Energywise iconEnergywise


NOAA Model Finds Renewable Energy Could be Deployed in the U.S. Without Storage

The majority of the United States's electricity needs could be met with renewable energy by 2030—without new advances in energy storage or cost increases. That’s the finding of a new study conducted by researchers from the National Oceanic and Atmospheric Administration (NOAA). The key will be having sufficient transmission lines spanning the contiguous U.S., so that energy can be deployed from where it’s generated to the places where its needed.

Reporting their results today in Nature Climate Change, the researchers found that a combination of solar and wind energy, plus high-voltage direct current transmission lines that travel across the country, would reduce the electric sector's carbon dioxide emissions by up to 80 percent compared to 1990 levels.

Conventional thinking around renewable energy has been that it is too variable to be broadly implemented without either fossil fuels to fill in the gaps or a significant ability to store surplus energy, says Sandy MacDonald, co-lead author of the paper and previously the director of NOAA's Earth System Research Laboratory. However, MacDonald thought that previous estimates had not used accurate weather data and so he wanted to design a model based on more precise and higher resolution weather data.

In the study, the team used historical and projected carbon dioxide emission and electricity cost data from the International Energy Agency, which projects that U.S. electricity will cost 11.5 cents per kilowatt hour, on average, in 2030, and that carbon dioxide emissions will be 6 percent above 1990 levels.

They designed a model called National Electricity with Weather System that took into consideration demand across one-hour time increments as well as generation capability. The main constraint of the model was that it had to use existing technologies.

The researchers ran three different scenarios: one that assumed renewables at a low cost and natural gas at a high cost; a second that accounted for a low cost of natural gas and a high cost of renewable energy; and a third that assumed mid-range prices for both.

For all three scenarios, both carbon emissions and price were reduced. The low-cost renewables/high-cost natural gas scenario resulted in the greatest reduction in carbon emissions (78 percent below 1990 levels), and average electricity prices at 10 cents per kilowatt hour. The mid-range model resulted in a 61-percent drop in emissions, and electricity prices at 10.2 cents per kilowatt hour. The high-cost renewables/low-cost natural gas scenario reduced carbon emissions by 33 percent; electricity cost 8.6 cents per kilowatt hour.

MacDonald says that some of the findings were a bit counterintuitive and highlighted the cost benefits of having a national electricity grid. For instance, the model chose to implement very few offshore wind generators, finding that building transmission lines from wind generating plants in North Dakota to New York, was in fact cheaper than building wind off the coast of New York, despite the longer distance it would have to travel. However, “as you start to make the geographical area smaller, it does pick up offshore wind because you're restricting access to some areas,” MacDonald says.

The study also looked at land and water use requirements, finding that water consumption in the electric sector could be reduced by 65 percent. The amount of land that would need to be converted for use by renewables would be 6,570 square kilometers, or about .08 percent of the U.S. Land use has proven to be a contentious issue for energy development, and although the model prohibited renewable energy development on protected lands, urban areas and steep slopes, and restricted natural gas development to sites where a fossil fuel plant existed in 2012, there could still be hurdles.

Christopher Clack, co-lead author of the paper and now a research scientist at the University of Colorado, says that one major difference between the group's model and other recent research evaluating the impacts of renewable energy is the resolution at which they evaluate weather data and the timescale at which they anticipate implementing renewables.

For instance, a recent study published in the Proceedings of the National Academy of Sciences, came to the conclusion that water, wind, and solar could supply the bulk of U.S. energy needs by 2050.

That study focused on more than just the electric sector; plus those researchers designed their model using weather data at a resolution of 250 kilometers. The NOAA team's weather resolution was much higher, at 13 kilometers. “The resolution of the weather data is a key point,” Clack says, given how variable wind can be over even small regions.

Another key difference is that the PNAS study predicts 2050 costs for energy and energy storage, while the NOAA model “optimizes in a similar way that markets operate today,” Clack adds.

“We are agnostic to technology and allow the model to select the cheapest mix. What we find is the cheapest mix, at a national scale, is large amounts of wind and solar, enabled by cost effective transmission,” he says.

And although the model still selects some amount of natural gas, hydro, and nuclear, it is based on technology available today and doesn't make far-out predictions of price, MacDonald adds.

Clack and MacDonald acknowledge that there will be significant hurdles in implementing such a model. Although electricity markets in various states do coordinate with each other now, they don't to the extent that would be required for the model to work.

But, MacDonald likened the model to the U.S. interstate highway system, which was overlaid atop regional, state and local systems. “If you have a national transmission network, it's less expensive and more reliable,” he says.

“In the coming years, different entities will have to work out what their energy mix will be to meet legislation requirements that are in the works,” Clack says. “The idea of this tool is to give options to help policy makers decide what's best.”


Environmentally-Friendly Liquid Battery

A new liquid battery that is more environmentally friendly than its existing counterparts could help lead to safe, inexpensive storage of renewable energy for power grids, researchers in Shanghai say.

