Posted on February 17th, 2017 in wind by Spencer R.
While homeowners are more familiar with photovoltaic solar panels, large-scale wind power is an increasingly important part of the growth in renewable energy.
For the first time, the total installed capacity of wind energy in Europe now exceeds the total output of electric powerplants fueled with coal.
And that imbalance is likely to grow as more wind generation comes online over the next decade, both on land and offshore.
The statistics, collated by WindEurope, are laid out in a blog post this week by Navigant Research.
Total new wind-generating capacity installed in 28 EU member countries last year added up to 12.5 gigawatts, with a bit more than 10 percent of that located offshore.
The 2016 number was down slightly on the previous year's total, but that reflected a fast push to complete wind projects in 2015 before Germany reduced its incentives as of January 1 last year.
Total installed wind capacity in Europe is now up to 154 gigawatts, though of course capacity is generally larger than actual utilitzation for renewable sources.
Still, wind provided more than 10 percent of Europe's electricity last year, and renewables—both wind and solar—grew enough to allow older fossil-fuel plants to be decommissioned altogether.
Europe's total coal generating capability now stands at 152 gigawatts, and will almost surely fall further in coming years as countries work to reduce the greenhouse-gas emissions of the generating sector.
Fully 86 percent of the 24.5 gigawatts of new generating capacity installed in Europe last year was renewable.
Total investment in wind generation last year was $30 billion, and Germany led the field with 44 percent of the total new wind capacity installed.
For the decade and a half since 2000, the 342.3 gigawatts of new capacity in wind (41.7 percent) and solar power (29.5 percent), along with natural gas (28.8 percent) allowed retirement of a like amount of generation from fuel oil, coal, and nuclear.
Analysts, including those at Navigant, expect offshore wind to represent the bulk of new capacity going forward.
The U.K., for one, has eliminated financial incentives for wind installations on land, but retained them for offshore wind farms—whose costs have already fallen below levels not expected until 2020.
While it can be hard to generalize about grid mix in Europe as a whole, Germany, the U.K., and much of Eastern Europe carry a legacy of largely coal-fired generation due to their natural deposits of the fossil fuel.
Germany has led the switch to renewable energy over the last decade, although France points to its nuclear power—which provides more than half the nation's electricity—as another low-carbon technology.
Posted on February 17th, 2017 in solar by Spencer R.
A local scientists is paving the way when it comes to solar energy. He is hoping we could soon see the technology developed at Sandia Labs in Albuquerque homes.
It is a growing field.
“It works by getting sunlight in and turning it into electricity,” Murat Okandan, mPower CEO said.
Scientist Murat Okandan says people are realizing the benefits of solar energy and are using it more and more, but he says there are limitations.
“The standard cells are fragile and brittle so if you bend and flex them, they’ll break,” Okandan said.
It is why Okandan worked with other Sandia Labs scientists to develop new ways of processing cells.
He calls them Dragon scales. They are flexible, durable, solar cells.
“This will allow you to make it lighter, make it larger areas and fold up into very tight areas lets say for satellites or UAV’s and be able to then fly longer distances or cover larger areas,” Okandan said.
Imagine a version of these prototypes folded up to fit in your backpack. Take it on a camping trip to charge your laptop or phone. Its flexibility even makes it possible to go on clothing.
Eventually, Okandan sees this wrapped around homes or even cars, covering all exposed areas to get the most out of the sun’s rays.
“Having it start here and hopefully go at a much larger scale is a very exciting opportunity,” Okandan said.
This was made possible thanks to a program at Sandia labs. It allows scientists to leave to start their own business with their technology, while guaranteeing their job at the labs for up to three years.
“mPower is taking technology developed at the labs to the energy sector, so its a win-win,” Mary Monson, Sandia National Labs said.
mPower just got its license to commercialize the technology last month. The program at Sandia labs that allowed Okandan to start mPower has also allowed for 46 other tech companies to form in New Mexico.
Posted on February 17th, 2017 in solar by Spencer R.
Posted on February 16th, 2017 in solar by Spencer R.
While our recent look at residential solar may lead you to believe harnessing that power is a newer initiative, humans have been exploiting solar energy for thousands of years to heat their homes, cook, and produce hot water. Some of the earliest written references to technology consciously designed to capture the Sun’s rays come from ancient Greece. Socrates himself said, “in houses that look toward the south, the sun penetrates the portico in winter, while in summer the path of the sun is right over our heads and above the roof, so that there is shade.” He is describing how Greek architecture exploited the different paths of the Sun through the sky at different times of the year.
