Post on 08-Mar-2023
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Introduction to renewable energy (RE) inTrinidad and Tobago (T&T)The Government of the Republic of Trinidad and Tobago iscurrently developing state policies on both renewable energy andcarbon (emission) reduction due to the growing internationalconcern over global warming caused by fossil fuels, and theirreversible depletion of natural resources. These policies, ifsuccessful, will foster both conservation and use of renewableenergy, resulting in reduced emissions and reduced demand on thediminishing gas reserves of the country. GORTT initiatives towards REThus the GORTT initiated the Renewable Energy Committee to createa policy on renewable energy and to promote feasibility studieson renewable energy projects. A Renewable Energy Policy in theform of a green paper was developed by Government and itspartners in 2008. Already, the Government has introducedincentives for renewable energy projects in the form of capitalsubsidises, grants and rebates, investment and other taxcredits. At the same time, various renewable energy devices havemoved from the experimental stages to mature commercialproducts.
In recent times, renewable energy (RE) has been seen as anobvious choice to reduce carbon dioxide and other pollutantscontributing to global warming. However, the high cost of REtechnologies is the main obstacle facing the diffusion of REpower generation, therefore economic and political interventionis inevitable. These interventions usually include legislation,incentives to investment, energy generation targets, guidelinesfor energy conservation, strategies to stimulate the energyindustry, and taxation.
Laws governing electricity in T&TThe Trinidad and Tobago Electricity Commission (T&TEC) under theElectricity Commission Act (54:70) enables the commission togenerate and supply electrical energy and for other purposes inconnection therewith. Being the sole authorize provider of theelectricity supply the commission, is poised to play a crucialrole in the thrust towards the development of RE technologieslocally and has been a key participant in responding to thenational policy challenge of developing renewable energyresources. This is based on an understanding of the significanteconomic and environmental benefits of RE technology including:
the conservation of our finite reserves finding higher value uses for saved natural gas diversification of the energy sector and by result the local
skill set reduced environmental impact resulting from a decrease in
the level of pollutants released into the atmosphere; and the potential for the accumulation for carbon credits.
T&TEC’s two (2) key responsibilities are in the policy making andthe research and development areas. As a member of the cabinet-appointed Renewable Energy Committee (REC), T&TEC is directlyinvolved in the formulation of the nations’ policy on RE and asthe entity responsible for national generation planning, whichincludes capacity, location, timing and energy mix, T&TEC isengaged in research geared towards the development of RE,particularly wind, solar, tidal and waste to energy.
Bureau of Standards wiring codes
As part of the drive to facilitate renewable energy projects andin an effort to facilitate research and development, as well astraining, in the area of PV, T&TEC partnered with the ElectricalCode Committee of the Board of Engineering of Trinidad and Tobago(B.O.E.T.T.), as well as the University of Trinidad Tobago and
the Electrical Inspectorate Division and the Ministry of PublicUtilities, to conduct a pilot project to install a small numberof small-scale PV systems for training purposes and to test thereliability of the newly developed TTBS 171 Part 3 Wiring Codefor Renewable Energy Sources. This code was developed to allowfor the grid connection of power generated from renewablesources. Hence, the code is designed to allow individualhouseholds or businesses to install permanently-connectedrenewable generation, exporting power to the mains in times ofsurplus production and taking from the mains in times of need.
RE Committee input on green power projects
TTEC being viewed as the experts in electrical energy and wasmandated to produce these pilot projects to test the code.Thevery important issue of real-time grid integration was examinedwith safety and metering considerations in mind.
Therefore the three (3) pilot projects were identified:
2.2kW Solar energy pilot at University of Trinidad andTobago O'Meara Campus
2.2kW Solar Energy Pilot at TTEC Mt. Hope 2.2/2.5kW combined solar and wind at the Islamic Home for
Children in Gasparillo.
These pilot projects are all being closely monitored using smartmeters and other real time technology interface devices to bothcapture and view data as time progresses.
