Geothermal Development Project

Geothermal In The Lesser Antilles

Emera Caribbean Inc. and Reykjavik Geothermal, in association with the Government of St. Vincent and the Grenadines, are planning a 10 MW geothermal power plant at the foot of La Soufriere on the northern part of St. Vincent.
 
By: Gestur Gislason, senior geochemist at Reykjavik Geothermal &
      Snorri Gudbrandsson, PhD geochemist at Reykjavik Geothermal
 
Annually, about 140 GWh of electricity is produced to meet the needs of St. Vincent Electricity Services’ (VINLEC’s) customers. The planned 10 MW geothermal power plant has the potential to serve about 60% of the electricity needs of St. Vincent’s residents and businesses.
 
About geothermal around the world and in the Caribbean
 
Geothermal power plants have been built in 25 countries around the globe, with a total 12,635 MW installed capacity and an annual production of 73,549 GWh. Closer to home, the eastern boundary of the Caribbean geological structure is the Lesser Antilles Volcanic Arc, with its numerous volcanoes and related geothermal activities. The Volcanic Arc is located in the subduction zone were the Atlantic plate moves beneath the Caribbean Plate, forming the Lesser Antilles Volcanic Arc.
 
subduction zoneThe heat source which keeps the geothermal systems active in geological settings in the Lesser Antilles is magma, which is formed more than 100 km deep under the Volcanic Arc. Only a small portion reaches the surface in an eruption, but the bulk of the magma settles as intrusions or in magma chambers above the location of formation (melting). Most of the intrusions are found at great depth, but magma chambers can reach up to 7 km in depth.
 
Drilling for geothermal steam
 
Geothermal is used either directly, providing energy for an array of uses such as space heating or cooling, in aquaculture and drying, or for electricity production. In St. Vincent, we are exploring the possibility of using geothermal steam for electricity production. For this purpose, temperatures above 200°C are necessary, which requires drilling through the cap rock. The depth of a geothermal well is most commonly 2-2.5 km deep.
 
Eruption hazard
 
Geothermal activity is a product of magmatic activity. As a consequence, most geothermal power stations are located in volcanic areas near lava and eruptive sites. Eruptions occur when lava, gases or ash escapes from a magma chamber below. Because geothermal wells are rarely deeper than 3.5 km and the magmatic heat source is generally below 7 km depth, direct contact, and therefore eruption, is unlikely. 
 
Thousands of geothermal wells have been drilled into active geothermal reservoirs, and there has been no triggering of volcanic activity. Indonesia and the Philippines have subduction zones that are similar to St. Vincent. In Indonesia, which produces 1,340 MW of geothermal energy annually, and in the Philippines, at 1,870 MW annually, more than 600 5-MW geothermal boreholes have been drilled without triggering eruption. 
 
There have been a small number of cases where a borehole has been drilled into a body of molten magma without causing any major problems, where the equipment was safely retrieved and no magma was ejected to the surface.
 
We will continue to share information with the St. Vincent public as progress on geothermal exploration at La Soufriere continues. If you have questions about geothermal energy, please contact the team’s lead geo-scientists: This email address is being protected from spambots. You need JavaScript enabled to view it. or This email address is being protected from spambots. You need JavaScript enabled to view it.This email address is being protected from spambots. You need JavaScript enabled to view it..">.

 

ELECTRICITY PRODUCTION USING GEOTHERMAL ENERGY 

By: Gestur Gislason, senior geochemist at Reykjavik Geothermal &
      Snorri Gudbrandsson PhD geochemist at Reykjavik Geothermal
 
Emera Caribbean Inc. and Reykjavik Geothermal, in association with the Government of St. Vincent and the Grenadines, are planning a 10MW geothermal power plant at the foot of La Soufriere on the northern part of St. Vincent.
 
Geothermal steam has been used for over 100 years to produce electricity. The first power plant was built in Italy in 1904. Since then, more and more geothermal resources have been harnessed for power production.
 
With over a century-long history and world-wide distribution, geothermal power is a well-known and thoroughly tested technology. The USA has the world ́s highest installed capacity at 3,450 MW, mostly in the Geyser fields and Salton Sea, CA. The Philippines has the second highest installed capacity with 1,870 MW, followed by Indonesia at 1,340 MW.
 
Today, there are geothermal power plants in 25 countries with a total 12,635 MW installed capacity and an annual production of 73,549 GWh. For comparison, the annual production of VINLEC is about 140 GWh. The planned 10 MW geothermal power plant will potentially serve about 60% of the electricity needs of the island.
 
Geothermal energy has proven to be a reliable energy source, ideal as a firm power source not subject to weather conditions, oil prices, etc.
 