By the fifth century BCE, the Greeks were struggling with an energy crisis. Their predominant fuel, charcoal from trees, was scarce since they had stripped their forests in order to cook and heat their houses. Wood and charcoal were rationed, and olive groves needed protection from the citizenry. The Greeks addressed their energy shortage by carefully planning the layout of their cities to ensure that each house could take advantage of the sunshine in the way Socrates described. The combination of technology and enlightened government policy worked, and a crisis was avoided.
Technologies for harnessing the thermal energy in sunlight have only continued to grow over time. Colonists in New England borrowed the ancient Greek homebuilding techniques to keep warm in the harsh winters. Simple passive solar water heaters, little more than a black-painted barrel, were sold commercially in the United States in the late 19th century. And more elaborate solar heating systems were developed to pipe water through absorbing and/or focusing panels. The hot water is stored in an insulated tank until needed. In climates subject to freezing, a two-fluid system is used, where the Sun heats a water/antifreeze mixture that passes through coils embedded in the storage tank, which does double-duty as a heat exchanger.
These days, a variety of sophisticated commercial systems are available for water and space heating in the home. Solar thermal systems are deployed throughout the world, with the largest installed base per capita found in Austria, Cyprus, and Israel.
But modern solar truly starts in 1954 with the discovery of a practical way to make electricity from light: Bell Labs uncovered the fact that silicon could make a photovoltaic material. This finding created the foundation for today's solar cells (essentially the devices converting light energy into electricity) and ushered in a new era of solar power. Aided by intense research ever since, it's an era that continues today as solar appears poised to become the dominant source of power in the future.
What is a solar cell?
The most common type of solar cell is a semiconductor device made from silicon—a cousin of the solid-state diode. The familiar solar panels are made from a number of solar cells wired together to create the desired output voltage and current. Those cells are surrounded by a protective package and topped with a glass window.
Solar cells generate electrical power using the photovoltaic effect, a fact that didn't come from Bell Labs. Instead, this was first discovered in 1839 by French physicist Alexandre-Edmond Becquerel (son of physicist Antoine Cesar Becquerel and father of physics Nobelist Henri Becquerel, the discoverer of radioactivity). A little more than a century later, Bell Labs had its solar cell breakthrough, providing the foundation of the most common solar cells.
In the language of solid state physics, a solar cell is formed from a p-n junction in a silicon crystal. The junction is made by “doping” different areas of the crystal with small amounts of different impurities; the interface between these regions is the junction. The n side is a conductor with electrons as the carriers of current, and the p side has “holes,” or areas with missing electrons that act as current carriers within the crystal. In the region near the interface, the diffusion of charges creates a local “built-in voltage” across the interface. When a photon enters the crystal, if it has enough energy, it may dislodge an electron from an atom, creating a new electron-hole pair.
The newly freed electrons are attracted to the holes on the other side of the junction, but they are prevented from crossing it due to the built-in voltage. However, if a pathway is provided through an external circuit, the electrons can travel through it and light our homes along the way. When they reach the other side, they recombine with the holes. This process can continue as long as the Sun continues to shine.
The energy required to transform a bound electron into a free one is called the “band gap.” It’s the key to understanding why photovoltaic (PV) cells have an intrinsic limit on efficiency. The band gap is a fixed property of the crystal material and its dopants. Those dopants are adjusted so that solar cells have a band gap close to the energy of a photon in the visible region of the spectrum. This is a practical choice, because visible light isn’t absorbed by the atmosphere (phrased differently, we humans have evolved to see in the most common wavelengths).
Photons come in fixed amounts of energy, which means their energy is quantized. That also means a photon with energy less than the band gap (say, one in the infrared part of the spectrum) won’t create a charge carrier. It will simply heat the panel. Two infrared photons together will do no better, even if their combined energy would be enough to bridge the gap. A photon with excess energy (an ultraviolet photon, for example) will knock an electron loose, but the excess energy will also be wasted.
Since efficiency is defined as the ratio of light energy striking the panel divided by electrical energy extracted—and since much of this light energy will necessarily be wasted—the efficiency can not be 100 percent.
