More and more families are moving in to Japan's first "net zero-energy" neighborhood that officially opened this summer in the western Japanese prefecture of Osaka, ushering in a new era in an "ecological" living concept.

The residential development is a pioneer in the new philosophy about modern living that promotes the use of renewable energy resources as a way to enjoy the extra bonus of the power generated by one's own home.

The new residential zone, called "SMA-ECO (smart and ecological) Town Harumidai," has been developed by Sakai City in southern Osaka Prefecture, in cooperation with Daiwa House Industry Co., one of the country's major housing manufacturers, as part of a government-led project aims to promote environmental-friendly suburban living.

In Harumidai, 29 family homes and a multiple-purpose meeting hall have been built in the first construction block which the city officially opened in June. The second phase of construction is now in progress and the full opening is expected at the end of the year, when the remaining 16 houses will be built.

According to Daiwa House, the new zone, covering a total of 16, 754 square meters where an elementary school once stood, is situated atop a hill. The company says the average land area for each home is 176 square meters, and a typical two-story steel frame house with parking and a lawn was priced at 43 million yen ( about 430,000 US dollars).

The house builder said that the most distinguishing characteristic of the area is that each home is equipped with solar panels, with an output capacity of 4.3 to 5.2 kilowatts (kw) depending on the size of the house. These are placed on the southern roof. A 6.2 kwh-class lithium-ion battery would store the generated electricity and supply it to the house, which uses light- emitting diode bulbs.

To promote the use of all the power generation equipment, the city covered the installation costs of 100 million yen (about 1 million US dollars).

The builder, meanwhile, devises ways to lay out routes or fix windows in houses to more effectively use the wind blowing over the hill for air circulation. It also uses special fiberglass as heat insulation material for the external wall of each house to prevent excessive changes in room temperature during the summer and winter.

Naoki Wakihama, section manager of the company's Osaka Urban Development Department, told Xinhua that all the houses in the first block were already sold out, emphasizing that many are occupied by families with owners in their 30s to 40s who are looking for an "ecological" life with their children.

But, Wakihama added, the most popular aspect among their products in the environmentally-advanced neighborhood is not just that residents can eliminate electric bills from their expenses.

They can also earn money by reducing consumption since all the houses' solar panels are systematically connected to the local grid to sell their excess electricity, in line with a new national feed-in-tariff scheme for renewable energy launched last summer.

According to Daiwa House, those houses have attained a self- sufficiency energy rate of 100 percent thanks to strong sunny weather over the past few weeks, while this rate may change depending on weather conditions.

"We were able to achieve net zero-energy with an overall self- sufficiency energy rate of 110 percent for the new development, which would produce a total of 191 gigajoules a year," said Wakihama.

"Calculating the latest performance, each household that has moved in can earn around 10,000 yen (about 100 US dollars) per month as an extra bonus from the local power company."

To check how much a family is consuming or saving electricity, the household is provided with a gadget running software that provides all the time data on the house's electricity consumption as well as by the residential zone as a whole.

Meanwhile, the residential district has its own self-government council which not only sells the whole community's electricity to the local utility, Kansai Electric Power Company, but also runs a car sharing service that provides all residents with access to an electric vehicle that is usually parked at the meeting hall, where high-powered batteries are connected to the solar power system.

The council also manages streetlights and security cameras on the area's roads.

According to Sakai City, the association also aims to promote environmental-friendly policies that encourage residents to maintain greenery in their neighborhood, especially on outer wall surfaces facing public roads and lawns to reduce the area's air temperature.

In addition to these eco-friendly policies under the energy independence system, the new eco-friendly development has another way to avoid inconvenience in the event of a major disaster by fully utilizing the system.

In the meeting hall, which stores supplies such as emergency rations, there is a couple of benches on the deck outside where residents can quickly make use of emergency cooking stoves and toilets whose auxiliary power unit is operated by the solar generation control system.

"When a disaster causes serious infrastructure problems, the residents here can temporarily spend their time using these emergency facilities that are powered separately from the local grid and use the electric car as a power source," Wakihama said.

Ahead of the full opening at the end of this year, this unique Osaka neighborhood has already become a hot destination for public administrators. So far, more than 20 official groups have visited the site, many of whom came from the area devastated by the earthquake and tsunami in 2011.

This "smart" and "ecological" residential zone design developed by the city in Osaka to better manage energy consumption may be an example of the next generation's lifestyle in Japan, which is now seeking the best ways to use renewable sources for further growth.