Figure 1: Picture of TTEC's Renewable energy Projects
The main objectives of this pilot study were:
To serve as a live demonstration project and also providehands-on experience for Electrical Inspectorateofficials.
To allow individual households or businesses to installpermanently-connected renewable generation, exporting powerto the mains in times of surplus production and taking fromthe mains in times of need.
To test the interconnection procedures as outlined in theTTBS Interconnection Document
To provide lessons learnt analysis and results
The main project champion and sponsor was the MEEA. Boardapproval from T&TEC was not required since this project was fullyfunded by the Ministry of Energy and Energy Affairs (MEEA). This
case study would look into TTEC experience with the pilot studyat TTEC Mt Hope offices.
TTECOrganizational Structure and Industry Position
Trinidad and Tobago Electricity Commission (TTEC) is managed by aBoard of Commissioners that is appointed by the Government ofTrinidad and Tobago and an Executive Management Team headed bythe General Manager.
The Commission is structured into six functional Divisions:Administration, Engineering, Finance, Human Resources,Transmission and Distribution.
Figure 2: TTEC Corporate Structure
Two departments that played an important role in the design andimplementation of these pilot projects are the Engineering
General Manager -
TTEC
Administration
Engineering Finance Human
ResourcesTransmissi
onDistributi
on
Division and the Transmission Division. Assistant General Manager– Engineering, Courtney Mark, who lead TTEC’s project team saidthe country has the potential to realize in the order of 100MW ofRE by 2020. He noted that RE technologies will not replace theneed for the installation of fossil fuel generators, butacknowledged that it undoubtedly achieve a reduction in the useof natural gas, thus prolonging natural gas availability andeconomic potential
The Engineering Division within TTEC is generally responsible forgeneration planning, generation interface, transmission and sub-transmission systems planning, systems planning and control,communications systems, and system protection. Within theAdministration Division of TTEC lays the Metering Servicesdepartment that is responsible for revenue collection viaindividual metering systems tailored and installed to accuratelymeasure consumption of kWh from each grid connected customer.Both the Generation Interface and the Metering Servicesdepartments played critical roles in the design and standardsseeing the pilot project of the ground as the appropriate methodsto test the viability of the installation against the standardswere in place to ensure the safety and security of the customersand the integrity of the national grid network.
In Trinidad and Tobago, electricity generation is primarily fromnatural gas. This natural gas fuel is burnt and the heat energyreleased is used to produce steam. This steam is then used toturn a steam turbine which is connected to an electricalgenerator to produce electricity. In some instances, the steamportion of the cycle is omitted and the gas is burnt directly ina gas turbine connected to a generator to produce electricity.
The Trinidad and Tobago Electricity Commission (T&TEC) came intobeing by virtue of the Trinidad and Tobago Electricity CommissionOrdinance No. 42 of 1945. It was formed to generate electricity
and to distribute it outside the city of Port of Spain and thetown of San Fernando.
Over the years T&TEC has moved from an integrated power company(power generation, transmission and distribution) to anorganisation where focus is on design, construction operation andmaintenance of the country's electrical transmission anddistribution network, with generation being done by IndependentPower Producers (IPPs) - Powergen and Trinity Power. Bulk poweris supplied to Trinidad and Tobago via a single electricity grid.
Power Generation
Located at Cove Estate, TobagoCapacity of 64 MWCan operate on both natural gas and diesel
TTECCapacity of 1344 MWThree major natural gas power generation plants at Port of Spain, Penal and Pt Lisas
Powergen
Capacity of 225 MWSingle natural gas power plant located at Pt LisasTrinity Power
Capcity of 720 MWSingle natural gas power plant located at La Brea
TGU
Steam (13%)260MW
Gas Turbine (74%)1553MW
Combined Cycle (9%)
196 MWDiesel (4%)
86.1 MW
Total Generation installed:2095.1 MW
Figure 3: Installed Power Generation by type
1999
2001
2003
2005
2007
2009
2011
2013
2015
2017
2019
2021
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
Year
Natural Gas Consumed
(MCF)
Figure 4: Natural Gas consumption 1999 - 2020
Customer Base
As of 2008, the customer base of T&TEC comprises approximately402,8010 customers with sales of 7,722 GWh. Industrial customersaccount for approximately 65% of the total energy sales. Theseindustrial customers, ranging from small manufacturing entitiesto a large 230MW Steel Complex, include many world scalepetrochemical plants.
