Sunday, March 18, 2012

Tame the Renewable with Hydrogen

The sun is bright and warm and your roof top solar panels and solar heaters are working hard to generate power and hot water. But the rate of power generated is too small to use immediately. The hot water is not hot enough for your shower. Your 200watt rooftop solar panel generates only 0.12 kwhrs after 5 hours of hard work. It does not meet your expectations. You expect 200 watts solar panel to generate about 1000 watt.hrs (1kwhr) in 5 hours. It is not happening. You don’t think renewable energy can meet your electricity demand. There is a strong wind in the island and the wind turbines are rotating faster than usual but there are hardly any people living there. Wind turbine generates good power when the wind velocity is above certain level. But the electricity generated by the wind has no immediate takers. There is a good rain this year and the dams are overflowing and the Hydro is generating surplus power but not many people are living near the catchment area. The power has to be transmitted hundred of kilometers to the nearby town through a sub-station. When the dams are dry there is hardly any power generation and power supply is rationed to the town. When there is a demand for power Mother Nature does not offer the resources for power generation. When Mother Nature offers the resource we do not need power. This anomalous situation is the single largest obstacle that is undermining the potential of renewable energy. Of course, the high initial cost and half-hearted approach by Governments to offer subsidies or grants for renewable energy are other factors that add to the anomaly. The only option to get over this situation is to store the energy 24x7 when it is generated and use them when we need them. It requires good storage technology, automation and information technology that can communicate with Natures energy resources and harness them, store them and deploy them judiciously and intelligently to meet our demands. Current battery technology cannot be a long term sustainable solution; it is expensive, requires constant maintenance and replacement, which adds to the expensive initial investment on renewable systems. The best option is to generate Hydrogen on-site whenever sun shines or wind blows and store them under pressure that can be used as and when we require electricity using Fuel cell. It is easier to handle gas than stored electricity in batteries. Batteries are very heavy, has a limited life cycle and poses health hazard and not suitable for large scale power storage and not sustainable in the long run. An Elecrolyzer can generate Hydrogen from water onsite whenever there is a sun or wind energy available and they can operate from 10% to 100% capacity depending upon the availability of renewable resources. The surplus power from Hydro can be converted into Hydrogen and stored. With so much advancement in information and communication technology, harnessing nature’s energy, storing them and deploying them in a timely manner is not major issue. Hydrogen can bridge the gap between Natural resource availability and human demand. This is what science is all about. We developed science by learning from Nature or duplicating Nature and Renewable energy is nothing different.