In 2006, Java developer Adam Bien started to hack his heating system to reduce energy consumption and heating costs. Then this has turned into an award-winning open-source heating system regulator called GreenFire.

Two years ago, Bien installed a new heating system in his house in Bavaria, Germany. The system is based on solar pawardanels and a wood stove with pellets. Shortly after installation, he noticed that that the system’s parameter settings were less than optimal. The primary heating was turned on each day at 4pm, regardless of whether or not the solar panels had been heated during the day.

After having tweaked various parameters of the heating system manually for some time, Bien started to develop a Java EE 5-based heating system regulator. He developed a prototype in four days that could access and control indoor and outdoor temperature sensors that formed part of the heating system.

The prototype became GreenFire, a heating system regulator that is now operational in Bien’s house. According to Bien, GreenFire has reduced his energy consumption by 30 to 50 percent. Every five minutes, GreenFire reads off a weather forecast in addition to all heat sensors (some SunSPOTs as well) that are connected to the heating system. Based on this information, GreenFire decides whether to turn the heating on or off. The decision and the sensor data is saved in database.

The saved data can be monitored remotely through a mobile browser and it is also possible to turn the heating on and off with his mobile phone.

“The system was really easy to build, including the mobile integration,” Bien says. “Even a real beginner could do it, you just need some familiarity with servlets and Java EE. I simply invested some of my free time in order to save energy and money without sacrificing comfort of living.”

While that does sound like a simple and obvious thing to do, the fact is that no one had done it before. This was recognized at this year’s annual JAX conference, which was held in Wiesbaden in Germany, April 21-25, where Bien was given the Innovation Award by the audience.

The award came in the same month that Bien went public and released GreenFire as an open-source project on java.net.

“Since then, people have downloaded and played around with it, but I don’t know how many installations there are out there,” he says.

Bien says that there definitely is a market for energy-saving applications like GreenFire, but he says that the heating system industry does not seem to be interested.

“I have thought about going commercial, but I am developing GreenFire in my spare time and I am already almost overbooked in the Java EE space. If I go commercial, I have to do marketing, provide support and so on, and I don’t have time to do that. Anyway, I am more interested in saving energy worldwide.”

By Olle Blomberg

Related links:
The JAX award
Interview with Adam Bien in Javalobby
GreenFire’s home on java.net
Adam’s weblog
SunSpotWorld