A few years ago, solar power became the “cheapest electricity in history”, but it still lacked the ability to meet demand 24 hours a day and 365 days a year.
Since then, there have been significant improvements in the cost and performance of batteries, making it cheaper than ever to pair solar with energy storage using batteries.
In our new Ember “white paper”, we present modelling showing that solar with batteries in major sunny cities, such as Las Vegas or Mexico City, can now get more than 90% of the way to continuous generation, at costs below those of coal or nuclear power.
Even in cloudier cities away from the equator, such as Birmingham in the UK, it is possible to run on solar plus storage across the majority of hours in the year.
The white paper sets out how near-continuous “24/365” solar power has become an economic and technological reality in sunny regions.
Solar and storage ‘gamechangers’
A solar panel generates most electricity when the sun is shining, meaning it cannot provide constant power throughout the year. Put another way, 100 watts (W) of solar capacity only generates around 20W on average – and that output will be concentrated in daylight hours.
Our report shows that battery energy storage can unlock solar’s full potential, by turning daytime generation into around-the-clock electricity.
Indeed, when paired with sufficient battery storage, that same 100W of solar capacity can provide electricity around the clock – up to 100% of the time.
This also means up to five times as much solar generation can be delivered using the same connection to the electricity network, reducing the need for costly grid upgrades.
Battery energy storage is now cheaper than ever, with global average prices falling by 40% in 2024 alone. The cost of a full battery system fell to a record-low $165 per kilowatt hour (kWh), according to BloombergNEF.
Additionally, there have been a number of technological improvements boosting battery energy storage.
Recent innovations mean almost all grid batteries are now cobalt- and nickel-free, reducing the need for so-called “critical minerals”. They are longer-lasting than ever, with some batteries now having 20-year warranties. And they are safer than ever – with fire risk improving by a hundred-fold since 2019.
Improved container design has also cut maintenance and installation costs.
Our white paper shows that supply is ready to scale, with manufacturing capacity already exceeding demand. There is also significant new production capacity under construction outside of China.
The next frontier is sodium-ion “salt” batteries, which would eliminate the need for lithium and drive prices down even further. One large salt-battery plant has already been commissioned in China.
These technological advances and declining costs mean the world’s first “24/365” battery and solar plants are now coming online:
- In Hawaii, several solar-plus-battery projects are providing electricity through the night after the decommissioning of the last coal power plant in 2022.
- In the United Arab Emirates (UAE), at 100 megawatt (MW), Moro Hub is the world’s largest 100% solar-powered data centre, commissioned in 2022.
- In Saudi Arabia, a tourist mega project, including 16 hotel resorts that are all powered entirely by solar electricity, was completed in 2023.
- The first gigawatt-scale 24-hour solar project is already under development in the UAE. Emirati state-owned renewable energy company Masdar is leading the project, which was announced in January 2025 and will consist of a 5.2 gigawatt (GW) solar photovoltaic (PV) plant coupled with a 19 gigawatt hour (GWh) battery storage system to provide 1GW of uninterrupted solar electricity supply to the grid.
These examples show that 24/365 solar electricity has already been supplying customers and that it will increasingly start being used to power parts of the grid.
Cheaper in the sun
In order to investigate the potential for 24/365 solar, Ember’s white paper modelled a hypothetical system, using real weather data, for a series of cities around the world.
The modelling is based on a system with 6GW of solar capacity and 17GWh of battery storage, because there are roughly 15 hours of darkness in winter in the mid-latitudes.
The modelling shows that solar and battery in the sunniest cities could already get more than 90% of the way to 24/365 solar generation, covering almost every hour of every day in the year.
For example, Muscat in Oman could draw on 1GW of continuous solar electricity for 99% of hours in the year, if it paired 6GW of solar panels with 17GWh of battery capacity.
Las Vegas in the US, Mexico City in Mexico and Johannesburg in South Africa could all rely on such solar-plus-storage systems for at least 95% of hours in the year.
