Much has been written, and deservedly so, on Atlanta as an emerging hub for technology startups.

Most of the light on startups – from the news media, investors and economic developers – shines on entrepreneurs with perceived potential to scale large and fast with their mobile/digital/Internet apps.

Little attention, however, has so far been directed to the products, services and technologies emerging from the small but growing clean technology sector in Atlanta’s startup community — entrepreneurs on a mission not only to make money, but to help solve significant societal and environmental challenges.

SoldeSal, for example, develops and deploys sustainable, cost-effective, solar thermal desalination technology for water-scarce areas. It is applicable to coastal ocean water and inland brackish water. And Reviresco Corporation’s technology generates electricity from processed municipal waste, diverting tons of raw waste from landfills annually.

A cluster of these “green” entrepreneurs can be found in a mentorship program of the Green Chamber of the South — an organization dedicated to the adoption of green energy, clean technology and sustainable business practices. Its nonprofit Greenhouse Accelerator program supports early stage entrepreneurs with technologies, products and services that foster renewable energy, reduced energy consumption, redirected waste streams, and more efficient use of natural resources

For example, through proprietary engineering innovations, Norcross-based Intelligent Energy Optimizers has improved the light output, lifespan and energy efficiency of commercial induction lighting fixtures — a type of fluorescent lighting — beyond other systems in the market today. One such advancement decreases the operating temperature of the bulb which, in turn, reduces air conditioning costs on the shop floor.

Another startup, Retrofit America, has a mission to jump start demand for energy-efficiency retrofits in 67 million older homes across America. It seeks to do so by licensing its proprietary software and services IT platform to a national network of home performance contractors. Retrofitting, or sealing air and duct leaks, adding insulation, and upgrading heating and cooling systems, has multiple impacts: lowered energy cost, improved comfort, job creation and greenhouse gas emission reduction.

The Greenhouse Accelerator distinguishes itself from other Atlanta entrepreneur programs in a number of ways. It focuses exclusively on green/clean tech sectors; offers pro bono mentoring services and long-term support (up to three years) including no-interest loans; and emphasizes local green job creation, impactful mitigation and long-term value rather than a large and quick return on investment. It also focuses on community outreach – linking participants with local universities and companies and senior business executives who provide pro bono guidance.

While all early stage startups face funding challenges, those in green tech sectors often are overlooked by investors. Development cycles can take longer. Customer demand may be unclear. Opportunity for “scale up and exit” may be deemed insufficient. Large sums of money can be needed for proof of concept (for example, to build a demonstration plant).

The Greenhouse Accelerator helps its entrepreneurs address such challenges. It connects them with industry for market validation and encourages “organic growth” when external funding is elusive. Mission is the driver for these entrepreneurs determined to make the world a better place.

Carol Jordan is on the advisory board of the Greenhouse Accelerator, an entrepreneur program.