Australia’s first major waste-to-energy power plant has begun accepting rubbish, marking the start of a contentious nationwide shift towards burning household refuse to generate electricity.

At least 10 developments are under way across the country, sparking concern from some conservationists who argue the trend will be environmentally damaging and at odds with plans to develop a circular economy.

Local councils have started sending truckloads of garbage to Kwinana Energy Recovery facility, south of Perth, as the country’s first commercial-scale project heads towards full-scale operation.

The Kwinana plant is designed to burn up to 460,000 tonnes of non-recyclable waste annually – about a quarter of the amount Perth sends to landfill.

Another 300,000-tonne-a-year generator is under construction just down the road at East Rockingham. Four licences to build major waste-to-energy facilities have been issued in Victoria and there are proposals in New South Wales, Queensland and South Australia. Combined, the projects in development would have the capacity to incinerate 2m tonnes of waste a year – a quarter of what Australian households throw away.

Waste-to-energy has experienced a surge of interest in Australia as landfills near capacity. Proponents say it could mean an end to landfill, and that air pollution and ash can be managed under existing environmental regulations. ​

But not everyone is convinced. The environmental group Zero Waste Australia calls the approach “the most polluting and expensive way to generate energy and manage waste” and has raised concerns about the environmental and health consequences.

Jane Bremmer, the group’s campaign coordinator, says the number of waste-to-energy proposals is “gobsmacking”, and a sign the “incineration industry” is trying to gain a foothold in Australia as it was being pushed out of Europe, where some plants are being decommissioned.

Better than landfill?

The City of Gosnells, a council with 130,000 residents south-east of Perth, is among 10 local governments sending waste to Kwinana to be burnt.

The city’s mayor, Terresa Lynes, says the change comes after a decade of planning, and a long-term contract with the facility shields ratepayers from increasing and unpredictable landfill levies.

“This is the end of landfill for the City of Gosnells,” she says, with power produced an added benefit. The council is focusing on recycling and green waste too, she says, emphasising waste-to-energy is only “part of the solution”.

In recent years, circular economy and waste policies in Western Australia, Victoria, NSW, Queensland, South Australia and Tasmania have preferred waste to energy over landfill for disposing of non-recyclable waste. However, the practice is prohibited in the ACT.

Jennifer Macklin, a circular economy researcher with the Monash Sustainable Development Institute, says the underlying principle of a circular economy is to keep materials circulating at their highest value for as long as possible, for example through repair and reuse.

The waste-to-energy process – which typically involves burning non-recyclable waste in large furnaces at high temperatures to generate electricity or heat – is the “lowest value way of circulating” because the value in the materials is lost, she says.

Using the energy “definitely offered a small benefit over landfill”, Macklin says, but poses a larger risk to higher-value reuse and recycling efforts.

She says evidence from other countries indicates recycling rates can plateau after the introduction of waste-to-energy plants, partly because once the infrastructure is built “you’re locked in feeding it”.

The arrival of waste to energy can also dampen motivation and participation in reuse and recycling at the household, organisation and even government level, she says.

The NSW chief scientist, Prof Hugh Durrant-Whyte, provided independent advice on the technology to the NSW government in 2020. He said waste to energy was well established in Europe, but as some countries improved their waste reduction, sorting, reuse and recycling efforts, some facilities were being decommissioned. “They’re shutting them down, not because of air emissions but because they no longer have the waste to actually burn.”

Across Europe, there are about 500 waste-to-energy plants, but circular economy efforts have led some countries to reduce their reliance on the technology. Denmark, for example, plans to reduce waste incineration capacity by 30% between 2020 and 2030.

Is power from plastic renewable?

Gayle Sloan, CEO of the Waste Management and Resource Recovery Association, says waste combustion is better for the climate than creating methane in landfills. “We shouldn’t be throwing things in the ground. If we can’t recover it, we should be using it for energy,” she says.

Government policies support the approach as an option for residual waste – the materials left over after recyclable, green and food wastes have been removed. In many states, that’s the “red bin” waste, containing soft plastics, nappies and synthetic textiles.

In Australia, energy produced by burning plastics is not renewable even though projects promote their power as clean and green.

Acciona, owner of the Kwinana facility, says converting waste into energy “addresses both the waste crisis and the need for clean, reliable power in WA”.

The WA facilities – Kwinana and East Rockingham – both received funding from the Australian Renewable Energy Agency (Arena).

An Arena spokesperson says while the projects demonstrated lower emissions compared to landfill, not all waste-to-energy facilities were “renewable”, and the agency did not intend to support any new funding applications. “Arena’s investment priorities do not align with investing in further projects incinerating waste for energy.”