Even Birmingham in the UK could achieve 1GW of solar output for 62% of hours annually. (This is lower than for sunnier cities due to a stronger seasonal cycle and cloudier weather.)
In the sunniest places, solar and storage could generate reliable output, close to 24/365, for around $100 per megawatt hour (MWh), based on average global costs for solar and batteries in 2024.
For each city, the yellow shading in the figure below shows the share of hours each year that it could rely on 1GW of solar output if it installed a 6GW solar plus 17GWh battery system, given historical weather conditions.

Over the past year alone, the levelised cost of electricity (LCOE) for solar-plus-storage systems fell by 22%, driven by a 40% fall in battery prices. This is based on $165/kWh, which was BloombergNEF’s assessment of the global battery pack price at the end of 2024. The LCOE of solar and battery had fallen by 28% over the previous four years.
This makes solar with battery storage cheaper than both coal and nuclear when compared with US-based LCOE, as shown in the chart below.

There is evidence that 2025 solar and battery prices will continue to fall again. Already in early 2025, tenders for large-scale battery storage projects in Tabuk and Hail, Saudi Arabia, reported battery prices as low as $72/kWh.
Cloudy day challenges
Our modelling shows that the greatest challenge to generating constant, year-round electricity from solar plus storage is not nighttime, but clouds.
In the mid-latitudes, with around 15 hours of darkness in winter, around 17 hours of battery capacity is sufficient to bridge the period from sunset to sunrise.
This is because batteries typically do not fully charge and discharge to maintain high performance over time.
However, getting to 24/365 solar is harder, as while every day has daylight, not every day has full sunlight. Even though clouds do not reduce solar generation to zero – and despite batteries being cheaper than ever – extra battery storage is still not an economical option for bridging cloudy periods across multiple days.
The graphic below illustrates this, based on the same 6GW solar plus 17GWh storage system as described before, generating electricity under the weather conditions and seasonal cycles of the same 12 cities around the world.
The chart for each city runs from January to December on the horizontal axis and across 24 hours of each day on the vertical axis. Direct use of solar power is shown in orange, with stored solar from the battery shown in yellow and periods with a shortfall in dark blue.
The figure shows that, even on the cloudiest day of the year in Muscat, this solar-plus-storage system would generate constant electricity for 18 hours. Madrid in Spain would see lower output on some shorter and cloudier days in November, December and January. In contrast, Hyderabad in India would be impacted in the summer by cloudy monsoon days.
Overall, the figure shows that the sunniest cities would only fall slightly short of 24/365 solar electricity, but clouds would have a larger impact elsewhere.

The trade-off
The International Energy Agency (IEA) has described solar power as offering the “cheapest electricity in history”.
For example, solar power costs just $41/MWh in Las Vegas, according to Ember’s calculations using average global equipment and borrowing costs. However, this is only delivering electricity through daytime hours. As a result, on average around the world, solar has a “capacity factor” of 21% – meaning each unit of solar capacity generates 21% of its maximum theoretical output.
Raising this all the way to 97% raises the price to $104/MWh. However, this also substantially improves the value of solar, now that it is delivering close to 24/365. However, as the chart below shows, meeting the last few percent of demand from solar and storage alone significantly increases the price.
The best value between solar alone or solar with plentiful storage depends on the use case.
It may be optimal to build solar without a battery, so long as a factory can access cheap grid electricity when the solar panels are not generating, for example.
On the other hand, it may be optimal to build solar and batteries to get to 99.7% for an off-grid data centre that values reliability over price. Even in the most sunny places, exactly 100% supply will generally be uneconomic – but it is possible to get very close.

For many cases and based on current prices, the sweet spot may be to size the system for a constant supply of solar electricity for 60-90% of the time, our modelling suggests.
This provides cheap, low-carbon solar power most of the time. It would enable electricity to be used flexibly through the night or during high-price hours.
If widely deployed, such systems would allow for a significantly downscaled need for grid investment, whether they are large-scale solar farms exporting more electricity to the grid or industrial sites drawing from public supplies less often.