The band gap of a silicon PV solar cell is 1.1 electron volts (eV). As can be seen from the diagram of the electromagnetic spectrum reproduced here, the visible spectrum lies just above this, so visible light of any color will produce electrical power. But this also means that for each photon absorbed, excess energy is wasted and converted into heat.
The upshot is that even if the PV panel is flawlessly manufactured and conditions are ideal, the theoretical maximum efficiency is about 33 percent. Commercially available solar panels typically achieve about 20 percent efficiency.
Most of the solar panels commercially deployed are made from the silicon cells described above. But research into other materials and strategies is underway in laboratories around the world.
Some of the most promising recent research for silicon alternatives has involved materials called perovskites. The mineral perovskite (CaTiO3) was named in 1839 in honor of Count Lev Aleksevich Perovski (1792-1856), a Russian mineralogist. It can be found on every continent and in the clouds of at least one exoplanet. The word “perovskite” is also used for synthetic compounds that have the same orthorhombic crystal structure as the naturally occurring mineral (or a closely related one) and share a structurally similar chemical formula.
Depending on which elements are used, perovskites can display a wide variety of useful properties, such as superconductivity, giant magnetoresistance, and photovoltaic activity. Their use in PV cells has generated a great deal of optimism, as they have shown an unprecedented increase in efficiency from 3.8 percent to 20.1 percent in the past seven years of laboratory research. This rapid rate of progress inspires confidence that further gains are likely, especially as the factors limiting efficiency are becoming clearer.
Recent experiments at Los Alamos showed that solar cells made from certain perovskites attained efficiencies similar to silicon’s, while potentially being cheaper and easier to work with. The secret to perovskite’s appeal is the ability to routinely grow defect-free crystals of millimeter-scale in a thin film. This is a huge size for a perfect crystal lattice, which allows the conduction electron to travel through the crystal without interference. This crystal quality partly compensates for the somewhat less-than-ideal band gap of about 1.4 eV, compared with silicon’s nearly optimal 1.1 eV.
Much of the research directed toward increasing the efficiency of perovskite cells involves searching for ways to eliminate as many crystal defects as possible. The ultimate goal is to manufacture an entire cell’s perovskite layer in the form of a perfect crystal lattice. Researchers at MIT have recently made significant progress on this. They have discovered how to “heal” the defects in a film made from particular perovskites by exposing it to intense light. The advantage over previously devised methods of defect removal, involving chemical baths or electrical current, is that no physical contact with the film is required.
Whether or not perovskites will lead to revolutions in solar panel cost or aggregate efficiency is still unknown. While they’re easy to make, so far most perovskites decompose rapidly, which sharply limits their utility.
Research is underway in many places to attack the decomposition problem. A collaboration between scientists in China and Switzerland invented a novel way to form perovskite cells that obviates the need for hole motion (see above). Since the layer devoted to hole conduction is susceptible to degradation, the material will be far more stable once that layer can be eliminated.
A recent report from Berkeley Labs describes how perovskite solar cells might one day attain their theoretical maximum 31 percent efficiency while still being cheaper to manufacture than silicon cells. The Berkeley researchers measured the conversion efficiency of individual grain surfaces using photoconductive atomic force microscopy. They found, to their surprise, that different facets have markedly different efficiencies, with some exhibiting the maximum possible.
The researchers now believe that they can find a way to grow bulk films with only the most efficient facets interfacing with the electrodes. This could lead to the entire cell running at 31 percent. If this pans out, it would amount to a revolutionary advance in solar cell technology.
Other research directions
Research in photovoltaics is proceeding rapidly on many fronts. Some of these approaches are still in the early stages and far from being put into production, but they may become mainstream in the future.
Making a solar cell with several layers is possible since the band gap can be tuned by adjusting the doping. Each layer would have a band gap tuned to a particular wavelength of light. These “multi-junction” cells can attain 40 percent efficiency but remain expensive. As a result, they’re more likely to be found on NASA spacecraft right now than on a terrestrial roof.
The layering concept has been combined with perovskites in research performed by a collaboration between Oxford and the Institute for Silicon Photovoltaics in Berlin. While attacking the material deterioration problem that is a critical weak point of this class of materials, the team found that it had discovered a perovskite with a tunable band gap. The team was able to create a version with a 1.74 eV band gap, nearly ideal for layering with silicon. This might lead, after further development, to an inexpensive cell with 30 percent efficiency.
