DRRG Connection Guidelines Final
DRRG Connection Guidelines Final
DRRG Connection Guidelines Final
Connection Guidelines
for Distributed Renewable
Resources Generation
connected to the
Distribution Network
1 INTRODUCTION.............................................................................................................................................4
1.1 Scope ............................................................................................................................... 4
1.2 Definitions.......................................................................................................................... 4
1.3 Reference documents...........................................................................................................7
2 PHOTOVOLTAIC INSTALLATION.................................................................................................................... 8
2.1 Orientation and Inclination of PV modules............................................................................ 8
2.2 Equipment.......................................................................................................................... 9
2.2.1 Solar PV modules..................................................................................................... 9
2.2.2 Inverter................................................................................................................... 9
2.2.3 Metering System.....................................................................................................10
2.2.4 Other equipment....................................................................................................10
2.3 PV array system configuration............................................................................................. 11
2.3.1 PV system architectures and earthing....................................................................... 11
2.3.2 Series-parallel configuration of modules and strings................................................. 11
2.3.3 Use of inverters with single and multiple DC inputs................................................... 11
2.3.4 DC/AC converters (Microinverters) in combination with PV modules.......................... 12
2.3.5 Mechanical design.................................................................................................. 12
2.4 Safety issues....................................................................................................................... 13
1.2 Definitions
The most relevant definitions for the present Guidelines Authorisation to Produce Authorisation issued
are listed below. after the Final Inspection of the Renewable Resource
Generating Plant.
AC module - A PV module with an inverter mechanically
secured to it so that the electrical output is a.c. and no Connection Agreement - The agreement between DEWA
d.c. plug/socket connections are in use between the and a RRG, which stipulates the terms and conditions for
module and the inverter. the connection and operation of the Electricity Generator
into the Power Distribution System and its operation.
Active Power - Active Power is the real component of the
apparent power, expressed in watts or multiples thereof Connection Point - Is the location at which Renewable
(e.g. kilowatts (kW) or megawatts (MW)). In the text Resource Generating Units, Renewable Resource
this may be generically referred as P or Pn in case of rated Generating Plants as well as consumer loads are
active power of equipment. connected to the Network and where the Main Meter is
installed. In the connection schemes this is also referred
Apparent Power - Is the product of voltage (in volts) and to as POC (Point Of Connection).
current (in amperes). It is usually expressed in kilovolt-
amperes (kVA) or megavolt-amperes (MVA) and consists Consultant A company enrolled with DEWA as Electrical
of a real component (Active Power) and an imaginary & DRRG Solar PV Consultant, which carries out the design
component (Reactive Power). In case of inverters, the of Electrical facilities of all types including design of
rated apparent power corresponds to the maximum active Solar PV plants.
power deliverable by the inverter at unity power factor.
Contractor A company enrolled with DEWA as Electrical
Application for Connection - is filled by an Applicant for & DRRG Solar PV Contractor, which carries out Electrical
a new RRG Connection. This application shall be made Consulting/Contracting works of all types including
through the Distributed Generation Application Form Solar PV plants. The Contractor may also perform design,
in the prescribed format and shall contain the required supply equipment and materials or labour, especially
information. for constructing, building and installing Solar PV plants.
Current - Unless stated otherwise, current refers to the Non-isolated inverter An inverter without the
root-mean-square value of phase current. minimum separation between the main power output
and PV circuits or with leakage currents greater than the
Distribution System / Network - Is the medium (6.6, requirements for an isolated inverter.
11 or 33 kV) or low voltage (0.4 kV) electricity grid for
supplying electricity to the end consumers. Junction box Closed or protected connecting device
were one or several junctions are performed.
DRRG - Distributed Renewable Resources Generation
Low Voltage (LV) Network A Network with nominal
Solar NOC A NOC for the purpose of constructing a Solar voltage lower than 1kV.
PV plant.
