Tag: california

Powered by the Sun: Boosting Solar Efficiency

solar1Improving the efficiency of solar power – which is currently the most promising alternative energy source – is central to ensuring that it an becomes economically viable replacement to fossil fuels, coal, and other “dirty” sources. And while many solutions have emerged in recent years that have led to improvements in solar panel efficiency, many developments are also aimed at the other end of things – i.e. improving the storage capacity of solar batteries.

In the former case, a group of scientists working with the University of Utah believe they’ve discovered a method of substantially boosting solar cell efficiencies. By adding a polychromat layer that separates and sorts incoming light, redirecting it to strike particular layers in a multijunction cell, they hope to create a commercial cell that can absorb more wavelengths of light, and therefor generate more energy for volume than conventional cells.

EMSpectrumTraditionally, solar cell technology has struggled to overcome a significant efficiency problem. The type of substrate used dictates how much energy can be absorbed from sunlight — but each type of substrate (silicon, gallium arsenide, indium gallium arsenide, and many others) corresponds to capturing a particular wavelength of energy. Cheap solar cells built on inexpensive silicon have a maximum theoretical efficiency of 34% and a practical (real-world) efficiency of around 22%.

At the other end of things, there are multijunction cells. These use multiple layers of substrates to capture a larger section of the sun’s spectrum and can reach up to 87% efficiency in theory – but are currently limited to 43% in practice. What’s more, these types of multijunction cells are extremely expensive and have intricate wiring and precise structures, all of which leads to increased production and installation costs.

SolarCellResearchIn contrast, the cell created by the University of Utah used two layers — indium gallium phosphide (for visible light) and gallium arsenide for infrared light. According to the research team, when their polychromat was added, the power efficiency increased by 16 percent. The team also ran simulations of a polychromat layer with up to eight different absorbtion layers and claim that it could potentially yield an efficiency increase of up to 50%.

However, there were some footnotes to their report which temper the good news. For one, the potential gain has not been tested yet, so any major increases in solar efficiency remain theoretical at this time. Second, the report states that the reported gain was a percentage of a percentage, meaning that if the original cell efficiency was 30%, then a gain of 16% percent means that the new efficiency is 34.8%. That’s still a huge gain for a polychromat layer that is easily produced, but not as impressive as it originally sounded.

PolyChromat-640x353However, given that the biggest barrier to multi-junction solar cell technology is manufacturing complexity and associated cost, anything that boosts cell efficiency on the front end without requiring any major changes to the manufacturing process is going to help with the long-term commercialization of the technology. Advances like this could help make technologies cost effective for personal deployment and allow them to scale in a similar fashion to cheaper devices.

In the latter case, where energy storage is concerned, a California-based startup called Enervault recently unveiled battery technology that could increase the amount of renewable energy utilities can use. The technology is based on inexpensive materials that researchers had largely given up on because batteries made from them didn’t last long enough to be practical. But the company says it has figured out how to make the batteries last for decades.

SONY DSCThe technology is being demonstrated in a large battery at a facility in the California desert near Modeso, 0ne that stores one megawatt-hour of electricity, enough to run 10,000 100-watt light bulbs for an hour. The company has been testing a similar, though much smaller, version of the technology for about two years with good results. It has also raised $30 million in funding, including a $5 million grant from the U.S. Department of Energy.

The technology is a type of flow battery, so called because the energy storage materials are in liquid form. They are stored in big tanks until they’re needed and then pumped through a relatively small device (called a stack) where they interact to generate electricity. Building bigger tanks is relatively cheap, so the more energy storage is needed, the better the economics become. That means the batteries are best suited for storing hours’ or days’ worth of electricity, and not delivering quick bursts.

solarpanelsThis is especially good news for solar and wind companies, which have remained plagued by problems of energy storage despite improvements in both yield and efficiency. Enervault says that when the batteries are produced commercially at even larger sizes, they will cost just a fifth as much as vanadium redox flow batteries, which have been demonstrated at large scales and are probably the type of flow battery closest to market right now.

And the idea is not reserved to just startups. Researchers at Harvard recently made a flow battery that could prove cheaper than Enervault’s, but the prototype is small and could take many years to turn into a marketable version. An MIT spinoff, Sun Catalytix, is also developing an advanced flow battery, but its prototype is also small. And other types of inexpensive, long-duration batteries are being developed, using materials such as molten metals.

Sumitomo-redox-flow-battery-YokohamaOne significant drawback to the technology is that it’s less than 70 percent efficient, which falls short of the 90 percent efficiency of many batteries. The company says the economics still work out, but such a wasteful battery might not be ideal for large-scale renewable energy. More solar panels would have to be installed to make up for the waste. What’s more, the market for batteries designed to store hours of electricity is still uncertain.

