Thanks to the NDP victory in Alberta’s election last week, it isn’t just the price of crude that’s keeping Canada’s energy stocks down.

The NDP have pledged to review Alberta’s energy royalty structure, which, the market speculates, will lead to an overall higher cost of doing business going forward. In an environment where oil trades at $100 per barrel, this isn’t such a big deal. But when crude changes hands at $60, suddenly a few extra dollars per barrel in royalties matter.

The way I see it, investors are silly to focus on the short term. Yes, an increase in royalty rates will hurt the sector, but it pales in importance compared with the price of crude. When crude trades at $90 per barrel again, this will all be a non-issue.

Which is why, if you’re a value investor, I think now is the time to invest in the sector. There are many interesting opportunities out there with huge potential upside when crude returns to so-called normal levels. Let’s take a closer look at three.

Pacific Rubiales

In 2013 Pacific Rubiales Energy Corp. (TSX:PRE) borrowed billions in a massive attempt to diversify itself from the Rubiales Field in Colombia, which is one of the largest oil deposits on the planet. In hindsight, this might not have been the best move.

There are two big things weighing down the company. The first is all that debt, which doesn’t start coming due until 2019. That’s fortunate, since it gives management time to tread water until crude recovers.

Second, there’s the status of the Rubiales Field. The current contract with the Colombian government only runs until mid-2016, and hasn’t been renewed yet. If the contract isn’t renewed, there goes a big chunk of the company’s current production. That’s obviously bad news.

But management is confident the contract issue will work itself out, and the stock is incredibly cheap because of the uncertainty. It trades at just 0.6 times book value, 0.3 times sales, and shares are nearly 75% lower than a year ago. It’s a risky stock, but a couple of pieces of good news could send it soaring.

Athabasca Oil

Athabasca Oil Corp. (TSX:ATH) is absolutely flush with potential in the long term. It’s just a matter of getting its massive oil reserves out of the ground.

The company is sitting on more than 3.2 billion barrels of contingent reserves just in the oil sands alone, where it is currently building its Hangingstone project. Production will be 12,000 barrels of oil per day to begin with, eventually rising to 80,000 barrels per day around 2019.

Meanwhile, the company owns extensive light oil acreage as well, choosing to focus on its Dubernay assets first. It projects production could hit 60,000 barrels per day from that region by 2019, giving it a combined production of nearly 150,000 barrels per day. That’s the approximate production of Crescent Point, which currently has a market cap of 17 times that of Athabasca.

It won’t be easy to increase production that much, especially if the price of crude remains tepid. But considering the upside potential, I believe Athabasca might be the best value in the entire sector right now.

Canadian Oil Sands

Canadian Oil Sands Ltd. (TSX:COS) is a pretty easy stock to value. The company has costs of approximately $55 per barrel, which means that it’s slightly profitable with oil at $60. Since most of its costs stay the same no matter how much volume it produces, there’s really only one cure for its woes—higher oil prices.

Back in June when crude traded at more than $100 per barrel, Canadian Oil Sands traded at nearly $25 per share and paid out a dividend of nearly 6%. I’m obviously not expecting crude to get back to $100 anytime soon, but I think it’s very possible in the long term. When that happens, I’m confident that investors will be lamenting the missed opportunity, which is today’s price of under $12 per share.

Besides, Canadian Oil Sands is still sitting on enough reserves to continue production for another 40 years. That’s the kind of long-term investment that’s easy to get behind.

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Fool contributor Nelson Smith owns shares of CANADIAN OIL SANDS LIMITED.