Posted on January 5th, 2017 in environment by Spencer R.
Italian power firm Enel S.p.A., announces that through its subsidiary Enel Green Power North America, Inc. (“EGPNA”), it has started operations at the world’s first integrated, commercial-scale geothermal-hydro power plant at its Cove Fort site in Utah. At Cove Fort, EGPNA added a fully submersible downhole generator technology to a geothermal injection well, combining geothermal and hydroelectric power at one site.
“The operation of this technology, a world’s first, is a major milestone for the geothermal industry and a reinforcement of our commitment to innovation and energy efficiency,” said Francesco Venturini, Head of Enel’s Global Renewable Energies. “We are creating innovative solutions that are making renewable energy better, stronger and smarter. As a result we have once again discovered a more resourceful way to maximise plant operations and power generation with the aim of using this technology at our facilities around the world.”
Findings from the initial testing phase held between July and September 2016 reveal that the addition of the hydro generator to the geothermal injection well resulted in an overall increase in output of 1,008 MWh over this time, offsetting the energy consumption of the Cove Fort plant by 8.8%, therefore improving the plant’s operational efficiency.
The innovative generator technology captures the energy of the water flowing back into the earth to generate additional electricity while also better controlling the flow of brine back into the ground. The presence of the generator creates pressure against the brine flow, which reduces the flow’s turbulence into the well, hence minimising the likelihood of any potential damage to the well. The result is a first-of-its-kind innovation that can reduce operational and maintenance expenses, while also having the potential to generate additional revenues.
Cove Fort is EGPNA’s second hybrid power plant to begin operations in the United States. The company also operates the award-winning Stillwater facility in Fallon, Nevada, the world’s first power plant to combine medium enthalpy, binary cycle geothermal, solar thermal and solar PV technologies at the same site.
With an installed capacity of 25 MW, Cove Fort began operations in 2013 and generates up to 160 GWh of power each year, powering more than 13,000 US households while avoiding the annual emission of about 115,000 tonnes of CO2 into the atmosphere.
EGPNA is present in 23 US states and two Canadian provinces with more than 2.5 GW of installed capacity spread across four different renewable energy technologies: wind, solar, geothermal and hydropower.
Posted on January 5th, 2017 in environment by Spencer R.
Renewable energy can be a tricky business. If you’re not dealing with the intermittency of solar or wind power, you might struggle with some of geothermal’s more complex issues. For example, older geothermal plants rely on steam output that can diminish over time or harm the plant’s turbine components. Or, a geothermal plant can damage the subterranean aquifer that it’s taking hot water (called brine) from. Or, if the geothermal plant is air-cooled, a particularly hot day can reduce the plant’s efficiency.
To combat all of these issues, Italian renewable energy company Enel Green Power has been working to make its geothermal resources in Fallon, Nevada, and Cove Fort, Utah, more efficient by combining them with other renewable power sources. In its most recent endeavor in Cove Fort, Enel cleverly combines hydroelectric power with geothermal power to provide more electricity for the plant's operation.
Usually, geothermal plants pump mineral-rich brine up from areas of hot rock beneath the surface of the Earth, convert that heat to energy, and then re-inject that water back into the ground to heat back up again. The re-injection process is usually as simple as it sounds—just put the water back in the ground where you found it once it cools. Instead, Enel is harnessing power from all that falling water. Brian Stankiewicz, Enel’s Senior Operations Manager for geothermal and solar operations, told Ars that the company realized it “had an exponential amount of hydraulic energy that could be harnessed” shortly after it bought the defunct plant in 2007.
Enel called on the expertise of oilfield service provider Baker Hughes to help it install a downhole generator in the injection well, opposite the production well where the water is pumped up. The generator is placed at the bottom of the well receiving the recycled geothermal water, connected to a turbine above it that spins as the re-injected water is pulled down by gravity. The generator changes that mechanical energy into electrical energy, producing an additional 1,008 megawatt hours for the plant. Enel says the hydroelectric addition has improved Cove Fort's efficiency by 8.8 percent.
