One of the goals of this housing design is to reduce dependency on state electricity company PT PLN. Homeowners can produce electricity to suit their needs with an environmentally friendly electrical system.
Owning a house is everyone’s dream. In recent times, housing requirements have expanded to cover not only adequacy and comfort, but also affordability and environmentally friendliness. The University of Indonesia’s School of Engineering (FT UI) has proposed a new solution in affordable and energy-efficient homes that will not harm the environment: the Sofwan House.
It is an experimental house designed with millennials (born between 1980 and 1990) in mind from secondhand shipping containers. One house uses two containers.
“Containers are affordable materials and they are also earthquake-resistant. You don’t need a building permit [IMB] to build houses out of containers. The number of containers can be adjusted in line with the homeowner’s spatial needs,” Eko Adhi Setiawan, the director of the FT UI Tropical Renewable Energy Center (TREC), said on Thursday (10/25/2018) at the inauguration of the Sofwan House in Depok, West Java.
Eko said that containers were becoming popular building materials for houses across the country, especially in frontier regions where conventional housing materials, such as sand, brick, cement and steel, were hard to procure. Using containers also meant repurposing the containers that were formerly used to distribute goods on trucks and ships.
Dual-power electricity
Apart from the affordable materials, among the Sofwan House’s unique features is its dual-power electricity system, which uses solar panels and fuel cell technology. The solar panels are placed on the roof to absorb solar rays and store the energy in 48-volt solar cells. The directly absorbed energy can be used to power the house during the day, while the stored energy in the solar cells can be used to power the house at night.
If it is cloudy, the fuel cells can be used in place of the solar panels. The fuel cells use hydrogen to convert chemical energy into electrical energy, an environmentally friendly process that produces no emissions. The cells can be replaced once they are empty. Homeowners can also combine solar energy with the electricity supplied from PLN if the empty fuel cells have not been replaced.
Reducing dependence
Among the goals of the experimental house design is to reduce homeowners’ dependency on the PLN electricity supply. Instead, they can produce electricity to meet their needs.
“Switching from the solar panels to the fuel cells is still manual. We are developing a way to make the change automatic,” said Eko.
The Sofwan House is also different from conventional houses in its use of direct current (DC). Conventional homes commonly use the alternating current (AC), which can fluctuate and be inconsistent.
A DC power supply was more stable and had a lighter load. For instance, while a 230-volt DC power supply could be used fully, in contrast, the actual power available in a 220-volt AC power supply was 10 to 16 percent less than 220 volts.
The house is also equipped with a DC converter with a 2,500-4,000 watt capacity. The converter has been developed since 2016 on a grant from the Research, Technology and Higher Education Ministry, and aims to provide light and efficient power for public consumption.
Eko said that DC power supply was good for homes, as many household electronics used it. Using DC power may make the appliances last longer. Only several large appliances like refrigerators and water pumps used AC power.
Recently, DC power had become more prevalent among large appliances. Eko said he was optimistic that changes in the consumer mindset on electricity use would lead to many more producers of DC-powered electronic appliances.
PT Radiant Utama Interinsco director Sofwan Farisyi, the main donor of the Sofwan House project, said that the housing design project showed that the people did not need to depend on natural materials such as sand, wood and stone to build homes. Using solar panels and fuel cells to electrify homes were also breakthroughs that enabled homes in regions unconnected to PLN’s electricity grid to enjoy a stable supply of electricity.
“In terms of economics, the price of solar panels has continually declined over the past 15 years. It used to be dozens of millions of rupiah. Now it’s less than 20 million rupiah. The more widely it is used, the cheaper it will become,” said Sofwan.
The Sofwan House prototype has two containers with paneled walls to reduce heat inside. It has a living room, a bedroom, a kitchenette, a bathroom and an air conditioner, and costs Rp 250 million (US$16,695.38).
Two-pronged mission
The house project is a two-pronged mission.
Eko said that the house construction project was based on the idea that houses should not only be affordable, environmentally friendly and energy efficient, but also transformable and portable.
In the future, people would seek portable homes. The DC power line was used because it was simpler to install. Even with a small supply of electricity, such as during cloudy weather, the current would remain stable and safe for powering household electronics.
The shift towards using DC in the electronics industry was also driven by an ideal to contribute to energy efficiency. Waiting for changes in the industry would take much longer, so the Sofwan House project hoped to help accelerate the shift.
“We wish to transform the public mindset on household energy consumption. We are optimistic that, if the people clamor for change, the industry will follow suit by producing more DC-powered electronics,” said Eko.
