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Nighttime thermoradiative power converts outgoing infrared radiation into electricity using semiconductor photodiodes, leveraging negative illumination and sky cooling to harvest renewable energy from Earth-to-space heat flow when solar panels rest, regardless of weather.

Key Points

Nighttime thermoradiative power converts Earth's outgoing infrared heat into electricity using semiconductor diodes.

✅ Uses negative illumination to tap Earth-to-space heat flow

✅ Infrared semiconductor photodiodes generate small nighttime current

✅ Theoretical output ~4 W/m^2; lab demo reached 64 nW/m^2

There's a stark contrast between the freezing temperatures of space and the relatively balmy atmosphere of Earth, and that contrast could help generate electricity, scientists say – and alongside concepts such as space-based solar power, utilizing the same optoelectronic physics used in solar panels. The obvious difference this would have compared with solar energy is that it would work during the night time, a potential source of renewable power that could keep on going round the clock and regardless of weather conditions.

Solar panels are basically large-scale photodiodes - devices made out of a semiconducting material that converts the photons (light particles) coming from the Sun into electricity by exciting electrons in a material such as silicon, while concepts like space solar beaming could complement them during adverse weather.

In this experiment, the photodiodes work 'backwards': as photons in the form of infrared radiation - also known as heat radiation - leave the system, a small amount of energy is produced, similar to how raindrop electricity harvesting taps ambient fluxes in other experiments.

This way, the experimental system takes advantage of what researchers call the "negative illumination effect" – that is, the flow of outgoing radiation as heat escapes from Earth back into space. The setup explained in the new study uses an infrared semiconductor facing into the sky to convert this flow into electrical current.

"The vastness of the Universe is a thermodynamic resource," says one of the researchers, Shanhui Fan from Stanford University in California.

"In terms of optoelectronic physics, there is really this very beautiful symmetry between harvesting incoming radiation and harvesting outgoing radiation."

It's an interesting follow-up to a research project Fan participated in last year: a solar panel that can capture sunlight while also allowing excess heat in the form of infrared radiation to escape into space.

In the new study, this "energy harvesting from the sky" process can produce a measurable amount of electricity, the researchers have shown – though for the time being it's a long way from being efficient enough to contribute to our power grids, but advances in peer-to-peer energy sharing could still make niche deployments valuable.

In the team's experiments they were able to produce 64 nanowatts per square metre (10.8 square feet) of power – only a trickle, but an amazing proof of concept nevertheless. In theory, the right materials and conditions could produce a million times more than that, and analyses of cheap abundant electricity show how rapidly such advances compound, reaching about 4 watts per square metre.

"The amount of power that we can generate with this experiment, at the moment, is far below what the theoretical limit is," says one of the team, Masashi Ono from Stanford.

When you consider today's solar panels are able to generate up to 100-200 watts per square metre, and in China solar is cheaper than grid power across every city, this is obviously a long way behind. Even in its earliest form, though, it could be helpful for keeping low-power devices and machines running at night: not every renewable energy device needs to power up a city.

Now that the researchers have proved this can work, the challenge is to improve the performance of the experimental device. If it continues to show promise, the same idea could be applied to capture energy from waste heat given off by machinery, and results in humidity-powered generation suggest ambient sources are plentiful.

"Such a demonstration of direct power generation of a diode facing the sky has not been previously reported," explain the researchers in their published paper.

"Our results point to a pathway for energy harvesting during the night time directly using the coldness of outer space."

The research has been published in Applied Physics Letters.

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U.S. Utility-Scale Solar Delays driven by the coronavirus pandemic threaten construction timelines, supply chains, and financing, with interconnection and commissioning setbacks, module sourcing risks in Southeast Asia, and tax credit deadline pressures impacting project delivery.

Key Points

Setbacks to large U.S. solar builds from COVID-19 impacting construction, supply, financing, and permitting.

✅ Construction, interconnection, commissioning site visits delayed

✅ Supply chain risks for modules from Southeast Asia

✅ Tax credit deadline extensions sought by developers

About 5 gigawatts (GW) of big U.S. solar energy projects, enough to power nearly 1 million homes, could suffer delays this year if construction is halted for months due to the coronavirus pandemic, as the Covid-19 crisis hits renewables across the sector, according to a report published on Wednesday.

The forecast, a worst-case scenario laid out in an analysis by energy research firm Wood Mackenzie, would amount to about a third of the utility-scale solar capacity expected to be installed in the United States this year, even as US solar and wind growth continues under favorable plans.

