Archive for the ‘Energy’ Category

Electrifying West Africa with a renewable grid

May 31st, 2020
Image of a dam and generating building.

Enlarge / A new hydroelectric power station in the Ivory Coast. (credit: Xinhua News Agency)

There's been a lot of discussion about how areas that are seeing explosive renewable growth can manage the large amount of intermittent electricity sources. But these mostly focus on regions with mature electric grids and a relatively static growth in demand. What would happen if you tried to grow renewables at the same time you're trying to grow a grid?

A EU-US team of researchers decided to find out what a good renewable policy might look like in West Africa, an area similar in size to the 48 contiguous US states but comprised of 16 different countries. Some of these nations already get a sizable chunk of their power from renewables in the form of hydropower, but they are expected to see demand roughly double in the next decade. Although renewables like solar and wind are likely to play a role purely based on their price, the researchers' analysis suggests that a smart, international grid can balance hydro, wind, and solar to produce a far greener grid.

Hydro as a giant battery

The new work has a mix of focuses. It's run against the backdrop of the expectation that West Africa's demand for electricity will explode over the next decade. Right now, the region has nearly 400 million inhabitants who consume a bit over 100 terawatt-hours a year (compared to the United States' 4,000TW-hr). By 2030, that demand is expected to be more than 200TW-hr—a fourfold increase from where demand was in 2015.

Read 11 remaining paragraphs | Comments

Posted in Energy, green, hydroelectric, renewable energy, science, solar, west africa, Wind | Comments (0)

New material releases hydrogen from water at near-perfect efficiency

May 27th, 2020
Image of the setting Sun.

Enlarge (credit: NASA/Dimitri Gerondidakis)

Solar energy is currently dominated by photovoltaic devices, which have ridden massive economies of scale to price dominance. But these devices are not necessarily the best choice in all circumstances. Unless battery technology improves, it's quite expensive to add significant storage to solar production. And there are types of transportation—long-distance rail, air—where batteries aren't a great solution. These limitations have made researchers maintain interest in alternate ways of using solar energy.

One alternative option is to use the energy to produce a portable fuel, like a hydrocarbon or hydrogen itself. This is possible to do with the electrons produced by photovoltaic systems, but the added steps can reduce efficiency. However, systems that convert sunlight more directly to fuel have suffered from even worse efficiencies.

But a Japanese group has decided to tackle this efficiency problem. The team started with a material that's not great—it only absorbs in the UV—but is well understood. And the researchers figured out how to optimize it so that its efficiency at splitting water to release hydrogen runs right up against the theoretical maximum. While it's not going to be useful on its own, it may point the way toward how to develop better materials.

Read 16 remaining paragraphs | Comments

Posted in Energy, green, hydrogen, materials science, renewable energy, science, solar power | Comments (0)

Republican Congress members upset banks dropping support for fossil fuels

May 11th, 2020
Image of fossil fuel wells and the flames powered by vented gasses.

Enlarge (credit: NOAA)

Last week, Republican House members sent a letter to President Donald Trump in which they decried banks' recent re-evaluations of the risks of fossil fuel investments. While the letter doesn't call for any particular action, it repeatedly mentions the assistance offered to banks via the Coronavirus Aid, Relief, and Economic Security Act 9 (CARES Act), and it implies that the banks aren't living up to their end of the deal. And, throughout the letter, its signatories seem to ignore the fact that the fossil fuel sector is not the only component of the US energy economy.

The letter was sent to Trump by a collection of 14 senators and 22 representatives, all Republican. In addition to Trump, the letter cc'ed a few senior administration officials, including the secretaries of the Department of Energy and the Department of the Treasury and the CEOs of six banks. The CEOs of three fossil fuel industry groups were also included.

Financial headwinds

The letter comes as the recent events have accelerated banks' decisions to re-evaluate fossil fuel investments. In the long term, fossil fuel development faced two significant challenges. The first is that wind and solar generation have become cost-competitive with fossil fuels in most markets. The second is that the pledges made to limit future fossil fuel emissions will likely mean that some fossil fuel deposits will be left undeveloped. That means that some of the resources now held as assets by fossil fuel companies will end up "stranded"—meaning the assets will turn out to have no value.

