Establishing Sumatra’s First Large-Scale Geothermal Power Plant Project Sumitomo Corporation - Ulubelu1&2 geothermal power plant project (Indonesia)

Power Plant EPC Dept.
No.1, Sect. No. 2 Manager
Tomoaki Kaneko

“Sumitomo Corporation has accumulated experience in the Indonesian geothermal power business, and we were always determined to win new projects. When I visited the site to do some research before our bid was accepted, all I could see was a vast slope. I thought it was going to be a tough project. But I was determined to get the deal and build a power plant here by any means necessary.”

That’s how the project manager Tomoaki Kaneko remembers the time he first visited the uneven grounds of the Ulubelu geothermal power plant, completed in October 2012. Mr. Kaneko is Manager of Sumitomo’s Power Plant EPC Dept. 1, Sec. 2.

Sumitomo Corporation has handled a number of geothermal power projects, including Wayang Windu, where the first unit was completed in 2000. Mr. Kaneko was involved in the geothermal power business when the Ulubelu project was in the planning stage. After being stationed in Indonesia for 6 years, he assumed his current post. Through various positions, he has been involved in Indonesia’s geothermal power projects, including the Ulubelu project for several years, and he is very passionate about the project.

Japanese Manufacturers Take the Lead in the World’s Geothermal Turbine Market

With geothermal power generation, steam from deep within the earth turns the power generator’s turbine. A major feature of geothermal power is that it is a renewable energy source with a semi-permanent and stable supply. Since the groundwater is heated with magma, no fossil fuel is required and the carbon dioxide (CO2) emission is only 1/20 that of other types of thermal power generation. Additionally, there is no need for a vast amount of water for making steam, as with thermal or nuclear power. Unlike solar or wind power, geothermal power is not affected by environmental factors such as weather, season, or daylight hours— providing a stable supply 24 hours a day, 365 days a year. Therefore, geothermal power is considered to be the most environmentally-friendly and reliable form of power generation among the many types of renewable energy.

There are two main methods for power generation. One is the Steam Power Method where the steam itself turns the turbine. If the geothermal steam is used directly, it’s called the Dry Steam Method. If a mixture of steam and hot water comes out of the earth, a steam-water separator is used to create steam which turns the turbine, and this process is called the Flash Cycle Method. The other method is the Binary Cycle Method, which uses hot water and low-boiling-point fluids to create high-pressure steam that turns the turbine.

Flash Cycle Method

Binary Cycle Method
Source: “Mechanisms of Geothermal Power Generation”
from Resources and Energy Agency (Japan) website

The global mainstream is currently the Flash Cycle Method, as it is rare that only steam is produced, and the construction and operational costs for the Binary Method are higher than either of the Steam Power Methods.

In the field of Flash Cycle geothermal turbines, Japanese heavy electric machinery manufacturers hold approximately 80 percent market share of the world’s installed capacity. Various impurities, heavy metals and corrosive substances are included in the natural underground steam, so resistance to corrosion and prevention of scale accumulation are required for manufacturing geothermal power turbines. Japanese heavy electric machinery makers are far ahead of the global competition with their technology and know-how.