Perhaps that seems like a small amount for a geothermal plant that generates 160,000MWh annually, but the hydroelectric component also helps protect Cove Fort’s aquifer. On many geothermal projects, the amount of brine that can be re-injected is limited to prevent damaging underground rock formations, Stankiewicz told Ars, adding, “if the flows get too large for the well, it can create a lot of turbulence.” Enel’s downhole generator at Cove Fort controls the injection of the brine back into the aquifer and limits those damaging “turbulent vortexes,” as geothermal engineers call them.
The hydroelectric component is an interesting addition to what was, as recently as 2007, an old, non-operational geothermal plant. Construction began on Cove Fort in southwestern Utah in 1984, and it was a fully operational steam turbine geothermal plant between 1990 and 2003. But steam turbines at geothermal plants don’t always have the longest life—minerals in the brine can wear out turbine components faster than a steam engine using regular water. Stankiewicz also attributed the original plant’s degradation to aspects of the reinjection process. “A conventional flash style plant doesn’t allow you to reinject 100 percent” of the brine, he said. “There’s a lot of evaporation.”
So when Enel bought Cove Fort in 2007, it converted the plant to a more efficient Rankine binary cycle plant—instead of using straight steam to power turbines, Enel pumps the hot water up to a heat-exchange site where a secondary fluid with a lower boiling point than water (in this case pentane) is heated by the water and evaporates, creating hot vapor that can power the plant’s generators.
“Over the last couple of decades, geothermal development has shifted toward the use of liquid dominated resources and away from steam as new power generation technologies make lower temperature resources economical to develop and operate,” Stankiewicz explained in a follow-up e-mail.
Enel reopened Cove Fort in 2013, and since then the 25MW plant has powered approximately 13,000 homes served by the Salt River Project, a utility cooperative in Arizona.
Checking in on some 16ft-tall mirrors
The combination of geothermal and hydroelectric energy at Cove Fort is a first for North American geothermal plants. But it’s the second hybrid plant that Enel has built combining geothermal with other renewable resources. Enel’s Stillwater plant in Fallon, Nevada, is the only triple-hybrid renewable energy plant in the US, according to the Department of Energy (DOE), combining geothermal power with a 26MW array of photovoltaic solar panels, and a concentrated solar power (CSP) system that uses mirrors to add heat from the Sun to already hot geothermal water. In fact, Ars took a tour of Stillwater way back in 2014, when the company was still in the process of installing the 16-foot-long parabolic mirrors that currently concentrate heat on a 5” pipe full of geothermal brine.
The CSP system finally came online in 2015, and in October of this year, the US Department of Energy and Enel announced that they would be working together to conduct some studies on ways to optimize Stillwater’s three energy sources.
Currently the CSP provides some interesting efficiencies to Stillwater. Shortly after opening the geothermal portion of the plant in 2009, Enel realized that the ambient air temperature in the Nevada desert was reducing how quickly its air-cooled geothermal system could shed heat, which harmed how much energy the plant could produce in the middle of the day. While Enel can’t make a hot desert afternoon cooler, it realized it could make the geothermal brine it pumped from the Earth hotter. Its parabolic mirrors can heat the air in front of them to about 600 degrees Fahrenheit, while the brine inside goes from 300 degrees Fahrenheit out of the ground to 390 degrees Fahrenheit.
According to the DOE, this strategy has been working for Enel: “between the months of March and December 2015, the CSP component increased the amount of overall output by 3.6 percent, on average.” That, in combination with the solar PV array, means that Stillwater is a renewable energy plant that’s producing 24/7—during the day when geothermal energy production might drop off, the solar array is producing energy and the CSP system is boosting the weakened geothermal performance. At night when the solar array isn’t producing anything, geothermal is functioning well, and the cool night air means that the CSP system isn’t needed.
What’s does the future hold?
Enel couldn’t say if there are any more projects like this in the works, but Stankiewicz did say that Cove Fort’s Down Hole generator scheme could likely work on other geothermal sites. “The Cove Fort plant presented unique geological conditions that proved to be a good first testing facility for this technology,” he wrote to Ars in an e-mail. “We are actively looking at ways in which this technology can be applied at other sites around the world with the same geological conditions. An analysis needs to be done of individual injection wells to ensure there is enough head pressure and flow to allow the installation of the Down Hole Generator.”
