Posts about solar energy

Segun Oyeyiola Converted a Volkswagen Beetle to Use Renewable Power

This Nigerian College Student Built a Wind- And Solar-Powered Car From Scraps

The engineering senior at Nigeria’s Obagemi Awolowo University spent a year retrofitting a Volkswagen Beetle into a wind and solar-powered car, partly made of free scrap parts donated by friends and family. Everything else cost under $6,000.

Not only did Oyeyiola install a giant solar panel on top of the Beetle; he also inserted a wind turbine under the hood. As Preston explains, that allows air to flow into the grill while the car is moving, subsequently turning the turbine’s rotors and charging the battery at the back of the car. Oyeyiola also built a strong suspension system to deal with the weight of the battery itself.

It’s not perfect. The battery takes four to five hours to charge, but Oyeyiola says he’s working on that. The biggest challenges, he says, came from finding the best materials to use, and the people telling him he was wasting his time.

Super cool.

OAU student builds a solar-powered car

Another thing that distinguishes my car from the common ones you see around is that you can know the state of the car through your mobile phones. I wrote a software that you can install which will give you the basic information about the car while in your room.

My message to my fellow students is that Rome was not built in a day. It is better to start anything you want to do now and don’t never, I repeat, never expect someone to believe in your dreams because they may not understand it as you do. Endeavor to follow your heart and do what will make you happy and that which will not affect your fellow being negatively.

It is so great to read what creative engineers all over the globe are able to accomplish.

Related: Oyeyiola Segun on TwitterPromoting Innovation in Sierra LeoneInspirational Engineer Builds Windmill from TrashClay Water Filters for GhanaHelp Science Education in Tanzania

Do It Yourself Solar Furnace for Home Heating

Man builds $300 solar furnace, decreases heating bill

“I think it’s something that everyone should have affixed right to [their] house. I think it should be part of your design,” said Buchanan. “It would be very easy to do. [With a] south-facing house like mine, it’s perfect.

“Just mount it on the side. If you touch the side of the house, even at —20 C, it’s still hot. We should be gathering that heat and driving it inside as quickly as possible.”

It is great to see do it yourself solutions that easily tap the energy provided by the sun to heat your house.

I had a friend that had a south facing greenhouse (attached to her house) that had 2 huge water tanks. They would heat up in the sun and give off heat all night (the stone floor would do the same thing).

Related: Brian’s Pop Can Solar HeaterSolar DIY Space Heating ProjectsHow to Build a Soda Can HeaterPay as You Go Solar in IndiaSoda-can furnaces powered by solar energy heat Denver neighborhoodGreen Building with Tire BalesCost Efficient Solar Dish by Students (2008)

Continue reading

Loon – Balloon Enabled Internet

Project Loon, from Google:

The Internet is one of the most transformative technologies of our lifetimes. But for 2 out of every 3 people on earth, a fast, affordable Internet connection is still out of reach.

We believe that it might actually be possible to build a ring of balloons, flying around the globe on the stratospheric winds, that provides Internet access to the earth below. It’s very early days, but we’ve built a system that uses balloons, carried by the wind at altitudes twice as high as commercial planes, to beam Internet access to the ground at speeds similar to today’s 3G networks or faster. As a result, we hope balloons could become an option for connecting rural, remote, and underserved areas, and for helping with communications after natural disasters.

Google testing out this system now in New Zealand. If they can get it to work they plan to use ballons to provide wireless internet access to hundreds of millions, or even billions, of people that don’t have access now. These ballons would float about 20 km above earth in the stratosphere (so well above where commercial airline traffic) and they are really working somewhat like to satellites.

Though ballons are much cheaper to put in place than satellites they also offer significant problems as they get blow around by wind (which is why they haven’t been used before and why Google is going to experiment to see if they can get it to work). The ballons will use solar power and be controlled by a mission control to move into different wind zones to position themselves.


Continue reading

Pay as You Go Solar in India

Farmers Foil Utilities Using Cell Phones to Access Solar

In October, Bangalore-based Simpa Networks Inc. installed a solar panel on Anand’s whitewashed adobe house along with a small metal box in his living room to monitor electricity usage. The 25-year-old rice farmer, who goes by one name, purchases energy credits to unlock the system via his mobile phone on a pay-as-you-go model.

