Marty Spitzer is the director for U.S. Climate and Renewable Energy Policy at WWF. He contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

What can rotary dial telephones, cathode ray tube (CRT) televisions and door-to-door milk delivery teach us about the renewable energy revolution? They show us how once commonplace products and services have been, and will always be, replaced by newer ones. It's not farfetched to say 2014 is to renewable energy what 1955 was to the CRT TV — the golden age of renewable energy is just now upon us.

Many of America's largest companies also are convinced that a clean energy future is what they want, and they've set significant goals to get there. In fact, 43 percent of Fortune 500 companies have set renewable energy and efficiency targets, and better still, 60 percent of the Fortune 100 have set targets.

Windturbines near the North Sea coast. Wind energy is well developed in the Netherlands. (Image credit: © Michel Gunther / WWF-Canon)These corporations are demonstrating real progress toward their goals. For example, Mars, Inc., a food company known primarily for its candy brands and pet products, recently announced that it will invest in a massive 200-megawatt (MW) wind farm in Lamesa,Tex., equivalent to 100-percent of its electricity demand in the United States — which, according to Mars, is the largest long-term commitment to renewable energy made by any food-manufacturing business in the United States.

Companies across sectors are aggressively pursuing renewable energy — however, this transition hasn't been easy. The process of contracting directly for renewable energy is complicated, and even the largest companies often struggle with capacity to navigate complex deals and financial structures. At the same time, in a number of states, market structures actually prevent companies from directly procuring the renewables they are looking for and utilities have been slow to respond to their major customers' requests for more renewable energy.

To address these challenges, 12 major companies have signed onto a set of Renewable Energy Buyers’ Principles — a clear set of guidelines designed to help utilities and renewable energy providers understand how they can help make renewable energy investments easier for companies and meet rising demand.

The Sustainable Energy Development Authority Office's in Sydney's business district has installed solar panels on their roof. Sydney, Australia September 2003. (Image credit: © Adam Oswell / WWF-Canon)And companies like Sprint recognize that cost-competitive renewable energy exists, but the problem is that it's way too difficult for most companies to buy. Amy Hargroves, director of corporate responsibility and sustainability for Sprint knows first-hand that, "Very few companies have the knowledge and resources to purchase renewable energy given today’s very limited and complex options."Take Walmart for example. Walmart is the largest corporate user of solar energy in the United States, powered by more solar energy than consumed by 38 states. But they can't meet their long-term goal to be powered 100 percent with renewable energy, or even their 2020 goal to drive the production or procurement of 7 billion kilowatt hours globally, unless they have more options for procuring cost-effective renewable energy offsite. Even the largest retailer in the world doesn't have enough roof space to be 100-percent solar powered.

What do the companies want? The companies want utilities, utility regulators and providers of renewable energy to understand that they have large demand for clean, renewable energy. [7 Reasons to Celebrate Clean Energy Successes in 2013 (Op-Ed )]

In every other aspect of their business, companies are accustomed to a competitive market for the commodities they buy. The best quality goods at the most favorable terms win the contract. However, where energy is concerned — and particularly renewable energy — companies have far fewer choices. In many markets, companies have no choice at all. In others, choices are extremely limited or require a price premium over fossil-fuel produced energy, in quantities too small to meet the company needs, and subject to ongoing price volatility

Some companies like eBay have successfully lobbied state legislatures like in Utah to open up their ability to directly contract renewable energy. Others, like Facebook and American Express are siting new facilities where they can access green energy.

But companies are willing, and in many cases would prefer, to work with the key players to make renewable energy available more quickly.

If you're a topical expert — researcher, business leader, author or innovator — and would like to contribute an op-ed piece, email us here. On the upside, there is a huge opportunity available to utilities and renewable energy providers who can bring companies what they need. The companies that have signed onto the Corporate Renewable Energy Buyers' Principles alone account for 8.4 million megawatt hours of demand per year, enough electricity to power nearly 800,000 homes each of the next few years. Many of these companies would prefer to meet this need by purchasing renewable electricity through their local utility companies, but if utility companies are unable to provide it, they are — and will — continue to go elsewhere.

A more robust, open renewable energy market with innovative green tariffs would create the competition needed to encourage other companies to set and meet aggressive renewable targets, something that would literally benefit the entire planet.

Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.