Most batteries are capable of storing energy efficiently only for a few hours. But there are situations where energy needs to be stored for months together. Take a city in a cold region in Europe. The city might want to capture the heat from sunlight during the summer and use that for home or district heating in winter. But winter […]
While plants do an admirable job of converting sunlight and CO2 into food and fibers that we all use, what is the efficiency with which they convert sunlight into chemicals? Surprisingly, it is terribly low. For most plants, the photosynthetic efficiency is in the 1-2% range – that is, only about 1/50th of the total energy from sunlight falling on […]
Solar power plants use photovoltaic cells whose efficiencies are currently in the 20-23% range. In fact, there is even a theoretical upper limit of about 33.2% for the conventional “single-junction” solar cells – called the Shockley–Queisser limit. So how can some reputed research organizations claim that they have been able to reach efficiencies of much higher than 40%, even around […]
Is it possible to store heat in a salt? What a strange question! Even more strangely, the answer is: Yes. Sodium nitrate, for example, is used to store heat in what are called concentrated solar thermal applications, in which temperatures can reach above 400 degrees C. Why is a material like sodium nitrate used for storing heat? Because these fall […]
If someone told you that some of the ingredients in the food you eat or beverages you drink came from petroleum, you will not be amused. But it is true. Many food, beverage and even nutraceutical ingredients are still derived from chemicals which originate with petroleum. For instance, many of the colorants used in our foods, beverages, candies and ice […]
Globally, about 30 million tons of millets are produced every year. Over 500 million tons of rice are produced. That is: Over 15 tons of rice are produced for every ton of millet. But it perhaps should be the other way round. Millets are more nutritious than rice – they have higher proteins and fiber content Millets are more healthy […]
Even the world’s hottest place experiences a maximum temperature of about 57 degrees C! So, is it possible to achieve a temperature of 1000 degrees C using sunlight? Sounds impossible? But it can be achieved through the principle of sunlight concentration. A specialized field called concentrating solar thermal (CST) has existed for quite a while. CST solutions have been able […]
Industrial heating worldwide consumes massive amounts of energy, and is a significant source of CO2 emissions. Interestingly, a sizable portion of industrial heating requires temperatures less than 100 degrees C – studies in the EU have shown that about 30% of all the industrial heating applications required temperatures of 100 deg C or less. Sub 100 deg C temperatures for […]
When we talk about solar energy, most times we discuss electricity from solar panels. But solar energy has been contributing to low carbon energy use long before solar panels made their appearance – in the form of solar water heaters. As of 2023, while there are around 25 million rooftops using solar panels for electricity, there are an estimated 250 […]
Solar panels need to be in the hot sun to be in business. High sunshine – especially in tropical regions – might mean a lot of electricity generated, but this in most cases also implies that the panels can get quite hot. Will high temperatures affect the output of the solar panels? They sure will. Solar panels generate at their […]
