Understanding the Basics of Geothermal Power
Understanding Closed-Loop Binary ORC Technology
Understanding Geothermal Drilling
Nevis Geothermal - A 24/7 Available Compliment to Wind and Solar
Recent Challenges. Like many island nations, St. Kitts and Nevis is heavily reliant on fossil fuels for electricity generation, leaving it vulnerable to global oil price fluctuations that directly impact the cost of electricity. The government subsidizes the fuel charge for residential customers, partially shielding that sector from price volatility.
Grid Instability. While renewable energy sources are being promoted as a means of reducing the use of fossil fuels, the utilities on both islands indicate that the amount of renewable energy it can place on its grid is limited. Nevis has also experienced up to 20.3% in transmission & distribution losses that are reportedly attributed to nontechnical losses such as unmetered consumption.
Current Base-load Power. The existing Diesel Power Plant consists of seven diesel engines with fuel supply that have been quite expensive to maintain.
Current Diesel Prospect Power Plant
Solar. The twin islands have adopted solar energy with one plant on St. Kitts generating just below 1 megawatt of electricity and another is under development.
Wind. Nevis has an existing 2.2 MW Wind farm that has been in service since 2010 but it provides less power than its nameplate rating. Outside advisors previously recommended not to add more than 4.4 MW of wind and solar (combined) on the grid, as this could result in a greater level of instability.
Limitations with Intermittent Renewables. When the sun no longer shines and the wind no longer blows, other base-load and flexible resources (that can quickly ramp up) are needed to balance the load of intermittent power sources. Utilities can't provide power from wind and solar without supplementing it with another flexible generation source (able to ramp up and down) to balance the load resulting in more costs to consumers. These costs, known as “pass-through fees” are derived from the Integration, Transmission and Delivery process.
The Answer in Geothermal.
Geothermal power on the other hand, is both flexible and base-load. Geothermal plants need only a small amount of acreage compared to other renewables. Geothermal resources also come with benefits such as Automatic Generation Control (AGC), intertia, dispatch-ability, voltage regulation, reactive power regulation, and flexibility.
Through the use of geothermal heat and a closed-loop binary cycle power plant, virtually nothing will be emitted to the atmosphere making the island into the cleanest running country on the planet. In this type of binary cycle (closed-loop) geothermal system, any extracted fluids are re-injected into the subsurface. The first plant of its kind on the island will supply 9MW of power that is immediately expandable to meet the ongoing power needs of Nevis and easily capable of exporting 40-50MW of additional power to other islands. The power plant's footprint will be no more than to 2-3 acres in size with an initial capacity of 10MW and expandable to 40MW.
Energy Security for Nevis
Utilities must not only generate a reliable supply of power but they must have the ability to protect and deliver sufficient energy to meet the growing demands of its users. Energy security involves removing any opportunity for external threats to the electricity supply. In the unlikely event of a hurricane or severe weather geothermal can keep producing power, unlike wind or solar.
Cost Savings for Nevis
Continuing to reduce energy use and costs is a constant challenge. One that can only be achieved by constantly looking for new ways to maximize the efficiency of necessary resources, optimize performance and reduce energy demands. These are the benefits for the Nevis Utility when TEP's Geothermal power plant comes online as it will eliminate CO2 emissions and decrease energy costs by fifty percent.