And, despite the incoming Trump administration’s aversion to renewables, the company is publicly optimistic that there will continue to be a market for renewable energy in the US. Besides the geothermal plants, Enel has a handful of solar and wind farms, and it announced a deal in October to construct a 300MW wind farm in Missouri. “Our company is well positioned to continue its growth in the US as evidenced by its more than 1 GW under construction and continued investments in both renewables and the US market,” a company spokesperson said.
Correction: The story originally said that Fort Cove was the first geothermal plant to use hydroelectric power and geothermal power together, but a project from the Northern California Power Agency actually predates Enel's project.
Posted on January 5th, 2017 in environment by Spencer R.
As reported by Enel Green Power, geothermal energy production in Tuscany, Italy has reached yet another record in the past year of 2016.
With 34 geothermal power plants in operation in the region in 2016, production increased by 51 GWh to 5,871 GWh of produced electricity by geothermal power plants in the region.
This new record was made possible by optimizing technological innovation and excellence of the plants whose plant efficiency was greater than 98% and availability of mine shafts operated by Enel Green Power with a view to a careful geothermal cultivation environment and the balance of the geothermal loop.
In the more than 100 years of geothermal power production in the region, the level production has never been as high and highlights the sustainability of the resources. When managed well through the reinjection of water output and technological innovation, there has been growth in terms of availability and performance by keeping a balance with the environment and proving that geothermal energy is completely renewable.
At Larderello in Tuscany, Enel Green Power operates the oldest geothermal complex in the world and has the know-how of geothermal energy that exports all over the planet.
Of 34 geothermal power plants (for a total of 37 production units) of Enel Green Power, 16 are in the province of Pisa; 9 are in Siena (total of 10 units), as well as 9 plants in the province of Grosseto (total of 11 units). At the provincial level, the province of Pisa stands at a geothermal production of 2,976 GWh, the highest figure of the three Tuscan provinces.
The territory of Siena has had a production of 1,492 GWh and Grosseto of 1,403 GWh . The nearly 6 billion KWh produced in Tuscany are the average annual consumption of more than two million households and provide useful heat to warm over 10 thousand residential customers as well as companies of geothermal areas , about 30 Ha hectares of greenhouses, dairies and a major agricultural sector, gastronomic and tourism.
In terms of organization, power plants are grouped in so-called “Geothermal Areas” (each of which includes plants from different provinces) of Larderello, Radicondoli, Lake Boracifero and Piancastagnaio / Amiata: the areas of Larderello and Lake showed a production respectively 1,822 and 1,851 GWh, the area of Radicondoli of 1,217 GWh and the plants of Piancastagnaio, Santa Fiora and Ardicosso combined 981 GWh.
“Geothermal has showing record production figures year after year – said Massimo Montemaggi , Head of Geothermal at Enel Green Power – confirming that it is an ancient resource but able to constantly renew itself and contributing to the development of renewable energy in Tuscany and Italy. Our business, highlights the excellence for the technologies used, the environment and the frontiers of innovation on energy, electricity and heat. The record this year confirms that we are on track, thanks to our know-how and cooperation with regional and local institutions, entrepreneurs and trade associations with the aim of continuing to be an international leader, increase further local development and consolidate the Tuscan geothermal district in Italy and in the world “.
Posted on January 5th, 2017 in solar by Spencer R.
In sunny Israel, solar energy supplies only a small percentage of the nation's power needs, leaving it far behind countries with cloudier and colder climates.
Now the fledgling solar industry is trying to make a leap forward with a large-scale project boasting the world's tallest solar tower, as a symbol of Israel's renewal energy ambitions.
With Israel traditionally running its economy on fossil fuels, renewable energy has long been hobbled by bureaucracy and a lack of incentives. But the country is starting to make an effort, setting a goal of generating 10 percent of its energy from renewable sources by 2020, up from the current 2.5 percent.
The Ashalim project, deep in the Negev desert, is made up of three plots, with a fourth planned for the future, each with a different solar technology. Together, the fields will be Israel's largest renewable energy project when completed by 2018. They are set to generate some 310 megawatts of power, about 1.6 percent of the country's energy needs — enough for about 130,000 households, or roughly 5 percent of Israel's population, according to Israel's Electricity Authority.