Light Industrial
24%
Heavy Industrial
36%
Residential29%
Commercial10%
Street Lighting1%
Figure 5: Electricity Consumption by sector 2011
Case studyProject Identification
The Trinidad and Tobago Electricity Commission and the ElectricalInspectorate seek to install a few small-scale photovoltaic (PV)
systems for training purposes as part of the drive to facilitateRE projects through the demonstration of actual gridinterconnectivity. The eventual goal is to allow individualhouseholds or businesses to install permanently-connectedrenewable generation, which will export power through the mainsin times of surplus production and take from the mains whenrequired.
Scope of works
The contractor is required to finalise the design and supply allmaterials, labour, equipment and supervision and consumables tocarry out the works for the supply of the PV systems.
The Contractor is expected to allocate sufficient resources, andstaff to complete the Work within the time specified in hisproposal.
TECHNICAL SPECIFICATIONS
For photovoltaic panels:
Electrical Characteristic Specifications
Cell Type Mono or PolycrystallineSilicon
Panel Output Minimum 150W
Panel Array Output Power(Pmax)
Minimum 2000W
For Grid Tie Inverters - DC
Electrical Characteristic Specifications
Rated Power >2.0 kW continuous atambient
Ambient 32oC
Mains Voltage 115 – 230V AC
Wiring Single Phase, 3 wire
Frequency 60Hz +/- 0.6Hz
Protection Anti-islanding (IEEE1547),over/under voltage ofgrid,
over/under frequency ofgrid.
Figure 7: Diagram showing the conceptual schematic of the PVsystem
Figure 1 above shows the conceptual layout of the proposed PVsystem to be installed.
CODES, STANDARDS AND PERMITS
All equipment and works are to meet the applicable standards forphotovoltaic systems. These include but are not limited to:
1. IEC 60364-7-712 - Electrical installations of buildings - Part7-712: Requirements for special installations or locations -Solar photovoltaic (PV) power supply systems.
2. IEC 61194 - Characteristic parameters of stand-alonephotovoltaic (PV) systems
3. IEC 62116 -Test procedure of islanding prevention measures forutility-interconnected photovoltaic inverters
OTHER REQUIREMENTS
1. The Contractor shall provide supports for mounting panelarrays on (a) concrete roofing; and (b) corrugated ironsheet roofing.
2. The Contractor shall provide a projected work scheduleand description of intended work methods when submittinghis quote for the job.
3. The Contractor shall provide drawings of the design ofthe PV System illustrating all components and theconnection to the utility.
4. Provide “as built” drawings and all product manualsafter the installation are completed.
SAFETY PRACTICES
The Contractor and all employees who will be working at the jobsite are required to attend a safety briefing by T&TEC’s SafetyOfficer. The contractor shall also supply a list of the personnelthat will be working on the job. The contractor must comply withT&TEC’s Safety and Environment policies and procedures forContractors.
The contractor’s employees working at the site will be requiredto have the following protective gear:
Hard Hat
Steel Toed Safety Boots
Safety Glasses
WORK ENVIRONMENT
The site is located at the rooftop of the UTT’s O’Meara officebuilding and T&TEC’s Mt. Hope Office Building as shown in theattached diagram. The Contractor shall ensure that the necessaryprecautions are taken when working on the rooftop of the buildingas will be highlighted by T&TEC’s Safety Officer.
WARRANTY
The Contractor shall be responsible for making good with allpossible speed defects arising from defective design, materials,or workmanship or from any act or omission of the Contractor thatmay develop under the conditions provided for in the Contract.The Contractor should clearly state the Warranty Period for whichthe work will be valid.
