I'd love it if every community on Earth could produce enough clean, safe, renewable power to meet all of its energy needs, but in the vast majority of cases, we are simply not there yet. Oil and natural gas companies are going to be with us for a while.

Some of these companies pollute. Some of them have been linked to questionable business practices, especially in other countries.

And one is about as close to a model corporation as an oil company can get.

I first read about Statoil (NYSE: STO) in an article about Scotland's plan to have 100% renewable energy by 2020. Scotland's eastern coast is on the North Sea, known for its strong winds and becoming something of a renewable-energy hub shared with several neighboring countries - chief amongst them Norway.

I recently blogged about Norway's sovereign fund, which hasn't suffered in the least from focusing on ethical companies. Statoil is a Norwegian company, and the government owns 67% of the company's shares.

Statoil is the world's 13th largest oil and gas company - not a global dominator, but it has other good points. A look into the company's history showed far fewer controversies than most oil and gas providers (I have yet to find an energy company with a spotless record).

Statoil's Hydrogen Technologies division is a leader in alkaline electrolysis technology (creating hydrogen and oxygen from water), which could eventually replace depleted fossil fuel reserves. The company has also begun branching out into biofuels, wind power, and geothermal energy.

Perhaps most impressively, Statoil has publicly stated a goal of "zero harm to people and the environment" and is backing it up with careful water management, waste management, attempting to reduce emissions from their facilities, capturing and storing carbon dioxide, and integrating environmental monitoring on a daily basis.

Some companies flagrantly violate human rights in faraway countries. Not Statoil. Their corporate policies stipulate human rights and fair labor conditions, including the rights of indigenous people who may be affected by Statoil's operations. The company belongs to the Business Leaders' Initiative on Human Rights, and supports the United Nations and Amnesty International.

And it gets better: Statoil has an outstanding balance sheet. P/E is excellent at 5.7, and the company pays a 4.1% dividend. I would prefer it if Statoil had a little more cash and a little less debt, but their debt is more than acceptable given the company's high market cap and the equipment-intensive nature of their operations. Statoil's production is also rising, and will likely continue to rise due to recent successful exploration in Tanzania, the Gulf of Mexico, and along the Norwegian continental shelf.

Statoil's current price is $22.70, and although I would love to snatch it up at a lower price (I am considering selling the October $20 puts), I consider it a good buy under $25. Oil wells and wind farms take time to build, so it may take a few years, but I believe Statoil will deliver healthy returns.

Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.

Not so very long ago, entire families often shared one email account (usually a parent's work account), jpeg images took several minutes to load, and the internet was a haven for geeks like me. Now, virtually everything is online. It seems like everyone has at least one email address and spends a significant portion of their lives on the internet.

The number of Facebook users is inching closer and closer to one billion. At least 50 million people currently use Yelp each month. Facebook is poised to make its initial public offering; Yelp already has.

Having a lot of users and internet buzz does not, however, make a web-based business a good investment. Experienced investors know it is much more complicated than that. And for readers of this blog, there are ethical issues to consider before buying as well.

First, let's take a long, hard look at Yelp (NYSE: YELP). Searching and reviewing local businesses is not a new idea; sites like Citysearch offered that opportunity to their users years before Yelp did. Yelp's popularity boils down to a cuter website, a catchier name, rewards for users who are the first to review a business or who are especially prolific, and far greater social networking capability than its predecessors.

Yelp made its initial public offering a few weeks ago. The stock immediately fell, and the chart has resembled a roller coaster track ever since. The company's business plan depends almost entirely on advertising, something many businesses have had to cut back on in recent years - and may eventually dispense with, since many consumers resent the prevalence of ads and a growing number use ad-blocking software to avoid them. Although Yelp's revenue has grown, the company is still not profitable, and growth will eventually slow to a crawl because there is a limited number of markets left for the company to bully its way into.

And I do mean bully.

Yelp has a history of using tactics that I, as an ethically focused citizen and entrepreneur, frown upon, as do my friends who have also owned their own businesses.