When his balance runs low, Anand pays 50 rupees ($1) — money he would have otherwise spent on kerosene. Then he receives a text message with a code to punch into the box, giving him about another week of electric light.
When he pays off the full cost of the system in about three years, it will be unlocked and he will get free power.

Across India and Africa, startups and mobile phone companies are developing so-called microgrids, in which stand- alone generators power clusters of homes and businesses in places where electric utilities have never operated.

Very cool. Worldwide, approximately 1.6 billion people have no access to electricity and another 1 billion have extremely unreliable access. The poorest spending up to 30% of their income on inefficient and expensive means of providing light and accessing electricity. Solutions like this, finding engineering solutions for basic needs that are market based, are great.

That the poor end up owning their solar system after just 3 years is great.

Creating great benefit to society with the smart adoption of technology and sustainable economics is something I love.

Related: Solar Power Market Solutions For Hundreds of Millions Without ElectricityAppropriate Technology: Solar Hot Water in Poor Cairo NeighborhoodsEngineering a Better World: Bike Corn-ShellerWater Pump Merry-go-Round

Using a Virus to Improve Solar-cell Efficiency Over 30%

Solar and wind energy are making great strides, and are already contributing significantly to providing relatively clean energy.

Researchers at MIT have found a way to make significant improvements to the power-conversion efficiency of solar cells by enlisting the services of tiny viruses to perform detailed assembly work at the microscopic level.

In a solar cell, sunlight hits a light-harvesting material, causing it to release electrons that can be harnessed to produce an electric current. The research, is based on findings that carbon nanotubes — microscopic, hollow cylinders of pure carbon — can enhance the efficiency of electron collection from a solar cell’s surface.

Previous attempts to use the nanotubes, however, had been thwarted by two problems. First, the making of carbon nanotubes generally produces a mix of two types, some of which act as semiconductors (sometimes allowing an electric current to flow, sometimes not) or metals (which act like wires, allowing current to flow easily). The new research, for the first time, showed that the effects of these two types tend to be different, because the semiconducting nanotubes can enhance the performance of solar cells, but the metallic ones have the opposite effect. Second, nanotubes tend to clump together, which reduces their effectiveness.

And that’s where viruses come to the rescue. Graduate students Xiangnan Dang and Hyunjung Yi — working with Angela Belcher, the W. M. Keck Professor of Energy, and several other researchers — found that a genetically engineered version of a virus called M13, which normally infects bacteria, can be used to control the arrangement of the nanotubes on a surface, keeping the tubes separate so they can’t short out the circuits, and keeping the tubes apart so they don’t clump.

The system the researchers tested used a type of solar cell known as dye-sensitized solar cells, a lightweight and inexpensive type where the active layer is composed of titanium dioxide, rather than the silicon used in conventional solar cells. But the same technique could be applied to other types as well, including quantum-dot and organic solar cells, the researchers say. In their tests, adding the virus-built structures enhanced the power conversion efficiency to 10.6% from 8% — almost a one-third improvement.

Read the full press release

Related: Using Virus to Build BatteriesUsing Viruses to Construct ElectrodesUsing Bacteria to Carry Nanoparticles Into Cells

Google Invests $168 million in Largest Solar Tower Power Project

Google is investing in a new solar tower power project located in California that will generate 392 gross MW of clean, solar energy. That’s the equivalent of taking more than 90,000 cars off the road. Google has now invested $250 million in clean energy.

Investing in the world’s largest solar power tower plant

works by using a field of mirrors, called heliostats, to concentrate the sun’s rays onto a solar receiver on top of a tower. The solar receiver generates steam, which then spins a traditional turbine and generator to make electricity. Power towers are very efficient because all those mirrors focus a tremendous amount of solar energy onto a small area to produce steam at high pressure and temperature (up to 1000 degrees F).

Several large solar projects are in the works in the sunny Southwest (and around the globe), but Ivanpah will be the first solar power tower system of this scale. The Ivanpah Power Tower will be approximately 450 feet tall and will use 173,000 heliostats, each with two mirrors.

The Department of energy is also providing financing for this project. The project is 10 times larger than the largest solar photovoltaic project in California.

