Researchers at Rice University are on to a relatively simple, low-cost way to pry hydrogen loose from water, using the sun as an energy source. The new system involves channeling high-energy “hot” electrons into a useful purpose before they get a chance to cool down. If the research progresses, that’s great news for the hydrogen […]
12 May 2017
“The solar energy business has been trying to overcome … challenge for years. The cost of installing solar panels has fallen dramatically but storing the energy produced for later use has been problematic.”
“In a single hour, the amount of power from the sun that strikes the Earth is more than the entire world consumes in an year.” To put that in numbers, from the US Department of Energy Each hour 430 quintillion Joules of energy from the sun hits the Earth. That’s 430 with 18 zeroes after it! In comparison, the total amount of energy that all humans use in a year is 410 quintillion Joules. For context, the average American home used 39 billion Joules of electricity in 2013.
Clearly, we have in our sun “a source of unlimited renewable energy”. But how can we best harness this resource? How can we convert and “store” this energy resource on for sun-less days or at night time … when we also have energy needs?
Now therein lies the challenge!
Would you buy a smartphone that only worked when the sun was shining? Probably not. What it if was only half the cost of your current model: surely an upgrade would be tempting? No, thought not.
The solar energy business has been trying to overcome a similar challenge for years. The cost of installing solar panels has fallen dramatically but storing the energy produced for later use has been problematic.
Now scientists in Sweden have found a new way to store solar energy in chemical liquids. Although still in an early phase, with niche applications, the discovery has the potential to make solar power more practical and widespread.
Until now, solar energy storage has relied on batteries, which have improved in recent years. However, they are still bulky and expensive, and they degrade over time.
Trap and release solar power on demand
A research team from Chalmers University of Technology in Gothenburg made a prototype hybrid device with two parts. It’s made from silica and quartz with tiny fluid channels cut into both sections.
The top part is filled with a liquid that stores solar energy in the chemical bonds of a molecule. This method of storing solar energy remains stable for several months. The energy can be released as heat whenever it is required.
The lower section of the device uses sunlight to heat water which can be used immediately. This combination of storage and water heating means that over 80% of incoming sunlight is converted into usable energy.
Suddenly, solar power looks a lot more practical. Compared to traditional battery storage, the new system is more compact and should prove relatively inexpensive, according to the researchers. The technology is in the early stages of development and may not be ready for domestic and business use for some time.
From the lab to off-grid power stations or satellites?
The researchers wrote in the journal Energy & Environmental Science: “This energy can be transported, and delivered in very precise amounts with high reliability(…) As is the case with any new technology, initial applications will be in niches where [molecular storage] offers unique technical properties and where cost-per-joule is of lesser importance.”
The team now plans to test the real-world performance of the technology and estimate how much it will cost. Initially, the device could be used in off-grid power stations, extreme environments, and satellite thermal control systems.
Editor’s Note: As Solomon wrote in Ecclesiastes 1:9: “What has been will be again, what has been done will be done again; there is nothing new under the sun.”
Storing Solar Energy chemically and converting ‘waste heat’ has and is the subject of many research and implementation Projects around the globe. Will this method prove to be “the one?” This writer (IMHO) sees limited application, but not a broadly accepted and integrated solution.
Solar Energy to Hydrogen Fuel
So where does that leave us? We have been following the efforts of a number of Researchers/ Universities who are exploring and developing “Sunlight to Hydrogen Fuel” technologies to harness the enormous and almost inexhaustible energy source power-house … our sun! What do you think? Please leave us your Comments and we will share the results with our readers!
