Storing thermal solar energy from summer to winter

Posted on January 12th, 2017 in solar by Spencer R.

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(phys.org)

Can thermal solar energy be stored until wintertime? Within a European research consortium Empa scientists and their colleagues have spent four years studying this question by pitting three different techniques against each other.

We are still a far cry from a sustainable energy supply: in 2014, 71 percent of all privately-owned apartments and houses in Switzerland were heated with fossil fuels, and 60 percent of the hot water consumed in private households is generated in this way. In other words, a considerable amount of fossil energy could be saved if we were able to store  from sunny summer days until wintertime and retrieve it at the flick of a switch. Is there a way to do this? It certainly looks like it. Since autumn of 2016, following several years of research, Empa has a plant on a lab scale in operation that works reliably and is able to store heat in the long term. But the road to get there was long and winding.

The theory behind this kind of heat storage is fairly straightforward: if you pour water into a beaker containing solid or concentrated sodium hydroxide (NaOH), the mixture heats up. The dilution is exothermic: chemical energy is released in the form of heat. Moreover, sodium hydroxide solution is highly hygroscopic and able to absorb . The condensation heat obtained as a result warms up the sodium hydroxide solution even more.

Summer heat in a storage tank

The other way round is also possible: if we feed energy into a dilute sodium hydroxide solution in the form of heat, the water evaporates; the sodium hydroxide solution will get more concentrated and thus stores the supplied energy. This solution can be kept for months and even years, or transported in tanks. If it comes into contact with water (vapor) again, the stored heat is re-released.

So much for the theory, anyway. But could the beaker experiment be replicated on a scale capable of storing enough energy for a single-family household? Empa researchers Robert Weber and Benjamin Fumey rolled up their sleeves and got down to work. They used an insulated sea container as an experimental laboratory on Empa's campus in Dübendorf – a safety precaution as concentrated sodium hydroxide solution is highly corrosive. If the system were to spring a leak, it would be preferable for the aggressive liquid to slosh through the container instead of Empa's laboratory building.

Unfortunately, the so-called COMTES prototype didn't work as anticipated. The researchers had opted for a falling film evaporator – a system used in the food industry to condense orange juice into a concentrate, for instance. Instead of flowing correctly around the , however, the thick sodium hydroxide solution formed large drops. It absorbed too little water vapor and the amount of heat that was transferred remained too low.

Then Fumey had a brainwave: the viscous storage medium should trickle along a pipe in a spiral, absorb water vapor on the way and transfer the generated heat to the pipe. The reverse – charging the medium – should also be possible using the same technique, only the other way round. It worked. And the best thing about it: spiral-shaped heat exchangers are already available ex stock – heat exchangers from flow water heaters.

Fumey then optimized the lab system further: which fluctuations in NaOH concentration are optimal for efficiency? Which temperatures should the inflowing and outflowing water have? Water vapor at a temperature of five to ten degrees is required to drain the store. This water vapor can be produced with heat from a geothermal probe, for instance. In the process, 50-percent sodium hydroxide solution runs down the outside of the spiral heat exchanger pipe and is thinned to 30 percent in the steam atmosphere. The water inside the pipe heats up to around 50 degrees Celsius – which makes it just the ticket for floor heating.

"Charged" sodium hydroxide

While replenishing the store, the 30-percent, "discharged" sodium hydroxide solution trickles downwards around the spiral pipe. Inside the pipe flows 60-degree hot water, which can be produced by a solar collector, for instance. The water from the sodium hydroxide solution evaporates; the water vapor is removed and condensed. The condensation heat is conducted into a geothermal probe, where it is stored. The sodium hydroxide solution that leaves the heat exchanger after charging is concentrated to 50 percent again, i.e. "charged" with thermal energy.

"This method enables solar energy to be stored in the form of chemical energy from the summer until the wintertime," says Fumey. "And that's not all: the stored heat can also be transported elsewhere in the form of concentrated sodium hydroxide solution, which makes it flexible to use." The search for industrial partners to help build a compact household system on the basis of the Empa lab model has now begun. The next prototype of the  storage system could then be used in NEST, for example.