Read 8 remaining paragraphs | Comments

Posted in Banking, congress, Energy, fossil fuels, loans, science | Comments (0)

Why it took so long to dial back oil production, despite the glut

May 2nd, 2020
Why it took so long to dial back oil production, despite the glut

Enlarge (credit: Jose Luis Stephens | Getty Images)

Something weird happened on the oil market last week. For a few minutes on April 20, the price of a barrel went negative for the first time ever. The unprecedented collapse of prices is linked to the pandemic, which has caused people to stop doing oil-guzzling things like flying and driving. There’s now so much extra petroleum on the market that the world is running out of places to put it. If you’re an oil producer, it seems like the sensible thing to do in this situation would be to … stop producing so much oil.

On Friday, members of the Organization of the Petroleum Exporting Countries, Russia, the US, and others will begin scaling back their production by nearly 10 million barrels per day. They hope that this will help stabilize prices and take some pressure off of producers and refineries that are scrambling to find a place to store the excess. But the rollback isn’t likely to be enough. Oil producers would have to reduce production by almost three times that amount to match the downturn in demand. So why don’t they?

Read 11 remaining paragraphs | Comments

Posted in Energy, oil, science | Comments (0)

2019 saw over 60 gigawatts of wind power installed

March 27th, 2020
Image of a boat near the base of an offshore wind farm.

Enlarge (credit: Gary Norton/DOE)

On Wednesday, the Global Wind Energy Council, an industry trade organization, released its review of the market in 2019. During the past year, wind power saw its second-largest amount of new installed capacity ever, with over 60GW going in. But the news going forward is a bit more uncertain, with the report predicting that after years of double-digit growth, the industry would see things tail off into steady-but-unspectacular territory. And that prediction was made before many key markets started dealing with the coronavirus.

A very good year

Wind power is now one of the cheapest options for generating electricity. In many areas of the globe, building and maintaining wind power is cheaper per unit of power than it is to fuel a previously constructed fossil fuel plant. While offshore wind remains more expensive, its prices have dropped dramatically over the last several years, and it is rapidly approaching price parity with fossil fuels.

But cost isn't the only thing at issue. Renewables may require new transmission lines to feed their power to where people actually live, and managing wind's intermittent nature may require grid upgrades once its percentage gets high enough. And due to the past successes of wind, a significant number of the best sites are now already in use in some regions. Given those issues, it can be difficult to justify shutting down power plants that may have decades of service left in their expected lifespan. This is especially true in fully industrialized countries, where total electricity use has been trending downward, largely due to gains in energy efficiency.

Read 11 remaining paragraphs | Comments

Posted in Energy, green, green energy, offshore wind, science, wind power | Comments (0)

Battery charging meets machine learning

February 19th, 2020
Image of a car plugged into charging hardware.

Enlarge / The seemingly simple act of charing is getting increasingly complex. (credit: Argonne National Lab)

Batteries tend to involve lots of trade-offs. You can have high capacity, but it means more weight and a slower charge. Or you can charge quickly, and see the lifetime of your battery drop with each cycle. There are ways to optimize this—figure out the fastest charging you can do without cutting into the battery life—but that varies from product to product and requires extensive testing to identify.

But perhaps that testing is not so extensive, thanks to a new system described in the journal Nature. The system uses a combination of machine learning and Bayesian inference to rapidly zero in on the optimal charging pattern for any battery, cutting the amount of testing needed down considerably.

Not so fast

Fast charging is obviously useful for everything from phones to cars. But when a battery is subjected to fast charging, it doesn't store its ions quite as efficiently. The overall capacity will go down, and there's the potential for permanent damage, as some of the lithium ends up precipitating out and becoming unavailable for future use.

Read 12 remaining paragraphs | Comments

Posted in batteries, Computer science, Electric vehicles, Energy, gadgets, green energy, materials science, science | Comments (0)

Google parent pulls the plug on power-generating kite project

February 19th, 2020
Google parent pulls the plug on power-generating kite project

Enlarge (credit: Makani)

Google-parent Alphabet is shutting down its power-generating kites company Makani, the first closure of a so-called moonshot project since founders Larry Page and Sergey Brin stepped back from management in December.

