Technology

IIT Madras presents an efficient and affordable SolarDC technology for powering off grid/near to off grid homes. Though several solutions have emerged in the past for powering these homes , they have been expensive and energy inefficient. These solutions rely on several DC to AC and AC to DC conversions, to feed the widely used AC home loads, thus, wasting a large chunk of the expensive power. The Inverterless 500 Solar DC solution for off-grid homes is developed to use the generated PV power efficiently. With this solution, the panel and battery size is reduced by 2 to 2.5 times and the cost to power a house is reduced to nearly half the cost of the existing solutions.

Lighting, fans and electronic devices form a significant and growing portion of power-load at homes and need power back-up support in case there are frequent power-cuts. A Diesel generator is generally used today in multi-storied buildings to provide this backup. Inverterless 2400 system, provides a far more energy-efficient alternative using renewable power-source for backup. It creates a pull for a home to move towards far more energy efficient DC loads. The solution provides a GREEN option to the existing solution. This system provides a fresh perspective on the problem of eliminating conversion losses for uninterrupted operation of DC appliances. A cost benefit analysis shows that this DC system can reduce costs to the consumer by eliminating the complex electronics embedded in the inversion process. A rough measurement of the conversion losses for commercially available inverters and battery chargers illustrates that gains of 30% to 45% are easily obtainable.

UDC technology presents a load-management innovation to provide a limited but uninterrupted DC power supply to homes in India. In a typically power deficient situation, load shedding becomes unavoidable. The duration and areas where load is shed are typically cycled. In worst situation, power outages last for a greater part of the day. To enable every home to get at least a limited amount of power 24×7, an innovative approach that combines use of DC power and load management has been proposed and implemented in several hundred homes in various locations. In order to make best use of limited power, a DC power line and energy efficient DC appliances are introduced and installed at homes. The approach also enables addition of solar power directly to the DC power line and use of battery, without any converter; the power-limit on DC line can thus be overcome.