Law change means renters and flat owners may be able to cut bills as energy costs soar amid Iran war

British households will be able to buy plug-in solar panels later this summer after the government changed the law so the UK’s biggest retailers could bring them to market for the first time.

People across the country will be able to join the millions across Europe generating their own electricity using “balcony solar panels” from 27 August, according to legislation passed last week.

Apartment living can be a barrier to solar and battery adoption. Here’s how to navigate the hurdles and practicalities

• Change by degrees offers life hacks and sustainable living tips each Saturday to help reduce your household’s carbon footprint

• Got a question or tip for reducing household emissions? Email us at changebydegrees@theguardian.com

Australia is a world leader in household solar, but the benefits of rooftop renewables are unevenly distributed – and many of the 2.5 million people living in apartments or units are missing out.

About 39% of Australians living in detached or semi-detached houses have solar, compared with 6% of those in apartments or units, research by Energy Consumers Australia (ECA) finds. A gap also exists in the take-up of batteries, installed in 7% of houses but only in 3% of apartments or units.

EV owners were sent hefty PCNs but say some signs in private car parks fail to warn of fees to park and recharge car

Does refuelling your car class as parking? The answer appears to be yes if it’s an electric vehicle. Guardian Money has been contacted by several readers who were fined after charging their cars away from home.

The motorists report being caught out by signs that fail to make clear that charging points are subject to parking tariffs or to store opening times. Also, they have found some chargers being advertised as available for use when it would be a breach of the car park’s terms and conditions to use them.

The long-running series in which readers answer other readers’ questions considers a hot topic within renewable energy

This week’s replies: Are there places on Earth where humans haven’t been?

I would like to know why we build solar farms over green space, when we could just put them over massive car parks as a popular current internet meme suggests. Chris, Middlesbrough

Post your answers (and new questions) below or send them to nq@theguardian.com. A selection will be published next Sunday.

Top 10% generate climate and biodiversity damage bill that exceeds economies of most countries, say researchers

The environmental damage bill racked up by the highest-consuming 10% of the world’s population has reached up to $5.7tn a year – larger than the economy of every country except the US and China, a study has found.

Mega-consumers in this group are concentrated in the global north, accounting for more than half the population of the US and 40-45% of people in the EU.

Third of world’s energy needs should come from electricity by 2035, says Murat Kurum, as priorities set out for this year’s UN climate summit

The world should aim to meet a third of its energy needs from electricity within a decade to cut greenhouse gas emissions, the host of the next UN climate summit has said.

While about a third of global electricity generation already comes from renewable sources, other energy-intensive sectors – chiefly transport, heating and industries – have lagged behind. Close to four-fifths of final energy still comes from fossil fuels, as a result.