Queen’s Park Power Station
The first Generation plant on the island of Grenada was owned and commissioned by the Grenada Electricity Services Limited (GRENLEC) on Feb 14th 1928 and was located at Burn’s Point, St. George’s where presently the Grenada Postal Corporation is located.
In the year 1960 the total installed capacity was 1700 kW.
As part of the Company’s’ continued generating expansion, in 1961 two 600 kW Ruston-Hornsby Gensets was installed at Queen’s Park, St. George’s, where the lone Generating facility remains to this day. Later in the same year, the 375 kW Lister Blackstone and the 375 Ruston-Hornsby units were moved from the Burn’s Point Plant to the Queen’s Park Power Station. The Queen’s Park Power Station increased installed capacity totaled of 1950 kW.
The company’s largest single generating unit up to 1962 was added in the form of a 1000kW Ruston-Hornsby unit. In 1968, a completely new type of unit, which was different from the existing fleet, an English Electric unit, was added to the Generation fleet. This unit was a 16 Cylinder, 1.425 MW Diesel generating set. In 1971 another 16-cylinder unit 1.450 MW Genset was installed. The next major Generation addition was completed in 1984 when two 1.82 MW, 12RKC Ruston units were added to the system these are currently the #8 and #9 units. In 1986 another 12RKC, 1.82 MW Diesel Prime Mover was installed, this was coupled to an old alternator and was de-rated to 1.425 MW.
In 1987 the unit #10 was installed. It is an EMD645 (General Motors), rated at 2.04 MW. From the period 1980, smaller, containerized, standby units were installed as backup with black-start capabilities. The first one in 1980 being a Caterpillar Engine, although the Genset carried the name Woodlands.
The Mirlees Blackstone unit (#11), which is now decommissioned, was installed in 1991. This unit had an alternator that was rated just over 4MW and an engine rated at over 5MW. Subsequent to this addition another relatively large unit in the form of the Vaasa32, Wartsila generating set was installed. This set is rated at 5.2 MW.
The latest plant expansion, which was commissioned on July 23rd, 2002, includes a new building named (Plant B) and the installation of two Caterpillar MaK units each rated at 5.5 MW. The present total installed capacity stands at 33MW.
We generate power to feed the entire island from this location. At present we have a total of 17 generating units ranging in size from 1280KW to 5500KW. To distribute the power generated here we have 7 feeders that take the power to the consumers.
These Feeders are named Gouyave (Cherry Hill to La Mode), Grenville (Mt. Gay to La. Mode on one end and Soubise on the other end), Industrial (Mt. Gay to Soubise on one end and Red Gate on the other end), Belmont (Lucas Street to Red Gate, and parts of the Grand Anse area), Grand Anse (Mt. Gay to Grand Anse), St. George’s West (Queen’s Park to Sendall Tunnel. This incorporates the Hospital, CID and many of the businesses in and around the Market area), St. George’s East (Queen’s Park to Sendall Tunnel. This goes in the opposite direction incorporating River road, Tempe, Lowthers Lane and the Carenage).
At the Plant the Generators use Diesel fuel to run the engines. Diesel is pumped from a tanker at sea to the three bulk fuel tanks located on the North end of the compound. With all the tanks filled we have 1.5 Million Gallons of fuel on site, which could last approximately 6 weeks. Fuel is then gravity fed from these tanks to smaller tanks, which feed the Plant. Each engine has it’s own day service tank. Oil is also stored on site and pumped to the engines as required.
How is electricity generated? Basically a coil of wire which, when it cuts a magnetic field, induces a voltage in the coil of wire. This is the same principle as used on a bicycle generator. However in this case it is three phase power and on a much larger scale.
By design the Generators are sized differently as mentioned before, both in terms of their rated voltages and output power. For example we have sets rated at 1280KW @ 400V and 5500KW @ 3300V. In each case a step-up transformer is used to transform the voltage to 11000V (11kV). 11kV is the Distribution Voltage and the Bus as well as the main circuit breakers are rated at 11kV. As a result of this many differently rated units can be paralleled together onto the common Bus. A Power Plant is unique to other installations on the island in that we have to parallel a number of generating sets to meet our demand. In order to parallel two or more gensets three conditions have to be met. The frequency / speed of the generators have to be equal, the Voltages have to be equal and the phases must match. Only after all these conditions are met can the two units be paralleled.
System Demand is 20MW and highest peak recorded was 22.7 MW. We have an installed capacity of 33MW. This power is then distributed via the seven feeders to all areas around the island. Near to your homes or villages the voltage is stepped-down to 400V for commercial applications and 230V for domestic applications. The main reason
for stepping up the voltage to 11kV is that at that high voltage the current is very small and as a result smaller cables can be used to transfer the power. Additionally there are fewer losses as a result of using the smaller cables; therefore most of the power we produce reaches the consumer. Smaller support structures and longer distances between poles can be achieved by using smaller cables.
How do we operate?
We have on site Power Plant Operators, Maintenance Personnel, and System Control Operators.
The Power Plant Operators, they monitor and control the generators. They start, stop, load and unload the units as required to maintain the system frequency, voltage, and to meet the demand. The operators monitor the engines and the alternators as well as the auxiliary equipment needed to run the gensets. They look at temperatures and pressures of the oil, air, water, and fuel systems of the mechanical components, voltage, current, system frequency of the electrical components. To aid in their monitoring they have specialized equipment as well as equipment we are all familiar with. Thermometers, manometers, voltmeters and ammeters are some of the basic instruments.
Maintenance personnel who are mechanics or technicians maintain the equipment to manufacturers specifications.
System Control Operators are responsible for the system. That is from Queen’s Park covering the entire network. They are responsible for answering the trouble calls and fault reports that consumers call in. They also direct service crews to the areas of faults to rectify the problems. The System Control Operators however belong to a separate department that is Planning and Engineering.