Groups at Notre Dame University and elsewhere have developed a photovoltaic paint made from semiconducting nanoparticles. The material is not yet efficient enough to replace conventional PV panels, but its manufacturing process is simpler. Among the advantages of semiconducting nanoparticles is how they can be applied by painting over a variety of surfaces. This makes installation potentially far easier than attaching rigid panels.
A few years ago, a team at MIT made significant progress in the search to develop a practical solar thermal fuel. This is a substance that can store solar energy internally and stably over a long period of time and release it as heat “on demand” when exposed to a catalyst or some triggering heat. Solar thermal fuel accomplishes this through non-reactive transformations of its molecules. In response to solar radiation, the molecules are transformed into photoisomers: the chemical formula is the same, but the shape is different. The light energy is stored as added energy of the intramolecular bonds in the isomer, which can be thought of as a higher energy state of the original molecule. When triggered, the molecules snap back to their original shape, transforming the stored bond energy into heat. The heat can be used directly or converted to electricity with a thermoelectric generator, or heat engine. This idea potentially eliminates the need for batteries, as energy storage is integral to the system. The fuel can be transported if desired, allowing the energy to be used elsewhere.
Since the work at MIT, which used fulvalene diruthenium, several laboratories are trying to solve problems with manufacturing and material costs in order to develop a system where the fuel is sufficiently stable in its energized state and can be “recharged” then used many times without deterioration. Just two years ago, the same scientists at MIT (along with others from that institution and from Harvard) created a solar thermal fuel that they demonstrated could be put through at least 2,000 cycles with no decrease in performance.
Their innovation was to attach the fuel (in this case, azobenzene) to carbon nanotubes. This caused its molecules to line up in an orderly array. The result is a solar thermal fuel with 14 percent efficiency and an energy density similar to a lead-acid battery.
More recent work has given birth to a solar thermal fuel in the form of a transparent film that can be applied to car windshields, where it can melt ice at night using energy absorbed during the day. The pace of progress in this area leaves little doubt that solar thermal fuels will soon make the leap from the laboratory to becoming a familiar technology.
Another way to create fuel directly from sunlight (an approach sometimes described as artificial photosynthesis) has been developed by researchers at the University of Illinois at Chicago. Their “artificial leaves” use sunlight to convert atmospheric carbon dioxide into “syngas,” which is a mixture of hydrogen gas and carbon monoxide. Syngas can be burned directly or converted into more conventional fuels. The process has the added advantage of removing CO2 from the atmosphere.
A team at Stanford has created a prototype PV cell using carbon nanotubes and fullerenes rather than silicon. Its efficiency is far below that of even ordinary, commercially available silicon solar cells, but it uses nothing but carbon as a raw material. The Stanford prototype contains none of the toxic materials that form part of the electrodes in conventional solar cells. It’s a more environmentally friendly alternative to silicon, but it still needs to see its efficiency rise before becoming economical.
Meanwhile, research into other materials and manufacturing techniques continues. One promising area of research involves monolayers, layers of materials one molecule thick (like graphene). These result in PV materials that, while only a few percent efficient in absolute terms, are thousands of times more efficient than conventional solar cells per unit mass.
Other researchers are attempting to develop practical “intermediate band” solar cell materials. The idea here is to use nanostructured materials or special alloys to create a lower energy level that can be used as a stepping stone for photons without enough energy to bridge the band gap. This makes it possible for two low-energy photons to kick an electron into the conduction zone, something that is impossible with standard solid-state devices. These cells are potentially more efficient, since they can convert a wider range of wavelengths into electrical power.
This variety of research in diverse approaches to photovoltaic cells and materials, and the rapid and steady progress since the invention of the silicon solar cell in 1954, inspires confidence that the enthusiastic adoption of solar electricity will not only continue but increase in the near future.
And such efforts won't come a minute too late. A recent meta-study concluded that PV power has exceeded the energy investment return of oil and gas: more energy is returned from solar power per unit of energy invested than for these fossil fuels—a dramatic turning point.
There is now little room for doubt that solar energy will eventually be a significant, if not the dominant, form of power both on an industrial and an individual scale. So for the scientifically minded, one can only hope that the consequent reduction in the need to burn fossil fuels happens before the global climate suffers irreversible changes.
Posted on February 16th, 2017 in solar by Spencer R.
Beginning as soon as April, Attleboro schools will be saving up to $100,000 a year in electricity costs thanks to the largest roof-top solar project in the state.