Durrant-Whyte says: “I would hesitate to call it renewable energy. But is it better than digging a hole and putting it in the ground? Yes.”

Bremmer says contrary to industry claims, waste-to-energy doesn’t divert waste from landfill. Combustion converts the material into smaller volumes of toxic waste ash, which is then disposed of as hazardous waste.

A better solution would be to shift away from a focus on disposal and move towards a more sustainable, zero waste model, she says.

“The industry is really being pitched as being part of a circular economy, but it’s a linear process.” Those materials are lost forever, Bremmer says. “You can’t get that back and reuse or recycle it. It’s gone.”

When Antony Blinken, the US secretary of state, told reporters in New York on Friday that the coming days will determine the future path of the Middle East, he could not have been more prescient, even if at the time he was hoping that Hezbollah and Israel could be persuaded to step back from the brink.

Now, with the Hezbollah leader Hassan Nasrallah confirmed killed, the region, after 11 months, has finally stepped over the brink and into a place it has truly never been before.

All eyes will turn to the response by Tehran. It faces the fateful choice it has always sought to avoid and one its new reformist leadership in particular did not wish to make.

If it simply angrily condemns Israel for the destruction of the centrepiece of the axis of resistance that it has laboriously built up over so many years, or calls on others to take unspecified action, Iran’s credibility is in jeopardy.

But pragmatism may lead Iran to advise Hezbollah to absorb the losses and accept a ceasefire that does not also bring about a ceasefire in Gaza, Hezbollah’s stated objective.

If on the other hand Iran instead launches a direct military reprisal against Israel, it has to be meaningful. It knows it will be going into battle against a military that has proved the deadly value of its vastly superior technological and intelligence capabilities. Israel’s intelligence has clearly penetrated deep inside Hezbollah and may have done the same in Tehran.

For the new president, Masoud Pezeshkian, elected on a ticket of lifting economic sanctions partly by building better relations with the west, Nasrallah’s death could not come at a worse time.

His foreign minister, Sayeed Abbas Araghchi, had just spent a full week in New York on the sidelines of the UN general assembly, meeting European politicians such as Germany’s foreign minister, Annalena Baerbock and the British foreign secretary, David Lammy, in an attempt to persuade them to reopen talks to restore the nuclear deal that was sealed in 2015 – and Donald Trump tore up in 2018.

Rafael Grossi, the head of the UN nuclear inspectorate, had been impressed by what he heard from the meetings, saying: “I think this is the moment when it is possible to do something about the nuclear issue. The advantage of Mr Araghchi is that he knows everything about this process so he allows it to move faster”. Nasrallah’s killing makes it that much harder for the reformists to persuade the Iranian military that an olive branch still makes any sense.

Pezeshkian had already been complaining that he had received little in return for listening to western-inspired pleas not to seek immediate revenge for the killing of Ismail Haniyeh, the Hamas leader assassinated by Israel in Tehran.

Pezeshkian said he had been promised that a Gaza ceasefire deal that would see the release of hostages and Palestinian political prisoners was only a week or two away. The deal never materialised because, in Iran’s eyes, the US refused to put the pressure required on Benjamin Netanyahu to accept the ceasefire terms.

Let down once, Pezeshkian is hardly inclined to believe US vows that it had no prior knowledge of the plan to kill Nasrallah – and, anyway, Netanyahu might have sanctioned his death from a hotel bedroom in New York, but it was US-supplied bombs that exploded in Beirut.

In what is likely to be a holding statement, Iran’s supreme leader, Ayatollah Ali Khamenei, called on Muslims on Saturday “to stand by the people of Lebanon and the proud Hezbollah with whatever means they have and assist them in confronting the … wicked regime [of Israel]”.

For Washington, this is a diplomatic humiliation and a display of its inability, or refusal, to control its troublesome ally.

Netanyahu hopes to have played American diplomats for fools in New York. The US state department insists it had a clear understanding on the basis of conversations with Ron Dermer, Israel’s strategic affairs minister, and Netanyahu that Israel would accept a 21-day ceasefire, and yet as soon as the plan was announced, Netanyahu reneged on the deal.

In some ways, it is the culmination of nearly 12 months of an American strategy that now lies in ruins. Time after time since the 7 October attacks by Hamas, the US has asked Israel to adopt a different strategy over the delivery of food into Gaza, protection zones, a ground offensive in Rafah, the terms of a ceasefire and, above all, over avoiding conflict escalation.

