Clean EnergyGeothermal Energy
Geothermal energy encompasses the utilization of thermal energy stored under the Earth’s surface. Depending on the application and its location, geothermal energy can be used both for heating and cooling, as well as for power generation. Many practical applications of geothermal energy are used to increase energy efficiency by reducing heating and cooling costs in buildings.
Geothermal energy is also a very low carbon emitter and has particularly strong development potential across Latin America, including in Peru. The geographic distribution of geothermal sources of heat are limited mostly to regions along tectonic boundaries, but there are a number of potential geothermal projects that can be implemented without the significant heat source produced by forces at work under the Earth’s surface.
The International Geothermal Association says that there is more than 10.7 GW of installed electricity generating capacity online globally utilizing geothermal sources of energy, and this accounts for a 20% increase over the previous 5 years. This indicates a significant step forward for the geothermal industry in achieving costs that are competitive in energy markets and in the development of technology for safely and reliably producing energy from geothermal sources.
Scale of Resource
It is estimated that Peru itself has potential geothermal energy resources of more than 2.8 GW equivalent that is situated in the central highlands and southern regions of the country, the vast majority being in Moquegua, Tacna and Puno departments. Below is a map detailing the potential regions of geothermal development in Peru (MINEM).
Regionally, it is estimated that geothermal energy sources are merely 5% developed indicating that there is enormous room for growth. At present, Mexico, El Salvador and Costa Rica lead the pack with 24.3 GW, 697 MW and 205 MW respectively.
Heat pumps or ground source heat pumps are shallow (around 6 to 7 meters deep), sub-surface systems that essentially use the constant temperature of the ground surrounding a facility as a heat exchanger. During warm months, this subsurface temperature is lower than the atmosphere allowing a heat pump to store heat in the ground and circulate cooler air into a building. In cooler months, this subsurface temperature is higher than the atmosphere allowing a heat pump to extract heat from the ground and circulate warmer air into a building. Of course, this relationship is highly dependent upon latitude and the seasonal characteristics of a location. Heat pumps can be utilized to increase the energy efficiency of a building’s HVAC equipment to reduce costs of operation.
Heat pumps rely on a field of spooled or coiled tubing buried near a building, which circulates a liquid or refrigerant that is then brought into contact with a heat exchanger associated with HVAC equipment in the building. Small ponds and streams can also be utilized as a heat sink to provide cooling for a building. There are many different commercially available configurations for heat pumps to fit with a wide variety of applications.
Dry Steam Power Station
Dry Steam Power stations (DSP) are the oldest, simplest, and most efficient geothermal power plant configuration. However, these systems require the high sub-surface temperatures of 150°C or higher to function. In DSPs, steam is extracted from a well to turn a turbine and generate power. The water is then condensed and returned to the ground.
Flash Steam Power Station
Flash Steam Power stations (FSP) are the most common geothermal station in operation around the world today. Because they rely on high pressure wells, they are more sophisticated and also rely on higher geothermal temperatures of 180°C or greater, the highest of the three main types of geothermal power stations. In FSPs, high pressure hot water is pumped up from the ground and released into low-pressure tanks. This produces flashed steam that is then run through a turbine to power a generator. Remaining water is then condensed and returned to the ground. However, some FSPs have experienced depletion of the groundwater source the system depends on, reducing a plant’s generating capacity.
Binary Cycle Power Stations
Binary Cycle Power stations (BCP) are a recent technological development in geothermal power stations that can operate at much lower temperatures around 60°C. BCPs utilize a liquid medium that has a lower boiling temperature than water. This medium is brought into contact with lower temperature geothermal water, flash vaporized and used to turn a turbine to generate power.
Given the lower geothermal temperatures required to operate a BCP, there is a wider applicable range where these plants can be developed, making them the most common plant type under development today. However, BCPs are the least efficient of the three main geothermal power plant types at 10-13% thermal efficiency.
There are currently no operating geothermal power stations in Peru. However, the Ministry of Energy and Mines has working proposals for several stations in Moquegua and Tacna departments.
Peru boasts one of the largest and untapped regions for geothermal energy development. Many sites are being tested currently for potential geothermal energy development. Remarkably, geothermal energy could dramatically improve energy efficiency of existing buildings around the country and could expand renewable energy production substantially.
 International Geothermal Association – “Geothermal Energy: International Market Update” – http://www.geo-energy.org/pdf/reports/GEA_International_Market_Report_Final_May_2010.pdf
 Fabíola Ortiz – The Guardian, April 13, 2016 – “The heat beneath our feet: the potential of Latin American geothermal power” – https://www.theguardian.com/global-development-professionals-network/2016/apr/13/heat-potential-latin-american-geothermal-power
 CEPAL – “Istmo Centroamericano: Estadísticas del Subsector Eléctrico” – http://www.eclac.org/publicaciones/xml/1/30101/L809.pdf
 Fridleifsson,, Ingvar B., et al. – “The possible role and contribution of geothermal energy to the mitigation of climate change” – http://iga.igg.cnr.it/documenti/IGA/Fridleifsson_et_al_IPCC_Geothermal_paper_2008.pdf
 Scientific American – https://books.google.com/books?id=pGfQmBtXYx0C&pg=PT160
 Erkan, K.; Holdmann, G., et al. – Geothermics – http://linkinghub.elsevier.com/retrieve/pii/S0375650508000576