The solar panels are being erected on a large industrial building in West Bridgewater.
The city school system committed to get power from the project, which is being built by Green Street Solar Power of the Bronx, N.Y., and will get an annual credit of approximately $100,000 a year to reduce its electric bills.
Green Street estimates the savings for Attleboro schools could come to about $3.5 million over the next 25 years, but school officials think it could be closer to $2 million as prices change over the years.
Still, the school will be getting a $100,000 annual break in the immediate future.
"That's a pretty good sum," Superintendent David Sawyer said.
Years ago, the schools looked into having their own solar panels placed on schools, but the idea never came to fruition.
Sawyer said when Marc Furtado came back to the Attleboro schools after leaving for another job in Somerset, he made contact with a company he was familiar with which was looking for large entities to commit to solar power.
Reggie Dormeaus, marketing administrator for Green Street, said his firm is erecting 12,000 solar panels on the building in West Bridgewater, making it the largest project of its kind in the state.
The roof space is being leased from a firm called Ajax, which owns the building. Ajax is also involved with the New England Sports Village in Attleboro.
The panels are expected to generate 4.1 megawatts of power, saving money and making for a healthier environment, he said.
He said he expects the project to be completed and the panels to be producing power in April after several months of construction.
Posted on February 15th, 2017 in solar by Spencer R.
Springfield Medical Care Systems is going solar.
The corporate parent of Springfield Hospital and the Springfield Health Center has completed its first solar project, with the installation of four solar panels in front of the entrance of the health center at One Hundred River Street.
Larry Kraft, a hospital spokesman, said the hospital will build a full solar array on land adjacent to the hospital later this year.
Kraft said Friday the two solar systems were different: One would produce hot water for use for the doctors and patients at the health center, and the larger system at the hospital would produce electricity to offset the hospital’s usage.
He said the original intent of the project was to install a system on the rooftop, but the center’s engineers determined the roof was not suitable.
But he said a portion of the building near the river is sheltered and receives what he called “excellent sunlight,” and the panels were installed there.
The four panels were installed before the onset of winter and have already started decreasing the center’s use of fossil fuels, he said.
During the next 10 years, the hot water system will offset the use of 2,500 gallons of propane, which would ordinarily heat the 600,000 gallons of water used annually by staff members, patients and visitors to the health center. He said the total cost of the system was $30,000, and panels were installed by Springfield Heating and Ventilating Co. The system was paid for by donors, including a grant from the Jack and Dorothy Byrne Foundation. Kraft said that while a rooftop installation was originally considered, it was determined that the system would produce more electricity from the ground. He said the solar installation would be built on “unbuildable ground” farther up Ridgewood Road and across the road from the hospital. He said the site is currently wooded.
“We will produce electricity,” he said, with a netmetering project, rather than hot water at the health center system.
Under a net-metering project, the hospital will receive credits for the electricity it generates, and those credits will be used to offset its electric bill.
Posted on February 15th, 2017 in environment by Spencer R.
Pueblo, Colorado and Moab, Utah, this week became the 22nd and 23rd cities in the U.S. to commit to transition to 100 percent clean, renewable energy. The Pueblo City Council approved Monday a measure committing to power the community entirely with renewable sources of energy like wind and solar by 2035. The vote was immediately followed on Tuesday by the Moab City Council approving a resolution committing Moab to 100 percent renewable energy by 2032.
"No matter who is in the White House, cities and towns across the country will continue leading the transition to 100 percent clean, renewable energy," Sierra Club Executive Director Michael Brune said. "Pueblo and Moab join a growing movement of communities which are charting a course away from dirty fuels."
Cities like Pueblo and Moab have long suffered the consequences of dirty energy and utility reliance on fossil fuels. Pueblo, for example, has a sizable low-income population that has been suffering from the high cost of electricity due to the local utilities' decision to build new gas infrastructure and saddle the cost with ratepayers. More than 7,000 people in Pueblo have had their electricity shut off due to the high cost of electricity.
In Utah, Canyonlands National Park has been marred by haze pollution from two neighboring coal plants, which threatens the local Moab tourism industry—the economic lifeblood of the community. With this week's announcements, both communities are poised to confront these threats by transitioning away from fossil fuels to clean, renewable energy.
