Energy power plays leveraging the sun

In may be a couple of years from now, your electricity meter reading personnel would not have to enter your home but stand about 200 feet away and press a button to know how much energy you have consumed. Please don't mistake this to be India as imagined in 2020; it's an innovation in the offing.

Engineers at the Bangalore office of Dallas-headquartered chipmaker Texas Instruments (TI) have been working on a smart meter that would transmit an RF signal or  radio frequency to the hand-held digital device of the personnel, giving the meter reading for the period.

The technology has been tested by Texas Instruments at its facility in Bangalore. The company, known primarily for making semiconductor chips has a long list of smart devices to its credit that run on chips designed by engineers at the Bangalore lab.

The Power Management division at the company, headed by Director Ram Anant is actively working on chips that would make our households much more efficient and smart metering is just an iota of the vast amount of research and development going on in the facility tucked away among other tall buildings at Bagmane Tech Park here.

One of their major area of focus being solar energy harvesting, the company has central inverter solutions, micro inverter solutions, micro converter solutions and battery charging solutions to its credit.

Central, or “traditional” inverters are centralised power control units that convert DC power from a string of 72-cell solar panels to AC power for use on the electrical utility grid. These are usually large scale, commercial or residential systems producing in excess of 1 kW of power.

Micro inverters operate similar to central inverter systems, but are installed on each individual panel and handle much less power, typically 300 W.

Micro converters maximise the DC power point of a single solar panel and convert (down or up) the DC voltage to be transported downstream to a centralized AC (grid-tied) inverter.

And off-grid solar power systems often need to charge a battery, or array of battery cells, that provide continuous power to the load when solar energy is no longer present. According to Anant, the price of photovoltaic panels (PV) has fallen drastically and with government subsidy, it is possible to have a rooftop photovoltaic setup that produces 100 watts of electricity for Rs 85,000. “You would need Rs 40,000 for the panel (Rs 40/watt), Rs 15,000 for the battery, Rs 20,000 for the inverter and Rs 10,000 for the battery charger,” he explains, adding that returns are still not that great but with electricity tariffs going up rapidly, it is viable to invest in rooftop photovoltaic setups (RTPV) which have a life of around 30 years.

Sunny outlook

In January 2010, the government launched the Jawaharlal Nehru National Solar Mission with an ambitious target of deploying 20,000 MW of grid-connected solar power by 2022.

According to a research paper by Center for Study of Science, Technology and Policy (CSTEP) the target set for Phase 1 of 500 MW of utility-scale solar PV is sliced in different ways as a means of illustrating the societal and budgetary impact. The net present value of cash outlays for generation-based incentives for electricity generated from solar PV installations alone in Phase 1 is around Rs 110 billion (at a 10 per cent discount rate).

Though a lot of research and development in this field happens in India, Anant explains, “The market is global now and I can’t say that TI India caters to India alone. Whatever effort we put in here has global ramifications.” “Close to two years back, everybody went after solar and there is a glut of panels in the market now. All these additional panels have made the setup much cheaper from Rs 120 per watt to Rs 40 per watt.” According to Anant, the whole idea of rooftop solar is not to go on generating electricity but to optimally use what is available today and make it accessible to more people.

Though in the 1980s Karnataka used to be a power surplus state depending heavily on hydel power, a lot has changed in the last 10 years. The dependence of Karnataka on thermal power has gone up to approximately 67 per cent and the usage of hydel has fallen to 27 per cent. Experts believe that insitu production of solar power would not only help the individual but would also take some stress off the grid.

When asked if the RTPV would be useful in giving back some energy to the grid as well, Anant says that India doesn't yet have the technology in practice that would allow such a thing.

Feeding to the grid gives credit to the individual, which happens only when one has excessive energy. Since the payoffs are not so great at present, it is hardly worth the investment in 2 kW of solar panel to give to the grid when you just need 500 watts in the household.

The Jawaharlal Nehru National Solar Mission (JNNSM) was seen as one of the eight missions under the National Action Plan for Climate Change (NAPCC) and the first phase of the mission has come to a close by March 2013. A total of 1,300 MW (1,100 MW grid-connected and 200 MW off-grid) capacity was targeted for Phase I of  the solar mission. Talking about implementation of technologies pertaining to solar Anant says, “The rate at which you can progress and implement depends on government policies to a certain extent. You can keep the technology ready; today if you want to design an inverter to put the solar energy back to the grid we can do it but we do not have a credit system in place today . So one needs to be in step with the government.”

Texas Instruments is actively engaged with the Union government through its Director of Corporate Affairs Deepak Bharadwaj who informs them what exactly the Centre and the states are looking at with regards to solar energy implementation.