 

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Nigerian community benefit from solar energy to rebuild homes after Boko Haram attacks

Posted on January 12th, 2017 in solar by Spencer R.

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(www.africanews.com)

Vandalized houses in Gahara Mojiri, a village in Nigeria’s northeastern Adamawa state, bear the hallmarks of militant Islamist group Boko Haram.

 

The houses were destroyed by the militants who raided people’s homes and meted out attacks on residents in early 2015.

Many of those who fled the violence have since returned home since the militants lost most of the territories they took over from the Nigerian army.

Residents are now able to access clean water using solar powered water pumps and street lighting to help improve on security.

In an effort to help residents rebuild, the Energy Commission of Nigeria (ECN) and the UN Development Programme (UNDP) introduced solar panels in the village located in the Hong Local government area.

“Before the solar, we used to fetch water in the stream but since the solar comes we stop going to the stream because the solar gives us water so much,” said Gahara Mojiri, Jacob Musa

“All the people of this community are benefiting from this borehole. One of the boreholes has stopped functioning properly, but we are hoping it will be fixed in time,” added another Gahara Mojiri resident,” Abraham Bulgumi.

Tapping renewable energy is helping tackle persistent energy shortages in the region as people work to develop themselves.

The solar panels have been set up in 8 villages, benefiting over 13,000 people. Residents are also now able to charge their mobile phones as well as use clean energy to light up their homes.

At the nearby Garaha Health centre, patients can access vaccines that were not available to them a few years ago. Joel Markus is the facility manager at Mojili Health Centre.

“There is even so many cases of hepatitis in this community now and the problem is because they did not have the vaccine earlier, so that is the cause of the problem they are having. But now since we have the vaccine, I believe the cases going to be less,” ha said.

Though Nigeria’s army has pushed the Islamist group back to its base, the militants still stage suicide bombings.
In recent years Boko Haram’s attacks have spilled into neighbouring Niger, Cameroon and Chad.

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Smaller Businesses Want Renewable Energy Developers To Spread The Green

Posted on January 11th, 2017 in environment by Spencer R.

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(www.forbes.com)

Smaller enterprises want energy developers to spread the green, allowing them to get in on the renewable wave rolling through America. The dynamic has made it easier for larger corporations with more demand to buy wind and solar electricity but it has nudged out the less brawnier brands.

The guys at Google and Facebook, for example, are stimulating the need for wind and solar energy that they are using to feed their electricity-starved data centers. The developers of those energy projects, in return, are getting solid customers that are buying their output at a fixed price over a certain period of years.

But individual commercial and industrial customers aren’t generating the type of demand that can propel big energy projects into the market. Now, though, that may change. The same so-called power purchase agreements that are used to attract the likes of Microsoft, Intel and SAP can also be parceled out to smaller businesses, albeit in much smaller blocks of energy and for much shorter time frames.

 

“We connect the corporate community to power purchase agreements,” says Paul Schuster managing director for Altenex, a unit of Edison Energy, in an interview. “We have noticed those larger-to-mid-sized energy users need to achieve cost efficiencies, which can be done by buying smaller blocks of renewable electricity.”

 

A traditional power purchase agreement, for example, might require a company to buy 100 megawatts and it would last 20 years. But the contract now offered to the smaller players might be for 10 megawatts over 10 years.

So how does all this work? A wind developer can’t go forward until it knows that it can sell its output into the market at a fair price. Because there are tax breaks for both building the project and buying the output, developers have proved able to sell that product into wholesale markets.

Let’s say it is an insurance company or a bank that buys the bulk of the wholesale power before it would be resold into retail markets: They often line up the major corporate outlets or Internet giants and contact with them to sell the energy at fixed prices over a set number of years. What Altenex is doing is going to that insurer or banker — in this example — and offering to market smaller blocks of electricity to commercial and industrial businesses.

