Thursday, September 11, 2014
Forget Battery Swapping Tesla Aims to Charge Electric Cars in Five Minutes
Electric vehicles take too long to recharge. To charge a Tesla Model S just halfway takes five hours at a typical home or public charging station. But in its effort to make electric vehicles more practical, Tesla Motors is quickly reducing the charging times. Last September, it unveiled a network of “supercharging” stations—designed exclusively for its Model S and future electric vehicles—that could charge a battery halfway in 30 minutes. In May, it announced an upgrade that cut that time to 20 minutes. Now Tesla’s chief technology officer, JB Straubel, says the company eventually could cut the time it takes to fully charge the battery to just five minutes—or not much longer than it takes to fill a gas tank.Straubel isn’t referring to the battery swap technology Tesla recently unveiled (see “Why Tesla Thinks It Can Make Battery Swapping Work”). That system doesn’t charge batteries quickly. It simply takes out a depleted battery and replaces it with a fully charged one. He’s talking about what might be a more appealing option for drivers: recharging the battery in your car while you wait.
“It’s not going to happen in a year from now. It’s going to be hard. But I think we can get down to five to 10 minutes,” Straubel said in an interview with MIT Technology Review. He noted that the current superchargers, which deliver 120 kilowatts of electricity, “seemed pretty crazy even 10 years ago.” Conventional public charging stations deliver well under 10 kilowatts.
Monday, September 1, 2014
Kenya Aims to Make Geothermal Energy Main Power Source By 2014
Kenya, Africa’s largest producer of geothermal power, is aiming for the energy supply to surpass hydro as the top contributor to the country’s electricity grid by 2014, said Silas Simiyu, chief executive officer of the state-owned Geothermal Development Co.
A 10-year, $2.6 billion exploration plan will involve sinking 566 wells in the Great Rift Valley, where shifting tectonic plates provide a key source of the energy, the company said in a statement yesterday. GDC is expected to begin drilling in Menengai in central Kenya this week, with an initial aim to find sufficient reserves to feed a 400-megawatt facility by 2014, Simiyu told reporters yesterday.
Over the next decade, the company aims to discover 2,336 megawatts of steam produced by hot underground rocks that boil water. The vapors are used to power turbines. Geothermal energy currently accounts for 12 percent of Kenya’s 1,405 megawatts of generation, including an installed capacity of 212 megawatts at a plant at Olkaria, about 120 kilometers (75 miles) outside of Nairobi, the capital.
“We should not see a situation of power shortages like we had before,” Simiyu said.
Drought in Kenya two years ago depleted water levels at hydropower dams, which supplies 55 percent of the country’s electricity. The resulting power rationing between August and October 2009 hindered growth in East Africa’s largest economy.
Kenya estimates the extent of its unexploited resources ranges between 7,000 megawatts and 10,000 megawatts at 14 “high- potential” locations valued at $30 billion, according to the statement.