Related: Google Investing Huge Sums in Renewable Energy and is HiringGoogle.org Invests $10 million in Geothermal EnergyGoogle’s Energy InterestsMolten Salt Solar Reactor Approved by CaliforniaSolar Tower Power GenerationFinding Huge Sources of Energy Without Increasing Carbon Dioxide Output

Molten Salt Solar Reactor Approved by California

California has approved a molten salt solar reactor project. The plan is for a 150-megawatt solar power tower project. From the press release: the “Solar Energy Project has the ability to collect and store enough thermal energy each morning to operate at full power all afternoon and for up to 8 hours after sunset. The game-changing technology featuring inherent energy storage affords utilities with a generator that performs with the reliability and dispatchability of a conventional power generator without harmful emissions that are associated with burning coal, natural gas and oil.”

diagram of solar energy project using molton salt

molten salt solar system diagram

The heliostats focus concentrated sunlight on a receiver which sits on top of the tower. Within the receiver, the concentrated sunlight heats molten salt to over 1000 degrees Fahrenheit. The heated molten salt then flows into a thermal storage tank where it is stored, maintaining 98% thermal efficiency, and eventually pumped to a steam generator. The steam drives a standard turbine to generate electricity. This process, also known as the “Rankine cycle” is similar to a standard coal-fired power plant, except it is fueled by clean and free solar energy.

This is another green energy project that has a great deal of potential. There is a great need for such new energy sources and hopefully quite a few of these projects will let us enjoy a greener and more sustainable way to meet our future energy needs.

For those interested in the business aspects of this energy project: United Technologies provided SolarReserve with an exclusive worldwide license to develop projects using the proprietary molten salt power tower technology, which has been in development for nearly three decades.

Related: Solar Thermal in Desert, to Beat Coal by 2020Wind Power Capacity Up 170% Worldwide from 2005-2009Cost Efficient Solar Dish by StudentsSolar Tower Power Generation

Green Building with Tire Bales

Recycling is better than throwing things away. But reuse is better than recycling. And in fact, avoiding use is best. I was at dinner with Duncan Hagar last week when he talked about the house he and his wife built in Colorado. They use tire bales and took advantage of passive solar. They have a blog with interesting details on the green house built by 2 engineers. Tire bales area form of reuse (and while some tires are recycled into asphalt and such things, most waste tires go into landfills).

A tire bale is a “big square brick” of about 100 compressed whole tires. Each bale is approximately 5 feet deep by 5 feet wide by 2.5 ft. high and weighs about 2,000 lbs. (1 ton). A tire bale (by itself) has an energy rating of somewhere between R-40 and R-200 depending on which study you read and how it’s used. The tire bales are encased in concrete, effectively making the tire bale walls of our house about 6-feet thick.

Our house uses approximately 170 full bales and about 5 half bales or about 17,000 tires. Tire bales are FREE as long as one presents a building permit. All we had to do was get the bales hauled from Sedalia to Granby Colorado, a distance of about 135 miles.

The tire bales are stacked like bricks to make up all of the outer walls. These walls form the structural integrity of the house. Shot-crete (sprayed on concrete) is applied to finish the walls, effectively creating a minimum 6-foot thick wall. The entire south of our house is glass windows and doors. This creates a large, active thermal mass, which should maintain a relatively constant temperature of 65-degrees. Imagine the energy savings!

Tire bales are not that new. They have been used for quite some time for building barns, holding river banks, and road construction. Using them for house construction is a fantastic and practical idea whose time has come.

Tire Bale Home Keeps Us Toasty Warm

The house has been warm through the winter months on sunny days, it gets as high as 84 degrees even hotter when sitting directly in the sunshine. At night the temperatures hang around 60 degrees without a fire going in the wood stove and 70-74 degrees with a fire going when outside temperatures are above 10 degrees. We have noticed that when outside temperatures dip under 10 degrees or go sub-zero, we have to really boost the heat in the house either by a constant rip-roaring fire and/or using the baseboard heaters. Fortunately, we have had a mild winter. You see, it takes about 3 years for the thermal mass to completely “heat up” and we’re just now coming into the third year. The most notable difference in the temperature of the house seems to be how much sun we get during the day and are the window coverings closed as quickly as possible when the sun sets or when the sun goes behind clouds for too long.

