Shares of Tesla Motors (TSLA) have picked up speed since mid-January, zooming some 80% to around $250 per share. Since going public three-and-a-half years ago, Telsa’s stock has soared 15-fold. Its market value has jumped to more than $30 billion, or roughly half that of established carmakers General Motors (GM) and Ford (F), which sport market capitalizations of about $60 billion each.

If you haven’t gotten to enjoy the Tesla ride so far, should you jump into shares and take them for a spin?

There’s certainly a lot to salivate over. After reports of battery fires late last year for its Model S vehicle, Tesla still turned in strong fourth-quarter deliveries and said it expects Model S sales to jump a whopping 55% to 35,000 this year thanks in part to expansion in China and Europe. Tesla says it expects sales in Europe and Asia to be double the sales in North America by the end of this year. First deliveries of the Model S to China are scheduled for this spring.

Next came an announcement last week that really revved up investors’ engines: Tesla plans to build a battery “Gigafactory” that would enable it to produce as many as 500,000 cars a year by 2020 and lower its cost per kilowatt-hour of a battery pack by 30%, which is now roughly $200 to $300 per kilowatt-hour. That’s a sharp production ramp over six years, considering the company expects to deliver 35,000 Model S vehicles this year, up from just over 20,000 cars last year.

Digging a bit deeper, in addition to allowing Tesla to produce more cars, the factory will enable Tesla to make a more affordably-priced vehicle for the “mass market” thanks to the less expensive lithium-ion batteries. Tesla intends to price the vehicle around $35,000, compared with current vehicles starting at $70,000. And while the factory would make powerful batteries that power its cars, it will also make storage batteries for electric utility uses.

Tesla’s numbers dovetail nicely with its specs. Last year the company nearly quintupled sales to $2.5 billion and swung to an adjusted profit of $0.87 per share from a net loss of $3.20 per share in 2012. This year, analysts forecast sales will jump nearly 47% to $3.63 billion and earnings will soar 143% to $1.90 per share.

But even with alluring business prospects stacking up, analysts who value companies based on earnings in relation to stock price will tell you Tesla’s stock is nothing short of “bubblicious.” At $250 per share, the stock trades around 131 times 2014 projected earning per share of $1.90. Tech giant Apple (AAPL), in comparison, trades at just about 12 times expected 2014 earnings.  

“While we see prospects for sharply higher sales and profits and believe Tesla’s technological and business model innovation warrant a premium multiple to auto peers, we’re worried about valuation,” said S&P Capital IQ analyst Efraim Levy, who has a $200 price target on the stock.

Others aren’t sure Tesla can achieve its production goals. Stifel Nicolaus analyst James Albertine said Tesla could only achieve 300,000 sales per year by 2020, or 60% of the company’s stated goal of 500,000 vehicle sales per year.

“If you want to hit 500,000 cars by the end of the decade you should be doing a significant percentage of that already in the U.S. before going abroad,” Albertine, who has a “hold” rating on the stock, said in an interview.

“[Tesla is only] 18 months into the Model S rollout in the U.S. and you’re already talking China? That’s pretty quick. The Model S has been successful, I’m not sure a new model will be all that different. But, I don’t think they’ve disrupted the mold.”

Tesla: An Energy Company?

But investors may be sizing up Tesla through the wrong lens. Perhaps investors should be thinking of Tesla as an energy company that makes cars on the side. Let’s go back to the Gigafactory. While the factory will enable Tesla to make batteries to power its cars, it will also allow the company to make batteries that can store energy for use by electric utilities in a more cost-effective way. One of the biggest roadblocks to making renewable energy work is the inability to store energy cheaply. Tesla could change that.

Consider this: When it’s 100 degrees outside, your power company is going at full strength for every ounce of power it generates to support demand. But if the market demands 110%, the utility has to buy the extra power on the spot market, which is extremely expensive during peak demand times.

If Tesla’s battery allows utilities to store alternative sources of power to use when demand spikes, it will create a more efficient, cost effective system for power generators. The Gigafactory is estimated to drive down the cost per kilowatt-hour of a battery pack by 30%, which is now roughly $200 to $300 per kilowatt-hour. At that price, the batteries are cheap enough to become affordable as backup power supplies to the electric-power industry, analysts said.

And the market for energy storage is large and untapped. Electric utility demand is estimated to be a $400 billion business in the U.S. and $2 trillion globally, according to Morgan Stanley.

“If it can be a leader in commercializing battery packs, investors may never look at Tesla the same way again,” said Adam Jonas, auto analyst for Morgan Stanley, who just last week raised his price target on the stock to $320 based on the new Gigafactory factory announcement.

Stifel’s Albertine, who’s down on Tesla’s car business, believes the energy storage business offers Tesla a bigger, more successful business opportunity fraught with less risk than its car business. The analyst points to satisfying fewer customers, in this case utilities, to contract and service than making cars. He also notes U.S. demand for renewable energy pays for Tesla’s investment in its Gigafactory without having to look abroad for more business.

Also, the company won’t have to rely on as many suppliers to make the batteries. \

“Relying on vehicle sales alone will require Tesla to quickly build-out international assembly, distribution, and service, which carries significant ongoing costs and risks for a growing manufacturer,” said Albertine.

Still, given how little we know so far about Tesla’s plans for an energy storage business, Albertine thinks at around $250 per share, selling battery packs to utilities is priced in to Tesla’s stock. “[The stock is] overvalued based on what we know,” he said.

Valuation: Is it Relevant for Tesla?

But does valuation matter for a stock like Tesla? Tesla’s growth is accelerating at rapid-fire clip. From 2010 to 2011 sales jumped 75%; from 2011 to 2012 sales soared more than 100%; and from 2012 to 2013 sales rocketed 500%.

“What do you pay for this in an emerging bull market where growth is accelerating and [most other companies] lack top-line growth?” asks Craig Johnson, senior technical research strategist for Piper Jaffray.

This year, Wall Street is rewarding companies that drive sales through acquisitions because organic revenue growth is still difficult to generate in a tepid economy. Investors will pay up for pure growth companies like Tesla, which is increasing earnings through sales growth. That helps explain why it’s trading at such a high valuation.

The stock has already breezed through Johnson’s short-term target of $242, but he sees shares hitting $300 to $325 by year end based on its chart and recent price action. The strategist thinks the stock will consolidate, falling back to around $230 per share from around $245 currently before moving higher.

“The risk-reward is still very favorable,” says Johnson.

Tesla is a risky bet and based on traditional valuation metrics, the stock is nosebleed expensive. But if the company executes on even a fraction of its energy-storage business – and even its cars -- it might be worth taking shares for a test drive.

Here’s to betting on Elon Musk and good ‘ol fashion innovation.

Jennifer Schonberger is on Twitter @Jenniferisms.