You'll be able to get the electric Model S sedan with an impressive 300 mile range next year, but it will cost you a hefty premium over the base model.

Tesla Motors last week provided a snapshot of the development of the Model S, an all-electric luxury sedan critical to Tesla's financial success. The car is now in alpha testing and the company plans to start delivering them to customer with reservations in the middle of next year.

Tesla plans to offer three models of the Model S based on driving range--160 miles, 230 miles, and 300 miles. For comparison, the battery-electric Nissan Leaf has an estimated range of about 100 miles.

The company said it plans to finalize pricing and options this summer, but in a company blog indicated the cost difference between the different models and expected release dates.

The first Model will be a limited edition Model S Signature Series with the full 300-mile range expected for delivery in North America in mid-2012. That will cost $20,000 more than the base model, which is $57,400. The 230-mile range option costs $10,000 more than the base model.

People who buy any of the Model S options will be eligible for a $7,500 tax credit, which effectively knocks the starting price for the base model to $49,900. Tesla said the shorter-range options will be ready for delivery later in 2012. The base model's batteries can be charged overnight with a 220-volt charger.

Tesla projects that next year it will produce between 5,000 and 7,000 vehicles in its California factory and ramp that up to 20,000. The company received a $465 million loan from the Department of Energy for the Model S plant.

In terms of battery life, Tesla said drivers can expect the lithium ion batteries to retain 70 percent of their initial capacity after seven years of 100,000 miles.