Maximum Capacity - The maximum continuous Active
Downstream For a RRGP, Downstream means Power which a Generating Plant can feed into the Network
generator bound, e.g. towards the distribution network. as agreed between DEWA and the Plant Producer. This
Upstream, instead, means the PV panel for a PV plant. corresponds to the sum of the maximum active power
deliverable by the inverters at the AC side, that is also the
Generating Unit/Plant - A Generating Unit is an indivisible sum of the rated power of the inverters at unity power
set of installations which can generate electrical factor (to be noted that this latter may also be lower
energy. A set of Generating Units, circuits and auxiliary than the sum of the power at STC of the photovoltaic
services for the generation of electrical energy forms a modules). In the text, this maximum capacity will also
Generating Plant. See also the definition of Renewable be indicated as PMC.
Resource Generating Unit/Plant.
Medium Voltage (MV) Network- A Network with nominal
Grid Connection: The connection of a Renewable Resource voltage included in the range from 1kV up to 33 kV.
Generating Plant (RRGP) to the electrical grid. In Dubai, four voltage levels may be found on the MV
distribution network, namely 6.6 11 22 33 kV. The 11
Grid Connection fee: The fee to be paid for the connection kV voltage level is the most used and diffused.
to the grid.
Main Electricity Meter - The main electricity meter installed
Interface Protection - The electrical protection at the Connection Point (DEWA side) and will perform the
required to ensure that either the Generating Plant or Net Metering of: i) the electricity delivered by the RRGP to
any Generating Unit is disconnected for any event that the Distribution Network; and ii) the energy absorbed from
could impair the integrity or degrade the safety of the the Distribution Network on a monthly basis.
Distribution Network.
Microinverter - An inverter that converts direct current
Inverter Device which converts the direct current produced by a single PV module to alternating current.
produced by the photovoltaic modules to alternating The output from several microinverters is combined in
current in order to deliver the output power to the grid. order to deliver the output power to the grid.
The inverter is also capable of controlling the quality of
output power. PV Generation check-meter - Electricity meter installed
at the common output point of all the Generating Units,
Isolated inverter An inverter with, at least, simple to measure the total energy produced by the RRGP.
separation between the main power output circuits
and PV circuits (usually by means of a transformer) Network - Plant and apparatus connected together and
and with leakage currents less than the limits required operated by DEWA in order to transmit or distribute
to be classified as an isolated inverter (IEC 62109-2). electrical power.
The separation/ isolation may be either integral to the
inverter or provided externally, e.g. an inverter with an
Photovoltaic (PV) string combiner box A junction box Process Duration: The overall time needed to complete a
where PV strings are connected which may also contain specific process of the PV project lifecycle.
overcurrent protection devices and/or switch-disconnectors.
Process Step: A step is one of a sequential succession of
Photovoltaic (PV) array Assembly of electrically actions that need to be executed in order to satisfy the legal-
interconnected PV modules, PV strings or PV sub-arrays. administrative and the other requirements of a process.
Photovoltaic (PV) sub-array An electrical subset of a PV Producer: Any entity authorised by the Authority to produce
array formed by parallel-connected PV strings. electricity connected to the network in the Emirates. In
other documents the term Generator may be used.
Power Factor - Is the ratio of Active Power to Apparent Power.
PV Project Lifecycle: All the procedures required to
Protective earthing Earthing of a point in equipment or authorise, install and finally connect a PV system. The
in a system for safety reasons. Project Lifecycle is defined as a sequential succession
of Processes, each of them described by a sequence of
Power Generating Plant (Power Plant) - Set of Process Steps (either administrative or technical).
The following documents available on DEWA website DEWA Power Supply Guidelines for Major Projects,
www.dewa.gov.ae have been quoted: March 2013
DEWA Design Requirements & Guidelines for MV
Standards For Distributed Renewable Resources (11kV-22kV) supply, December 2008
Generators Connected To The Distribution Network DEWA Customer Guide, 3rd edition
(in the following only Standards) Safety of People: Recommendations for DRRG Solar
DEWA Regulations for Electrical Installations, 1997 PV, Edition 2015
Edition Safety of Environment: Recommendations for DRRG
DEWA Distribution Substation Guideline, 2014 Solar PV, Edition 2015
Edition
There are several factors to be accounted for when planning to install photovoltaic panels on rooftops. Considering
the geometry of the PV array, these factors are (see Figure 1):
Orientation of PV modules to the sun;
Inclination (tilt) angle of PV modules; and
Shadowing from objects or other buildings.