"It's the most significant single building block in Israel's commitment to CO2 reduction and renewable energy," said Eran Gartner, chief executive of Megalim Solar Power Ltd., which is building one part of the project.
The centerpiece is a solar tower that will be the world's tallest at 250 meters (820 feet).
Solar towers use a method differing from the more common photovoltaic solar panels, which convert sunlight directly into electricity. Instead, towers use a solar-thermal method: Thousands of mirrors focus the sun's rays onto the tower, heating a boiler that creates steam to spin a turbine and generate electricity.
Encircling the Ashalim tower are 50,000 mirrors, known as heliostats, in a shimmering blanket of glass over the desert. The tower is so tall because the panels were squeezed together to maximize use of the land — and the closer the panels are the taller the tower must be, Gartner explained.
Another solar-thermal plot at Ashalim will be able to store energy even when the sun goes down. A third plot will use photovoltaic solar technology to produce energy.
Yaron Szilas, CEO of Shikun & Binui Renewable Energy, the lead developer of the second solar-thermal plot, said combining the three technologies was a wise move because each has its own advantage. The amount of electricity it produces will be comparable to large-scale solar fields in California and Chile.
There are around a dozen solar tower fields around the world, the largest being the Ivanpah plant in California with some 170,000 heliostats around three 140-meter-tall (460-foot) towers.
Israel has developed some of the world's most advanced solar energy equipment and enjoys a nearly endless supply of sunshine. But Israeli solar companies, frustrated by government bureaucracy, have mostly taken their expertise abroad.
Countries with cooler climates have outpaced Israel. Germany, for example, gets nearly 30 percent of its energy from renewable sources.
"Israel has a potential to be a sunshine superpower," said Leehee Goldenberg, director of the department of economy and environment at the Israel Union for Environmental Defense, a non-governmental organization. Despite some steps in the right direction, "Israel's government hasn't really been pushing to reach its small goals regarding solar energy."
Israel has often been reluctant to hand out huge parcels of land, a necessity for large-scale solar power production, Gartner said. Large projects also demand access to state-owned infrastructure like gas, water and electricity, and connecting to those utilities out in remote plants in the Negev desert often takes time.
Israel's Finance Ministry said the price of generating solar power in Israel has come down, and the ministry has pushed new laws to promote the industry. Recent legislation has also provided incentives and cut down some of the bureaucracy for Israelis wanting to install solar panels on their roofs.
The ministry said if Ashalim is successful, it will aim for more such facilities.
After the discovery of major natural gas deposits offshore, Israel now gets 70 percent of its energy from cleaner-burning gas. That discovery was welcome, Szilas said, but it has also delayed the impetus for promoting renewable energy.
The developers in the Ashalim project say they want Israel to step up its renewable energy goals.
"With all the sun that we have and how progressed we are in technology, these goals are very, very, very modest," Szilas said. "But these are the goals that were set, and we are working toward it."
Posted on January 5th, 2017 in solar by Spencer R.
Solar cells could be placed under the skin for the process of recharging implanted electronic medical devices. New research published by Swiss scientists shows that as little as 3.6 square centimeters (0.55 square inch) of solar cell would generate enough power throughout winter and summer so as to power a generic pacemaker.
The research is the first of its kind, as no other study has ever published real-life data about the implications and mechanisms of using solar cells for the purpose of powering devices, such as pacemakers.
Medical Implants On Solar Energy Now Possible
The research, published in Springer's journal Annals of Biomedical Engineering, comes as a solution for patients who have battery-based implants and who have to go through surgical procedures every time their device's batteries wear off.
At this moment, the vast majority of electronic implants are battery-based, and their size is directly proportional to the battery volume that is necessary for a longer life. However, should the power of these batteries be consumed, they have to be either changed or recharged.
Most of the time, this means that patients have to undergo a surgical intervention through which their implants are changed, which is both expensive and disquieting for the patients. Additionally, depending on the patient's health status, these interventions could lead to complications and alter the quality of life of the patients in the long run as well as on a short-term basis.
