This month’s best buys are very different companies, but they do have two things in common: They both stand to gain from a strengthening U.S. economy, and they’re also “clean,” operating in growing sectors where sustainability is the buzzword.

Our first pick is an existing Conservative Holding that offers attractive value right now. The second is a company we’ve long rated a buy in our How They Rate universe. Now its strong prospects have earned it a promotion to  the Aggressive Portfolio.

River Runner

Conservative Holding Brookfield Renewable Energy Partners LP (TSX: BEP-U, NYSE: BEP) is a high-dividend-paying clean-energy specialist. It’s one of the world’s largest pure-play renewable power companies, with $19 billion in assets. Brookfield gets 85% of its power from 180 hydroelectric stations on 72 different river systems. The other 15% comes from wind. 

In all, the company has 6,700 megawatts (MW) of generation capacity. With 234 facilities spread across five countries, it also has a broad geographic base: Brookfield generates 55% of its gigawatt (GW) hours in the U.S., 25% in Canada, 15% in Brazil, and 5% in Europe.

The company’s large fleet of power plants also cuts its reliance on any one station and insulates it from low rainfall in any single river basin, which can cut water flow—and so reduce power from its plants.  

Long-Term Contracts

Predictable long-term contracts are another key to Brookfield’s stability. Here’s a rundown of its contracted generation capacity for 2014 through 2018:

2014:  92%

2015:  87%

2016:  86%

2017:  82%

2018:  81%

That’s a significant chunk of locked-in cash flow, enough to support Brookfield’s long-term goal of hiking its distribution rate by 5% to 9% a year.

The company continues to complement its hydroelectric plants with wind power. It now owns 28 operating wind farms with about 1,300 MW of capacity. And like Brookfield’s other assets, these projects sell power under long-term deals. They’re also in markets where there isn’t a lot of other wind generation. 

Brookfield has set ambitious growth targets for the next five years.

Right now, for example, the company’s development pipeline contains 2,000 MW of projects, and it plans to spend $500 million to $700 million to build out 500 MW to 750 MW of that total. These projects could add about $140 million to Brookfield’s funds from operations (FFO) by 2019.

At the same time, Brookfield plans to spend $3 billion to $5 billion on acquisitions, with a focus on European hydroelectric projects and Brazil, where it recently announced it bought a 488 MW renewable portfolio for $935 million. 

Brookfield can also look forward to rising FFO from its existing businesses, thanks to inflation escalators in the deals it’s signed. This represents about $100 million to $130 million of fresh FFO—similar to what it’s looking for from new developments—without having to issue any shares.

In sum, the company is boosting its installed renewable capacity at about 10 GW a year, or about $200 million worth of new supply, while cutting costs and improving efficiency across its portfolio. 

Rising Income, Attractive Price

If you do invest, note that Brookfield is treated as a partnership for U.S. and Canadian tax purposes. That means it isn’t subject to tax. Instead, its income is taxed in shareholders’ hands. Because it pays no corporate tax, withholding tax may still apply to IRAs. You can recover dividend taxes withheld from U.S. non-IRA accounts as a credit by filing a Form 1116 with your U.S. income taxes. The amount you can recover per year depends on your own tax situation.

The stock trades at 1.63 times book value and 16.4 times trailing 12 months’ FFO. With a strong case for long-term distribution growth, Brookfield offers compelling value.

Brookfield Renewable Energy Partners—currently yielding 4.9%—is a buy under $34 for income and growth.

Treasure from Trash

A more aggressive “clean” play is Progressive Waste Solutions Inc. (TSX: BIN, NYSE: BIN), North America’s third-largest non-hazardous waste hauler. This vertically integrated, full-service environmental-solutions outfit offers growing quarterly income and exposure to both the U.S. and Canada.

Progressive has been boosting its efficiency with moves like switching to natural gas–powered and automated vehicles. It’s also making tuck-in acquisitions, where it aims for smaller companies that fit nicely with its current operations. Both plans should keep its share price and dividends rising.

The company’s North American diversification is a plus, though the U.S. did supply 62% of its 2013 revenue.

That means it benefits from the improving U.S. economy, as rising GDP generally results in more garbage to handle. The company has bid on a number of major contracts recently, setting itself up for higher future earnings. 

At the same time, it enjoys some protection from downturns because, like Brookfield, it operates under long-term contracts with high-quality customers. 

Progressive shares surged after the company revealed a favorable change to its tax structure in its October 30 third-quarter earnings announcement.

The change, related to Progressive’s mid-2014 debt refinancing, should cut its effective tax rates and cash taxes paid, boosting free cash flow by about $15 million a year. 

Meantime, Progressive reported that its internally generated sales, not including acquisitions, rose 2.2% in the third quarter, as the company raised its prices and disposed of more garbage. Adjusted operating earnings before interest, taxation, depreciation and amortization (EBITDA) were up 10.8%, while adjusted earnings per share grew 33%.

Progressive said its full-year revenue would come in near the high end of its full-year forecast of $1.99 billion to $2.01 billion. Adjusted EBITDA, meanwhile, would likely be near the bottom of its expected $528 million to $538 million range. Based on its new tax structure, the firm now expects to generate $231 million to $237 million of free cash flow for 2014, up from a prior range of $210 million to $225 million.

Summer Dividend Hike Likely

The company boasts an enterprise value-to-EBITDA ratio of 9.74, just below the ratio of 10 that traditionally indicates value. It’s raised its dividend three times in the past 18 months. If current trends hold, it will announce a 6% to 7% dividend hike in July 2015.

Progressive Waste Solutions, a new addition to the CE Aggressive Portfolio, is a buy under $34.