The favourable orientation (azimuth) for fixed solar cells in Dubai throughout the year is South (0 S) with an inclination
(tilt) of about 24 with respect to the horizontal plane. This allows an average annual irradiation on a horizontal plane
of about 2000-2100 kWh/myr for Dubai 1 when both the direct and diffused radiation are considered, which means
about 1500-1800 kWh/yr per kWp installed.
Small variations around these values do not significantly affect the production. For instance, an energy reduction
not greater than 5% can be noticed by maintaining a South orientation and varying the tilt from 5 (this value to be
raised to 10 to allow a better cleaning) to 40. It is also possible to stay below a 5% loss by varying the azimuth of PV
modules from -60 to +60, if the tilt is maintained at 24.
It is essential to avoid any shadows on the PV modules, because this can cause a substantial drop in the system
performance. In contrast to solar thermal collectors, any shadow on a PV array causes a significant reduction of
the power produced. Furthermore, especially in UAE, where the beam fraction of the solar radiation is high, partial
shadowing on PV modules causes strain on shadowed PV cells which may, in turn, cause local temperature escalation
(hot-spots) and may thus compromise the durability and safety of these components.
It is important that PV modules are kept clean and to avoid deposits of dirt and dust, since these reduce the efficiency
of these components. The Emirate of Dubai is in a region prone to dusty desert environments and frequent dust
storms, therefore, it is recommended to clean the PV system as to avoid dust, sand and dirt accumulation. A flatter
position of PV modules may increase the deposits on PV modules and render their cleaning and washing more difficult,
especially in case of large surfaces. It is therefore recommended to adopt a minimum tilt angle of at least 10.
In a building, PV modules are usually installed on the roof in order to reduce shadowing and also to exploit surfaces
often left unused. When possible, PV modules may be integrated in the building structure as Building Integrated
Photovoltaic (BIPV) systems; these are frequently adopted to mitigate the visual impact of PV systems. Although
often attractive from the point of view of aesthetics, PV facades (tilt = 90 or similar) are not recommended from an
energy efficiency point of view, because their production is approximately 50% less than when optimally positioned.
1 Data from Research Center for Renewable Energy Mapping and assessment atlas.masdar.ac.ae
The connection schemes also show another important element, namely the Interface Protection, which prevents
the current of the plant from being injected into the network whenever a faulty event is detected on the latter. This
protection may also be included in the inverter as specified in the Standards. The required protection functions are
also specified in the Standards.
The switch on which the Interface Protection acts (Interface Switch) may also be used to disconnect the plant for
maintenance purposes, without causing any shortages on the existing loads.
Solar PV modules can consist of PV cells of different technologies. In commercial and non-concentrating applications,
single-crystalline and multi-crystalline cells achieve the maximum efficiency while thin-film technologies need
more surface to produce the same power than their crystalline counterparts. Most manufacturers often guarantee
a life time of 25 years or more, but they seldom take into account harsh conditions like those in Dubai. Furthermore,
manufacturers indicate that PV modules undergo a loss of performance over time and therefore, a guaranteed
efficiency is provided (e.g. usually 90 % after 10 years and 80 % after 25 years). However it is advisable to have a
workmanship warranty of at least 10 years and, given the harsh conditions in Dubai, also a third party insurance
backing for medium-large size plants (e.g. greater than 1 MW).
In general, Bypass diodes should be installed in order to prevent reverse bias in the PV modules and to avoid
consequent hot spot heating.
PV modules are to be certified according to the compliance requirements defined in the Standards. The
manufacturer shall then provide the Producer with certificates, proving that the PV modules are compliant with
these requirements. The certification document will be requested by DEWA during the connection process. A list
of the updated certified equipment is available at DEWA on request.