Sundar Pichai, who took over as Alphabet chief executive, is under pressure to stem losses from the company’s “Other Bets” segment, which includes endeavors such as self-driving cars and Internet-providing balloons. Other Bets lost $4.8 billion last year—widening from a $3.4 billion loss in 2018.

Makani was acquired in 2013 and taken into the experimental “X” lab. It was developing airborne wind turbines that could be tethered to floating buoys, removing the need for the expensive ocean bed structures needed to support permanent turbines.

Read 14 remaining paragraphs | Comments

Posted in Alphabet, Energy, google, Kites, Makani, science, Tech | Comments (0)

Variant of photovoltaic power could generate 24 hours a day

February 4th, 2020
Image of grey panels in front of brown buildings.

Enlarge / A test of radiative cooling panels at the University of Colorado. (credit: University of Colorado)

Moving from the present world to one where renewable power dominates our energy economy is going to require some additional technologies. These may include storage, enhanced grid management, and demand-response power management, but they could also include something entirely new. Recently, a paper took a look at a technology I hadn't realized even existed.

The paper evaluates the potential of what its authors are terming "nighttime photovoltaic power," and the simplest way of thinking about it is "running solar panels in reverse": generating electricity by radiating energy away into space. The efficiency is nothing like that of standard photovoltaics and can't even get there except in unusual circumstances. But as the name implies, it can keep generating power long after the Sun goes down.

Photovoltaics at night

The easiest way to understand this tech is to think of a photovoltaic device in equilibrium with its environment. Here, incoming photons will occasionally liberate an electron, leaving behind a positively charged hole. These can then combine, radiating a photon back out of the device. When operating as a photovoltaic device, there's a large excess of photons coming in, producing a corresponding excess of electrons and holes that can then be harvested as electricity.

Read 11 remaining paragraphs | Comments

Posted in Energy, materials science, renewable energy, science | Comments (0)

US government sees renewables passing natural gas in 20 years

January 30th, 2020
Image of wind turbines in the waters beyond an island.

Enlarge / The United States' first offshore wind farm. (credit: University of Rhode Island)

Each year, the US Energy Information Agency is required to track trends in the nation's energy markets and project those trends forward. Projections based on 2019's trends were released this week, and for the first time, the EIA's default projection places renewables as the largest single source of electricity generation, with renewables surpassing natural gas somewhere around 2040.

These reports are very conservative due to some of the assumptions that are included in the projections, and they've done a terrible job projecting the rapid growth of renewable power. And despite the current report showing steady growth of renewables, there are indications it may still be underestimating renewables' potential. But the report is still worth looking at, as it can help to understand how more realistic assumptions could change the future direction of the United States' energy mix.

How to project

Some of the issues with the EIA's projections are baked into the system. For example, the reports are required to assume existing government policies are the only ones that apply. So while there is some talk of extending tax credits for renewable energy facilities, which has happened in the past, the report assumes that these policies will terminate in the near future as planned.

Read 16 remaining paragraphs | Comments

Posted in carbon emissions, coal, Energy, fracking, natural gas, Nuclear, renewable energy, science | Comments (0)

We calculated emissions due to electricity loss on the power grid

December 26th, 2019
We calculated emissions due to electricity loss on the power grid

Enlarge (credit: Lawrence Berkeley Lab)

When it comes to strategies for slowing the effects of climate change, the idea of reducing wasted energy rarely gets a mention. But our recent Nature Climate Change article makes the case that reducing wastage in the power sector, focusing specifically on the grid, can be a critical lever in lowering national emissions.

Inefficient global power transmission and distribution infrastructure requires additional electricity generation to compensate for losses. And countries that have large shares of fossil fuel generation and inefficient grid infrastructure, or a combination of the two, are the predominant culprits of what we call “compensatory emissions.” These emissions are the result of the extra electricity—often generated from fossil fuels—required to compensate for grid losses.

We calculated that worldwide, compensatory emissions amount to nearly a billion metric tons of carbon dioxide equivalents a year, in the same range as the annual emissions from heavy trucks or the entire chemical industry. In surveying 142 countries’ transmission and distribution infrastructures, we also determined that approximately 500 million metric tons of carbon dioxide can be cut by improving global grid efficiencies.

Read 13 remaining paragraphs | Comments

Posted in carbon emissions, climate change, electricity, Energy, grid management, science | Comments (0)