Solar energy is now so cost-effective that, in the sunniest countries, it costs as little as £0.02 to produce one unit of power, making it cheaper than electricity generated from coal, gas or wind, according to a new study from the University of Surrey.

In a study accepted for publication in Energy and Environment Materials, researchers from Surrey’s Advanced Technology Institute (ATI) argue that solar photovoltaic (PV) technology is now the key driver of the world’s transition to clean, renewable power.

Professor Ravi Silva, co-author of the study and Director of the ATI at the University of Surrey, said, “Even here in the U.K., a country that sits 50 degrees north of the equator, solar is the cheapest option for large-scale energy generation.

“Globally, the total amount of solar power installed passed 1.5 terawatts in 2024—twice as much as in 2020 and enough to power hundreds of millions of homes. Simply put, this technology is no longer a moonshot prospect but a foundational part of the resilient, low-carbon energy future that we all want to bring to reality.”

The research team also found that the price of lithium-ion batteries has fallen by 89% since 2010, making solar-plus-storage systems as cost-effective as gas power plants. These hybrid setups, which combine solar panels with batteries, are now standard in many regions and allow solar energy to be stored and released when needed, turning it into a more reliable, dispatchable source of power that helps balance grid demand.

Despite many reasons to be optimistic, the ATI research team points to several challenges—particularly connecting large amounts of solar power to existing electricity networks. In some regions, such as California and China, high solar generation has led to grid congestion and wasted energy when supply exceeds demand.

Dr. Ehsan Rezaee, co-author of the study from the University of Surrey, commented, “Connecting growing levels of solar power to electricity networks is now one of the biggest challenges. Smart grids, artificial intelligence forecasting and stronger links between regions will be vital to keep power systems stable as renewable energy use rises.”

Professor Silva added, “With the integration of energy storage and smart grid technologies, solar is now capable of delivering reliable, affordable and clean power at scale. Innovations in materials such as perovskite solar cells could boost energy output by up to 50% without increasing land use.

“However, progress will depend on consistent, long-term policy support. Initiatives such as the Inflation Reduction Act in the US, the EU’s REPowerEU plan and India’s Production Linked Incentive scheme show how clear direction can drive investment and innovation. Sustained commitment and international collaboration will be essential if we are to accelerate the world’s transition to a clean and reliable energy system.”

Performance was consistently good throughout my home, with some of the fastest speeds I have recorded at close and medium range. My top pick, the Orbi 770 Series, outperformed the BE67 in some scenarios. By default, the 6-GHz band is a separate SSID, appended _6GHz, and MLO is switched off. I joined with my Pixel 10 Pro XL, and after multiple speed tests at close range (up to 8 feet away), I generally got download speeds around 100 Mbps faster than on the 5-GHz band, but this dropped sharply with distance. The range of 6 GHz is significantly shorter, and just one room over, the signal strength was visibly weaker than that of 5 GHz. If you want to take advantage of 6 GHz for wireless backhaul, you can’t have the routers too far apart or with too many obstacles, or you will have dead zones. I don’t think the coverage is as wide as TP-Link suggests, though much depends on your home; the Orbi 770 offered slightly better range for me.

Disappointingly, the free tier of HomeShield offers only limited security, and Security+ costs $5 a month or $36 a year for web and intrusion protection with notifications and reports, while Total Security costs $70 a year for the first year ($130 per year after) and adds antivirus for devices, VPN service, and a password manager. Advanced Parental Controls require a second subscription costing $3 a month or $18 a year for time limits, downtime scheduling, rewards, app time limits, safe search, insights, and reports. Quality of Service allows you to prioritize specific devices and set bandwidth allowances. There is also a mixed-mode security option for WPA2 and WPA3. You can also split the 2.4-GHz and 5-GHz bands and create guest or IoT networks.

The Deco app and web interface are solid but fairly limited in terms of options. The app was able to identify many of the devices on my network, but this required me to share data with a third party. There is now an option to run a speed test on the router to see what your ISP delivers, which is handy. Ultimately, this three-pack gave me reliable and speedy internet throughout my home and garden.

Deco App via Simon Hill

Deco App via Simon Hill

Deco App via Simon Hill

TP-Link does have far too many similar mesh systems, though, and I run through some of the alternatives below. Performance and price-wise, the BE67 falls between the BE63 and the flagship BE85, and I think it’s the sweet spot in TP-Link’s line-up for most people. The Deco BE68 is the same system as the BE67, but exclusive to Best Buy.

Best Wi-Fi 6 Mesh

The combination of speedy performance, impressive range, and lots of extra features earns the Asus ZenWiFi XT8 the title of best Wi-Fi 6 mesh system. (Even if it’s a bit of a mouthful.) I tested the two-pack, and the straightforward setup through the mobile app took minutes, though you have to keep the node close by during setup and then move it. This is a tri-band Wi-Fi 6 system with one 2.4-GHz band and two 5-GHz bands (one is reserved for wireless backhaul). Available in black or white, these units are fairly large, but they’re unobtrusive and look classy, with side vents to help dissipate heat. Each router offers three gigabit Ethernet ports, which is generous, as well as a 2.5 gigabit WAN port and a USB 3.1 port.

At short, medium, or long range, the XT8 was consistently one of the fastest systems I tested, and speeds never dropped. The inclusion of AiProtection Pro, which adds anti-malware and parental controls powered by Trend Micro, is very welcome, especially since it doesn’t require a subscription, unlike most competitors. Just remember that using AiProtection means sharing your data with Trend Micro, so you might want to read its privacy policy. I like the parental controls, too. You can set up and reuse profiles, schedule bedtimes, filter by age group, and review activity. The Quality of Service (QoS) option lets you prioritize activities like working from home, gaming, or streaming, and you can limit bandwidth for specific devices.

Semiconductor maker AMD will supply its chips to artificial intelligence company OpenAI as part of an agreement to team up on building artificial intelligence infrastructure, the companies said Monday.

OpenAI will also get the option to buy as much as a 10% stake in AMD, according to a joint statement announcing the deal. It’s the latest deal for the ChatGPT maker as it races to beef up its AI computing resources.

Under the terms of the deal, OpenAI will buy the latest version of the company’s high performance graphics chips, the Instinct MI450, which is expected to debut next year.

The agreement calls for supplying 6 gigawatts of computing power for OpenAI’s “next generation” AI infrastructure, with the first batch of chips worth 1 gigawatt to be deployed in the second half of 2026.

AMD also issued OpenAI with a warrant allowing the AI company to buy up to 160 million shares of AMD’s common stock. That amounts to about 10% of company based on AMD’s 1.6 billion outstanding shares. The warrant will vest based on two milestones tied to the amount of computing power deployed, as well as unspecified “share-price targets.”

Shares of AMD spiked 25% before the opening bell Monday. Shares of Nvidia, which have repeatedly set new record-highs this year, fell slightly.

“This partnership is a major step in building the compute capacity needed to realize AI’s full potential,” OpenAI CEO Sam Altman, said in a news release. “AMD’s leadership in high-performance chips will enable us to accelerate progress and bring the benefits of advanced AI to everyone faster.”

The deal is a boost for Santa Clara, Calif.-based AMD, which has been left behind by rival Nvidia. But it also hints at OpenAI’s desire to diversify its supply chain away from Nvidia’s dominance. The AI boom has fuelled demand for Nvidia’s graphics processing chips, sending its shares soaring and making it the world’s most valuable company.

Last month, OpenAI and Nvidia announced a $100 billion partnership that will add at least 10 gigawatts of data center computing power.

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