Research on the practical application of the innovative geothermal resource exploration method "pH Mapping"

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K20499
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64050:Sound material-cycle social systems-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Suzuki Yota 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 研究員 (70829499)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 地熱資源探査 / 地熱貯留層 / pH / Shadow効果

Outline of Final Research Achievements

To validate the concept of pH mapping, a field survey was conducted in an area with known neutral hydrothermal reservoir locations. As a result, we found that appropriate data selection is necessary to estimate the location of neutral hydrothermal reservoirs based on pH maps, and we developed a data screening method. More than 2,000 surface water samples were collected and digitized from major geothermal areas in Japan, and the applicability of pH mapping was verified. Furthermore, it was shown that considering topographic variables, such as drainage density, is effective when selecting the study area.

Free Research Field

地熱エネルギー

Academic Significance and Societal Importance of the Research Achievements

地熱発電は，再生可能エネルギーの中で唯一，安定電源という利点を持つが，国内の地熱発電設備容量は，1996年以降ほぼ横ばいとなっている。地熱開発停滞の要因として，高い開発リスクが知られており，地熱開発促進には，開発リスクを低減させる新しい技術が不可欠である。「pHマッピング」は，従来のものより迅速性・経済性の面で優位な地熱探査法として提案され，地熱開発リスク低減に効果的と考えられるが，未だ実用化には至っていない。本研究では，pHマッピングの概念を検証するとともに，性能評価・課題抽出等を実施し，pHマッピングの実用化に向けて重要な知見を獲得した。