We often write about a group of stocks known as the “Dividend Aristocrats.” These stocks have a long track record of dividend payment increases, which make them among the most reliable income-producing investments you can find.

But these stocks have one clear drawback: they are so loved by so many investors that their share prices often get pushed up to levels that translate into a mediocre dividend yield. Among the more than 50 stocks that qualify for Dividend Aristocrat status, only three of them — AT&T, Inc. (NYSE: T), HCP, Inc. (NYSE: HCP) and Consolidated Edison, Inc. (NYSE: ED) — have dividend yields above 4%. The 30-day SEC Yield on the ProShares S&P 500 Dividend Aristocrat ETF (NYSE: NOBL) is just 1.96%.

Yet there is another group of stocks that have no shot at ever joining the Dividend Aristocrats. They are simply ignored by any investor that craves dividend stability. These companies, by the very nature of their business models, are simply in no position to guarantee that dividends will remain constant and growing. In fact, from time to time, these companies decide not to pay a dividend at all.

Let me use Northern Tier Energy LP (NYSE: NTI) as example. This energy refiner takes in crude oil and creates a number of different products, from gasoline to jet fuel to other distillates. Refiners have little control over their input prices (crude oil) or their end-market selling prices and find that profit margins can shift from lean to fat to lean in a span of quarters. You can imagine the havoc this inconsistency wreaks on a dividend. 

When Northern Tier issued its first-ever dividend in 2012, the payout stood at $1.48. Profit margins expanded in 2013, pushing the dividend up to $3.49. Yet as refiners will tell you, the good times never last, and Northern Tier cut its dividend to $2.18 a share last year. This year’s dividend will likely be around $2.

Although it’s hard to anticipate what refinery profit margins will look like from one year to the next, analysts at Goldman Sachs project that stable energy prices and stable refining margins should enable Northern Tier to pay out around $2.50 a share next year and around $2.75 a share in 2017 and 2018.

Let’s do a bit of math. From 2012 through 2018, the average dividend will likely be around $2.45 a share. Shares of Northern Tier trade for around $25, so investors are getting a nearly 10% yield on that average annual payout. 

There’s even a reason to suspect that forward dividend assumptions are understated. Northern Tier gets much of its oil from the North Dakota shale region and the recent glut of crude oil across the globe has hit these shale producers especially hard. 

Oil producers in this area collected $80-to-$90 a barrel for oil last summer, though that figure plunged below $40 in the first quarter of 2015, according to the Energy Information Administration. That’s the result of insufficient demand from refiners for this oil. 

Northern Tier is one of the few with nearby refineries that can profit from this price gap. Indeed profit forecasts for the first quarter — and for the full-year — have been on the rise for this refiner over the past 90 days. 

This trend of erratic dividends is also the case for other small refiners such as Alon USA Partners LP (NYSE: ALDW) and CVR Refining LP (NYSE: CVRR). Every once in a while, they will announce that due to a drop in profit margins, or higher-than-expected spending on refinery maintenance, they will have to skip a dividend. That’s tough news for anyone counting on dividend streams for their living expenses. But for investors that can afford to forego the occasional dividend, the reward is a higher than average yield. 

Risks To Consider: The energy market is notoriously fickle, and it is completely unclear where oil prices and refinery profit margins will be from quarter to quarter.  

Action To Take –> Whenever you hear about a company that has announced a sudden missed dividend payment, take a look at the bigger picture. If it is merely a hiccup in an otherwise stable dividend stream, then chances are you’ll be able to pick up shares at a very good price while other investors are in a selling mood. 

Now you have erratic dividend payers, but what about reliable ones? My colleague Nathan Slaughter just released a new report detailing how to lock in a paycheck of $16,200 for every $100,000 invested and how to keep dividends… sometimes surpassing the original stock price. Invest like this and it just might change the way you think about investing forever. To access the report, click here.