The post Guest post: How solar panels and batteries can now run ‘close to 24/365’ in some cities appeared first on Carbon Brief.
Guest post: How solar panels and batteries can now run ‘close to 24/365’ in some cities
Climate Change
Australia’s nature is in trouble.
Australia’s new environmental standards are supposed to protect wildlife. Right now, they don’t.
We have one of the worst mammal extinction rates in the world. We’ve already lost 39 species, including the Christmas Island Shrew and the desert rat-kangaroo, while iconic species like the Hairy-Nosed Wombat, Pygmy blue whale and Swift Parrot continue to slide towards extinction. Forests are still being bulldozed at an alarming rate. Rivers and reefs are under serious pressure.

Fixing this sorry state of affairs was why the Federal Government promised to fix Australia’s broken national nature laws—a promise that culminated in the nature law reforms passed late last year.
A big part of these reforms is the creation of new “National Environmental Standards” — rules intended to guide decisions on projects that could damage nature.
But the Government’s latest draft standards—open for consultation until May 29th—fall dangerously short.
Instead of setting clear environmental guardrails, the draft rules risk making it easier for damaging projects to get approved, while nature continues to decline. Legal experts are warning that unless the standards are changed, they could weaken protections rather than strengthen them.
So what are these standards, exactly?
The new standards are a centrepiece of major reforms to the Environment Protection and Biodiversity Conservation Act (EPBC Act), which were passed late last year and are designed to fix a broken environmental regulatory system. They are meant to set clear rules for what environmental protection should actually look like.
In simple terms, they’re supposed to answer questions like:
- What measures should developers be made to put in place to protect threatened species?
- How do we ensure the most important habitats and natural places are not hacked away, “death-by-a-thousand-cuts”-style, from ongoing development proposals?
- When should a project simply not go ahead?
- What rules should states follow if they’re in charge of assessing development projects?
- How do we make sure nature is actually improving, not just declining more slowly?
If designed and implemented properly, these standards could become the backbone of strong, effective reformed nature laws.
But right now, they leave huge loopholes open.

The biggest problem: process over outcomes
The biggest problem with the draft standards is that they focus too heavily on whether companies follow a process—not whether nature is genuinely protected in the end. That might sound technical, but it has real-world consequences.
Imagine a company wants to clear critical habitat for a threatened species. Under a strong system, the key question should be: Will this project cause unacceptable or significant environmental harm?
But under the current draft standards, if the company follows the required steps and paperwork, the project could still be considered acceptable — even if the damage to nature is clear.
This is deeply ineffective. Destruction that checks bureaucratic check-boxes is still destruction. The standards should enforce the protection of nature—not just the ticking of procedural boxes.
A smaller definition of habitat could leave wildlife exposed
Another alarming change in the draft standards is the narrowing of how “habitat” is defined, which could have serious consequences for wildlife protection.
Habitat is more than just the exact spot where an animal is seen sleeping, nesting or feeding today; we need to think more holistically about habitat as a connected network of ecosystems that species may rely on to survive, including breeding grounds, migration corridors, areas used during drought or fire, and places they may need to move to as the climate changes.
But the draft standards effectively shrink the areas considered important enough to protect by defining habitat as only very small areas that if destroyed would certainly send the species extinct, rather than habitat which maintains and restores healthy populations able to thrive well into the future.
For animals already under pressure from habitat destruction and climate change, protecting only the bare minimum is a dangerous approach. In practice, that could mean that places which are essential for threatened species to recover and survive long term are destroyed just because they are not classified under the standards as ‘habitat’—a lose-lose outcome for biodiversity and the Australian government’s nature protection goals.

Offsets are still doing too much heavy lifting
Australians have heard the promise before: “Yes, this area will be damaged — but it’ll be offset somewhere else.” In practice, environmental offsets have severely failed to replace what was lost.
You can’t instantly recreate a centuries-old forest. You can’t quickly rebuild complex wildlife habitat. And some ecosystems simply cannot be replaced once destroyed. Yet the draft standards still rely heavily on offsets rather than prioritising avoiding harm in the first place.