Related: Concrete Houses 1919 and 2007How tire bales are madeHistorical Engineering: Hanging Flumeposts on mortgages

Wall street journal video on the house and difficulty of financing unique green homes:
Continue reading

Why Wasn’t the Earth Covered in Ice 4 Billion Years Ago – When the Sun was Dimmer

Climate scientists from all over the globe are now able to test their climate models under extreme conditions thanks to Professor Minik Rosing, University of Copenhagen. Rosing has solved one of the great mysteries and paradoxes of our geological past, namely, “Why the earth’s surface was not just one big lump of ice four billion years ago when the Sun’s radiation was much weaker than it is today.” Until now, scientists have presumed that the earth’s atmosphere back then consisted of 30% carbon dioxide (CO2) which ensconced the planet in a protective membrane, thereby trapping heat like a greenhouse.

The faint early sun paradox
In 1972, the late, world famous astronomer Carl Sagan and his colleague George Mullen formulated “The faint early sun paradox. ” The paradox consisted in that the earth’s climate has been fairly constant during almost four of the four and a half billion years that the planet has been in existence, and this despite the fact that radiation from the sun has increased by 25-30 percent.

The paradoxical question that arose for scientists in this connection was why the earth’s surface at its fragile beginning was not covered by ice, seeing that the sun’s rays were much fainter than they are today. Science found one probable answer in 1993, which was proffered by the American atmospheric scientist, Jim Kasting. He performed theoretical calculations that showed that 30% of the earth’s atmosphere four billion years ago consisted of CO2. This in turn entailed that the large amount of greenhouse gases layered themselves as a protective greenhouse around the planet, thereby preventing the oceans from freezing over.

Mystery solved
Now, however, Professor Minik Rosing, from the Natural History Museum of Denmark, and Christian Bjerrum, from the Department of Geography and Geology at University of Copenhagen, together with American colleagues from Stanford University in California have discovered the reason for “the missing ice age” back then, thereby solving the sun paradox, which has haunted scientific circles for more than forty years.

Professor Minik Rosing explains, “What prevented an ice age back then was not high CO2 concentration in the atmosphere, but the fact that the cloud layer was much thinner than it is today. In addition to this, the earth’s surface was covered by water. This meant that the sun’s rays could warm the oceans unobstructed, which in turn could layer the heat, thereby preventing the earth’s watery surface from freezing into ice. The reason for the lack of clouds back in earth’s childhood can be explained by the process by which clouds form. This process requires chemical substances that are produced by algae and plants, which did not exist at the time. These chemical processes would have been able to form a dense layer of clouds, which in turn would have reflected the sun’s rays, throwing them back into the cosmos and thereby preventing the warming of earth’s oceans. Scientists have formerly used the relationship between the radiation from the sun and earth’s surface temperature to calculate that earth ought to have been in a deep freeze during three billion of its four and a half billion years of existence. Sagan and Mullen brought attention to the paradox between these theoretical calculations and geological reality by the fact that the oceans had not frozen. This paradox of having a faint sun and ice-free oceans has now been solved.”

CO2 history iluminated
Minik Rosing and his team have by analyzing samples of 3.8-billion-year-old mountain rock from the world’s oldest bedrock, Isua, in western Greenland, solved the “paradox”.

But more importantly, the analyses also provided a finding for a highly important issue in today’s climate research – and climate debate, not least: whether the atmosphere’s CO2 concentration throughout earth’s history has fluctuated strongly or been fairly stable over the course of billions of years.

“The analyses of the CO2-content in the atmosphere, which can be deduced from the age-old Isua rock, show that the atmosphere at the time contained a maximum of one part per thousand of this greenhouse gas. This was three to four times more than the atmosphere’s CO2-content today. However, not anywhere in the range of the of the 30 percent share in early earth history, which has hitherto been the theoretical calculation. Hence we may conclude that the atmosphere’s CO2-content has not changed substantially through the billions of years of earth’s geological history. However, today the graph is turning upward. Not least due to the emissions from fossil fuels used by humans. Therefore it is vital to determine the geological and atmospheric premises for the prehistoric past in order to understand the present, not to mention the future, in what pertains to the design of climate models and calculations,” underscores Minik Rosing.

Full press release from the University of Copenhagen in Denmark.

