As a researcher in Photovoltaics(read solar cells), I think a lot about renewable energy. For the Rip Van Winkles of the world, we seem to be running out of oil. Also most scientists believe that all the fossil fuel burning is heating up the planet too much (Let me be precise here. We know that earth is heating up but we are not sure if it is caused by humans.). So we need alternative sources of energy that are not exhaustible and do not produce prodigious amounts of excess greenhouse gasses.
Enter renewable energy. By definition it refers to energy derived from sources that can regenerate ("renew") naturally. Biggest examples are wind, water, geothermal, sunlight, etc. Also included are solutions like bio-diesel, which do emit carbon dioxide but that carbon is subsequently recycled it back into fuel.
Now the big question. Compared to fossil fuels, why are all the renewable energy sources so expensive? No matter what technology you chose, solar-electric, solar-thermal, algae-diesel, wind, etc. compared to fossil fuels it is always more costly. It turns out that the problem is not availability but the low density of energy. Let me explain....
What is the ultimate source of all energy on the planet, other than nuclear power, it is the Sun. Everything from weather to food is ultimately being powered by our star. On an average day the Sun beats down around 174 pentawatts of power; that is more energy in one hour than what the total energy consumed by the world in 2002 [1]. Where does all this energy go? A substantial portion is radiated back to space. In fact it is the reduction in this reflected power, due to green house gasses, that is responsible for global warming. The rest of the energy gets dissipated as wind, stored as biomass, etc.
While this is a lot of energy, it is very dilute. The amount of energy falling on the surface of a typical car (~8 m sq. [2]) is only 8 kW, i.e. 10.5 bhp. Compare this to the power of an average gasoline engine (~110 bhp) and you realize that even if we capture 100% of the incident energy, we can't power a car purely from sunlight falling on it. To make a solar powered car, we need to concentrate the Sun's energy into a more dense form. We can store the energy into a battery, or make bio-diesel, or generate hydrogen from water, etc. Now fossil fuels have done this concentration naturally over the course of many million years, but renewable sources do not have that long! Since this extra time is not being priced by the market, all such technologies seem more expensive.
In some sense we have been spoiled by oil. Our requirements of energy density are just way too high and unfair. May be we need to reduce standards by going for efficiency. Smart grids, lighter cars, smaller cars, etc. are all needed before renewables can take off.
[1] http://en.wikipedia.org/wiki/Solar_energy
[2] http://www.usatoday.com/money/autos/2007-07-15-little-big-cars_N.htm
Tuesday, March 29, 2011
Monday, March 28, 2011
Technology and Development
Today I came across a fascinating bit of news on BBC. It details the business model of a small supply chain company, United Villages, based in rural Rajasthan, India.
While there has been a lot of talk about fortunes at the "bottom of the pyramid", not many businesses have yet reached out to the poor rural masses of India. As it turns out, the bottleneck is cost. In the isolated pockets of India, i.e. the middle-of-nowhere villages with a population of less than 5000, it is just not cost-efficient to establish a supply chain. This is especially true for small and medium businesses that typically have a short return horizon. The downside of this is that retailers in these villages need to shut down shop and trudge to the nearest "big" market to restock. This is not only inefficient but also leads to revenue loss.
The solution according to United Villages is technology, specifically the ubiquitous mobile phone. The idea is to send restocking orders via cell phones to state level hubs. The requested goods are dispatched to the retailers! A simple idea but I am sure it is making a huge difference to the productivity of the system.
Of course there are bottlenecks. It turns out that the retailers are pretty conservative when it comes to technology and who can blame them? Most of them are on razor thin margins and without a security net to fall back on, they are risk averse. On top of that, I guess most of them are either unfamiliar or totally ignorant of the technology. This makes the sales staff with the requisite local connections very valuable, leading to problems in finding and retaining staff.
But on the whole a very neat idea that is being implemented well. This is similar to a wave of schemes that leverage proliferation of mobile phones to help the poor in India ( for e.g. banking, news, etc. ). Entrepreneurship, especially the low-cost targeted-for-the-poor type is the only way towards sustainable and equitable growth.
While there has been a lot of talk about fortunes at the "bottom of the pyramid", not many businesses have yet reached out to the poor rural masses of India. As it turns out, the bottleneck is cost. In the isolated pockets of India, i.e. the middle-of-nowhere villages with a population of less than 5000, it is just not cost-efficient to establish a supply chain. This is especially true for small and medium businesses that typically have a short return horizon. The downside of this is that retailers in these villages need to shut down shop and trudge to the nearest "big" market to restock. This is not only inefficient but also leads to revenue loss.
The solution according to United Villages is technology, specifically the ubiquitous mobile phone. The idea is to send restocking orders via cell phones to state level hubs. The requested goods are dispatched to the retailers! A simple idea but I am sure it is making a huge difference to the productivity of the system.
Of course there are bottlenecks. It turns out that the retailers are pretty conservative when it comes to technology and who can blame them? Most of them are on razor thin margins and without a security net to fall back on, they are risk averse. On top of that, I guess most of them are either unfamiliar or totally ignorant of the technology. This makes the sales staff with the requisite local connections very valuable, leading to problems in finding and retaining staff.
But on the whole a very neat idea that is being implemented well. This is similar to a wave of schemes that leverage proliferation of mobile phones to help the poor in India ( for e.g. banking, news, etc. ). Entrepreneurship, especially the low-cost targeted-for-the-poor type is the only way towards sustainable and equitable growth.
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