"The climate crisis is a global challenge, but many of our strongest leaders are at the local level," Ken Berlin, CEO of The Climate Reality Project, said. "We have a lot of hard work ahead, but it is encouraging to see more and more communities, businesses and universities understand that renewable energy is not only the right moral choice, but also the right economic choice."
Posted on February 14th, 2017 in solar by Spencer R.
Two firms have signed an agreement to provide power to 25 communities across Nigeria using solar energy.
The communities are in Bayelsa, Ondo, Ogun and Osun states.
A Nigerian firm, Community Energy Social Enterprises Limited, CESEL, and its American counterpart, Renewvia Energy Corporation, signed a $767,512 agreement to provide solar energy for the communities on 'pay-as- you-go' basis.
The CESEL Managing Director, Patrick Tolani, signed the agreement on behalf of his company while Clay Taber, Managing Director of Renewvia, signed for his firm, at the Power Africa office in Abuja.
The MoU signing was witnessed by Power Africa Coordinator, Andrew Herscowitz, and the United States Agency for International Development mission director in Nigeria, Michael Harvey.
Mr. Tolani said the benefitting communities were those that had no access to electricity for more than 10 years, including Brass in Bayelsa and Magboro in Ogun State.
Others, he said, include Ilajera and Gbokoda in Ondo State and a community which was completely cut off the grid because of isolation in Osun State.
Mr. Taber in his remarks said Renewvia would install and operate micro-grid systems with solar photo-voltaic generation capacity and battery storage in the 25 benefiting communities.
According to him, the design of the micro-grids for the project will include PV panels, string inverters, aluminium racking and energy storage backup power.
He said, "Renewvia and CESEL would sell micro-grid customers electricity by Kilowatts through a 'pay as you go' structure.
"The competitiveness of the system helps to ensure payment, as the project would provide consistent and reliable power at a less expensive price than current rural power generation by diesel."
He added that Renewvia and CESEL also planned to facilitate the transaction through mobile payments, noting that the project would employ local and remote resources to support the needs of the power plant for each micro-grid.
The project was supported by Power Africa, a U.S. energy project initiated in 2013 to assist African countries in accessing energy.
It is expected that the project would provide up to 10 megawatts and connect over 10, 000 households, according to a study by Renewvia.
The project is also expected to be completed in one year.
CESEL is a private Nigerian company that has led the community engagement for six operational micro-grid projects in Nigeria. These micro-grids received funding through the Nigeria Bank of Industry and United Nations Development Programme.
Renewvia is a private U.S renewable energy developer and solar power plant operator established in 2009. Renewvia specialises in providing mini-grid and solar energy solutions for residential, commercial and utility-scale applications.
Micro-grid is a small network of electricity users with a local source of supply that is usually attached to a centralised national grid but is able to function independently.
Posted on February 14th, 2017 in environment by Spencer R.
Harnessing this cheap form of power would be a huge advance. Minneapolis-based TerraCOH intends to fire up a small-scale commercial version of its power system this year.
MINNEAPOLIS — TerraCOH's vision is grand. The fledgling firm would use carbon dioxide emissions — a nemesis to the planet — to power a geothermal energy system, which would in turn produce low-cost, clean electricity.
And TerraCOH's patented geothermal technology could serve as a big underground battery, effectively storing renewable — but intermittent — wind and solar energy.
Now, the Minneapolis-based company just needs money to turn its plans — about eight years in the making — into reality.
The good news: TerraCOH believes it will fire up a small-scale commercial version of its power system this year. "We are ready to build the power plant," said Jimmy Randolph, TerraCOH's chief technical officer. "And we're trying to raise the money to do that," chimed in Chief Executive John Griffin.
TerraCOH, which has its roots at the University of Minnesota, so far has been financed with more than $5 million in grants from the National Science Foundation and the U.S. Department of Energy. Last year, the company began soliciting private investors to commercialize its ideas, with Griffin leading the way.
Griffin is a mechanical engineer with an MBA from the University of Minnesota who has worked with technology companies large and small over the past 30 years. Randolph graduated summa cum laude in physics and math from St. Olaf College, and then got a Ph.D. in geophysics in 2011 from Minnesota, where he's currently a senior research associate.
Randolph's adviser at Minnesota was Martin Saar, a professor of earth sciences. The pair, along with Thomas Kuehn, a mechanical engineering professor, invented a renewable energy technology called CO2 Plume Geothermal. The university holds the patent and would split royalties with the three researchers if the technology becomes a hit.