Yelp has already faced class-action lawsuits from companies claiming that Yelp employees offered to remove negative reviews in exchange for purchasing advertising. Some companies who declined to purchase advertising subsequently found that their positive reviews suddenly disappeared. Yelp also claims to have taken measures to prevent fake reviews, but in some cases, negative reviews have obviously been posted by rival businesses, or by users who have clearly never visited the business. One such victim is chef Graham Elliot, who received a one-star review of his sandwich shop before it had even opened - and who claims to have been forced off of Yelp on three occasions for responding to factually inaccurate reviews.

In the interest of full disclosure, a personal friend of mine has faced this sort of treatment from Yelp. Marla (not her real name) could not afford to purchase advertising, and suddenly found her three best reviews vanish. When she moved her business to another state, she updated the contact information on her business' Yelp profile…and soon discovered that the information had been changed back. Despite several complaints, this wasn't resolved for months.

An unprofitable company facing legal bills is a recipe for losses. Not only is Yelp a poor investment, the company does not qualify as ethical in the least.

Moving on…Facebook hasn't IPO'ed yet, but it will probably do so fairly soon. The company is profitable, but its entire business plan is based upon storing and selling user information to marketers. And while the site has more users than Google, there are only so many people in the world with internet access who would be interested in opening accounts - or able to do so. Facebook overconfidently mentioned China multiple times in its SEC filing, but cannot count on ever being unblocked by China's strict censors. And prior to Facebook, several other social networking sites flourished - I won't be surprised if Google Plus or another competitor eventually renders the site obsolete. For these reasons, I suspect the company could be overvalued.

Facebook is notorious for privacy issues - user accounts are simply not safe enough, as proven when Mark Zuckerberg's private photos were leaked. The company has already been taken to task by the Federal Trade Commission for sharing users' private information, and by privacy advocates for its previous refusal to remove users' profiles upon request. Additionally, ever since Craigslist banned ads for "adult services", prostitution has migrated to Facebook, prompting some concerned citizens to report Facebook to the FBI. And while Facebook did not cause the cyberbullying phenomenon, much of it takes place on Facebook, thus creating the possibility of liability. I wouldn't rule out future lawsuits.

Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.

As an environmentalist and a fiscally intelligent American, I was not happy when Solyndra went bankrupt after receiving a $535 million loan guarantee. When I found out that Solyndra executives might receive $30,000 bonuses while lower-level employees are still being denied back pay and accrued vacation time, I was outraged.

Lifelong Sun Belt resident that I am, I believe in solar power. I've used solar-powered gadgets, I've eaten food prepared in solar cookers, and I even know a small business owner whose tiny storefront is solar-powered (thanks to a cooperative landlord). I understand the importance of supporting companies in the clean energy sector.

However, when buying stocks, it's not enough for these companies to be green. They must also be financially viable. While Solyndra was not publicly traded, it is a prime example of a fiscally unsound business.

A century ago, there were over a hundred automotive companies, most of them based in Detroit. Now, there are only a few dozen, and the majority are based in Asia. As the industry progressed, the most profitable car companies stayed in business while their less profitable counterparts closed down or faced takeovers, one by one. I believe something similar will eventually happen with clean-energy companies.

I have read profiles of several dozen companies in the solar power business, and sadly, most of them lack a competitive edge and are simply not growing quickly enough to pay off their debts. That's not to say there aren't a few worth considering.

First Solar, Inc. (Nasdaq: FSLR) is one of the brightest spots in the solar power field. Like Solyndra, First Solar makes and sells thin-film solar semiconductors, and also makes and sells photovoltaic solar power systems. However, unlike Solyndra, First Solar has one of the best balance sheets in the solar power industry. The company is profitable, is growing, has a P/E under 6, and has $763 million in cash. At $610 million, debt is higher than I prefer, but I consider the debt reasonable for as long as growth continues. First Solar has also recently stated that the company must develop new markets that are not dependent on subsidies, realizing they cannot rely on government incentives to build a healthy business. The stock is currently $36.40 - try and get it under $35 if you can.