The new battery also has a much longer cycle life and much greater power than any current rechargeable battery, the scientists add.

The sun and wind are variable sources of power. As such, utility companies want massive rechargeable battery farms that can store the surplus energy from these renewable power sources for use when the sun goes down and the wind does not blow.

Read More

Energous Readies Wireless Power Tech for Consumer Devices

Long range wireless power is one of the most exciting things we saw at CES this year. We've already talked about Ossia, and now, we're going to take a close look at Energous, whose WattUp technology we first saw at CES 2015. A few months ago, we spoke with Energous CTO Michael Leabman about the efficiency of his company’s system. Earlier this month, we spent over an hour in Energous' CES demo suite checking out demos, and speaking with Leabman about the future of wireless power and what the company has in store for 2016.

Read More

Lithium-Ion Battery Warms Up, Operates In Subzero Temperatures

A new “all-climate” lithium-ion battery can rapidly heat itself to overcome freezing temperatures with little sacrifice in energy storage capacity and power, researchers say.

This advance might enable applications for which high-performance batteries are needed in extremely cold temperatures, such as electric cars in cold climates, high-altitude drones, and space exploration. EC Power is now creating all-climate battery cells in pilot-production volumes that can be put directly in vehicles, says study lead author Chao-Yang Wang, a mechanical and electrochemical engineer at Pennsylvania State University.

Lithium-ion batteries not only can suffer problems from overheating, but they also typically experience severe power loss at temperatures below zero degrees Celsius. The consequences of this weakness include slow charging in cold weather, limited regenerative braking, the need for larger, more expensive battery packs to start cold engines, and the reduction of vehicle cruise range by as much as 40 percent, researchers say.

Read More

The Catalyst That Finally Gets Fuel Cell Vehicles on the Road?

One problem that has been plaguing the development of hydrogen-fueled vehicles is that hydrogen gas needs to be stored and transported in expensive pressurized tanks. Liquid energy carriers such as hydrogen dissolved in a salt solution are viewed as possible alternatives, but they’re also fraught with problems including the accumulation of byproducts. The simplest hydrogen carrier is water. But splitting hydrogen from oxygen requires, besides catalysts, a lot of energy. 

But now a research group called Team FAST, comprising students at the Technical University Eindhoven (TUE), in the Netherlands, thinks it has the hydrogen storage problem licked. To supply the one-meter-long scale model fuel cell vehicle they’ve developed with as much hydrogen as it needs, they’ve turned to formic acid (HCOOH). The liquid compound that can be created by joining carbon dioxide molecules with hydrogen with the help of catalysts and stored under atmospheric pressure. What’s more, catalysts can do the job of splitting formic acid into hydrogen and CO2—without an external energy source. 

Though this idea is not new, the efficiency of catalysts had been too low to deliver a stream of hydrogen sufficient to run fuel cells that could power a car. That is, until research completed last year by Georgy Filonenko, a recently-departed graduate student there, led to the discovery of a catalyst that is 10 times as efficient.

"The catalyst is a ruthenium complex which dissolves in the formic acid, and it is so active that you need only, what I call 'homeopathic' quantities, to dissociate the formic acid,” says Emiel Hensen, a chemist who supervised Filonenko's PhD research. Besides being required in small quantities, the ruthenium complex is, unlike other catalysts, not fouled by air or water, facilitating its use in a automotive applications, says Hensen.

To test out the advance, the FAST team set out, a year and a half ago, to build a working an one-meter scale model of a hydrogen car. It contains an off-the-shelf fuel cell and a catalytic reactor the size of a coffee mug, explains Pieter Ottink, who is the spokesperson for the team. Having shown off this proof-of-concept version, they say the next step is to power a full-scale model, hopefully by the end of this year. The team also reports that they have struck a deal with a company that will supply them with a hydrogen bus.   

“We are not yet sure about how we will design the big system; scaling up a chemical reaction like this is dependent on a lot of variables,” says Ottink.  However, they plan to proceed carefully. “It does not seem to be efficient to make one big reactor, so we will [likely equip the bus with] multiple small ones,” he says. But who knows? “This technology is in a very early stage," Ottink adds.   

A fortuitous coincidence will certainly make things easier, however. “The catalytic reaction is efficient at around 80 degrees C, so you should warm it up. We have the advantage that the fuel cell also produces heat, and this heat can be used to warm up the reactor,” says Ottink.

Unfortunately, the CO2 liberated during the catalytic reaction is released into the air. But if the formic acid can be produced in a sustainable way—by, say, drawing CO2 from the flues of fossil-fueled power plants—the process would be carbon neutral.


Fluttering Flag Generates Power From Wind

Just by flapping in the wind, a new energy-generating flag produces enough electricity to power small electronic devices. The flag converts mechanical energy into electricity using the effect behind static electricity. Floating high above the ground using balloons, it could harvest high-altitude winds to power weather and environmental monitoring sensors, as well as navigation systems.