The standards must reduce their reliance on offsets, and instead prioritise actual habitat protection. Because once extinction happens, there’s no offset for it.
Australia cannot afford another backwards step on nature
The Albanese Government came to office promising to end Australia’s extinction crisis and repair national nature laws. But this will be a broken promise if the huge loopholes in the National Environmental Standards aren’t addressed.
Right now, Australia is losing wildlife and ecosystems faster than they can recover. Scientists have warned for years that incremental change is no longer enough.
Strong standards could help turn things around by:
- stopping destruction in critical habitat,
- setting firm limits on environmental harm,
- requiring genuine recovery for nature,
- and making decision-makers accountable for real outcomes rather than process.
If the Government locks in rules that prioritise process over protection, Australia risks entrenching the very system that caused the crisis in the first place.
What needs to change?
The Government still has time to fix the draft standards before they are finalised over the next month.
Greenpeace Australia Pacific is calling on the government to:
- ensure decisions are based on outcomes, not just process
- ensure that all important habitat is protected, not just narrow areas
- ensuring that death-by-a-thousand-cuts is avoided by considering the “cumulative impacts” of multiple projects in a region
- ensuring offsets are only used as an absolute last resort
Australians were promised stronger nature laws—not more loopholes. Australia’s wildlife cannot afford another missed opportunity.You can help ensure the Federal Government’s final standards put to parliament are as strong as possible by putting in a quick submission here.
Climate Change
Duke University Plans a Data Center It Says Will Boost ‘Environmental Responsibility and Sustainability’
The small project is underway at Central Campus, with room for expansion. Its energy usage could complicate the university’s climate goals.
DURHAM, N.C.—Duke University plans to build a small data center at Central Campus, potentially the first of several similar-size projects, which has raised questions among some faculty about whether the energy- and water-intensive endeavors could derail the institution’s climate commitments.
Climate Change
UN General Assembly backs “climate obligations” set by world’s top court
The UN General Assembly on Wednesday adopted a “historic” resolution calling on countries to comply with their climate obligations, as outlined in a landmark advisory opinion issued last year by the International Court of Justice (ICJ).
Last July, in the opinion first requested by the Pacific island state of Vanuatu, the world’s top court ruled that harming the climate by increasing fossil fuel production may constitute an “international wrongful act”. This could result in affected countries claiming compensation from those responsible, the court said.
To follow up on the ICJ ruling, a dozen nations led by Vanuatu submitted a proposal to the UN’s main deliberative body to recognise the advisory opinion and identify ways of implementing it.
Several large oil-producing nations mounted a late push to weaken the text by introducing last-minute amendments, but the General Assembly rejected those and adopted the resolution with 141 countries in favour at a plenary session in New York.
The resolution urges countries to implement measures to cut carbon emissions, including by tripling renewable energy capacity, “transitioning away from fossil fuels in energy systems”, and phasing out “inefficient” fossil fuel subsidies.
It also requests the UN Secretary-General to draft a report “containing ways to advance compliance with all obligations in relation to the court’s findings” by next year’s UN General Assembly in September 2027.

Pacific islands celebrate “historic” resolution
The group of Pacific island nations, which led the diplomatic push for the resolution, as well as Latin American nations and the European Union, celebrated its adoption as a “historic” moment, while some countries noted the persistence of diverging views.
Belize’s UN representative Janine Coye-Felson said in a statement on behalf of the Alliance of Small Island States (AOSIS) that the General Assembly resolution, as well as the ICJ advisory opinion, are important because “climate change is not governed only” by the Paris Agreement, but that “climate justice requires the application of the full breath of international law”.
“When future generations look back at this moment, they will ask whether we rose to meet the defining crisis of our time with the full force of international law. Today, this General Assembly answers: yes,” she told the plenary.
The EU said in a statement during the session that, with the adoption of the resolution, countries are moving beyond “simply recognising” the ICJ’s work and instead “actively upholding the legal integrity” of the multilateral system by seeking to implement the court’s recommendations.