Each time, Netanyahu acknowledged the US position, sidestepped a clear response and then ultimately ignored Washington. Each time, the US – vexed and frustrated – has expressed misgivings about Netanyahu’s strategy, but each time it has continued to pass the ammunition.

With a presidential election near and Netanyahu enjoying a surge in domestic popularity – as well as few Arab states shedding tears about Nasrallah’s demise – the US appears to have few options available. Netanyahu insists he is winning and on course for total victory.

At the moment, unless Iran proves to be more decisive than it has been so far, it is Netanyahu the great survivor who is in the driving seat.

North Carolina’s lieutenant governor, Republican Mark Robinson, received burns on Friday night while attending a truck show as he was campaigning for governor, his campaign said.

Robinson was making an appearance at the Mayberry truck show in Mount Airy when he was injured, campaign spokesperson Mike Lonergan said in a statement.

Robinson was treated at Northern regional hospital in Mount Airy for second-degree burns, he added.

“He is in good spirits, appreciates the outpouring of well wishes, and is excited to return to the campaign trail as scheduled first thing” on Saturday morning, Lonergan said.

Lonergan didn’t immediately respond to texts seeking details on how and where the burns occurred. Robinson had made campaign stops starting on Friday morning with Moore county Republicans. He has four appearances scheduled for Saturday.

Robinson, the lieutenant governor since 2021, is running against Democratic gubernatorial nominee Josh Stein, the current attorney general. The current governor, Roy Cooper, a Democrat, was barred by term limits from running this fall.

Many Republicans have distanced themselves recently from Robinson following a 19 September CNN report alleging he posted strongly worded racial and sexual comments on an online message board. A dozen staff members on his campaign or in his lieutenant governor’s office have quit in the fallout.

Robinson, who has faced criticism for other inflammatory comments, has denied writing the messages more than a decade ago and has hired a law firm to investigate.

Mount Airy, located about 100 miles (161km) north of Charlotte near the Virginia border, is where the late television star Andy Griffith grew up. The community served as the inspiration for the fictional town of Mayberry in The Andy Griffith Show, which aired during the 1960s. City leaders have embraced that history with homages and festivals associated with the show.

Cows may belch methane into the atmosphere at alarming rates, but new data shows they may play an important role in renewing farm soil.

Research by the Soil Association Exchange shows that farms with a mixture of arable crops and livestock have about a third more carbon stored within their soil than those with only arable crops, thanks to the animals’ manure.

This also has an effect on biodiversity: mixed arable and livestock farms support about 28 grassland plant species in every field, compared with 25 for arable-only and 22 for dairy-only.

Joseph Gridley, chief executive of SAE, which was set up by the Soil Association in 2021 to support and measure sustainable farming, said it was unlikely that carbon captured in soil would balance out the enormous amounts of methane created by cattle. Farm livestock around the world creates about 14% of human-induced climate emissions.

“It’s pretty unequivocal in the data that having livestock on your farm does mean you have more emissions – five or six times more emissions,” he said. “But if you integrate livestock into the system, on every metric on soil health, there’s an improvement, and on a lot of the biodiversity measures as well.”

Soils are degrading, but by how much exactly is unclear. In 2015, the UN Food and Agriculture Organisation claimed that the world had only 60 harvests left, but researchers at Oxford University and Our World In Data said in 2021 that there was a complex picture, and that while there were 16% of soils with an expected lifespan of fewer than 100 years, a third were expected to last at least 5,000.

The Department for the Environment, Food and Rural Affairs has been investigating so-called methane blockers as a way to reduce emissions. Adding substances such as essential oils, probiotics and even seaweed to cattle feed can reduce the amount of burps and wind they generate.

Last month the Green Alliance charity said that feeding Bovaer, a methane blocker, to a third of the UK’s dairy cows would cut the country’s emissions by about 1%. Yet this is not happening, the campaign group warned, because farmers were unwilling to pay extra for something they did not benefit from. It said methane blockers should be subsidised, as other green farming schemes were.

Kamala Harris has stretched her lead over Donald Trump in the US presidential election race, the latest polling averages show, even while the two candidates appear to be running neck-and-neck in most battleground states.

The Guardian’s newest poll tracker, based on a range of surveys conducted across a 10-day period, shows the vice-president and Democratic nominee at 48.2%, compared with 44.4% for Trump, the Republican candidate and former president – giving Harris a 3.6-point advantage.

That’s one point up from the lead she held a week ago and broadly consistent with most – though not all – recent survey findings.

To put it in perspective, the polling analysis website 538, also known as Five Thirty Eight, gave Harris a 2.9-point advantage on Friday morning, smaller than the Guardian’s advantage but within range. The site translated that into Harris having a 58% chance of winning November’s election, against 42% for Trump.