A combination of advanced weather forecasts, responsive fossil-fuel power plants, better transmission networks, and smart controls for wind and solar power could delay the need for them. California is requiring its utilities to invest in energy storage but hasn’t specified what kind, and it’s not clear what types of batteries will prove most valuable in the near term, slow-charging ones like Enervault’s or those that deliver quicker bursts of power to make up for short-term variations in energy supply.

Tesla Motors, one company developing the latter type, hopes to make them affordable by producing them at a huge factory. And developments and new materials are being considered all time (i.e. graphene) that are improving both the efficiency and storage capacity of batteries. And with solar panels and wind becoming increasingly cost-effective, the likelihood of storage methods catching up is all but inevitable.

Sources: extremetech.com, technologyreview.com

 

Winning Ideas: The Bodyheat Powered Flashlight!

body_heat_flashlightEvery year, IT giant Google holds an online competition open to students aged 13-18 from around the globe to come up with new and challenging scientific ideas. And this year, one the winners just happens to hail from my hometown of Victoria, British Columbia. Her name is Ann Makosinki, a 15 year old high school student who invented a way to power a flashlight using only the warmth of your hand.

She claimed a trophy made of Lego for the 15-16 age category at an awards gala that was held on Monday, Sept. 23rd. Her prizes were a $25,000 scholarship and a “once-in-a-lifetime experience” from either CERN (the European Organization for Nuclear Research), LEGO or Google. Quite the impressive accomplishment for a 11th grader, but then again, Makosinki has been a scientist at heart ever since she was a little kid.

google-science-fair-winners-2013For starters, when other children were playing with toy cars and dolls, she busied herself with transistors and microcircuits. What’s more, by Grade 6, she began submitting projects to science fairs and began showing an interest in alternative energy. Still, Makosinki was surprised to be getting an award, given her competition. As she said:

I’m in shock, I’m in shock. It’s actually kind of embarrassing because I didn’t even change [before the awards ceremony]. I didn’t even comb my hair or anything. I must have looked like an absolute mess on stage because I didn’t expect to go up at all.

As for the invention itself, it is easy to see why she won. Basically, it is an LED flashlight that relies on the thermoelectric effect to generate electricity when held. This is done through a series of devices that are known as Peltier tiles, which produce electricity when heated on one side and cooled on the other. The tiles are fixed to the outside of the flashlight while the tube itself is hollow.

peltier-figure-9When held one side of the Peltier tiles are heated by the warmth of the person’s hand, air flowing through the hollow tube helps keep the other side cool. This combination of body heat and air cooling allows enough power to be generated to maintain a steady beam of light for 20 minutes. And all without the need for batteries and the resulting ewaste when they go dead.

Makosinki came up with the idea while researching different forms of alternative energy a few years ago. Already, she had experimented with Peltier tiles for her Grade 7 science fair project. While researching her project, she thought of them again as a way to potentially capture the thermal energy produced by the human body. After doing some calculations, she found that the amount of energy produced by a person’s hand was theoretically sufficient to power an LED light.

ann_makosinksiHowever, putting it into practice proved somewhat more difficult. After buying some Peltier tiles on eBay, she tested them and found that while they generated more than enough power, the voltage produced was only a fraction of what she needed. She rectified this problem after doing some further research, where she discovered that the addition of transformers could be used to boost the voltage.

She spent months doing research on the internet, experimenting with different circuits and even building her own transformers, which still didn’t provide enough voltage. In the end, she came across an article on the web about energy harvesting that suggested an affordable circuit that would provide the voltage she needed when used with a recommended transformer. Finally, the circuit worked.

ann_makosinksi1Makosinski admitted there were points in the experiment when she thought it would never work. But as she said:

You just kind of have to keep going. This took quite awhile ’cause I had to do it during the school year as well and I had homework, plays, whatever that I was also doing.

After making it to the Google Science Fair, she and her colleagues spent the day presenting at Google’s headquarters in Mountain View, California. Here, the 15 judges – which included scientists from a variety of fields, science journalists, an astronaut, and a former Google Science Fair winner – witnessed their creations and tried to determine which held the most promise.

The other winners included Viney Kumar, an Australia student who captured the 13-14 age category for an Android app that warns drivers of an approaching emergency vehicle more than a minute in advance, in order to help clear a path for it. And then there was Elif Bilgin of Turkey, a 16-year old who took home the Scientific American Science in Action Prize and the Voter’s Choice Award for inventing a way to make plastic from banana peels.

Ann-Makosinski-Google-Science-Fair-2The Grand Prize for the 17-18 age category went to Eric Chen, a 17 year old student from San Diego who is researching a new kind of anti-flu medicine using a combination of computer modelling and biological studies. He received the top prize of a $50,000 scholarship and a 10-day trip to the Galapagos Islands.