2.2.2 Inverter
The inverter converts the DC current produced by PV modules into AC current that can be used directly in the house/
premises and/or injected into the external network. Ideally, the inverter should be located close to the photovoltaic
modules to avoid losses, but this cannot always be possible because of the harsh outside conditions. High
temperatures and dust in particular, require special caution in order to avoid any damage or performance reduction
of the equipment.
It is therefore recommended to verify that the highest temperature to which the inverter can be exposed in
summer does not cause any damage to it or reduce its life. Moreover, it is necessary to avoid high temperatures
that may trigger any protection system aimed to reduce the internal temperature of the inverter by reducing
its power (de-rating protection). If these conditions are not satisfied by mounting the inverter outside it is
As specified in the Standards, the inverters shall be provided with an IP65 enclosure for outdoor application and
IP54 enclosure for indoor application. In this latter case, lower protection grades shall only be permitted if the
characteristics of the room will be properly conceived to protect the equipment (e.g. air conditioned rooms with
means to avoid dust penetration).Whatever the case may be, the inverter shall be able to withstand the maximum
temperatures with effective heating dispersion and with a power derating smaller than or equal to 25 % of its
rated power as determined for an ambient temperature of 50 C at the DC design voltage. This temperature is to
be considered the maximum outdoor value at which all equipment, apparatus, materials and accessories used in
electrical installations must be capable of operating with satisfactory performance in the climatic conditions of the
Emirate of Dubai. In addition, provisions which prevent the increase of the internal heating of the inverters shall be
taken for outdoor installation (e.g. protections against direct exposition to the sun). For those inverters which do not
comply with the above set rule, a placement in cooled room or enclosures with effective ventilation shall be required,
inside which the ambient temperature will be kept below the value which determines a power derating equal to 25 %
of the inverter rated power at the DC design voltage.
To measure the electricity generated by the renewable generation unit and electricity consumed by the house/ building, two
bidirectional energy meters must be installed:
1. The first bidirectional meter supplied and installed by DEWA in the Connection Point measures the power injected
to the Distribution Network and the energy consumed from the Distribution Network. (Main Electricity Meter).
This meter is already present in existing installations, however it shall be substituted by a smart meter if this has
not already been done.
2. The second meter supplied and installed by DEWA measures the electricity generated by the photovoltaic system
(PV Generation check-meter).
During the connection process, the RRGP will be inspected by DEWA before the metering system can be installed. The
inspection aims to ensure that the RRGP complies with the Standards and with safety rules.
All the components and equipment used in the PV plant shall comply with applicable standards and laws in force in
Dubai. Any component or equipment that may introduce harmful or hazardous conditions shall be rejected.
All components and equipment is chosen adequately in order to assure its integrity and operation for a long lasting
period. All equipment should be of an IP rating suitable for the location and this particularly applies to:
Cables and connectors exposed to sunrays (UV in particular), external temperature and other weather conditions. This
equipment is to be certificated for its application (e.g. solar cables). In DC circuits single-wire cables shall be used with
different colours for the two poles: red for positive (+) and black or blue for negative (-).
Switchgears and controlgear assembly shall be properly protected against temperature, sunrays (UV in particular),
dust, salinity and all other weather conditions present on the site. Installation in a safe room is recommended.
Their compliance to applicable standards shall be properly certificated (IEC 61439 series).
PV string combiner boxes shall be properly protected against temperature, sunrays (UV in particular), dust,
salinity and all other weather conditions present on the site. Their location shall be visible without obstacle to
The relation of a PV array to earth is determined by whether any earthing of the array for functional reasons is in
use, the impedance of that connection and also by the earth status of the circuit. This and the location of the earth
connection all affect safety for the PV array. The requirements and recommendations of manufacturers of PV modules
and manufacturers of inverters to which the PV array is connected will be taken into account when determining the
most appropriate system earthing arrangement.