“The return on equity should be infinite,” says Schuster. “Customers, in fact, are not putting down any upfront capital. Hopefully, they are buying renewable energy at the same cost or lower cost than they are paying for fossil energy.”

Is the corporate green market on fertile ground? PriceWaterhouseCoopers says that it has grown over the last 24 months and that it will continue to expand. Seventy-two percent of the companies it surveyed said that they are pursuing renewables, noting that they want to be more sustainable and to use green energy to hedge against volatile energy prices.

Green electricity sales in the form of voluntary power purchase agreements grew by 4% in 2015, adds the National Energy Renewable Laboratory. Contracted green power sales from those deals grew by 13% in 2015, it notes, and now total 10.2 million megawatt hours.

The larger companies are the main drivers with the likes of General Motors, Hewlett Packard, Johnson & Johnson, Tata Motors and Walmart setting a goal to run their entire operations using green energy. That includes a number of different options — everything from investing directly into deals to buying their electricity through power purchase agreements.

“The contracts are pretty favorable to the corporate buyers,” says Lori Bird, senior analyst for the National Energy Renewable Lab, in an interview. “Because companies are doing this, they are getting a credit and the energy is going into the grid. The companies are playing a vital role in driving renewable energy projects. Utilities have played that role and still do. But companies are now doing so with these financial arrangements.”

But the smaller businesses also want in on the action. Historically, such enterprises have bought so-called renewable energy credits that guarantee green energy gets generated and fed into the grid, she adds. But those purchases are nominal and have often been procured through their local utilities. 

More than 860 utilities offer green power programs to their customers, the renewable energy lab says, giving more than half of the electricity customers nationwide the option to buy renewable energy. But the aim now is to ratchet up the stakes and to offer commercial and industrial businesses a chance to contractually buy more green power.

“Until now, the market has only worked well for large companies willing to take large amounts of renewable energy on long-term contracts,” says Marty Spizer, with the World Wildlife Fund. “This promising market development could be really important to meet the needs of the critical middle-market segment that need easy, flexible, and cost-effective options.”

What it signals above all else is that the trend to go green is, in fact, a sustainable one and not a fad that will get ensnared by current political happenings. Indeed, big businesses started the momentum and the smaller ones now have the potential to carry it forward.

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Solar energy powers an entire island in American Samoa thanks to Tesla, SolarCity

Posted on January 11th, 2017 in solar by Spencer R.

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(www.accuweather.com)

Located over 4,000 miles from the west coast of the United States in the South Pacific Ocean, the island of Ta’u in American Samoa is powered almost entirely by the sun.

The island previously relied on diesel generators for power, but thanks to government funding and contributions from SolarCity and Tesla, the remote island operates on solar power, a cleaner and more cost-effective energy source.

Back in November, SolarCity announced in a blog post that a microgrid of 5,300 solar panels and over 60 battery packs had been completed on the island within a year’s time. The solar panels can generate 1.4 megawatts of energy, while Tesla Powerpacks provide 6 megawatt hours of battery storage. 

Unlike with diesel generators, which can lose power when powerful storms hammer the island, Ta'u's microgrid is able to store energy for several days, which is a huge benefit to the island of nearly 600 people.

Located in the South Pacific, American Samoa will get the occasional encounter from a tropical cyclone. Most recently, Tropical Cyclone Tuni hit the island chain in November 2015, causing significant property and crop damage.

American Samoa has a wet, tropical climate, with over 120 inches of rain falling per year, said AccuWeather Meteorologist Jim Andrews.

However, while solar panels are most effective in direct sunlight, they can still function when it's cloudy. Rain can be beneficial in that it helps keep panels operating efficiently by washing away dirt or dust, the Solar Energy Industries Association states.

The region still gets plenty of sunshine. Island resident Keith Ahsoon, whose family owns several stores on the island, told SolarCity that "it's always sunny out here" and being able to retain the sun's energy and not lose power will allow him to sleep "a lot more comfortably at night."