TerraCOH has also worked on its technology with researchers at Ohio State University and Lawrence Livermore National Laboratory in California.
Geothermal is the cheapest form of energy, according to data from the U.S. Energy Information Administration, but it's not widely deployed. Traditional geothermal energy projects must be near places where the earth is hot relatively close to the surface. These hot spots, though, are limited geographically.
The deeper you go, the hotter the earth gets. So, Randolph and his co-inventors developed a method to tap geothermal heat that is 1 to 3 miles below the earth's surface. This deep heat resource is much more widespread, but mining it in a cost effective manner is difficult.
TerraCOH's technology uses "supercritical" CO2 to efficiently unlock that thermal energy. Supercritical is a chemical state somewhere between a gas and a liquid. It's dense and has a lower viscosity than water, so it flows easy. Oil companies use compressed CO2 to scour the last bits of petroleum from conventional wells.
In TerraCOH's system, supercritical CO2 heats up as it's pumped lower into the earth and is stored in porous sedimentary rock. The hot CO2 can then be drawn back up to the earth's surface — without costly pumping — where it spins a turbine to create electricity. It's an energy loop, basically.
The equipment needed for this process has become viable over the past year, Griffin said. TerraCOH needs to raise $2 million to build two small power plants with 100 to 200 kilowatts of generating capacity. By contrast, a good-size wind farm can pump out 200 megawatts.
TerraCOH is eyeing existing oil and gas fields for its early projects, since they've already been drilled.
The company is planning a small power plant at a conventional oil well in northwest North Dakota that will produce electricity for that site. For this project, TerraCOH will harness the geothermal energy provided by oil and gases coming up the well, heating CO2 in an above-ground tank, which will then power a turbine.
But the long-term goal is to place TerraCOH Plume Geothermal systems near coal-fired or gas-fired power plants, directly capturing CO2 emissions, pumping them into the ground for eventual use in bigger CO2 fired-power plants. These plants would initially generate up to 15 megawatts, but could eventually be up to 300 megawatts.
Another goal is to use the geothermal system as a "battery" for solar and wind power. The drawback to renewables is that they are intermittent, only producing when the weather is sunny or windy. Currently, chemical batteries are too expensive to store large amounts of renewable energy.
But excess wind and solar power could be transmitted to a TerraCOH plant, powering pumps that would inject CO2 into the earth, from where it could eventually be turned back into electricity when needed. Plume Geothermal "is not intermittent," Randolph said. "It's 24/7. You can run it on demand."
Posted on February 10th, 2017 by Spencer R.
In a release, by Hungarian PannErgy it is reported that Audi Hungaria, the Hungarian subsidiary of German car maker Audi is the largest industrial user of geothermal energy in Hungary.
Since the installments of geothermal heating, Audi Hungaria has been able to grow the volume of the company’s geothermal energy consumption to 100 GWh, which so far has reduced carbon dioxide emission by 20,170 tons.
“Sustainability and efficiency is a dominant element of Audi Hungaria’s efficiency, and therefore we put great emphasis on their encouragement in day-to-day operations, as well as manufacturing processes”, said Axel Schifferer, Audi Hungaria’s Managing Director for Finance.
“Its reliance on geothermal energy ensures the company’s environmentally sparing operations in the long term, because this way we can cover nearly 70% of our heat energy demand in a carbon-neutral manner.”
Two years ago, the company placed its energy supply on brand new foundations, and since November 2015 renewable geothermal energy has been supplied by the Heating Center of Böny. Within the framework of the Geothermal Project of Gyor, Audi Hungaria has entered into a long-term heat energy supply agreement for the provision of geothermal energy to the company’s Gyor site with PannErgy Plc’s subsidiary, DD Energy Ltd. This cooperation has been forged for 17 years, and can be optionally extended for an additional period of 15 years.
The Györ based AUDI HUNGARIA Ltd is an entity of the AUDI Group, the key engine supplier of the Audi and Volkswagen Group. The Györ site manufactures the Audi A3 Limousine, A3 Cabriolet, as well as Audi TT Coupé and Audi TT Roadster models. Since 2006, Audi Hungaria has been delivering a number of aluminium car body elements for various brands belonging to the Volkswagen Group. For years, Audi Hungaria has been Hungary’s top-ranking company in terms of sales revenues, and is one of the country’s largest exporters. Audi Hungaria employs approximately 11,500 people in Gyor.