The report comes two weeks after the head of the top U.S. solar trade group called the coronavirus pandemic (as solar jobs decline nationwide) "a crisis here" for the industry. Solar and wind companies are pleading with Congress to extend deadlines for projects to qualify for sunsetting federal tax credits.

Even the firm’s best-case scenario would result in substantial delays, mirroring concerns that wind investments at risk across the industry. With up to four weeks of disruption, the outbreak will push out 2 GW of projects, or enough to power about 380,000 homes. Before factoring in the impact of the coronavirus, Wood Mackenzie had forecast 14.7 GW of utility-scale solar projects would be installed this year.

In its report, the firm said the projects are unlikely to be canceled outright. Rather, they will be pushed into the second half of 2020 or 2021. The analysis assumes that virus-related disruptions subside by the end of the third quarter.

Mid-stage projects that still have to secure financing and receive supplies are at the highest risk, Wood Mackenzie analyst Colin Smith said in an interview, adding that it was too soon to know whether the pandemic would end up altering long-term electricity demand and therefore utility procurement plans, where policy shifts such as an ITC extension could reshape priorities.

Currently, restricted travel is the most likely cause of project delays, the report said. Developers expect delays in physical site visits for interconnection and commissioning, and workers have had difficulty reaching remote construction sites.

For earlier-stage projects, municipal offices that process permits are closed and in-person meetings between developers and landowners or local officials have slowed down.

Most solar construction is proceeding despite stay at home orders in many states because it is considered critical infrastructure, and long-term proposals like a tenfold increase in solar could reshape the outlook, the report said, adding that “that could change with time.”

Risks to supplies of solar modules include potential manufacturing shutdowns in key producing nations in Southeast Asia such as Malaysia, Vietnam and Thailand. Thus far, solar module production has been identified as an essential business and has been allowed to continue.

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Renewable Energy Tax Incentive Extensions urged by US trade groups to offset COVID-19 supply chain delays, tax equity shortages, and financing risks, enabling direct pay, PTC and ITC qualification, and standalone energy storage credits.

Key Points

Policy measures that extend and monetize clean energy credits to counter COVID-19 disruptions and financing shortfalls.

✅ Extend start construction and safe harbor deadlines

✅ Enable direct pay to offset reduced tax equity

✅ Add a standalone energy storage credit

Renewable energy and other trade bodies in the US are calling on Capitol Hill to extend provision of tax incentives to help the sector “surmount the impacts” of the COVID-19 crisis facing clean energy.

In a signed joint letter, the American Council on Renewable Energy (ACORE), American Wind Energy Association (AWEA), Energy Storage Association (ESA), National Hydropower Association (NHA), Renewable Energy Buyers Alliance (REBA), and the Solar Energy Industries Association (SEIA) stated: “With over $50bn in annual investment over each of the past five years, the clean energy sector is one of the nation’s most important economic drivers. But that growth is placed at risk by a range of COVID-19 related impacts”.

These include “supply chain disruptions that have the potential to delay utility solar construction timetables and undermine the ability of wind, solar and hydropower developers to qualify for time-sensitive tax credits, and a sudden reduction in the availability of tax equity, which is crucial to monetising tax credits and financing clean energy projects of all types.”
The letter goes onto state: “Like all sectors of our economy the renewable and clean grid industry – including developers, manufacturers, construction workers, electric utilities, investors and major corporate consumers of renewable power – needs stability.

“The current uncertainty about the ability to qualify for and monetise tax incentives will have real and substantial negative impacts to the entire economy.

On behalf of the thousands of companies that participate in America’s renewable and clean energy economy, the coalition of organisations is requesting the US Government, echoing Senate calls to support clean energy, take three “critical” steps to address pandemic-related disruptions.

The first is an extension of start construction and safe harbour deadlines to ensure that renewable projects can qualify for renewable tax credits amid the Solar ITC extension debate and despite delays associated with supply chain disruptions.

The second is the implementation of provisions that will allow renewable tax credits to be available for direct pay to facilitate their monetisation, supporting U.S. solar and wind growth in the face of reduced availability of tax equity.

Thirdly, the signatories have requested the enactment of a direct pay tax credit for standalone energy storage to foster renewable growth as the industry sets sights on market majority and help secure a more resilient grid.

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EU Renewable Energy Transition is accelerating under REPowerEU, as wind and solar generation hit records, improving energy security, efficiency, and decarbonization while reducing reliance on Russian fossil fuels across the EU grid.

Key Points

EU shift to wind and solar under REPowerEU to cut fossil fuels, boost efficiency, and secure energy supply.