The Environmental Protection Agency, Department of Interior and American Samoa Power Authority, which operates the system, funded the project. The island was chosen as part of an initiative by the Manu'a islands, which include Ta'u, to become fully free of fossil fuel-generated electricity. 

According to SolarCity, the project will offset the use of more than 109,500 gallons of diesel per year.

Ahsoon has seen the effects of climate change firsthand and said this endeavor will help lessen the carbon footprint around the world.

"Beach erosions and other noticeable changes are a part of life here. It’s a serious problem, and this project will hopefully set a good example for everyone else to follow,” said Ahsoon.

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Obama: Renewable Energy Revolution Is 'Irreversible', Will Outlast Trump

Posted on January 11th, 2017 in environment by Spencer R.

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(www.ecowatch.com)

Barack Obama, outgoing president of the U.S., has stepped directly into the climate debate. He believes that the U.S. is on the way to a "clean energy" world and he delivers four reasons why he thinks the shift is now irreversible.

In an article for the journal Science, President Obama said that although the understanding of the impact of climate change is increasingly and disturbingly clear, "There is still debate about the proper course for U.S. policy—a debate that is very much on display during the current presidential transition."

That is almost his only acknowledgment of President-elect Donald Trump's declared belief that climate change is a hoax, invented by the Chinese.

Clean Energy Economy

"But putting near-term politics aside," he wrote, "the mounting economic and scientific evidence leave me confident that trends toward a clean energy economy that have emerged during my presidency will continue and that the economic opportunity for our country to harness that trend will only grow."

First of these is that between 2008 and 2015, the U.S. economy grew by 10 percent while carbon dioxide emissions from the energy sector fell by 9.5 percent, an outcome that "should put to rest the argument that combating climate change requires accepting lower growth or a lower standard of living."

Renewable energy costs fell dramatically during his years in office: 41 percent for wind, 54 percent for rooftop solar photovoltaics and 64 percent for big solar-power installations. Clean energy now attracts twice as much global capital as fossil fuels.

President Obama also believes that businesses now understand that reducing emissions works for the benefit of business—it cuts costs for consumers and delivers returns to shareholders.

It also matters to the workforce: 2.2 million Americans are now employed in the design, installation and manufacture of energy-efficiency products and services, while 1.1 million Americans are employed in producing fossil fuels and generating electric power with those fuels.

The power sector of the economy has changed too. It has shifted from coal to natural gas, largely because of market forces, and the drop in renewable electricity costs has prompted big businesses such as Google to promise that 100 percent of their energy will be from renewable sources in 2017.

Global Momentum

And, he argues, there is already global momentum. Nations in Paris in 2015 agreed on "smart" climate policies for all. It would undermine U.S. economic interests to walk away from the agreement.

"This should not be a partisan issue. It is good business and good economics to lead a technological revolution and define market trends," wrote President Obama.

"Despite the policy uncertainty that we face, I remain convinced that no country is better suited to confront the climate challenge and reap the benefits of a low-carbon future than the United States, and that continued participation in the Paris process will yield great benefit for the American people, as well as the international community."

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China Aims to Spend at Least $360 Billion on Renewable Energy by 2020

Posted on January 10th, 2017 in environment by Spencer R.

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(www.nytimes.com)

China intends to spend more than $360 billion through 2020 on renewable power sources like solar and wind, the government’s energy agency said on Thursday.

The country’s National Energy Administration laid out a plan to dominate one of the world’s fastest-growing industries, just at a time when the United States is set to take the opposite tack as Donald J. Trump, a climate-change doubter, prepares to assume the presidency.

The agency said in a statement that China would create more than 13 million jobs in the renewable energy sector by 2020, curb the growth of greenhouse gasses that contribute to global warming and reduce the amount of soot that in recent days has blanketed Beijing and other Chinese cities in a noxious cloud of smog.

China surpassed the United States a decade ago as the world’s biggest emitter of greenhouse gasses, and now discharges about twice as much. For years, its oil and coal industries prospered under powerful political patrons and the growth-above-anything mantra of the ruling Communist Party.