JA Solar (NasdaqGS: JASO) is worth considering. JA Solar is the world's largest solar cell producer, and can manufacture inexpensively due to being based in Shanghai. The company makes and sells solar products under its own name, and also produces solar products for other companies under their brand names. This gives JA Solar a larger piece of the solar-power pie than the average solar company. However, I do not recommend buying the stock just yet. Although the stock is not expensive (at $1.91 per share, anyone can afford a few shares) and P/E is a very low 2.92, revenue has been shrinking significantly in recent months, and the company has more debt than cash. Rather, I suggest watching the stock for the time being, and investing only if the company's debt begins to fall and/or profits begin to rise. I suspect investors have been reluctant to buy JA Solar shares partly because the company is based in China; however, sooner or later, ethical consumers must accept the fact that the majority of solar companies are based in China, and that most solar products use Chinese materials, labor, or both.

I'm also watching Yingli Green Energy (NYSE: YGE). This photovoltaic product company, also based in China, has a global presence and a decent balance sheet. P/E is under 4, growth is good, debt isn't too terrifying, and the company has nearly $1 billion in cash. It's true that there are larger solar companies, but Yingli is making a profit while several of the biggest players are losing money and going deeper into debt. As an added bonus for ethical investors, earlier today Yingli's US subsidiary renewed its GRID Alternatives partnership, which provides solar-electric job training and inexpensive solar power to low-income California residents (the project will soon be introduced in Colorado as well). Today's price is $3.91; consider buying under $4.

Like the deep collapse of the automotive industry before World War II in the US, we should probably expect a number of solar firms to fail. They operate capital-intensive businesses in a highly competitive environment. If you choose, do so carefully - and use stop-losses so you don't get burned.

Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.

Way back in the 16th century, tanners and butchers were banned from keeping shops on Florence's Ponte Vecchio bridge because their industrial waste polluted the Arno River. The city of Niagara Falls, NY will always be remembered for its Love Canal neighborhood, built on a dump site and later demolished. And in 2003, a quarry near Cardiff, Wales erupted, sending toxic fumes into the air - a nasty shock for area residents, who had no idea that Monsanto Chemical had used the site for illegal dumping in the '60s and '70s.

Companies with ethical and environmental concerns often seek to reduce or eliminate their hazardous waste. This is wonderful, but what about companies who haven't reached that point yet? Chemical plants, oil refineries, factories, steel mills, biotechnology companies, medical institutions, and even the military produce waste that can't simply be left in a landfill or poured down a drain without causing harm. That waste has to go somewhere, and must be handled safely.

Enter US Ecology, Inc. (NasdaqGS: ECOL). US Ecology has provided safe disposal of radioactive waste since 1952, and added hazardous waste services in 1968 - one of the few companies in the USA to handle such delicate work. The company places safety at a premium - all four of their operating sites participate in OSHA's SHARP and VPP programs, which recognize small companies with exemplary health and safety management. US Ecology even posts its operating permits and compliance records online. That level of transparency is a far cry from Monsanto's sneaky dumping in Wales!

US Ecology handles transportation, treatment, disposal, and (where applicable) recycling of hazardous and radioactive waste from a variety of sources, with sites in Nevada, Idaho, Texas, and Washington. Companies and government agencies in much of the USA could easily rely on US Ecology for waste management because it has multiple distant locations, and many already do. The company even offers offsite management services for medical waste, mercury, batteries, cyanide, e-waste, and other refuse. Rather than exclusively using gas-guzzling trucks, US Ecology also takes the greener step of transporting waste largely by train, maintaining a dedicated fleet of rail cars for safety reasons.

US Ecology has adequate working capital and sufficient operating cash flow to handle its manageable debt, given its fairly consistent net income levels. The modern world shows no signs of eliminating hazardous waste anytime soon, so US Ecology should continue to deliver earnings for some time.

Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.

Geothermal power is produced by volcanic activity, mineral decay, and the Earth's core. It's renewable, cost effective, significantly cleaner than fossil fuels, and safe. Geothermal energy can be applied on a large or small scale - it is used in small towns in the Pacific Northwest and also supplies 30% of Iceland's electricity. Several years ago, environmentalists on both ends of the political spectrum were in uproar over the discovery that although George W. Bush's Texas home used clean energy sources including geothermal heating, Al Gore's house did not.

Geothermal energy does have a downside: in some areas, deep drilling and exploration are required to access geothermal power. The costs can be high (about $10 million per well in the state of Nevada), and about one well in five fails to produce sufficient results. Therefore, I hesitate to recommend a pure geothermal energy company.