✅ Wind and solar set record 22% of EU electricity in 2022

✅ REPowerEU targets over 40% renewables and 15% lower demand by 2030

✅ Diversifies away from Russian fuels; partners with US and Norway

Europe is producing all-time highs of wind and solar energy as the 27-country group works to reduce its reliance on fossil fuels from Russia, a shift underscored by Europe's green surge across the bloc.

Four months after Vladimir Putin’s full-scale invasion of Ukraine in February 2022, the European Commission launched REPowerEU. This campaign aims to:

• Boost the use of renewable energy.
• Reduce overall energy consumption.
• Diversify energy sources.

EU countries were already moving toward renewable energy, but Russia’s war against Ukraine accelerated that trend. In 2022, for the first time, renewables surpassed fossil fuels and wind and solar power surpassed gas as a source of electricity. Wind and solar provided a record-breaking 22% of EU countries’ electrical supply, according to London-based energy think tank Ember.

“We have to double down on investments in home-grown renewables,” European Commission President Ursula von der Leyen said in October 2022. “Not only for the climate but also because the transition to the clean energy is the best way to gain independence and to have security of energy supply.”

Across the continent, growth in solar generation rose by 25% in 2022, according to Ember, as solar reshapes electricity prices in Northern Europe. Twenty EU countries produced their highest share of solar power in 2022. In October, Greece ran entirely on renewables for several hours and is seven years ahead of schedule for its 2030 solar capacity target.

Meanwhile, Ireland's green electricity target aims to make more than a third of its power supply renewable within four years.

By 2030, RePowerEU aims to provide more than 40% of the EU’s total power from renewables, aligning with global renewable records being shattered worldwide.

To meet the European Commission’s goal to cut EU energy usage by 15%, people and governments changed their habits and became more energy-efficient, while Germany's solar power boost helped bolster supply. Among their actions:

• Germany turned down the heat in public buildings and lowered the cost of train tickets to reduce car usage, as clean energy hit 50% in Germany during this period.
• Spain ordered stores and public buildings to turn off their lights at night.
• France dimmed the Eiffel Tower and reduced city speed limits.

For the oil and gas that the EU still needed to import, countries turned to partners such as Norway and the United States.

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Siemens Gamesa SG 14-222 DD advances offshore wind with a 14 MW direct-drive turbine, 108 m blades, a 222 m rotor, optional 15 MW boost, powering about 18,000 homes; prototype 2021, commercial launch 2024.

Key Points

A 14 MW offshore wind turbine with 108 m blades and a 222 m rotor, upgradable to 15 MW, targeting commercial use in 2024.

✅ 14 MW direct-drive, upgradable to 15 MW

✅ 108 m blades, 222 m rotor diameter

✅ Powers about 18,000 European homes annually

Siemens Gamesa Renewable Energy (SGRE) has released details of a 14-megawatt (MW) offshore wind turbine, as offshore green hydrogen production gains attention, in the latest example of how technology in the sector is increasing in scale.

With 108-meter-long blades and a rotor diameter of 222 meters, the dimensions of the SG 14-222 DD turbine are significant.

In a statement Tuesday, SGRE said that one turbine would be able to power roughly 18,000 average European households annually, while its capacity can also be boosted to 15 MW if needed. A prototype of the turbine is set to be ready by 2021, and it’s expected to be commercially available in 2024, as forecasts suggest a $1 trillion business this decade.

As technology has developed over the last few years, the size of wind turbines has increased, and renewables are set to shatter records globally.

Last December, for example, Dutch utility Eneco started to purchase power produced by the prototype of GE Renewable Energy’s Haliade-X 12 MW wind turbine. That turbine has a capacity of 12 MW, a height of 260 meters and a blade length of 107 meters.

The announcement of Siemens Gamesa’s new turbine plans comes against the backdrop of the coronavirus pandemic, which is impacting renewable energy companies around the world, even as wind power sees growth despite Covid-19 in many markets.

Earlier this month, the European company said Covid-19 had a “direct negative impact” of 56 million euros ($61 million) on its profitability between January and March, amid factory closures in Spain and supply chain disruptions. This, it added, was equivalent to 2.5% of revenues during the quarter.

The pandemic has, in some parts of the world, altered the sources used to power society. At the end of April, for instance, it was announced that a new record had been set for coal-free electricity generation in Great Britain, where UK offshore wind growth has accelerated, with a combination of factors — including coronavirus-related lockdown measures — playing a role.

On Tuesday, the CEO of another major wind turbine manufacturer, Danish firm Vestas, sought to emphasize the importance of renewable energy in the years and months ahead, and the lessons the U.S. can learn from the U.K. on wind deployment.

“I think we have actually, throughout this crisis, also shown to all society that renewables can be trusted,” Henrik Andersen said during an interview on CNBC’s Street Signs.