The result was choking pollution and the growing recognition that China, many of whose biggest cities are on the coast, will be threatened by rising sea levels.

But even disregarding the threat of climate change, China’s announcement was a bold claim on leadership in the renewable energy industry, where Chinese companies, buoyed by a huge domestic market, are already among the world’s dominant players. Thanks in part to Chinese manufacturing, costs in the wind and solar industries are plummeting, making them increasingly competitive with power generation from fossil fuels like coal and natural gas.

Sam Geall, executive editor of Chinadialogue, an English- and Chinese-language website that focuses on the environment, said that the United States, by moving away from a focus on reducing carbon emissions, risked losing out to China in the race to lead the industry.

Mr. Trump has in the past called the theory of human-cased global warming a hoax and picked a fierce opponent of President Obama’s rules to reduce carbon emissions, Scott Pruitt, the Oklahoma attorney general, to lead the Environmental Protection Agency.

The investment commitment made by the Chinese, combined with Mr. Trump’s moves, means jobs that would have been created in the United States may instead go to Chinese workers.

Even the headline-grabbing numbers on total investment and job creation may understate what is already happening on the ground in China. Greenpeace estimates that China installed an average of more than one wind turbine every hour of every day in 2015, and covered the equivalent of one soccer field every hour with solar panels.

China may meet its 2020 goals for solar installation by 2018, said Lauri Myllyvirta, a research analyst at Greenpeace, who is based in Beijing.

But despite these impressive numbers, China’s push to clean its air and reduce its greenhouse gasses faces political pressure from the politically powerful coal industry.

Mr. Geall and Mr. Myllyvirta both said that Thursday’s announcement was missing any language on curtailment, or the amount of electricity generated by wind and solar that never finds its way to the country’s power grid. In China, wind power curtailment was 19 percent in the first nine months 2016, Mr. Myllyvirta said, many times higher than in the United States, where curtailment levels are often negligible.

The main reason for curtailment, he said, is that China is plagued by overcapacity in electricity generation and operators of China’s grid often favor electricity generated from coal.

In recent years the country has also been building coal-fired power plants at a furious pace, although that has recently slowed along with China’s economy. Another omission from Thursday’s announcements, Mr. Myllyvirta said, was the absence of any specific target to reduce coal consumption.

But both Mr. Geall and Mr. Myllyvirta said Thursday’s announcement set the stage for still more power generation from renewable energy and a gradual shift away from coal.

“My experience with China is when a numeric target gets written down, it gets implemented,” Mr. Myllyvirta said. “It doesn’t always get implemented in the way you like, but it does get implemented.”

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Creating the Culture for a Renewable Energy Future

Posted on January 10th, 2017 in environment by Spencer R.

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(www.zmescience.com)

Renewable energy has already won the battle against fossil fuels, despite the big subsidies for oil and gas. Renewable energy is cost-efficient when it’s compared to the cost of pollution. Also, renewable energy has been proven to be cost-effective when projects take advantage of partnerships and cooperative financing.

It is just a matter of time before the victory in this battle is shared with the majority of the world.

However, how soon this happens depends on how quickly the existing oil and gas energy generation culture changes. Culture has been defined as the learned and shared behavior of a community of interacting human beings. If culture is about learned and shared behavior, can we learn and share our way to a renewable energy future?

The oil and gas energy generation change is contingent on how governments consider culture when they implement effective renewable energy incentives and subsidies. The change also depends on how willing businesses are to evaluate and adapt their culture of renewable energy consumption.

The private sector, financing institutions and multilateral development agencies need to facilitate a culture shift in funding, developing and evaluating renewable energy projects. We must evaluate 11the culture in which we live and work and how the benefits of renewable energy influence that culture. Each of us must understand our history if we are going to change our reality in our lifetime and shape the future.

Overcoming Intimidation Created by Renewable Energy

The transition to renewable energy might seem intimidating – regardless of whether it is 20% by 2020 or 100% by 2060 – because it will require a culture shift. This may be why worldwide energy goals are like moving targets. They must adapt as the shift occurs, whether at the national level or within local companies.