Winds at high altitudes are faster and more consistent than those near the ground, but ground-based turbines are unable to reach those heights. Many groups are testing technologies such as floating turbines, kites, sails, and winged craft to harness these high-altitude winds.

“How about a little piece of fabric for wind power?” asks Zhong Lin Wang, a materials science and engineering professor at Georgia Tech, in Atlanta. The flag’s low cost and easy scalability could make it competitive with other airborne wind power technologies, he says.The details of the Georgia Tech team’s research appear in the journal ACS Nano.

The flag operates on the triboelectric effect. When the surfaces of two different materials touch and separate, electrons transfer from one to the other, building up opposite charges on the two surfaces. This can lead to a voltage that drives electric current.

Wang’s group has made several generators that scavenge energy from body movements and mechanical vibrations to produce electricity. In early 2015, the team reported a slinky-shaped generator and an energy-scavenging fabric that could power gadgets using human motion.

The flag is the researchers’ newest form of triboelectric generator. They made it by weaving together 1.5-centimeter-wide, 30-cm-long strips made from two kinds of fabric. The weft is a nickel-coated polyester textile belt and the warp is a polyimide plastic-coated copper film. All the nickel belts are connected using copper tape to form one electrode; all the copper belts are connected together as the other electrode. The flag, which weighs 15 grams, can be bent, folded and twisted. 

“The weave is loose and there is a few hairs’ distance between the two fabric strips,” Wang explains. So as the flag flutters in artificially generated wind, the two fabric units repeatedly touch and separate from each other, generating power.

At a wind speed of 22 meters per second, the flag produces a maximum of about 40 volts and 30 microamperes. Three flags connected in parallel could light up 16 commercial LEDs. As a demonstration, the researchers connected the flag’s output to a button cell battery that powered a humidity and temperature sensor node that transmits data wirelessly to a computer. This whole system was tethered to a meteorological balloon that hovered in an indoor laboratory where the researchers were able to vary temperature and humidity. 


Hydrogen Adds Longevity to Laptops, Phones, and Drones, But Is It Practical?

Back in August, when we wrote about Intelligent Energy’s prototype fuel cell iPhone, we weren’t totally convinced that it was an idea that would catch on. We’re still not totally convinced, but yesterday at the Consumer Electronics Show in Las Vegas, we stopped by Intelligent Energy’s suite to check out the prototype ourselves, along with a fuel cell-powered MacBook and a drone that can fly for up to two hours on a small canister of hydrogen gas.

Read More

Stable Perovskite Cell Boosts Solar Power

By adding cesium to a kind of crystal known as a perovskite, researchers say they can create tandem solar cells that may be much better at converting light to electricity than conventional solar cells while also being far more stable than previous comparable tandem cells.

Photovoltaic cells based on silicon currently make up about 90 percent of the global photovoltaic market. However, the rate at which the power conversion efficiency of silicon photovoltaics has improved has slowed dramatically, growing only from 25 percent to 25.6 percent in the past 15 years.

In order to create more efficient solar cells while making the most of the existing industrial capacity for silicon photovoltaics, researchers would like to create so-called tandem solar cells that combine silicon with other materials. One set of potential partners for silicon in these cells are perovskites, which are inexpensive and easily produced in labs.

Read More

A Renewable Supergrid in Russia

Russia and Central Asia could rely on an economically viable 100 percent renewable energy system—wind and solar—in 2030,  says a report commissioned by the Neo-Carbon Energy Research Project in Finland. (By economical they mean a price per kilowatt-hour slightly higher than € 0.045 but lower than the cost of energy produced by today’s solar plants.) It's highly doubtful that Russia will actually move to such an energy system, according to the report’s authors, but their simulation at least showed that it’s possible.

Read More

Ossia's Cota Wireless Power Tech Promises to Enable the Internet of Everything

Over the past year or so, we've seen enough companies promising to deliver truly wireless power that we're almost, almost starting to believe in it. But there's an awful lot of hype, compounded by the fact that there are a bunch of very different technologies all targeting the same goal: charging everything, everywhere, without plugs or cables or pads. Recently, we've taken a closer look at a few of these technologies, including uBeam's ultrasonic power transmitters and Energous' WattUp pocket-forming antenna arrays.

Yesterday at CES, we were introduced to Ossia, another company that wants to transform how we power our devices using wireless energy. Ossia's solution, called Cota, uses thousands of tiny antennas to deliver substantial amounts of power directly to embedded receiving antennas in devices located up to 10 meters away. Cota emphasizes safety, efficiency, and reliability, and their technology seems pretty incredible.

Read More

Newsletter Sign Up

Sign up for the EnergyWise newsletter and get biweekly news on the power & energy industry, green technology, and conservation delivered directly to your inbox.

Load More