Geothermal systems
 
Sourcing of geothermal resources suitable for power production are closely related to the Earth’s plate tectonics and volcanism. Most commonly the resources are located on or near plate boundaries, both where rifting occurs, such as in Iceland and Kenya, and on subductions boundaries, as is the case in the Philippines and Indonesia. With its complex tectonics, with both subduction and transverse faults the Caribbean Gulf and Central America is a promising area for geothermal energy for electricity production.
 
geo picThe heat source of geothermal systems is magma that indirectly heats deep-flowing water which seeps through permeable bedrock at great depths. The magma transfers heat to shallower levels in the crust. As the magma cools, it conducts heats through the surrounding rock formations as wells as the overlying rock towards the surface. The heat transfer can elevate the rock temperatures to as high as 250 – 500 °C at 1-5 km depth, forming ideal conditions for a geothermal reservoir. At this depth, the rock is still permeable enough to allow surface water (either fresh rainwater or seawater) to percolate through the reservoir rock. As the water heats up, it starts to rise back towards the surface due to lowered density of the hot water. With time, the system will develop into a convectional system where the hot fluid will rise above the heat source to shallower levels where it cools and starts to sink away from the main up- flow zone. The circular motion is driven by the continuous heat being brought to the system fromthe deep-seated magma. The elevated water temperature will alter the reservoir rock and form the so-called cap rock, sealing the geothermal system from the surrounding colder environment. Leakages in the cap rock will enable some of the geothermal fluid to escape to the surface, forming surface manifestations such as hot springs, mud pools and steam vents. 
 
The Soufriere volcano on St. Vincent is an example of a geothermal system as described above, with manifestations of geothermal steam in the crater area and the warm springs of Trinity Falls in the upper reaches of the Wallibou River.
 

Aim: To deliver a 10-15 MW geothermal power plant to St. Vincent & the Grenadines (SVG).
Partners: Reykjavik Geothermal, Light and Power Holdings Ltd, Government of St. Vincent and the Grenadines, Clinton Climate Initiative, VINLEC
Duration: 4 years
Cost: US $82M
Funding: Reykjavik Geothermal, Emera Caribbean Incorporated, GoSVG

Activities: Since the signing of the first Letter of Intent with the partners in January 2013:

  • A Kick-Off meeting was held on May 21st, 2013. This meeting involved all stakeholders of the Geothermal Development Project.
  • A desktop study was produced which was a summary and validated all previous studies and explorations.
  • Consultations were held in Sandy Bay on the 3rd and in Chateaubelair on the 4th of November. These consultations informed the surrounding communities on the geothermal surface explorations which were to take place.
  • Surface explorations were conducted on both the Leeward and Windward side of the island. A total of 34 of 50 intended points were tested.
  • A baseline ESIA was produced which outlined possible issues that may arise from specific activities and the methods of mitigation.
  • A report on the surface explorations was produced in March 2014 from which it was learned that there was some missing data from the testing due to the inaccessibility of the land.
  • Additional surface exploration has been completed which included LiDAR and multisensory mapping in the La Soufriere area.
  • Results have led to the identification of two preferred drilling sites in the Orange Hill area.
  • A community meeting was held in Orange Hill to engage the people and explain the processes what is to be expected.
  • The consortium has presented its Business Case to the GoSVG.

Status:

  • The Business Plan was presented to the Cabinet. The Clinton Climate Initiative (CCI) has engaged Delphos and the firm Holland and Knights from the US on behalf of the Government of SVG to conduct negotiations with the investors. Currently, documents such as the Stakeholders Agreement, Power Purchase Agreements and other legal documents are under negotiations in collaboration with the Ministry of Legal Affairs.
  • The CCI has also engaged the Carbon War Room and the Rocky Mountain Institute to conduct an assessment of VINLEC’s electricity grid, with support from the Global Environment Facility (GEF) amounting to $ 150,000 USD, to determine any challenges that may arise due to interconnection with the geothermal plant. Consultants visited SVG during the week of November 2, 2015 to collect data and conducted site visits of VINLEC’s generating stations.
  • Plans are being put in place to develop the infrastructure for the proposed drilling sites.

 

  • JICA has pledged its support for conducting the ESIA. They have hired international consultants Nippon Koei to conduct surveys and assessments of the proposed drilling sites. Two consultants have recently visited St. Vincent to conduct surveys with various stakeholders in preparation to assist with the development with their Scope of Works. During their visit, they identified some critical areas that need to be considered for compliance with the IF standards. These are; (i) the need for a biodiversity study, (ii) water availability assessment and (iii) a relocation plan for inhabitants at one of the proposed sites. The Geothermal Development partners have agreed to finance the biodiversity study if necessary.

 

  • The $15M US concessionary loan agreement from IRENA, through the Abu Dhabi Fund for Development will be signed soon. They have recently advised however, that it cannot be used for the drilling phase of the project, which is considered the most risky phase. It should therefore be used at a later stage when the resource has been confirmed.

 

  • The SVG Geothermal Resources Development Bill 2015 was passed in August 2015, which seeks to provide for the development and use of geothermal resources and other related matters.