One aspect of this intimidation might come from the notion that we’ve lived with fossil fuel energy so long that change is impossible. However, “so long” really is not that long in the context of human history.

It is only since the Industrial Revolution that fossil fuels have dominated our culture. Even then, we had hemp as biomass and oil, hydropower as dams, wind power as windmills and solar power as solar cooking. Before the Industrial Revolution facilitated migration from rural workplaces to urban manufacturing areas, we depended on decentralized ways of living and making a living.

Decentralization and the use of renewable energy is nothing new. Certainly, the amount of energy we consume can be correlated with the electrification of technology. But this does not necessarily mean our energy consumption needs to increase continuously.

With electrification, we increase our energy footprint in two ways: with the energy requirement to use products and the energy requirement of creating products. As we create more products, we still have to deal with the energy footprint of electronic waste. It makes sense that manufacturers are developing “smart” technology to optimize all aspects of product energy consumption.

Most of our ideas around energy consumption are not necessarily based on what we need to consume. Instead, they are based on what we want to consume for comfort, security, tradition – to reflect human progress, to satisfy ideas of development, to define wealth, to distinguish class and assert cultural identity.

Benefits from the Development of a Sharing Economy

Culturally, the truth is most of us in the Western Hemisphere are accustomed to the conveniences of having our own car, our own home, our own everything. However, these customs have changed and will continue to change. Innovative companies such as Uber are proof of those changes. We are also seeing examples from the development of a sharing economy.

However, Uber didn’t just grow exponentially because the company saw the benefits of sharing costs with drivers. Uber saw the benefits of creating a sharing economy.

So how can a sharing economy benefit from renewable energy? If we share both our energy consumption and our profits, we justify a shared investment in a renewable energy future. This investment can create the necessary capital for renewable energy projects.

How Do We Scale Out and Cooperate for a Renewable Energy Future?

For now, the only way to see an immediate return on investment from solar installation and a lower electricity bill is if the cost for energy consumption exceeds the cost of installation. Individually, this is a rare occurrence. More often, our energy consumption cost means that a solar installation is equal to electricity payment five to 30 years in advance.

But many of us wonder how we will pay our bills the next three months. Five years is simply too far forward to stretch our money.

There is a way to cooperatively create energy consumption clusters, which together can receive a return on investment sooner than in five years. That way, we not only share the installation costs, but also the financing and soft project costs.

This approach could further increase confidence in renewable energy investment, while helping individuals to understand their energy consumption. In turn, more of us would be willing to install energy-efficient products and give utilities the consumer energy demand information they need. That could lead to utilities adjusting fossil fuel costs for consumers who install solar panels that feed into centralized grids.

This consumer information is important because our existing electricity utilities and the culture of energy generation will not simply go away. The utility’s ultimate goal is to provide reliable and affordable electricity to everyone and that requires revenue and validated consumer demand data.

Reliability means meeting energy demands while avoiding power outages. But if we demand less energy, utilities earn less revenue. At the same time, a centralized grid structure, even if transitioning to renewable energy, still needs revenue to operate.

So where should this revenue come from? There are a range of policies and revenue-generating options. They include:

  • Renewable energy permits or licenses for energy generators and consumers
  • Rebates to customers who invest in energy storage, perhaps in the form of electric vehicles
  • Increases in the rates utilities pay customers who sell renewable energy back to the grid
  • Correlation of renewable energy rates with the cost of fossil fuel
  • Taxes on existing fossil fuel generation or products made primarily from fossil fuels such as Styrofoam
  • Private sector investment
  • Air pollution fines

The mix of policy options chosen must avoid the risk of having too many people come off the grid. When that happens, the cost of electricity will increase for those who either cannot afford an off-grid system or who are not part of a cooperative renewable energy project.

 

The transition to renewable energy will cost us on multiple levels beyond the technological cost. There is also the cost of transitioning systems that depend on fossil fuels, including companies, business clusters, communities, transportation and water infrastructure.