We have written and posted extensively about ‘Solar to Hydrogen Renewable Energy’ – here are some of our previous Posts:
HyperSolar has achieved a major milestone with its hybrid technology HyperSolar, a company that specializes in combining hydrogen fuel cells with solar energy, has reached a significant milestone in terms of hydrogen production. The company harnesses the power of the sun in order to generate the electrical power needed to produce hydrogen fuel. This is […]
Rice University researchers have demonstrated an efficient new way to capture the energy from sunlight and convert it into clean, renewable energy by splitting water molecules. The technology, which is described online in the American Chemical Society journal Nano Letters, relies on a configuration of light-activated gold nanoparticles that harvest sunlight and transfer solar energy […]
NREL researchers Myles Steiner (left), John Turner, Todd Deutsch and James Young stand in front of an atmospheric pressure MDCVD reactor used to grow crystalline semiconductor structures. They are co-authors of the paper “Direct Solar-to-Hydrogen Conversion via Inverted Metamorphic Multijunction Semiconductor Architectures” published in Nature Energy. Photo by Dennis Schroeder. Scientists at the U.S. […]
Photo shows a lead sulfide quantum dot solar cell. A lead sulfide quantum dot solar cell developed by researchers at NREL. Photo by Dennis Schroeder.
Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a proof-of-principle photo-electro-chemical cell capable of capturing excess photon energy normally lost to generating heat. Using quantum […]
14 Oct 2016
Recently, researchers at the National Renewable Energy Laboratory wanted to know, how well does NREL’s hydrogen infrastructure support fueling multiple fuel cell electric vehicles (FCEVs) for a day trip to the Rocky Mountains?
The answer-great! NREL staff took FCEVs on a trip to demonstrate real-world performance and range in high-altitude conditions. To start the trip, drivers filled three cars at NREL’s hydrogen fueling station. The cars made a 175-mile loop crossing two 11,000+ foot mountain passes on the way. Back at NREL, the cars were filled up with hydrogen in ~5 minutes and ready to go again. Learn more at http://www.nrel.gov/hydrogen.
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
Read More on Nano Enabled Fuel Cell Technologies for many more Energy Applications: Genesis Nanotechnology Fuel Cell Articles & Videos
From polyester shirts, plastic milk jugs and PVC pipes to the production of high-grade industrial ethanol, the contribution of the chemical feedstock ethylene can be found just about everywhere around the globe.
But ethylene’s ubiquity as a building block in plastics and chemicals masks an underlying environmental cost. The cheap hydrocarbon is made using petroleum and natural gas, and the way it is produced emits more carbon dioxide than any other chemical process. As concerns about levels of CO2 in the atmosphere have grown, some scientists have been experimenting with ways to make ethylene production more green. At the Department of Energy’s National Renewable Energy Laboratory (NREL), researchers are finding unexpected success with the help of cyanobacteria, or blue-green algae.
Jianping Yu, a research scientist with NREL’s Photobiology Group, is leading a team of researchers who are working with these organisms. In his lab, they have been able to make ethylene directly from genetically modified algae.
The researchers were able to accomplish this by introducing a gene that coded for an ethylene-producing enzyme—effectively altering the cyanobacteria’s metabolism. This allows the organisms to convert some of the carbon dioxide normally used to make sugars and starches during photosynthesis into ethylene. Because ethylene is a gas, it can easily be collected.
Making ethylene doesn’t require many inputs, either. The basic requirements for cyanobacteria are water, some minerals and light, and a carbon source. In a commercial setting, CO2 could come from a point source like a power plant, Yu said.
If this alternative production method becomes efficient enough, it could potentially replace steam cracking, the energy-intensive method currently used to break apart petrochemicals into ethylene and other compounds. Because the algae take in three times the CO2 to produce a single ton of ethylene, the process acts as a carbon sink. That would be a significant improvement over steam cracking, which generates between 1 ½ and 3 tons of carbon dioxide per ton of ethylene, according to the researchers’ own analysis. The captured ethylene gas can then be transformed for use in a wide range of fuels and products.
“I think it’s better to turn CO2 into something useful,” Yu said, comparing the approach to other methods of carbon capture. “You don’t have to pump CO2 into the ground, and [the products] will last for many years.”
Engineering genes to suck up carbon
Yu and his colleagues weren’t the first to come up with the idea of using cyanobacteria to make ethylene. The process was first attempted by researchers in Japan more than a decade ago. At the time, the researchers were not able to produce ethylene reliably. When Yu read the study years later, he thought that by genetically altering a different strain with which he had worked closely (Synechocystis sp. PCC6803), he might be able to make ethylene production more consistent.
