Electric sportscar maker Tesla Motors has delivered its 250th Roadster, and is now building 20 units a week, chairman and CEO Elon Musk said in a customer newsletter.

Car #250 went to Rob Wilder, CEO of WilderShares, who was described by Tesla as "an academic and entrepreneur who created the first index on Wall Street for energy efficiency and zero-carbon solutions".

Wilder recharges his new Roadster from his home's solar panels in Encinitas, California, and chose the 'very orange' paint colour to symbolise the car's connection with the sun.

"Buying [the Roadster] is helping push along EV adoption generally because Tesla is investing the money in lower-priced cars down the line," Wilder said.

Musk said Tesla would increase output to 30 cars a week this summer. The Roadster is sold out until the end of October.

Tesla will unveil the Model S prototype sedan on 26 March  at its design studio inside the SpaceX rocket factory in Hawthorne, California. The car is "likely" to be the world's first mass-produced, highway-capable EV when it starts production late in 2011, Tesla claimed.

Anticipated base price is US $57,400 but buyers will be able to claim a federal tax credit of $7,500.

"Because of tax incentives and relatively inexpensive maintenance and refuelling, the lifetime ownership cost will be closer to cars with far lower sticker prices," Musk said.

The company plans to open a midwest regional sales and service centre in Chicago, the first of seven retail facilities for launch this year.

After Chicago, Tesla plans to open a store here in the UK in London's Knightsbridge (home to the famous Harrods department store which sometimes displays new car models in its windows).

"We are also finalising site selection in Manhattan, Miami and Seattle and scouting sites in Washington, DC and Munich, Germany," Musk added.

Tesla asks owners to bring their cars in every 12,000 miles (20,000km) or annually for a diagnostic check and software upgrade.

The automaker has also begun selling cars in Canada with deliveries starting in the fourth quarter of 2009.

"We believe Canada will become a premier showcase for the Roadster," Musk said.

"In Canada, the majority of electricity comes from renewable resources, including run-of-river small hydro, wind, biomass, geothermal and solar energy. An EV recharged from the current Canadian grid, on average, would reduce greenhouse gas emissions by about 85% compared to an equivalent gasoline-powered vehicle. In hydro-dominant British Columbia, Quebec and Manitoba, the reduction would be an impressive 98%."

The base price in Canada will be set closer to the start of deliveries, and pricing will reflect exchange rates at the time. In the US, the base price is $109,000.