- Tesla’s second distinguishing feature is that its EVs use thousands of standard laptop cells, rather than several hundred much larger and pricier proprietary units. In Tesla’s case, the small, cylindrical “18650” lithium-ion cells (so called because each is 18mm in diameter and 65mm long) are wired together to form a flat battery pack that stretches beneath the floor of the vehicle. The pack can be detached from the car’s underside and a fresh one bolted on in minutes. So far, no such battery-exchange service has been offered. But the option is there if needed. The biggest advantage of using standard 18650 cells is that they are a commodity item. Apart from cost, there are technical advantages of using 18650 cells. Because they are small, they can shed heat rapidly. By pumping liquid coolant between them, Tesla can remove any heat produced so quickly that all individual cells are kept within a few degrees of one another.While all EV makers are notoriously shy about revealing the costs of their lithium-ion batteries, the consensus figure for the industry is between $400 and $500 per kilowatt-hour. Given its unique advantages, Tesla is probably nearer $350/kWh. If that is the case, the 85kWh battery in its Model S probably costs around $30,000—cheap, but still over a third the basic price of the vehicle.This is where the gigafactory in Reno, Nevada comes in. When in full production, the plant will be capable of producing 35 gigawatt-hours worth of lithium-ion cells a year—more than the world’s entire production of lithium-ion cells last year. When these are assembled into battery packs, they could provide power sources for 500,000 EVs.
- Some economy-class seats have already lost about 30% of their weight in the past 10 to 20 years, says René Dankwerth of RECARO, a seat-maker. But there is scope to do more: padding is being made thinner by replacing foam with netting; reclining mechanisms are being removed from some short-haul planes. Most of the extra room thus created is used to squeeze in extra rows of seats.Skift, a research firm, notes that this has prompted a seating war among the planemakers. First, Airbus increased capacity on its A320 short-haul plane from 180 to 189 to match that of Boeing’s 737. Boeing responded with a new, 200-seater 737. So Airbus is now promising a 240-seater. The new planes will be no longer than their older versions.
- WINNING a third term is a remarkable achievement for any political party. New Zealand’s centre-right National Party did so on September 20th, carried to victory, as expected, by its popular leader and the country’s current prime minister, John Key (pictured). But securing an increased majority over its first and second terms, as National did on Saturday, is astounding: it raked in 48.1% of the vote. The National Party campaigned on stability, sound economic management and educational changes which would give more weight to charter schools (which are privately run) and improve teacher quality. It favours changes to the employment law, to make it easier for employers to take on and dismiss staff. National says it will help first-home buyers and, in the long-term, promises only very minor tax cuts.
- More and more Britons are starting businesses. According to StartUp Britain, a website that uses data from Companies House, 526,000 new outfits were registered last year, up from 484,000 the previous year and 441,000 in 2011. This year the number has already passed 400,000, so last year’s record should be broken easily.It has never been so cheap to set up a business.They need only to construct a good website to get their products into the market. And the would-be entrepreneur has a plethora of other sources besides the often unhelpful banks from which to raise cash, such as crowdfunding and peer-to-peer lending. Yet a canker lurks in these rosy statistics—the large number of people who have become self-employed not out of choice but through necessity.
- Perhaps the greatest feat of engineering in London lies underground. Joseph Bazalgette’s sewerage network, built between 1859 and 1875, runs for about 21,000km (13,000 miles) underneath the city. But on September 12th the government approved a project which may match Bazalgette’s achievement.Some 8.4m people now live in London, and rising. Habits have changed, too, putting more pressure on the system.The Thames Tideway Tunnel, which will cost around £4 billion ($7 billion) to build, will run 25km from Acton in west London to Abbey Mills, one of Bazalgette’s original pumping stations, in the East End.