The caveat is that these figures relate to national polls, while the election outcome is almost certain to be decided by who wins certain key swing states under America’s electoral college system.

Nevertheless, the fact that Harris’s national poll lead may be increasing – even by small margins – may turn out to be significant.

Polling suggests that Harris is likely to win the popular vote – Democratic candidates have done so in five out of the past six presidential elections in the 21st century, yet Republicans eked out a victory in two of those contests.

The first was in 2000, when George W Bush edged out Al Gore – despite losing the nationwide tally by around 540,000 – after a weeks-long court battle to decide who had won Florida, where thousands of ballots were disputed.

More recently, Trump triumphed in the electoral college in 2016 thanks to wafer-thin victory margins in the three blue-wall states of Pennsylvania, Michigan and Wisconsin despite gaining around 2.7m fewer votes than Hillary Clinton across the nation.

The prospects of a repeat 2016 scenario are a recurring nightmare in the minds of many Democrats.

However, Harry Enten, CNN’s data analyst, painted a rosier outlook for Harris stemming from her range of national poll leads. Although his own network’s latest survey gave her only a narrow, one-point advantage, Enten acknowledged that other polls reflected a bigger lead, some as large as six points.

“We talk about these national polls, but the bottom line is, it’s a race to 270 [electoral college votes],” he said. “One way you can kind of get at this is: [what are] Harris’s chances, given a popular vote margin? And what’s the chance you win the electoral college?”

Continuing the theme, Enten argued that Trump would have an electoral college advantage if the national vote were tallied with the CNN poll that gave Harris a single-point lead – but that this would disappear if she were to win the national vote by a wider margin as suggested by other polls and reflected in the Guardian tracker.

“If you model it out, and we sort of get where that CNN poll is – plus one – I think Donald Trump would be favoured in the electoral college. Harris would just have a 33% chance of winning,” he said. “But if you get closer to where the average poll is, a plus-two to plus-three margin, then Harris is a slight favourite in the electoral college.”

The long-standing assumption underpinning that argument – common to pollsters and political partisans alike and reinforced by Trump’s 2016 winning-while-losing feat – is that Republicans have a natural advantage in the electoral college, meaning that a Democratic candidate needs to win the popular vote by a significant margin to be sure of securing the 270 electoral votes essential for victory.

Nate Cohn, the New York Times’ chief poll analyst, argued that there was evidence that this GOP advantage was being eroded.

Cohn detected the trend, counterintuitively, in a New York Times/Siena poll that showed Harris and Trump tied nationally at 47% – while the Democratic nominee is leading by an impressive four points in Pennsylvania, arguably the most important swing state of all.

“There’s growing evidence to support a surprising possibility: [Trump’s] once formidable advantage in the electoral college is not as ironclad as many presumed. Instead, it might be shrinking,” Cohn argued.

He went on: “According to the New York Times’ polling average, it does not seem that Kamala Harris will necessarily need to win the popular vote by much to prevail.”

The reason, roughly summarised, is that while Harris is sustaining narrow leads in Pennsylvania, Michigan and Wisconsin – three states that would be enough to get the vice-president to the coveted 270 electoral votes – Trump is polling better than four years ago in states he still has little chance of winning.

“On the one hand, Ms Harris is holding her own in Michigan, Wisconsin and Pennsylvania,” Cohn wrote, while cautioning that her lead was “tenuous”. “The second half of the explanation, oddly, is that Mr Trump is gaining in non-competitive states like New York, improving his position in the national popular vote without helping him in the most important states.”

With just over five weeks to go before polling day, none of this is predictive of a final outcome. But it may just suggest a scenario where the candidate destined for the White House is the one who wins the most votes – which, after all, is how democracy is meant to work.

This Monday, it will be two years since Julian and Juliette Rayner moved into their new zero-carbon home on a development about 20 minutes drive from Bristol.

The property boasts a range of new technologies that makes it highly energy-efficient and enable the couple to generate their own electricity and live a greener lifestyle.

Instead of the traditional gas boiler that so many people rely on for their heating and hot water, there’s an air source heat pump fitted to one of the outside walls, plus extensive solar panels, underfloor heating, an electric vehicle charging point and high levels of insulation. The Rayners also bought a battery for electricity storage.

Even though they were aware of the impact insulation and an energy-efficient boiler could have on their bills, moving to a green home had not been top of the couple’s wish list. But the more research they did into the benefits that a zero-carbon home could deliver, the more they liked the sound of it, so they took the plunge and bought one of the development’s 32 properties.

