Direct Heat Use
Geothermal energy is among the oldest, most versatile, and most common ways to use Earth’s natural heat. The simplest uses of geothermal energy harness heat or steam as it leaves the ground: bathing and thermal spas, space heating, greenhouses, district heating systems, and drying—all of which date to prehistoric human civilizations.
Low-grade geothermal resources (i.e., those cooler than 150°C or unable to support power generation) are abundant. The United States Geological Survey estimates that low-grade systems could produce nearly three times the annual thermal needs for residential heating, cooking, and clothes drying. This rises to eight times the thermal needs for these applications when incorporating sedimentary resources.
Direct-use applications extend beyond heating to include greenhouses, aquaculture, food processing, and industrial uses, such as pulp and paper processing and drying construction materials.
PROJECT SPOTLIGHT
Support for a Geothermally Powered Paper Mill
Carter Holt Harvey // Kawerau, New Zealand // 2007 - 2011
While working for Mercury Energy, RESPEC staff led a feasibility study to supply approximately 100-MWt geothermal fluids to a paper mill near the 100-MWe Kawerau Power Station, wellfield, and resource production system. The pulp and paper plant, which processes logs from the nearby Kaingoroa Forest, was built in the 1950s and relied on geothermal steam as a power source.
RESPEC staff worked with Sinclair Knight Merz (now Jacobs Engineering) and Carter Holt Harvey staff on a feasibility study with co-production and system management from the new Kawerau Power Station to replace the gas heater on a digestion tank. The study demonstrated that the project was commercially viable, with the potential for direct heat use and power generation to increase overall efficiency.
The Carter Holt Harvey and Mercury Energy Boards approved the project. The RESPEC team managed the budget and contractors to drill wells; installed the geothermally heated processing tanks, piping, and instrumentation; managed subcontractors; and led the startup.
PROJECT SPOTLIGHT
Deep Geothermal Borehole Drilling for the Toronto Waterfront
Waterfront Toronto // Toronto, ON, Canada // 2023 - Present
Waterfront Toronto sought a technical consultant to conduct a deep geothermal study in Toronto's eastern waterfront and assess the technical and commercial feasibility of a deep geothermal system. RESPEC was retained to perform a study that will collect data and describe the subsurface thermal and geological properties as key inputs to future business and energy infrastructure planning for Villiers Island and the broader Port Lands.
For this phased study, RESPEC is responsible for conducting a needs assessment, determining regulatory and permitting requirements, preparing a pre-tender cost estimate and procurement strategy (Phase 1), collaborating with Waterfront Toronto in the preparation of the Request for Proposals for a drilling contractor (Phase 2), analyzing data collected from the test borehole, and documenting the results of the borehole drilling program (Phase 3). RESPEC will also oversee the mobilization and implementation of borehole drilling operations; ensure the drilling contractor adheres to contract terms, specifications, and regulatory/permit requirements; and draft a final technical report.