Engineering and Procurement
TTEC embarked on two projects inviting bids for the engineeringand procurement of two mains-connected photovoltaic systems, forinstallation on the roofs of the UTT’s O’Meara Campus and T&TEC’sMt. Hope office building. The Commission sought to use fixedpricing quotations for the Contract and ensured a detailed Scope
of Works was done outline all possible aspects base on the natureof the job. On the 21st April, 2012 the contractors wereinvited by TTEC under tender # 9031 for the Engineering,Procurement and Installation of a Grid InterconnectedPhotovoltaic (PV) System at the two (2) locations mentionedabove. A sight visit was held on the 6th of May, 2011 which sawnineteen (19) contractors attending at both locations. Theclosing date for the tender was extended from 17th to the 24th
May, 2011 and saw nine (9) bids being received. Points for thequalifying bids were awarded base on the criteria laid out in thetender which was price, engineering design and quality control,past experience on similar type projects, technicalqualifications of personnel and time frame for projectioncompletion.
The contractor winning the bid was Energy Conservation Technology(ECT) Solutions Limited who scored the highest quality pointsincluding lowest cost of installation the table shows thebreakdown for the both installations.
Item # Description
Cost
(TT$)
1 Design drawings of PV System 1,000
2Initial payment for supply ofelectrical materials includingSolar Panels and Inverters 62,520
3Final payment for supply ofelectrical materials includingSolar Panels and Inverters 23,240
4 Supply of other materials 6,500
5 Construction of supportstructures for photovoltaic
14,080
panels
6 Installation of PV panels andgrid tie inverters 9,000
7 Test result documentation 1,200
8 As-built drawings 1,000
9 Contingency amount 6,500
10 Retention Fee 13,893
Total 138,933
The project started on the 8th December, 2011 and was completedon the 27th March, 2012 due to a couple minor delays the cost wasnot affected since it was base on a fixed price contractarrangement. The metering installation was done separately forthis project at a cost of TT$11,660.
PV systems and Grid Interconnection
Figure 8: Typical Gird Interconnection System
For electric companies like TTEC to receive power onto the gridfrom private producers there must be synchronization allowing forsmooth transfer of energy with matching voltages, phases
(rotation) and frequency. The average household in Trinidad andTobago has the electrical characteristic of supply is115/230ACvolts, 60Hz three (3) wire systems. Solar PV produces DCvolts this has to be inverted to grid synchronous alternatingcurrent (AC) before it can be grid-connected in addition theseinverters are equipped with an automatic disconnect feature whichseparates the installation from the system once it senses a lossof potential from the grid .
Inverter and normal MeterNet Meter at Mt Hope
Figure 9: Mt Hope inverter installation and net meter
Once grid connection is achieved the system must now be monitoredvia metering systems that can measure both energy delivered andenergy received. At the Mt Hope solar energy project Net meteringis installed, this metering system registers both energydelivered and received by TTEC and sums the net value for easybilling the table and graph below show some actual values takenfrom the Mt Hope installation between 11th to 19th November, 2012.
Reading EndTime Reading Value
Reg #101
Reg #104
Reg #105
11/11/2012 19:50
10,974.86 128.79
11,103.65
11/12/2012 19:55
11,036.23 129.24
11,165.48
11/13/2012 19:45
11,091.18 129.66
11,220.85
11/14/2012 19:45
11,151.17 130.18
11,281.36
11/15/2012 19:55
11,207.69 130.49
11,338.19
11/16/2012 19:55
11,250.04 131.14
11,381.20
11/17/2012 19:55
11,295.45 131.81
11,427.26
11/18/2012 19:55
11,344.90 132.33
11,477.24
101 Delivered By TTEC
104 Received By TTEC105 Net to Customer
The normal meter shown in figure 9 above is what is generallyused for all TTEC single phase three (3) wire 115/230Voltscustomers these meters are ordered undetented meaning for bothforward and reverse energy flow will be accumulated and theelectronic load indicator will flash at a rate equal to energyconsumption, regardless of the direction the energy flows. Whenthe meter in detent only forward energy flow will accumulate themeter will not accumulate if the energy flow is reversed.