They soon found that their energy bills plummeted, and they effectively pay as little as 50p to £1 a week to power their home – ie, all their hot water, cooking and heating needs – in the warmer months, when they are able to generate most of their power via the solar panels. In fact, in June this year they were £12 in credit.

During the winter, when they have to rely on the National Grid, they might spend more like £33 a week, or £150 a month.

“We’ve lived in much older properties in the past and know how much they cost to heat – and it’s a lot,” says Juliette.

So, two years after moving in, how are they finding their home and its green features – in particular, the heat pump?

“In a way, we don’t really think about our heating or energy bills any more, which I suppose is what you want, really,” says Julian.

“It’s definitely been an education, as it needs a bit of a behavioural shift if these are going to be the homes of the future. Neither us nor our neighbours knew much about heat pumps and solar panels before we moved here, but it’s been good in that we’ve all been in it together and finding our way as we go.”

Thankfully, their experience over the past two years has been positive. “It’s quite a change from a gas boiler. For instance, if you were to switch off the heating completely and it’s cooled right down, it can take longer to warm up than it would have done when we were using gas,” says Julian.

“However, this shouldn’t be seen as a negative. Instead, it means we get a more comfortable, consistent temperature all the time – rather than feeling cold and having to crank the heating up, like we used to when we had a boiler. It’s easier now, because we don’t have to think about times to turn it on and off. It’s just there and does its own thing responsively.”

The couple have also had friends and family ask about their heat pump, and how they find it.

“I knew what it was going to look like – a bit like an air conditioning unit at an office. It’s a square box, probably about 4ft long, 3ft wide and 1ft deep, with a big fan in the middle,” says Julian.

He adds: “People do ask the things you often see in the media – such as if they’re noisy. But once you’ve seen it working, you realise that it’s actually really quiet … You can sit outside and have a barbecue and you’re not even hearing it, and you’re about 4ft away from it.

“It lays to rest a lot of the misconceptions you often hear, or things people have picked up that aren’t necessarily true.”

The couple have been delighted about the savings they have enjoyed on their energy bills (though those figures quoted above don’t include the standing charge).

“We can’t all be expected to completely overhaul our lives when it comes to being greener, we have to be realistic. But we want to do what we can, and this house really makes us feel like we’re doing our bit to help,” says Juliette.

According to Tim Bannister, Rightmove’s property expert, searches for terms such as “solar panels” and “heat pumps” on its site have risen dramatically since 2020 – from outside the top 500 to within the top 100 for the panels, and into the top 200 from above 1,000th place for the pumps.

“They’re not top of buyers’ must-haves just yet, and more work is needed to raise awareness of the benefits, but we expect to see more of a focus on these types of features as the nation moves towards greener homes,” he says.

Heating the UK’s 28m homes creates almost a fifth of the country’s greenhouse gas emissions, so after decades of relying on gas and oil boilers, households will need to break their addiction to fossil fuels if the government hopes to meet its climate targets.

For most homes, the alternative to traditional heating systems is likely to be an electric air source heat pump.

This little-understood technology has divided opinion. There are those who believe heat pumps could play a vital role in climate action, and then there are the sceptics who claim their benefits are a lot of hot air. In between are millions of people with little clear information to hand, and some high-stakes financial decisions ahead of them.

The “heat pump revolution” is gathering pace: last month it emerged that the UK had passed the milestone of 250,000 certified heat pump installations, with 2024 said to be on track to be “a record-breaking year”. This week (23–29 September) is Heat Pump Week, and the technology also received a boost at the Labour party conference on Monday when the energy secretary, Ed Miliband, announced a “home upgrade revolution” aimed at making the country’s housing stock cleaner and cheaper to run.

An air source heat pump looks like a large air conditioning unit and works like a fridge in reverse: it captures heat from air and uses refrigerant gas and a compressor to raise the temperature enough to heat the water which flows through our home radiators. You can read more about exactly how a heat pump works here.

The Guardian has investigated the leading claims, counter-claims and grey areas to separate myth from reality.

Claim: Heat pumps are more expensive to run than gas boilers

Heat pumps are expensive. In the UK, the majority of homes are expected to opt for an air-source heat pump, which costs on average just over £12,500 to buy and install – four to five times the cost of a gas boiler.

To help bridge the gap, the government offers grants of £7,500 to households through its boiler upgrade scheme. But critics have said that even with the grants, households could face higher energy bills because in the UK the electricity used to run them costs roughly four times the price of gas.