Related: Sun Missing It’s SpotsSolar StormsWhy is it Colder at Higher Elevations?Magnetic Portals Connect Sun and Earth

Appropriate Technology: Solar Water in Poor Cairo Neighborhoods

Cairo Slums Get Energy Makeover

Since 2003 the nonprofit Solar CITIES project has installed 34 solar-powered hot water systems and 5 biogas reactors in Cairo’s poor Coptic Christian and Islamic neighborhoods.

Solar CITIES’ hot water systems are constructed from recycled materials and are uniquely tailored to the parts of a city where water and electricity availability are often sporadic. “The problem with professional solar hot water systems is that they’re made for cities with continuous water,” Culhane said. By contrast, Solar CITIES’s water heaters use a city’s water when it’s available but draw from a backup storage tank when it’s not.

The setup consists of an insulated rectangular box covered in clear glass or plastic on one side. Inside the box are copper tubes wrapped in sheets of aluminum, which are painted black. Sunlight striking the darkened aluminum is converted to heat, which is then used to warm water flowing through the pipes. The glass sheet on top of the box prevents the heat from being carried away by wind.

Solar CITIES also installs biogas reactors, which are based on designs Culhane saw while working in India. The reactors use microbes harvested from animal guts to break down food wastes into flammable gas that can be used for cooking and heating. If necessary, the reactors can draw hot water from the solar water heaters to maintain the warm temperatures the bacteria need to survive.

By attaching a simple plastic tube to the reactors, gas can be piped down several stories for residents to use. “In 24 hours, you’ve got 2 hours of cooking gas from yesterday’s cooking garbage,” Culhane said. The biogas reactors provide a more reliable supply of cooking gas than most residents currently have.

Awesome, I love to see people using engineering to make life better for those that can truly use help.

Related: Engineering Appropriate Technology SolutionsWater Pump Merry-go-RoundReducing Poverty15 Photovoltaics Solar Power InnovationsCurious Cat Egypt Travelogue

Seventh-grader’s Solar Cell Research

photo of William Yuan

Seventh-grader shines with solar cell research

Yuan worked on his project for the past two years with the encouragement of his science teacher Susan Duncan; support of his parents Gang Yuan and Zhiming Mei; and counsel of professional mentors Professor Chunfei Li of Portland State University’s Center for Nanofabrication and Electron Microscopy, Fred Li of Applied Materials Inc. and Professor Shaofan Li of the Department of Civil Engineering at the University of California – Berkeley.

“He is our youngest fellow in science that we’ve ever had,” Moessner said. “He is really spectacular. “His project will really make a difference in advancing the technology of solar cells. You would never know he’s 12 looking at the quality of his work.”

Beaverton boy lauded for solar cell invention

there have been many questions about the research by William Yuan. Some have even questioned whether he copied the research of others and claimed it as his own. That is far from the case. Yuan fully documented all of his sources and never tried to imply that he invented the 3D solar cell. He did create a new type of 3D solar cell that works for visible and UV light

William Yuan was awarded a 2008 Davidson Fellow award

In his project, “High Efficient 3-Dimensional Nanotube Solar Cell for Visible and UV Light,” William invented a novel solar panel that enables light absorption from visible to ultraviolet light. He designed carbon nanotubes to overcome the barriers of electron movement, doubling the light-electricity conversion efficiency. William also developed a model for solar towers and a computer program to simulate and optimize the tower parameters. His optimized design provides 500 times more light absorption than commercially-available solar cells and nine times more than the cutting-edge, three-dimensional solar cell.

Related: Solar Thermal in Desert, to Beat Coal by 2020Super Soaker Inventor Aims to Cut Solar Costs in HalfEngineering Student Contest Winners Design Artificial Limbposts on engineers

  • Recent Comments:

    • Anders Jytzler: I love this! Imagine how much of the ocean we haven’t explored yet. Combined with...
    • Maureen Coffey: Wound healing is actually an interesting subject. Both astronauts, who though having a...
    • Anonymous: That’s great news for engineers! Although I bet there is good amount of variability for...
    • Anonymous: Neat project, thanks for sharing! Projects like this are a great opportunity for students from...
    • Roni: your article was really good thank you
    • sandybrown: RoboBoat is a powerful technology.it’s also challenges and competitive.really...
    • batu: It looks good.Planes are well now but boats are new.I hope it will development
    • Angela: Video lectures are very good. Video easily understood and clear. I love this style of expression,...
  • Recent Trackbacks:

  • Links