacles (if any).
Roof mounted micro wind turbines may have a capacity of up to 1 KW. Pole mounted (slightly larger) ones may have a capacity of 2.5 KW to 6 KW. A small wind turbine can produce 30 KWH of power a month if the average wind speeds are around 6m/s (The average wind speed in Chennai is 2-4 m/s, depending on the month). It seems 30 KWH is the power used by an average household in the US per day. In India, it should be much lesser. (Source)
As you can see, micro wind turbines can’t really power all the systems in a house even if the house is located in a windy region. But, it can be a good back-up power source during power cuts, etc. A lot of people buy inverters these days, and instead of charging the batteries using electricity, they might want use micro wind turbines or solar panels.
There are hybrid systems that combine both wind turbines and solar panels and provide a combined power output. These systems may be more reliable and might generate a considerable amount of power.
In countries like US and UK, Government subsidies and tax-credits are available for either buying these systems or for generating power by such systems (feed-in tariffs). The Indian Government should also bring such incentives so that people can generate some power by themselves (at least enough power to offset power-cuts).
Of course there are limitations to micro wind turbines. Their cost (entry-level systems may cost around $1000 USD) is quite high for the amount of electricity they generate. Older (unmaintained systems) may produce some noise. We need to buy batteries (huge cost) to store the electricity as we can’t export electricity to the power grid in India. We need to buy inverters (to convert DC to AC) and charge controllers additionally. Birds may get hurt (don’t worry about crows though – they are too clever!). It’s placed outside, so there is a chance of burglary.
It seems, larger wind mills are much more efficient than the micro wind turbines. But for the sheer thrill of being able to generate electricity (to offset power-cuts) and showing off to neighbors/guests, some people might opt for it. Wind is a renewable source (pollution free) and it will not get exhausted. These turbines are expected to last for 15-20 years, so it might be a good investment after all. I hope some companies will come up with innovative/inexpensive models suitable for our country.
If you want some thrill and adventure, the best thing to do is to make one yourself! I came across this DIY blog post that details how to make a small wind turbine (the model is shown above and they spent around 7000 rupees to do it, it seems). I wish more college students like them take up such renewable power generation projects. Good job, guys!