“But we both know ... that that transformation of energy sources is not going to happen overnight, it’s not going to happen from a quarter to a quarter, it’s going to happen by consistently planning year in, year out.”

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PG&E 2024 Rate Hikes signal sharp increases to fund wildfire safety, infrastructure upgrades, and CPUC-backed reliability, with rates expected to stabilize in 2025, affecting rural residents, businesses, and high-risk zones across California.

Key Points

PG&E’s 2024 hikes fund wildfire safety and grid upgrades, with pricing expected to stabilize in 2025.

✅ Driven by wildfire safety, infrastructure, and reinsurance costs

✅ Largest impacts in rural, high-risk zones; business rates vary

✅ CPUC oversight aims to ensure necessary, justified investments

Pacific Gas and Electric (PG&E) is expected to implement a series of rate hikes that, amid analyses of why California electricity prices are soaring across the state, will significantly impact California residents. These increases, while substantial, are anticipated to be followed by a period of stabilization in 2025, offering a sense of relief to customers facing rising costs.

PG&E, one of the largest utility providers in the state, announced that its 2024 rate hikes are part of efforts to address increasing operational costs, including those related to wildfire safety, infrastructure upgrades, and regulatory requirements. As California continues to face climate-related challenges like wildfires, utilities like PG&E are being forced to adjust their financial models to manage the evolving risks. Wildfire-related liabilities, which have plagued PG&E in recent years, play a significant role in these rate adjustments. In response to previous fire-related lawsuits, including a bankruptcy plan supported by wildfire victims that reshaped liabilities, and the increased cost of reinsurance, PG&E has made it clear that customers will bear part of the financial burden.

These rate hikes will have a multi-faceted impact. Residential users, particularly those in rural or high-risk wildfire zones, will see some of the largest increases. Business customers will also be affected, although the adjustments may vary depending on the size and energy consumption patterns of each business. PG&E has indicated that the increases are necessary to secure the utility’s financial stability while continuing to deliver reliable service to its customers.

Despite the steep increases in 2024, PG&E's executives have assured that the company's pricing structure will stabilize in 2025. The utility has taken steps to balance the financial needs of the business with the reality of consumer affordability. While some rate hikes are inevitable given California's regulatory landscape and climate concerns, PG&E's leadership believes the worst of the increases will be seen next year.

PG&E’s anticipated stabilization comes after a year of scrutiny from California regulators. The California Public Utilities Commission (CPUC) has been working closely with PG&E to scrutinize its rate request and ensure that hikes are justifiable and used for necessary investments in infrastructure and safety improvements. The CPUC’s oversight is especially crucial given the company’s history of safety violations and the public outrage over past wildfire incidents, including reports that its power lines may have sparked fires in California, which have been linked to PG&E’s equipment.

The hikes, though significant, reflect the broader pressures facing utilities in California, where extreme weather patterns are becoming more frequent and intense due to climate change. Wildfires, which have grown in severity and frequency in recent years, have forced PG&E to invest heavily in fire prevention and mitigation strategies, including compliance with a judge-ordered use of dividends for wildfire mitigation across its service area. This includes upgrading equipment, inspecting power lines, and implementing more rigorous protocols to prevent accidents that could spark devastating fires. These investments come at a steep cost, which PG&E is passing along to consumers through higher rates.

For homeowners and businesses, the potential for future rate stabilization offers a glimmer of hope. However, the 2024 increases are still expected to hit consumers hard, especially those already struggling with high living costs. The steep hikes have prompted public outcry, with calls for action as bills soar amplifying advocacy group arguments that utilities should absorb more of the costs related to climate change and fire prevention instead of relying on ratepayers.

Looking ahead to 2025, the expectation is that PG&E’s rates will stabilize, but the question remains whether they will return to pre-2024 levels or continue to rise at a slower rate. Experts note that California’s energy market remains volatile, and while the rates may stabilize in the short term, long-term cost management will depend on ongoing investments in renewable energy sources and continued efforts to make the grid more resilient to climate-related risks.

As PG&E navigates this challenging period, the company’s commitment to transparency and working with regulators will be crucial in rebuilding trust with its customers. While the immediate future may be financially painful for many, the hope is that the utility's focus on safety and infrastructure will lead to greater long-term stability and fewer dramatic rate increases in the years to come.

Ultimately, California residents will need to brace for another tough year in terms of utility costs but can find reassurance that PG&E’s rate increases will eventually stabilize. For those seeking relief, there are ongoing discussions about increasing energy efficiency, exploring renewable energy alternatives, and expanding assistance programs for lower-income households to help mitigate the financial strain of these price hikes.

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