Believe it or not, the world's largest producer of geothermal energy is Chevron (NYSE: CVX). Ripley - take note. Although Chevron is usually associated with petroleum, the company has expanded into renewable power. Currently, Chevron is researching and developing solar, wind, biofuel, fuel cells, and hydrogen fuel in addition to its geothermal operations. The company has even trimmed its own energy usage by implementing hydrogen fuel cells and solar panels at Chevron facilities.

Chevron is not perfect - among other things, the company has refused to pay an $8.6 billion fine demanded by a court in Ecuador in reference to Texaco's pollution in the Amazon between 1972 and 1992. However, this was an "inherited" problem, and I like the direction Chevron is taking to provide energy from diversified green sources.

Chevron has also approved the Wheatstone Project, a proposed liquid natural gas plant and processing facility in Australia. With a price tag of $29 billion, this is not a light undertaking, but the project is expected to process nearly 9 million tons of liquid natural gas each year, much of which will be destined for growing Asian markets.

Chevron's balance sheet is solid, and its stock price is fairly valued. Growth is steady, debt is reasonable, and P/E is a good 7.7. Even better, investors receive a 3.1% dividend. Chevron is a world-class company demonstrating ethical behavior from its ventures into renewable power. I like the stock at its current level of $104.

Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.

For decades, a prominent Detroit automaker committed one sin after another.

This company spied on its employees during and after business hours, firing or failing to promote many of them for such "infractions" as having wives who worked outside the home. There is no excuse for the violent anti-union tactics formerly used by this company's management, regardless of your take on unions. In 1968, British female employees had to stage a walkout to receive equal pay.

One of the company's retired vehicle models is notorious for fuel-tank explosions, and was the subject of a product liability case in 1981. The company lost, and some sources allege that management knew about the car's design flaws but chose not to fix them before it was manufactured. The EPA has also linked this company to 54 current and former Superfund sites.

Thankfully, Ford Motor Company (NYSE: F) has turned a corner.

Many companies have received federal bailout money to ease them through the recession. Ford was offered bailout money but turned it down. Compare that to Bank of America, which was only too happy to accept a fat bailout and then disregard the terms specified for accepting the money. Or to Solyndra, which took over half a billion federal dollars, then went bankrupt. Ford has had serious losses in recent years, yet the company avoided filing for bankruptcy and chose not to take money that ultimately came out of taxpayers' pockets.

Ford acquired Volvo Car Corporation in 1999. As I've discussed previously, the company has since sold Volvo to Geely Automotive. However, Ford began implementing Volvo-developed safety features into their own cars not long after they purchased Volvo. Did Ford buy Volvo to learn how to make a safer car, as I suspect Geely did? Whatever the case, safer cars are a good thing, and for most consumers, Ford cars are much more affordable than Volvos. Installing Volvo-quality safety features in inexpensive cars is a far cry from cranking out the explosion-prone Pinto.

Ford has also been "greening" its product line and increasing the efficiency of its cars for several years. Compressed natural gas vehicles, flexible fuel vehicles, and hybrid electric vehicles are now made by Ford, with plans for all-electric vehicles, plug-in hybrids, and hydrogen fuel cell vehicles in the works. Ford also developed upholstery foam containing 25% soybean oil, which is now installed in three-quarters of their vehicles. Upholstery foam is petroleum-based, and replacing even one-quarter of the petroleum helps trim the company's carbon footprint and reliance on oil. (Henry Ford was an early proponent of soybean-based materials, even owning a soybean suit.)

Clearly, Ford's management has learned something about ethics. They also know how to keep a company financially viable during tough times. Ford's balance sheet is reasonably strong - debt is higher than I prefer, but the company has been significantly reducing its debt level in the past two years. Ford's sales are also on the rise again, with an 11% increase in just one month (August 2011).

Ford already has four plants under construction in China and plans to build more in India. Given the rising demand for Western goods in Asia, Ford is proving that they have a global strategy.

Ford is redeeming its past mistakes, and I expect the company to compete effectively over the next several years. As of today, the stock is trading at $12.59, significantly lower than its February 2011 high of $18.71, and will begin to pay a dividend in March. With a P/E of less than 8, the Ethical Investor likes Ford stock at current prices, but be patient - Detroit wasn't built in a day.

Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.