0.002,000.004,000.006,000.008,000.00
10,000.0012,000.00
Reading Value Reg # 101Reading Value Reg # 104
Solar input at base of panel and the electronic interface to thesolar installation to the computer.
Product and Service Design and Development
New product development requires that organization buildstructures internally that have open communication withcustomers, aggressive R&D, strong leadership, formal incentives,innovative cultures and training (Heizer,2011).
Figure 9: Product Development Stages
The figure above shows the stages of product development. In theprocess highlighted, product options go through a series ofsteps, each having its own screening and evaluation criteria butproviding a continuing flow of information to prior steps. Itshould be noted that Product development depends on thesuccessful integration of:
Design of goods and services Managing quality Process and capacity design Location strategy Layout strategy Human resources and job design Supply Chain management
Ideas from various sources and does the firm have the ability to carry out the idea?
Customer requirements to win ordersFunctional
specifications: how does the product work
Product specifications: How will the product be made
Design review: are these product specifications the best way to meet customer
requirementTest market: does product meet customer expectations?
Introduction to market and Evaluation
Inventory planning Scheduling (Intermediate and short-term) Maintenance
A product after being selected, designed and defined hasprogressed from an idea to a functional definition, to a design.Now management has to make a decision as to further developmentand production or termination of the product idea. This is knownas the transition to production. Once the decision is made formore development or production, there is usually a period oftrail production to ensure that the design is indeed producible.This trail also gives the staff the opportunity to develop propertooling, quality control procedures, and training of personnel toensure that production/operations can be initiated successfully.
Summary
The system has worked as expected. The system generates powertypically at the start of sunrise and turns off after sunset eachday. During periods of cloud cover, power generation is veryminimal or zero kW. In times of power failure from the grid, itsanti-islanding feature is initiated and turns off the system.This was a specific design requirement outlined by TTEC since,TTEC has taken the position that these interconnected systems arenot back up power supply. Its intention is one of energyefficiency. These renewable systems are designed to export powerto the mains in times of surplus production and taking from themains in times of need.
The results so far show that the system can deliver the peakWatts as designed but on average deliver 50 to 60% of itsdesigned capacity due to the fact that T&T has significant dailycloud cover and relative low wind speeds.
Lessons learnt:
Local contractors are not equipped with the knowledge base for instaling these systems. This was apparent as T&TEC performed alot of hand holding with local contractors involved in these pilots; and the lack of knowledge is even more apparent with contractors performing jobs for other Ministries as I have viewed solar panels installed for the Min. of Works alongs the highway at ah hoc angles with some pointing North, whlie the standard for T&T is 11degrees to the horizontal pointing South.
We are a long way from getting residential homes ready for meeting TTBS 171 part 3.
T&TEC was unable to convince other members of the Committee that since the Grid Tie Inverters have an Anit-Islanding Mode there is no chance of therebeign a back feed onto themain grid with the loss of T&TEC supply. As a result the aproved design has regretably NO battery back up. So the lesson learnt is that people are affraid of things they don't understand.
The angle at which these PV panels are mounted is critical to take into consideration Trinidad’s location north of the equator.
Important that all disconnects and protection devices are correctly installed and tested before systems go live to ensure that the system is safely connected.
Data storage via memory cards must be sufficiently large enough to store the amount of data that is being generated by the monitoring hardware and software for the system.
Dedicated resources be assigned for the analysis of these data
Important to have internet connectivity to allow for remote monitoring within network.
Ensure that the Electrical Inspectorate is on board with the project. Ensure that they are allowed to offer advice in terms ofwiring interconnection. Ensure also that the contractor is fully knowledgeable on the “TRINIDAD AND TOBAGO ELECTRICAL WIRING CODE – PART 3: RENEWABLE ENERGY SYSTEMS AND INTERCONNECTION REQUIREMENTS”. This document will be used by the Electrical