The whole idea of day trading is inherently flawed. Even if it were proven to be a more reliable way to make money over the long haul, it requires constant portfolio reshuffling and too many sleepless nights. I'd rather stick with the boring ultra-long-term approach: Buy excellent businesses and hold on for the long haul. On that note, I'm always on the lookout for businesses that I would feel comfortable owning for decades. Here are three: Apple (NASDAQ:AAPL), SolarCity (NASDAQ:SCTY.DL), and Tesla Motors (NASDAQ:TSLA).

When it comes to the premium market in consumer electronics, Apple irrefutably dominates. Consider, the success of its largest and most profitable business segment: iPhone.

iPhone 5s. Image source: Apple.

In Apple's two most important markets, the iPhone's prominence is unquestioned. In the U.S., Apple has a 41.8% share of the installed base of smartphones, according to a May report from comScore. Samsung comes in at a distant second with 26.1%. In China, the world's largest smartphone market and where Apple still has lots of room for growth, Apple's leadership is as clear as day. Of the 27% of smartphones in China priced at $500 or more, 80% are iPhones, according to a report from Chinese mobile developer services platform Umeng. 

Over the long haul, a "sticky" ecosystem of closely integrated hardware, software, and services will keep customers coming back to pay premium prices for the Apple experience.

If there's one technology that looks almost certain to eventually attract mass adoption, it's solar energy. As solar PV panel technology continues to improve and costs continue to fall, how can we not be compelled to tap into the most squanderable and powerful source of energy available to humanity?

Image source: SolarCity.

Among the different solar stocks, SolarCity and its ambitious chairman Elon Musk are out on the prowl to make the biggest difference in the smallest amount of time.

The company recently acquired solar PV panel manufacturer Silevo to help it build the world's largest solar panel plant to bring "massive economies of scale" and "achieve a breakthrough in the cost of solar power," the company said in a blog post.

The ultimate goal of the plant?


Tesla Motors
Another Elon Musk stock, and heavily reliant on the future of solar, is Musk's baby, Tesla Motors. Before the Model S, it wasn't so clear that Musk & Co. could succeed at making fully electric cars. But that notion quickly ended when the company went from selling hundreds of Roadsters per year to 22,500 luxury sedans in 2013 -- the first full calendar year of deliveries for the Model S. Tesla's sedan outsold all comparably priced cars in North America last year.

Model S. Image source: Tesla Motors.

Like in solar, in EVs we're looking at a massive potential road map for adoption in the future. Today, Tesla is a small rounding error in an automobile market that is selling over 80 million vehicles every year. 

Competing with well capitalized established auto players won't be easy. But Tesla's nearly flawless execution recently, combined with big plans to cut the cost of lithium-ion batteries by spending $5 billion on its planned Gigafactory, provide evidence that the company knows how to shatter the mold and disrupt antiquated practices. And the affordable fully electric car it has planned for a launch in 2016 or 2017 means that investors won't have to wait long for wider acceptance and mass adoption.

Shorter term, there's Tesla's massive international expansion and the upcoming release of the Model X, two factors that should serve as major catalysts for the business.

At the very least, these stocks are worth a closer look and a spot on your watch list.