So what does the research say? Experts have found that, on average, heat pumps are far more efficient than gas boilers, turning one unit of electricity into 2.5 to five units of heat. By contrast, a gas boiler often produces 0.9 to 0.95 units of heat for each gas unit because some heat is lost through the flue pipes.

The technical measure for this efficiency is known as the seasonal coefficient of performance (Scop), and any heat pump with a Scop of more than 3 will match the running costs of an 85% efficient gas boiler, according to research.

A study of 750 households by Energy Systems Catapult, an independent government-backed researcher, found that heat pumps typically have a Scop of 2.9, meaning they would cost slightly more than a gas boiler to run. A separate study by the Energy Saving Trust, an independent advisory group, put the cost at £14 a year more than using a new A-rated gas boiler.

There’s no need to settle for higher bills, though. Research has also shown that a new breed of energy tariff designed specifically for heat pump users could tip the balance in their favour. Octopus Energy and Ovo Energy have both released cheaper-than-average tariffs tailored for heat pumps, which would make one cheaper to run than a gas boiler even with a Scop score well below 2.9.

Claim: Heat pumps don’t work at freezing temperatures

Heat pumps are installed in two-thirds of homes in Norway, where the average winter temperature is -7C, but this hasn’t cooled fears in the UK that they would be unable to warm homes through Britain’s relatively mild winters.

In fact, a survey of more than 4,000 adults across the UK, Germany, France and the US last autumn, undertaken by the data company Electrify Research, found that more than 40% of Britons agreed that heat pumps are not up to the challenge, compared with 36% in Germany, 35% in the US and 26% in France.

But real-world data disproves these fears. In the study by Energy Systems Catapult mentioned above, the government-funded demonstration project analysed the performance of 750 heat pumps over a period of two years on some of the country’s coldest days, where mean daily temperatures fell to as low as -6C.

The study found that heat pumps needed to work harder in cold temperatures, but they still performed well. During periods when the temperature dipped to -6C, the efficiency rating fell from an average of about 2.9 to 2.44, meaning that the running costs would rise to just above those of a gas boiler, but only for these periods.

The science shows that heat pumps can work at winter temperatures. But poor advice and installation can upend even the most encouraging scientific findings. Richard Halsey, a director at ESC, said: “One of the key findings from our study is that proper design and installation is at the heart of delivering a heat pump that works for the home that it’s in.”

Claim: Heat pumps cannot be installed in older properties

The belief that heat pumps only work effectively in modern buildings has fuelled concerns that Britain’s large stock of Victorian and pre-second world war homes will scupper the government’s aim to install 600,000 a year by 2028.

A report commissioned in 2021 by the Energy and Utilities Alliance (EUA), a trade body that represents gas boiler manufacturers, in partnership with four gas network companies, said heat pumps would be impractical for up to 54% of British households who were using gas to heat their homes.

Again, the real-world experience proves this wrong. There will be some homes which won’t be suitable for a heat pump – such as high-rise blocks without any outdoor space – but the majority of households are expected to be able to use one, according to experts.

The two-year study mentioned earlier included homes across the country – from south-east Scotland and Newcastle to the south-east of England – to test the technical and practical feasibility of a large-scale rollout of heat pumps into existing homes. It found that properties including Victorian terrace houses and 1960s flats could have a heat pump successfully installed.

“The project has not identified any particular type or age of property that cannot have a successful heat pump installation,” the ESC report said. “The suggestion that there are particular home archetypes in Britain that are unsuitable for heat pumps is not supported by project experience and data.”

There are caveats: flats or terrace homes with limited outdoor space may need to consider wall-mounted or rooftop heat pumps. For all housing types, there will need to be space inside for a hot water tank, often where the old boiler used to be. And for older buildings, other upgrades – such as loft and wall insulation, or the replacement of old radiators with larger models and underfloor heating – may be needed.

Claim: I will need to spend a lot insulating my home

Improving the insulation of a home can only help its energy efficiency. The same is true for properties with heat pumps. But experts believe there is a misconception that these require intrusive and expensive home upgrades to work properly.

A study for the Department for Energy Security and Net Zero in 2021 found that the move to very low or even zero-carbon home heating could be undertaken “without necessarily carrying out extensive deep retrofit work”.

It said that “homes can convert to electric heating at a cost far lower than the accepted wisdom” and “with no threat to comfort”. Additionally, greenhouse gas emissions would “fall very dramatically as a result”.

The ESC study found that about 15% of properties required some energy-efficiency upgrades – but in the majority of cases this was loft insulation, which costs less than £1,000 and can be done with minimal disruption. Only “a few” properties required cavity wall insulation – which carries a cost of about £2,700 – or the replacing of old doors.