Yet the bloc also warned the process that follows must not “seek to establish new mechanisms or engage in any determination of state responsibility”, referring in particular to the upcoming report by the Secretary-General. Earlier drafts of the resolution contained proposals to establish a register of climate-driven loss and damage and a dedicated compensation mechanism, but these were removed during negotiations on the text.
France’s ambassador to the UN, Jérôme Bonnafont, highlighted the resolution’s provision to reduce dependence on fossil fuels, and said “science clearly establishes their role in climate change”. The recent increase in oil and gas prices, which have soared because of the war in Iran, “underscores the cost vulnerability of this dependence”, he added.
Push-back by oil-producing nations
Some oil-producing countries – among them the US, Saudi Arabia and Russia – were critical of the new resolution, arguing that it creates “quasi-binding” obligations from an advisory opinion that should be non-binding, and rejected the request for a report from the Secretary-General.
“This is a direct duplication of work that is being done at the [UN climate convention],” said Russia’s delegate. “Creating a parallel process will waste resources, will undermine the fragile consensus at the conference of the parties and will lead to the fragmentation of the climate regime.”
In an effort to weaken the resolution, a group of seven oil-producing Middle Eastern states – including Saudi Arabia, Kuwait and Iran – tabled four last-minute amendments proposing to delete certain paragraphs and softening the language on the obligations of states.
Webinar: From Santa Marta to Bonn – where next for the fossil fuel transition?
In response, Pacific island nations said these amendments sought to “reopen provisions that were [the] subject of extensive negotiation”, while the EU added that they were “difficult to reconcile with the spirit of cooperation”. They were all rejected in a series of votes.
The US, for its part, described the resolution as “highly problematic” and denied the obligation of preventing climate harm beyond its borders, as well as the assertion that climate change is an “unprecedented civilizational challenge”. The country urged others to vote against the resolution.
India, which abstained, said the text failed to address the need for climate finance flows from developed to developing countries, which is “a serious omission”. The Indian delegate pointed to the absence of the term “climate finance” in the text, which “deserves more attention in a resolution that deals with the obligations of states”.
“Turning point in accountability”, activists say
WWF’s climate chief and former COP president Manuel Pulgar-Vidal said the General Assembly’s vote was a step forward that “raises the pressure on all states to act in line with their obligations”.
Rebecca Brown, CEO of the Center for International Environmental Law (CIEL), said the UN resolution shows that “multilateralism works” and with it, countries “carry the ICJ’s historic ruling forward as a roadmap for climate action and accountability”.
“By acting together, we can prevent further climate harm, in line with science and the law, by speeding up a just and equitable transition away from fossil fuels, protecting climate-vulnerable communities, and advancing climate justice,” she added in a statement.
Vishal Prasad, director of Pacific Islands Students Fighting Climate Change – a group of young people who first made the push for an advisory opinion from the ICJ – said “the world has not only reaffirmed that ruling, but committed to making it a reality”.
“This must be a turning point in accountability for damaging the climate. Communities on the frontlines, like in the Pacific, have been waiting far too long and continue to pay too high a price for the actions of others,” he said. “The journey of this idea from classrooms in the Pacific to The Hague and the United Nations gives us continued hope that when people organise, the world can be moved to act.”
The post UN General Assembly backs “climate obligations” set by world’s top court appeared first on Climate Home News.
UN General Assembly backs “climate obligations” set by world’s top court
-
Greenhouse Gases9 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Climate Change9 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Greenhouse Gases2 years ago嘉宾来稿:满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
-
Climate Change2 years ago嘉宾来稿:满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
-
Climate Change2 years ago
Bill Discounting Climate Change in Florida’s Energy Policy Awaits DeSantis’ Approval
-
Renewable Energy7 months agoSending Progressive Philanthropist George Soros to Prison?
-
Carbon Footprint2 years agoUS SEC’s Climate Disclosure Rules Spur Renewed Interest in Carbon Credits
-
Greenhouse Gases10 months ago
嘉宾来稿:探究火山喷发如何影响气候预测