The researchers are able to make ethylene from algae by altering a part of the organism’s metabolism called the tricarboxylic acid (TCA) cycle, which is involved in biosynthesis and energy production. In genetically unaltered blue-green algae, the cycle can only take in a relatively small fraction, or 13 percent, of the 2 to 3 percent of fixed CO2. But in Yu’s lab, the algae are able to send three times more carbon to the TCA cycle and emit 10 percent of the fixed carbon dioxide as ethylene—at a rate of 35 milligrams per liter per hour. That might not sound like very much, but it represents a thousandfold increase in productivity since he first began working with the cyanobacteria in 2010. By the end of this year, Yu is aiming to increase that productivity to 50 milligrams.
“This is by no means close to the upper limit,” he said, explaining that the ultimate goal will be to convert 90 percent of fixed carbon to ethylene. “I cannot see why it cannot go higher; I haven’t run into a brick wall yet. I don’t know what would prevent that from happening, but of course it could.”
Surprisingly, even though the cyanobacteria are producing more ethylene, the organisms are still growing at the same rate as non-ethylene-producing algae. The results demonstrate that the cyanobacteria’s metabolism was much more flexible than previously thought, according to Yu.
“It’s like a person that’s losing blood all the time but appears healthy,” he said.
Yu and his colleagues aren’t certain how this is happening, but the mutation that enabled ethylene production has also stimulated photosynthesis.
“This system gives us a new insight into photosynthesis and gives us hope that we can learn from this and increase photosynthetic activity,” he said.
That insight into cyanobacteria’s metabolism is as important a finding as the creation of organisms that can consistently produce ethylene, said Robert Burnap, a professor of microbiology and molecular genetics at Oklahoma State University. He was not involved with the study, but did provide a reference for Yu’s application to this year’s R&D 100 Awards. Yu is now a finalist in the Mechanical Devices/Material category.
“It’s surprising how adaptive the metabolism is. It’s producing something it’s not evolved to make. There was a lot of controversy over whether or not that was even possible to have consistent ethylene production. It shows it is flexible,” he said.
The research could help other scientists better understand metabolic pathways in other plants and even in humans. The TCA cycle is even active in our cells’ mitochondria, Burnap said.
“What makes this study really special is the depths of analysis that they went into,” he said, describing the research as a whole as a “seminal piece of work.”
Manufacturing centers … in ponds?
It’s still much too early to say when or even if these algae will produce ethylene at a commercial scale. Yu estimates that development to that stage could take more than 10 years.
“It will take a lot of work to improve carbon efficiency to 50 percent or higher,” Yu said.
Philip Pienkos, principal manager of the Bioprocess R&D Group at NREL’s National Bioenergy Center, said the project is beginning to focus more on the development side, even as Yu continues to work to achieve higher ethylene volumes.
“How do you recover ethylene? What do you do with the biomass? This project is poised to answer these important questions,” Pienkos said.
Sometime next year, the researchers plan to move their work outdoors to see how the algae behave in an environment that more closely resembles how they would be grown commercially.
“We have to get a real scalable ethylene process so we have a better sense of what this will look like,” Pienkos said.
Yu envisions the cyanobacteria growing either in ponds, or possibly vertically, on newspaper-like sheets. In either case, the solid or liquid cultures would have to be enclosed to capture the ethylene, he said.
There are also some safety concerns associated with producing large quantities of the gas. The hydrocarbon and oxygen that are also produced by the algae are flammable, and certain safety precautions would have to be put in place to safely collect ethylene.
Even if the cyanobacteria can create large volumes of ethylene, their success will depend on whether the product can become cost-competitive. That won’t be easy because petrochemical-based ethylene is cheap and widely available. According to the researchers’ economic analysis, ethylene made from petrochemicals cost $600 to $1,300 per ton, while the gas coming from the algae is estimated to be about $3,240 per ton.
Proving the system’s economic viability down the road will also help maintain research funding from the Department of Energy, Peinkos said.
“Algae is not the primary focus of DOE; they’ve spent decades supporting work in cellulosics. Algae is a much smaller portfolio, and most of the work is in conversion directly to liquid fuels,” he said. “Ethylene stands out a little bit because it’s not a fuel, but it can be a fuel feedstock.”