Protective earthing of any of the conductors of the PV array is not permitted. Earthing of one of the conductors of the
PV array for functional reasons is not allowed, unless there is at least simple separation from mains earth provided,
either internally in the inverter or externally via a separate transformer.
Earthing of PV module frames and supporting metallic structures shall be executed according to IEC/TS 62548 and
other applicable standards.
All earthing connections in the PV plant (DC and AC sections) shall be part of a unique earthing system, i.e. a proper
bonding shall be assured.
All PV strings within a PV array connected in parallel are to be of the same technology and have the same number
of series connected PV modules. In addition, all PV modules in parallel within the PV array shall have similar rated
electrical characteristics, including short circuit current, open circuit voltage, maximum power current, maximum
power voltage and rated power (all at STC).
It is important that the characteristics of any array or sub-array be fully compatible with the input characteristics of
the inverter used. This in particular applies to:
PV arrays are often connected to inverters with multiple DC inputs. If multiple DC inputs are in use, overcurrent
protection and cable sizing within the various sections of the PV array(s) are critically dependent on the limiting of
any back-feed currents (i.e. currents from the inverter out into the array) provided by the input circuits of the inverter.
Where an inverter input circuit provides separate maximum power point tracking (MPPT) inputs, the overcurrent
protection of the sub-array connected to the inputs shall take into account any back-feed currents. Each PV section
connected to an input must be treated as a separate PV sub-array. Each PV array or sub-array shall have a switch-
disconnector to provide isolation of the inverter.
Microinverters are electrically connected to PV modules through direct wirings and may be used as:
Permanently mounted close to the PV module but not mounted to or in direct contact with the module backsheet
(also called Detached Microinverters). DC wiring are thus accessible to service personnel, although is deemed to
be not user-accessible.
Permanently mounted to the PV modules backsheet for both electrical and mechanical means of connection (AC
modules).
Differently from classical PV arrays, in PV systems that use microinverters the connections in the array are made by
using one or more AC parallel wiring systems (AC bus).
In case of detached microinverters, attention has to be paid to the characteristics of DC connectors when used as a
means to disconnect the DC circuit. When not rated to disconnect under load, all the necessary precautions have to
be taken before disconnecting them (e.g. covering of the module).
The PV array support structures shall comply with local standards, industry standards and regulations with respect to
loading characteristics.
PV modules, module mounting frames, and the methods used for attaching frames to buildings or to the ground
shall be rated for the maximum expected wind speeds in Dubai according to local codes.
In assessing this component, the wind speed observed (or known) on site shall be used, with due consideration to
wind events (cyclones, tornadoes, hurricanes, etc.). The PV array structure shall be secured in an appropriate manner
or in accordance with local building standards.
Wind force applied to the PV array will generate a significant load for building structures. This load should be
accounted for in assessing the capability of the building to withstand the resulting forces.
Module mounting frames, and the methods used for attaching modules to frames and frames to buildings or to
the ground, shall be made from corrosion resistant materials suitable for the lifetime and duty of the system, e.g.
aluminium, galvanized steel, zinc-coated steel, etc.
Care shall be taken to prevent electrochemical corrosion between dissimilar metals. This may occur between
structures and the building and also between structures, fasteners and PV modules.
Stand-off materials shall be used to reduce electrochemical corrosion between galvanically dissimilar metal surfaces;
e.g. nylon washers, rubber insulators, etc.. Manufacturers instructions and local codes should be consulted regarding
the design of mounting systems and any other connections such as earthing systems.
3.2.1 Enrolment
The first step, in case of a new Electrical & DRRG Solar PV Consultant / Contractor, is to register with DEWA e-Service
through DEWA website at www.dewa.gov.ae, that is exclusively designed for Electrical & DRRG Solar PV Consultant /
Contractor (hereinafter Applicant) to apply and track the application online.
Both the Electrical & DRRG Solar PV Consultant and the Contractor have to own a standard Trade License issued by the
Department of Economic Development, Government of Dubai.