Andrew Sissons, a deputy director at Nesta, a charity which undertakes research into home heating innovation, says: “Insulation is a good thing to do in its own right – but your home doesn’t need to be insulated to get a heat pump.” A well-insulated home can make heat pumps run more efficiently, but it is more important to make sure that the correct size heat pump and radiators are installed, he adds.

In short: if you live in a home where the heating keeps your rooms comfortably warm, it is very likely that you won’t need to undertake any extra insulation before installing a heat pump. But if you can afford to invest in low-cost measures such as draught exclusion, double glazing and loft insulation, you will get this money back in lower bills over the long term.

Claim: my heat pump might be a noise nuisance to neighbours

Heat pumps are designed to be installed outside the home to extract warmth from the air, ground or water. In densely populated areas, this could mean scores of heat pump fans humming within a relatively small location. One device typically emits a constant hum of between 40 and 60 decibels – about the same as a fridge or dishwasher – but could many of them amount to a noise nuisance?

The main source of heat pump noise is the fan, which draws in air, and the compressor, which raises the temperature of the refrigerant by increasing pressure on its gases. Concerns around noise pollution are tricky to disprove because the limited rollout means that, to date, there are few actual examples of lots of heat pumps working in close proximity to one another.

Earlier this year, one reader wrote to the Guardian complaining that a summer stay in a development where all eight properties had heat pumps was marred by the hum. “If you sat in the garden in the evening, it was an annoying, continual source of noise,” the writer said.

The Guardian reader’s experience may have been due to improper installation, or the use of older, noisier heat pump models, according to Jack Harvie-Clark, a director at Apex Acoustics, a noise-testing consultancy. “Modern heat pumps can be significantly quieter, and proper placement – away from property boundaries – can further reduce noise impact,” he says.

His advice? If households take a slow and steady approach to heating their homes, they will avoid making their heat pump work harder than it needs to. Overworking it would increase the noise it makes – and make it less efficient and cost-effective, too.

“I believe that many people in the UK try to operate their heat pumps the way they operate gas boilers – turning them on and off – but they can’t heat houses as quickly as gas boilers, so they need to run constantly to do that,” says Harvie-Clark.

Claim: Heat pumps could cause blackouts

Britain’s plans to meet its climate targets rely heavily on electrifying the economy. Heat pumps – alongside electric vehicles – are expected to contribute to the UK’s power demand more than doubling by 2040.

Heat pumps are also expected to have a big impact on how electricity grids run. A spell of cold weather could cause a collective surge in demand from millions of households. But are these challenges too great for grid operators, and can households expect power blackouts in exchange for a greener energy system?

National Grid ESO (NESO), the arm of National Grid which balances Britain’s electricity supply and demand, produces detailed annual forecasts of the country’s various potential routes towards its climate goals, as well as studies that analyse the changes expected to power supplies and electricity demand. These blueprints show that the UK should have enough power supplies to keep the lights on – but also that heat pumps, electric cars and batteries could help it use its available electricity better, too.

For example, homes and businesses can charge their electric vehicles or batteries overnight when power demand is lower, helping to keep the daily use peak from climbing too high. These same energy stores could help to keep the lights on, and heat pumps running, by releasing electricity back to the grid at times when demand for power reaches a peak.

ScottishPower, which runs regional networks as well as main transmission lines, has created an artificial intelligence-powered “digital twin” of its electricity networks to simulate how they might change by 2045. One of its key findings is that using heat pumps flexibly could help to reduce their contribution to peak demand by up to 32% by 2045, making it easier to keep the energy grid stable.

UK Power Networks (UKPN), which runs the grids serving London and parts of the south-east of England, is already monitoring real-time data from homes that have electric heating alongside an electric vehicle charger, solar panels or batteries, to understand the impact that heat pumps will have on the grid.

It will no doubt be trickier for the grid operators to keep the lights on than it was in the past but there is no reason to believe that we will experience more blackouts in the future as a result of heat pumps if careful modelling and upgrades continue.

Two people were arrested on Wednesday in connection with vandalism in an abandoned Hollywood Hills mansion owned by the son of a Philadelphia Phillies co-owner.

John Powers Middleton, a film producer, owns a property that has long been left vacant and become a popular target for graffiti artists and squatters.

Los Angeles police department officers patrolling the area near one mansion on Mulholland Drive responded to reports of a man and woman who had recently spray-painted the residence and fled in a white Mercedes-Benz.

The suspects, identified as 35-year-old Jacob Smith and 19-year-old Thomia Fagan, were arrested shortly after.