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All of Las Vegas’s City-Owned Buildings Now Run on Renewable Energy

Posted on January 10th, 2017 in environment by Spencer R.

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(www.motherboard.vice.com)

Las Vegas is best known for its blinding neon signs and indulgent venues, but more recently the city government has set its sights on keeping the lights on in a more sustainable way.

Las Vegas’s city-owned buildings and other public infrastructure are now entirely powered by renewable energy as of December, including about 48,000 streetlamps, lights inside City Hall and power at city parks, Las Vegas spokesman Jace Radke said.

“The move to renewable energy has been seamless,” Mayor Carolyn G. Goodman said in a statement. “The city of Las Vegas has long been a leader in sustainability, and becoming the first large city in the country to rely on 100 percent renewable energy [for city-owned buildings] is an incredible accomplishment that sets a great example for our residents and businesses.”

Of course, the restaurants, casinos and homes in Las Vegas still mostly get their power from plants that run on traditional fossil fuels. Nevada as a whole relies heavily on gas and coal for its power generation—63.9 percent of its energy comes from petroleum, and 18.2 percent comes from coal. About 18 percent of the state’s energy comes from renewable sources like geothermal, solar and hydroelectric energy, according to Colorado State University/The Nature Conservancy’s energy tracking tool.

More cities are expected to jump on the renewable energy bandwagon, either entirely or to power their municipal-owned buildings, as a way to meet climate targets and to save money. Cities across the country, including Denver, Los Angeles and San Francisco, are studying how to move their residents, businesses and city buildings toward renewable energy, Sierra Club spokesman Shane Levy told Motherboard. St. Petersburg, Florida, was one of the most recent cities to jump into that initiative, becoming the first city in Florida to make a commitment to renewable energy.

National Renewable Energy Laboratory spokesman Eric O'Shaughnessy told Motherboard about 10 percent of cities in the US have an established renewable energy goal, and most cities that reach 100 percent renewable energy start the process by converting their city-owned operations to green power. He said the 10 percent figure is from a 2016 survey by the International City/County Management Association.

“There is a general consensus that cities are increasingly interested in renewable energy for both environmental and economic reasons, especially if you are working on the timeframe of several decades,” he said.

“Environmentally, going 100% renewable is a big step toward achieving sustainability goals. Economically, some cities have been able to actually save money by entering into long-term contracts for renewable energy that beat the rates they were previously paying for electricity.”

Las Vegas had been moving toward the goal by working with energy company NVEnergy, and when a large solar project was completed near Boulder City, the city was able to buy the rest of the energy it needed to run all city-owned buildings on renewable energy, the Las Vegas Review-Journal reported.

The switch to renewable energy cost the Las Vegas city government about $47 million, and it is expected save $5 million a year in energy bills due to the switch, Radke said.

“So it is a nine- to 10-year pay-back, which is really good,” he said.

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The world’s first solar panel-paved road has opened in France

Posted on January 9th, 2017 in solar by Spencer R.

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(www.qz.com)

At this rate, just about every man-made surface there is could be covered in solar panels in the future.

Yesterday, Tourouvre-au-Perche, a small town in northern France, opened what is likely the first road paved in solar panels in the world, the Guardian reported. The road is roughly 1 km (0.6 miles) long, with one lane covered entirely in a patchwork of small solar cells that look rather like bathroom tiles, or a very dirty version of the road in the Wizard of Oz.

The panels are coated in a special silicon film that helps protect them from the weight of trucks. The road will likely see around 2,000 vehicles a day, passing through the town of roughly 3,400 residents.

The road was opened by France’s environment minister and former presidential candidate Ségolène Royal, who said that she would like to see the solar panel-paving installed on thousands of kilometers of French roadways. As the Guardian points out, this part of France, Normandy, isn’t exactly known for its sunny weather, receiving around 44 days of good sunshine a year on average. Royal and the French company behind the road, Wattway, are hoping to see over the next two years whether the road can generate enough electricity to power the town.