Recently, there have been numerous efforts from different researchers when it comes to electronic solar cells. Different teams of scientists have worked on prototypes of tiny electronic solar cells which can be employed in under-the-skin implants to recharge life-saving medical devices for patients.
The process of generating solar energy to power the implants works very similarly with any other solar energy device. Being implanted inside the body, the device will absorb the solar energy that the patient's skin comes in contact with, thus ensuring continual life.
In an attempt to apply the theory of solar cells to patients who need implants, the researchers tested their prototype for feasibility. As part of the testing process, the team designed devices that measure the output power of the solar generator. Additionally, every device subjected to tests was covered by optical filters, thus simulating how the skin's properties would affect the sun's penetration through the skin.
As part of the tests, 32 subjects volunteered to wear the cells on their arms for a week during three seasons: summer, winter and autumn. Regardless of the season, the cells were found to generate significantly more than the power that is generally necessary for powering a pacemaker, thus passing the feasibility test.
A Successful Test
"The overall mean power obtained is enough to completely power for example a pacemaker or at least extend the lifespan of any other active implant," noted Lukas Bereuter of Bern University Hospital and the University of Bern in Switzerland, lead author of the study.
The success of the tests means that this prototype could actually be implemented in patients, saving them the trouble of having to go through surgical operations every time the battery of their devices wears off.
According to Bereuter, wearing power-generating solar cells under the skin will one day save patients the discomfort of having to continuously undergo procedures to change the batteries of their life-saving devices.
Posted on January 5th, 2017 in environment by Spencer R.
Las Vegas may not be the first city you think of when you think of sustainability, but maybe it should be. When SunPower recently turned on the Boulder 1 solar project, the City of Las Vegas' government became the first in the country to be entirely powered by renewable energy.
This follows Las Vegas' leadership in water conservation, cutting consumption by 23% between 2005 and 2015. As cities across the country look for ways to cut costs and use resources more sustainably, maybe Las Vegas should be where they look to find a success story.
The abundance of renewable energy in Nevada
The same sun that makes the desert in Southern Nevada so punishingly hot is also a resource that makes renewable energy cheap. Solar energy in the state is among the cheapest in the country, and at 4.6 cents per kWh for energy from the Boulder 1 project it's competitive with fossil fuel. When the city threatened to leave Berkshire Hathaway subsidiary NV Energy, the utility agreed to buy more solar for the city's buildings to use, which now accounts for 100% of total energy consumed by the city.
But building renewable energy plants is only part of the story. The city has reduced electricity consumption by 30% through a combination of efficiency programs and on-site solar. Between efficiency and renewables, the City of Las Vegas says it's going to save $5 million annually, no small amount for a mid-size U.S. city.
It's worth noting that energy isn't the only place Las Vegas has improved its sustainability. The city has put a lot of effort into reducing water consumption, treating much of the water that's dumped down the drain and returning it to Lake Mead. But water conservation is more of a necessity than anything in the middle of the desert.
Las Vegas and the war with NV Energy
The City of Las Vegas threatening to leave NV Energy for cleaner sources of energy isn't entirely unique in Nevada. MGM Resorts and Wynn Resorts paid a combined $103 million earlier this year to leave NV Energy and begin buying their electricity elsewhere. MGM Resorts has a massive solar array at Mandalay Bay and will consider buying energy from solar developers in the future. Wynn has been quiet about its plans.
On top of the city and casino defections, voters passed a constitutional amendment that stripped NV Energy of its monopoly. The ballot initiative read like this:
Shall Article 1 of the Nevada Constitution be amended to require the Legislature to provide by law for the establishment of an open, competitive retail electric energy market that prohibits the granting of monopolies and exclusive franchises for the generation of electricity?
Voters passed the amendment with nearly three quarters of the vote. It'll take time to break up the energy monopoly, but energy choice is taking a big step forward in Nevada.
Sustainability is now in Las Vegas' culture
Maybe it's the desert location that makes Nevada so conscious about the sustainability of its city, and maybe it's the abundant resources that have made a move to renewables so attractive. Whatever it is, Las Vegas has become an example for other cities around the country. And sustainability isn't just good for the environment, it's good for the bottom line as well.