“The officers’ investigation revealed that both suspects had entered the private property and utilized spray paint to deface the property,” reads the statement by the LAPD. Officers said they recovered “several spray paint cans” as well as a loaded unregistered firearm.

Smith was charged with suspicion of vandalism, while Fagan faces charges of suspicion of a firearm in a vehicle, according authorities. Both are being held without bail.

A similar fate has fallen on Middleton’s other mansion about 5 miles (8km) away which has also been overtaken by squatters and graffiti artists. The properties owned by Middleton are located at 7571 Mulholland Drive and 1754 N Sunset Plaza Drive, according to KABC.

Middleton apologized to the residents of Los Angeles a day after the arrests were made, taking responsibility for the state of his properties.

“What’s happened to my property is criminal and I hope everyone caught will be prosecuted to the full extent of the law,” said Middleton in a statement to NBC News. “No one in Los Angeles should have to put up with squatters and vandalism that are out of control.”

He also said that private security measures had been in place, but the volume of break-ins and vandalism overwhelmed the teams that were hired. In the statement, Middleton promised to increase security, with 24/7 armed guards and crews actively working on repairs.

Middleton also said he would reimburse the city for any expenses incurred in securing the properties.

The abandoned mansions have attracted tourists, thanks to online viral posts, increasing the issue of trespassing and vandalism. In recent weeks, visitors were leaving tags on the mansion, one of which was reportedly owned by Sean “Diddy” Combs, the hip-hop mogul who was recently charged with sex trafficking and racketeering. One of the tags in the home reads: “Diddy was here.”

Councilmember Nithya Raman said her office had been in close contact with the Los Angeles police department and the department of building and safety regarding the incidents at the properties.

“These properties are both owned by the same individual, who is in egregious violation of the law,” Raman said.

“This is a public safety issue with serious consequences for both neighbors and the surrounding community. Irresponsible property owners must take accountability for their property or face action from the city,” she said.

The Los Angeles Times spoke to several neighbors who were baffled by the state of the mansions.

“It’s just insane,” said one neighbor. “There was once a gorgeous home there. I mean, who does that? Who walks away from a $10m house like that and just lets it go to squatters?”

“We’ve become known for the graffiti mansion,” said another neighbor. “It’s so embarrassing to have this in the heart of the Hollywood Hills.”

It was also reported that a crew of workers boarded up the windows earlier this week and erected a new chain-link fence around the property. Workers also painted over graffiti.

Donald Trump threatened on Friday to direct the justice department to pursue criminal charges against Google if he is elected president, claiming the company was unfairly displaying negative news articles about him but not his 2024 election opponent Kamala Harris.

The complaint – the latest threat on the campaign trail from Trump to wield the power of the presidency in response to enemies real or perceived – came in an abrupt post on Truth Social.

“It has been determined that Google has illegally used a system of only revealing and displaying bad stories about Donald J Trump, some made up for this purpose while, at the same time, only revealing good stories about Comrade Kamala Harris,” Trump said in the post.

“This is an ILLEGAL ACTIVITY, and hopefully the Justice Department will criminally prosecute them for this blatant Interference of Elections. If not, and subject to the Laws of our Country, I will request their prosecution, when I win the Election and become President of the United States.”

Trump did not address the possibility that there have been more negative stories about his campaign than Harris’s in recent weeks, and what prompted him to lash out at Google was not immediately clear.

Google has said it does not manipulate search results to benefit a particular party. “Both campaign websites consistently appear at the top of Search for relevant and common search queries,” the company said in a statement.

Still, conservatives have long complained that Google’s search results unfairly favor Democrats. The rightwing Media Research Center, which bills itself as a media watchdog for conservatives, has previously issued reports claiming Google helped Democrats.

The Trump campaign has also bitterly complained about the Harris campaign using the “sponsored” feature on Google search results to promote positive news coverage from outlets, including the Guardian, but with headlines rewritten by the campaign to favor Harris.

Trump’s post about the Google search results was the latest instance of him vowing to prosecute supposed opponents.

This month, Trump threatened in another Truth Social post to pursue criminal charges against any lawyers, donors, political operatives and a range of other people who he believes engaged in supposed election fraud against him if he wins the presidential election in November.

At a news conference on Thursday, Trump said former House speaker Nancy Pelosi should face criminal prosecution for not preventing the January 6 Capitol attack, which was caused by his own supporters rioting to stop the peaceful transfer of power after the 2020 election.

And at a campaign rally in Michigan on Friday, Trump called for an attorney general “in a Republican territory” to investigate Pelosi and her husband over reports that they had sold Visa stock before the justice department brought an antitrust lawsuit against the credit-card company.