Solar power is one of the most reliable forms of renewable power—but it’s still expensive. Now, a team has developed a smart, adaptive material that could slash the its cost in half.
Developed by start-up Glint Photonics, the new material has optical properties that can change to help it capture as much light as possible. Currently, large-scale solar plants have to use tracking technology to ensure that their cells maximize their exposure to sunlight; this new material changes its reflectivity in response to heat from concentrated light to capture light across a wide range of angles.
The new technology is a kind of coating for use in a solar cell which focuses light into a piece of glass. An array of thin lenses concentrate sunlight across a broad range of angles, before it’s passed to a glass sheet, coated on both sides with reflective coating. The front coating, however, is made of the new material, and Technology Review explains how it works:
When a beam of concentrated light from the array of lenses hits the material, it heats up part of it, causing that part to stop being reflective, which in turn allows light to enter the glass sheet. The material remains reflective everywhere else, helping to trap that light inside the glass—and the light bounces around until it reaches the thin edge of the glass, where a small solar cell is mounted to generate electricity.
As the day wears on, the lenses throw the light—captured across a broad range of incident angles, remember—onto a different spot on the glass sheet, always allowing light in only where the beam of light falls. In turn, it reduces the need to keep the device pointed directly at the sun. Glint Photonics claims that the technology could produce solar power at a cost of four cents per kilowatt-hour, compared to eight cents per kilowatt-hour for normal solar panels.
The technology is still a proof of concept—its efficines still need to be upped, and the whole thing need to be scaled to work at commercial volumes—but it’s a very promising development.
In Frankfurt, Germany, a team of students has found a new way to make buildings “climate neutral” without raising rents: Build a new rooftop apartment with each installation.
The usual way to add solar power to a building is just to attach some panels to the roof. But a new design goes a step farther with a solar attachment that doubles as extra housing. A single story of lightweight apartments are added to a rooftop and then covered in enough solar panels to generate power for the entire building.
For cities like San Francisco that are struggling with rising rents, the design has the potential to quickly provide some new homes–all without developing new land or changing city regulations about building height.
The OnTop design comes from a student team in Germany, a country where 70% of the population lives in cities and there’s also a housing crunch. “New living space is needed and the question is where to build it,” says Sebastian Fiedler, the professor at Frankfurt University of Applied Sciences who advised a team of architecture, business, and engineering students. “Building on top of an existing building doesn’t take up new land, and no additional infrastructure has to be created.”
The idea also takes advantage of new money flowing into a city to help renovate older buildings for long-time residents; renting or selling the new living units will directly fund upgrades for everyone else. “Many people want to live in the city and they are willing to pay a lot of money for it,” Fiedler says. “It is a powerful economic force. We want to use this force to enhance the existing building.”
Germany is aiming to make all buildings “climate neutral” by 2050, which will require a huge amount of renovation. Many projects could cause rents to rise, but the designers believe their system can help avoid gentrification by paying for itself. It also gives new people moving to a city the chance to live in older, established neighborhoods–instead of new developments in the suburbs– without the guilt of displacing long-time residents.
In Frankfurt, where the team will build its first set of new apartments on an existing building, the system will generate 40,000 kWh of electricity per year. Along with solar panels to generate electricity, the system also uses solar collectors and heat pumps to provide heat, so the whole building can run on renewable energy.
The design won first place in the “social housing” category of the recent Solar Decathlon Europe.
Solar power cells need to stay relatively cool for the sake of both efficiency and longevity, but active cooling (like ventilation) isn’t practical; it’s expensive, and may block the very rays the cells are supposed to collect. To tackle this problem, Stanford University researchers have created a new form of solar cell that cools itself. The technique embeds a pattern of very small cone and pyramid shapes into the collector’s silica surface, bouncing hot infrared wavelengths away while letting in the visible light that generates the most energy.
The result is a heavily optimized panel that not only scoops up more power, but avoids cooking itself to death — it’s very nearly ideal, according to scientists. The Stanford team has a long way to go (it still has to try the self-cooling tech outdoors), but it foresees commercial products. Don’t be surprised if you can eventually install a refined solar array at home that not only powers more of your gadgets, but doesn’t need to be replaced after suffering through a few too many scorching summers.
X Prize wants to award you with 2 million dollars… if you’ve got the best way to measure the pH of the oceans!
Microsoft took another step toward its goal of becoming carbon neutral, announcing its second enormous purchase of wind energy.
The company signed a 20-year power purchase agreement to buy 175 megawatts (MW) of wind energy — the entire output — of Pilot Hill Wind Project in Illinois. The wind farm is 60 miles from Chicago and will supply Microsoft’s data center there through the grid.
To give you an idea of how big the purchase is — and how much energy data centers consume — that’s enough power for the needs of 70,000 families a year.
In November, Microsoft made its first wind commitment, buying the entire 110 MW output from Keechi Wind Project in Texas to supply a data center there. Both purchases are partially funded by Microsoft’s internal carbon fee.
Pretty amazing that private companies, such as Microsoft, Google and Facebook, are sponsoring the construction of entire wind farms. Construction of Pilot Hill is underway and will be finished next year.
“The project builds on our commitment to renewable energy and our strategic objective to transform the energy supply chain toward radically greater efficiency and reduced environmental impact,” Microsoft stated.
Microsoft is putting its creativity to work on powering datacenters. The first zero carbon data center is in Cheyenne, Wyo., where biogas generated from the wastewater plant next door powers fuel cells. And Microsoft has demonstrated a proof-of-concept data center that runs on fuel cells mounted on server racks.