Alas, Makosinki felt the best part of the competition was getting to meet the other finalists in person at last.

It’s just so inspiring to see other people who are kind of like me and kind of want to make a difference in the community not just by talking about it but by actually doing stuff.

What’s next for the young inventor? Personally, I hope Makosinki and her fellow prize winners will be forming their own research group and looking for new and exciting ways to come up with renewable energy, recycling, vaccinations, and electronics. What do you think Makonsinky, Kumar, Bilgin, Chen? That’s what Andraka and his fellow finalists did after winning ISEF 2012, and they seem to be doing pretty good. So… hintedy, hint hint!

And be sure to enjoy this video of Ann Makosinki showing off her invention, courtesy of Technexo:


Sources: cbc.ca, (2), gizmag.com, technexo.com, huffingtonpost.ca

A Kinder, Gentler Internet: California’s “Erase Button”

cyber bullyingIn the early nineties, the internet was greeted with immense optimism and anticipation. Scarcely a week went by without some major personality – Al Gore and Bill Gates come to mind – championing its development, saying it would bring the world together and lead to “the information age”. After just a few years, these predictions were being mocked by just about everyone on the planet who had access.

Rehtaeh_ParsonsYes, despite all that has been made possible by the internet, the heady optimism that was present in those early days seem horribly naive by today’s standards. In addition to making virtually any database accessible to anyone, the world wide web has also enabled child pornographers, hate speech, conspiracy theorists and misinformation like never before.

What’s more, a person’s online presence opens them to new means of identity theft, cyberbullying, and all kinds of trolling and harassment. Who can forget the cases of Amanda Todd or Rethaeh (Heather) Parsons? Two young women who committed suicide due to relentless and disgusting bullying that was able to take place because there simply was no way to stop it all.

amanda_toddsuicide.jpeg.size.xxlarge.letterboxAnd with the ever expanding online presence of children and youths on the internet, and little to no controls to monitor their behavior, there are many campaigns out there that hope to reign in the offenders and protect the users. But there are those who have gone a step further, seeking to put in place comprehensive safeguards so that trollish behavior and hurtful comments can be stopped before it becomes a permanent part of the digital stream.

One such person is California Governor Jerry Brown, who recently signed a bill into law that requires all websites to provide an online “erase button” for anyone under 18 years of age. The stated purpose of the law is to help protect teens from bullying, embarrassment and harm to job and college applications from online posts they later regret. The law, which is designated SB568, was officially passed on Sept. 23rd and will go into effect Jan 1st, 2015.

kid-laptop-156577609_610x406Common Sense Media, a San Francisco based non-profit organization that advocates child safety and family issues, was a major supporter of the bill. In a recent interview, CEO James Steyer explained the logic behind it and how it will benefit youths:

Kids and teens frequently self-reveal before they self-reflect. In today’s digital age, mistakes can stay with and haunt kids for their entire life. This bill is a big step forward for privacy rights, especially since California has more tech companies than any other state.

The law is not without merit, as a 2012 Kaplan survey conducted on college admissions counselors shows. In that study, nearly a quarter of the counselors interviewed said they checked applicants’ social profiles as part of the admission process. Of those counselors, 35% said what they found – i.e. vulgarities, alcohol consumption, “illegal activities” – negatively affected their applicants’ admissions chances.

smartphoneteensBut of course, the bill has its share of opponents as well. Of those who voted against it, concerns that the law will burden websites with developing policies for different states appeared to be paramount. Naturally, those who support the bill hope it will spread, thus creating a uniform law that will remove the need to monitor the internet on a state-by-state basis.

At present, major social media sites such as Facebook, Twitter, Instagram and Vine already allow users of any age to delete their posts, photos and comments. California’s “eraser button” law requires that all websites with users in the state follow this policy from now on. And given the presence of Silicon Valley and the fact that California has one of the highest per capita usages of the internet in the country, other states are sure to follow.

facebook-privacyThe new law also prohibits youth-oriented websites or those that know they have users who are minors from advertising products that are illegal to underage kids, such as guns, alcohol and tobacco. Little wonder then why it was also supported by organizations like Children NOW, Crime Victims United, the Child Abuse Prevention Center and the California Partnership to End Domestic Violence.

In addition to being a legal precedent, this new law represents a culmination of special interests and concerns that have been growing in size and intensity since the internet was first unveiled. And given the recent rise in parental concerns over cyberbullying and teen suicides connected to online harassment, its hardly surprising that something of this nature was passed.

Sources: news.cnet.com, cbc.ca, huffingtonpost.com