Photovoltaic Systems

Archive for April, 2008

I just finished doing my DIY solar lantern project. I’ve always wanted to make one but I didn’t have the time to make one.

After the Earth Day, I decided to make time for this mini project of mine.

I’ve made a detailed documentation of this project including theory of operation, how it works, how to compute for the resistor value, and all these technical stuff.

Here’s a link to the detailed guide on how I did it.

DIY Solar Lantern part 1/3

DIY Solar Lantern part 2/3

DIY Solar Lantern part 3/3

Here are some of the pics.

Tags: solar lantern

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Powerenz, a manfacturer and retailer of portable solar power systems in Georgia, has designed a system to help pilots power up their light airplane avionics without having to start the engine. It can power up the aircraft avionics silently, without smoke, and without wasting aircraft fuel. The unit can be used for approximately 90 [...]

The global trend toward biofuels came under attack last week at the International Energy Forum in Rome. Blamed by industry insiders for the nascent food crisis, alternative fuels made from cash crops – particularly grains – have been subject to increasingly vociferous criticism as it becomes evident that they aren’t the much-touted panacea for global warming many had imagined. Though these comments aren’t especially surprising coming from a bunch of oil CEOs and government policy wonks, they shouldn’t be dismissed. More and more studies are indicating that biofuels such as ethanol use at least as much energy as they are purported to save, and that the reallocation of farm land for fuel crops is putting a strain on global food markets.

We shouldn’t be so quick to dismiss biofuels, however. While they make a convenient scapegoat for the current crisis and are clearly deserving of skepticism, they may not be entirely to blame, despite what the energy moguls claim. Biofuels will probably never live up to their original hype, but with continued technological progress and more intelligent legislation, they may still find their niche on a smaller, more sustainable scale. First, while most attempts to produce biofuels utilize processes and raw materials that are inefficient, some alternative methods offer hope. The International Energy Agency (IEA) supports the use of second-generation biofuels, which use non-food crops to produce the fuel. Other methods focus on genetically engineering certain tree species to reduce lignin levels, which prevent researchers from accessing the cellulose needed for ethanol production. Given their high levels of cellulosity, trees are otherwise perfect candidates for biofuels. Such methods are not without their own controversies, however; critics of bioengineering have raised concerns over compromising the structural integrity of these experimental trees, not to mention the threat of cross-fertilization with wild strains. Second, most current subsidy policies do little but promote such inefficiency. Corn-based ethanol – the bulk of biofuel produced in the U.S. – is especially inefficient given corn’s low cellulose content compared to other potential sources. Yet Congress continues to pass bills in favor of greater corn subsidies and cornthanol production. (Click here and here to read our past posts.) At the conference, recently ousted Italian prime minister Romano Prodi astutely commented that “We have to examine very closely subsidy policies so as to avoid distortions in the allocation of resources”. Such a prudent approach may prove better in the long run than the outright dismissal of biofuels, despite the significant limitations born out by recent events.

“Tortillanomics”, a slideshow on Frontline‘s website, also explores the effects of biofuel production on corn prices in Mexico. Click here.

In a news conference early this week in a gloomy Rose Garden, President Bush argued the main reason gasoline prices were so high was a lack of domestic oil production. While his silly assertion was widely disputed by reputable sources on NPR, his claim got me to thinking, “what exactly was his stance on energy [...]