The message is loud and clear?save power. That power is scarce, is not news. In India, the current demand is 2.1 billion units, and rising, whereas only 1.85 billion units are currently available. At the same time, fossil fuels, one of the largest sources of power, are fast becoming extinct. Power saving, thus, becomes critical to drive economic growth and to support a basic quality of life.
Fortunately, businesses across the world have risen to the challenge and have found innovative methods to save energy. For instance, India is estimated to have 300 million cellphones and as many chargers. Earlier, chargers would continue feeding on electricity even after cellphones are completely charged, amounting to a collective waste of around 300 mw of power! But now, manufacturers have come up with improved models that go into power save mode as soon as the device is completely charged.
Now imagine the units consumed by other household appliances such as camcorders, TVs, dish washers etc when lying idle. If all manufacturers innovate and install intelligent power-saving features in their products, a substantial amount of power could be saved. Consequently, when you don?t use power that much, you don?t have to generate as much. While countries across the globe are taking strides to save energy, it?s time to step onto the next level in this direction?energy harvesting.
The world is a fascinating place. Every movement, every transition, every change is basically a flow of energy. In our day-to-day lives we all experience ambient energy, be it the heat generated from our shoes against the floor, the swinging of the door, our body heat or the kinetic energy generated when we walk. Only, this ambient energy is not consistent and is generated in negligible quantities. However, the day is not far when technology will make it possible to capture and store this ambient energy in order to utilise it for large-scale commercial purposes.
Already oceanographic monitoring sensors derive energy from the movement of ocean waves for autonomous operations. There are wearable devices that derive energy either from the wearer?s body heat or body movement or even the surroundings. However, research in these areas is still in the nascent stages. The only two alternatives that have stood up as worthy competitors to fossil fuels are solar and wind.
Solar power is the most abundant and relatively constant source of energy. In fact, a 2006 Study conducted by Global Energy Network Institute states that covering 4% of the world?s deserts with photovoltaic cells could supply all the world?s energy. The same report goes on to state that India?s Thar Desert alone has the potential to produce 25,870 TW-h of power annually. We must ask ourselves that why India, a nation that receives surplus sunny days, has still not utilised this magnificent opportunity?
Wind power, in contrast, has grown considerably since the 1990s when it was first introduced in the country. Today, India has the fifth-largest installed wind power capacity in the world. Wind power accounts for 6% of India?s total installed power capacity and generates 1.6% of the country?s power.
Now going back to the growth of solar power in India; we come across two obstacles?non-consistency and installation costs.
The first challenge arises from the fact that solar power is available only for half a day, with possibilities of clouds and dust hampering the process. Therefore, storage options and combinations with other sources of energy need to be explored. As far as operational costs are concerned, though the cost of installation is still high, they are likely to come down over the next few years. While the high costs of photovoltaic cells limited their use to terrestrial purposes such as powering off-shore oil-rigs and navigational buoys till 1960s, the oil crisis in the 1970s catalysed their production.
Advances in the semiconductor industry has given further hope to proponents of solar energy. Semiconductor companies that have revolutionised computing are now confident of bringing the same level of precision and efficiency to harvesting solar energy. A recent report in the Wall Street Journal states that the market in 2009 could be as big as $6 billion. Even Research firm Gartner estimates that despite the downturn, the photovoltaic market will grow at a 17% CAGR between 2008 and 2013, to reach $34 billion in 2013.
This momentum is a result of the discovery of new solar applications for semiconductors that have enabled players to modify existing chips and hence make lower investment. These chips improve the performance of the entire system and lower costs. Solar panels can now be designed to execute maximum power point tracking, where they change their alignment through the day as per the sun?s movement, in order to capture maximum energy.
The efficiency of a photovoltaic system depends on the panel operating conditions and the inverter, which controls the flow of electricity between the module, battery, loads and power grid. The control maximises power, charges the battery, protects the circuit and matches the output of panels so that one does not feed the other. The advent of digital signal processor-based controllers have enabled a high level of computational performance and programming flexibility, enabling manufacturers to create more efficient and cost-effective solar panels.
This is an exciting time for semiconductor companies. The government must design appropriate policies to drive growth in this segment as it has done for wind energy. As Rupert Murdoch puts it: ?We need to push ourselves to make as many reductions as possible in our own energy use first? and that takes time. But we must do this quickly? the climate will not wait for us.? Truly, we must realise that Earth is our only home. We must preserve its resources and resort to intelligent ways of harvesting energy.
The writer is director, power management products, Texas Instruments India