If you were going to pick a word to turn the 2013 Bloomberg New Energy Finance summit into a drinking game, it would have to be "resilience." If you did, you would have been on the floor well before the networking reception officially got underway. (Ideally, you also would have been telecommuting to save energy in honor of Earth Day, and no one would have noticed if you spent your Monday at home playing drinking games while live-streaming a clean energy conference.)

The sixth annual event’s theme is New Energy ROI: Resilience, Optionality, Intelligence. The concept of resilience seems to come up everywhere, even though few stop to define it. The theme this year is vague, but the ten companies chosen from more than 200 as the 2013 New Energy Pioneers are more straightforward. Many of them are essentially pure-play energy efficiency companies, helping homes and businesses use less energy through technology or tools that shape behavior. Other recipients included everything fromsolarlighting for developing nations to water treatment for hydraulic fracturing.

Here are the winners:

Advantix Systems was a BNEF New Energy Pioneer finalist in 2012 and broke through as a winner this year. The Florida-based company makes air conditioners that use 30 percent to 80 percent less energy by using a brine solution as a liquid desiccant. Advantix has three products lines for industrial and commercial applications, including one that can run on renewable energy such as solar thermal or waste heat. The global air conditioning market is expected to double by 2018.

Australian-born BuildingIQ already has the attention of Siemens, Johnson Controls and Schneider Electric, so it’s no surprise that BNEF has kept its eye on this startup. BuildingIQ optimizes commercial HVAC and integrates it with other data streams, such as weather, not only to cut energy use but also to take part in demand response programs. The software-as-a-service company recently raised $9 million.

Many of the energy solutions we cover at Greentech Media are for energy-hungry consumers in developed nations. But what about delivering clean power to the nearly 2 billion people who do not have regular access to electricity? D.light design is one of the companies doing that with its affordable, solar-powered lamps that can also charge a mobile phone. The company’s target is not just to bring light to places that currently don’t have any, but to fundamentally improve the quality of life for 50 million people in the next two years. D.light is growing at a rate of 1 million customers a month and expects to be profitable this year.

Draker makes the list in 2013, after being reported number one in total new monitored megawatts for PV systems in 2011, according to GTM Research. Last year, the Vermont-based firm merged with Austin's Solar Power Technology (SPT) and garnered $8 million in venture capital for a total of $18 million.

Next time you’re passing through the Schiphol airport in the Netherlands, you might notice the extra light. That’s thanks to EcoNation’s LightCatcher technology, which helps bring more daylight into buildings using a mirrors-and-technology-based system. One of the reasons it was named a clean energy pioneer is that the company also offers a financial model that allows customers to realize immediate savings to be made without upfront investment.

There is no replacement for water, and yet investment in clean water technologies often lags other areas. One of the water-focused New Energy Pioneers is Ecosphere Technologies, which has an ozone-based, non-chemical water treatment and recycling technology for oil and gas companies. For every barrel of oil produced in the world, an average of three barrels of water are required, which then need to be treated. But oil and gas are just two markets, and Ecosphere also sees opportunities in municipal wastewater, agriculture and mining.   

Harvest Power is another company that was picked in part because of its strong momentum. Harvest Power closed a $100 million VC round in 2012, to build and manage biomass plants that produce fertilizer and renewable power. Germany already offers a feed-in tariff for biomass power production, and more U.S. cities are looking to keep organic waste out of landfills.

The other side of the energy market is transportation, and that’s where Joule is playing. Joule Biotechnologies makes renewable fuels from waste CO2 and sunlight, as well as chemicals. The company was recently working with Audi to test its drop-in fuels. The Massachusetts-based company commissioned its first demonstration plant in New Mexico last fall.

Utilities need all the help they can get when it comes to consumer engagement. Enter Opower, which has become the darling of utilities seeking to engage consumers with their basic energy use and encourage efficiency. The startup just launched its latest platform, which takes the company from an easy, light-touch customer engagement offering to an enterprise-level software platform.

Another water winner was Whitewater Technologies, which provides network management and water quality monitoring for utilities and industrial companies. Electricity gets most of the focus when it comes to the need for a smarter grid, but the water grid is often more outdated and badly in need of repair. Israel-based Whitewater not only offers water software for operational efficiencies but also has products for water quality testing.