It’s the not the first paved solar-panel project in the world—that honor went to Dutch company SolaRoad in 2014 with its solar-powered bike path—but it’s possible that this road will suffer the same issues. SolaRoad’s bike path can generate roughly 3,000 kilowatt-hours of power, but the estimated cost of building it was equivalent to paying for 520,000 kilowatt-hours’ worth of power.

France’s project was not cheap: The short stretch of roadway cost about €5 million ($5.2 million) to build. It may not prove to be the most cost-effective use of capital either. Solar panels are more efficient when they are tilted at an angle toward the Sun, rather than flat to the ground, and the road’s construction cost may well be greater than the amount of energy it can produce. “We have to look at the cost, the production [of electricity] and its lifespan,” Jean-Louis Bal, the president of the French renewable energy union SER, told the Guardian. “For now I don’t have the answers.”

Wattway aims to lower the cost of installing paneled roads as it builds more of them, and although the cost-effectiveness is in question now, it’s a novel use of otherwise wasted space. Many buildings around the world are covering their roofs with solar panels, in an effort to cut down on energy costs: Apple’s new campus is awash in solar paneling, and is aiming to be a nearly self-sufficient building, and Elon Musk’s Tesla plans to bring shingle-shaped solar panels to homes around the world in the near future. Solar panels also grace trash cans, tentsand planes, so perhaps it won’t be that long before they’re ubiquitous enough on our infrastructure to drive costs further down.

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Solar panel researchers investigate powering trains by bypassing grid

Posted on January 9th, 2017 in solar by Spencer R.

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(www.theguardian.com)

Imperial College London has partnered with the climate change charity 10:10 to investigate the use of track-side solar panels to power trains, the two organisations announced yesterday.

The renewable traction power project will see university researchers look at connecting solar panels directly to the lines that provide power to trains, a move that would bypass the electricity grid in order to more efficiently manage power demand from trains.

According to the university, the research team will be the first in the world to test the “completely unique” idea, which it said would have a “wide impact with commercial applications on electrified rail networks all over the world”.

“It would also open up thousands of new sites to small- and medium-scale renewable developments by removing the need to connect to the grid,” Imperial College London said in a statement.

Network Rail is currently investing billions in electrifying the UK’s railways in a bid to reduce the number of trains running on diesel fuel, curbing costs, air pollution, and greenhouse gas emissions in the process.

Combining this effort with increased renewable energy generation in the UK could significantly decarbonise train lines by 2050, according to 10:10, but in many rural areas the electricity grid has reached its limit for both integrating distributed energy generation and supplying power to train firms.

“What is particularly galling is that peak generation from solar and peak demand from the trains more or less match but we can’t connect the two,” explained 10:10’s Leo Murray, who is leading the project. “I actually believe this represents a real opportunity for some innovative thinking.”

Initially the project will look at the feasibility of converting “third rail systems” which supply electricity through a power line running close to the ground and are used on roughly one third of the UK’s tracks.

“Many railway lines run through areas with great potential for solar power but where existing electricity networks are hard to access,” explained Prof Tim Green, director of Energy Futures Lab at Imperial College London.

The university will collaborate on the technical aspects of the project with Turbo Power Systems – a firm that works on distribution and management of power in the railway sector – while 10:10 is leading on research looking at the size of the long-term power purchase agreement (PPA) market for directly connecting renewables to transport systems.

“I don’t think you get a better fit for PPA than a train line,” added Murray. “A rural train line even more so, the project would open up many investment opportunities across the country and further afield.”

The news comes as it emerged that every one of the Dutch state-owned railway company NS’s passenger trains are now being powered entirely by wind energy.

As of 1 January 2017 all trips taken by the estimated 600,000 people who ride NS trains everyday are being powered by wind energy.

Having teamed up with the energy firm Eneco in 2015 with the aim of reducing its emissions, NS has now reached its target of switching the sources of power for its trains to 100% renewables one year ahead of schedule, with the firm originally setting a target date of 2018 for the milestone.

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