Moreover, Electrical & DRRG Solar PV Consultant / Contractor has to be accredited for the installation of Renewable
Resources Generating plants.
The Applicant has to submit through DEWA website an application form for Solar PV Connection in order to obtain
from DEWA the DRRG Solar NOC (No Objection Certificate).
Identification of existing electricity connection (Contract Account No., ID of the meters at the Points of
Connection);
In case of positive answer from DEWA, the Applicant receives the Solar NOC.
This Solar NOC is mandatory prior to obtaining a Building Permit from Dubai Municipality (DM) and to start construction
activities at site.
If the Applicant decides to proceed with the Solar PV Plant Project, the Design Approval Application Form must be
submitted through the DEWA website.
The purpose of obtaining the Design Approval is to carry out the electrical installation work complying with DEWA
regulation for electrical installations:
Solar NOC;
DM Building Permit;
Detailed plan of project electricity connection points;
Connected load & maximum demand schedules at each connection point;
Production details (kWp and kWh per annum);
Single line diagram, with details of metering and protection system (relays, CTs and VTs when adopted, e.g. for
MV network connections);
Site setting out plan showing details of proposed works, PV panels layout, meter location(s), etc.;
Details on PV modules, for each kind used in the plant (Manufacturer, model reference, efficiency, warranty years for
manufacturing defects, peak capacity per single PV module [Wp], surface per single PV module [m], orientation
(South= 0, East= -90, West=90), tilt angle (inclination with respect to horizontal), number of modules of this
type);
Compliance (to applicable Standard) certificate of the modules;
Details on Inverters, for each kind employed in the plant (number of inverters of each type, manufacturer, model
reference, compliance with the Inverters approved by DEWA, warranty years, rated AC power, nominal power
factor and adjustable range, maximum DC input voltage, AC output voltage, connection phases, Total Current
Harmonic Distortion, synchronization method with DEWA network, environmental protection rating (IP), means
In some cases, particularly when the new RRGP has a relevant power capacity, this may be connected to the MV
Distribution network or to a LV feeder, if possible. If the capacity of the new RRGP exceeds the feeder technically
acceptable limits, a new substation might be envisaged by DEWA.
The following situations may then be possible:
PV plant with Maximum Capacity PMC 400 kW to be connected to an LV feeder, but where a new DEWA MV/LV
substation is required in Customers premises (e.g. inside a compound).
PV plant with Maximum Capacity PMC > 400 kW to be connected to a new DEWA MV/LV substation.
PV plant with Maximum Capacity PMC > 400 kW to be connected to a private MV substation and then to a new
DEWA MV RMU substation.
If the requirement of one or more substations is indicated in DEWAs Building NOC and, if a connection to the MV
network is needed (Maximum Capacity of the PV plant > 400 kW), the Applicant shall submit all the information
for the approval of each of the substations, providing the information required by the DEWA Distribution Substation
Guideline.
In cases where the electrical equipment of the substation (MV and LV panels, meters and so forth) will be the property
and responsibility of DEWA, then DEWA will take care of the installation either with own technicians or appointed
accredited Contractors. The Applicant will be required to complete the Civil works, including the substation building
and the cable trenching.
For the construction of MV private substations, the Applicant has to be aware of the following:
2 For low voltage connections it shall be specified if these currents are in accordance with either EN 61000-3-2 (rated currents of up to and including
16 A per conductor) or 61000-3-12 (rated currents above 16 A and up to and including 75 A per conductor). Conversely, the actual current spectra
must be specified by the Applicant in a table where the order of harmonic and the related current generated by the inverter have to be specified.
3 Not for DEWA approval, but only for information purposes. These drawings must be accompanied by a declaration signed by the civil designer on the
compliance of the structures to the in force laws and rules.
The Applicant then pays the connection fees and DEWA will carry out all the necessary intervention on the network,
in order to make the connection feasible.
Once the connection fee is paid, the Applicant can commission the construction of the plant.
Once the laying of the PV modules is completed, the Applicant needs to ensure Mechanical Inspection is completed
(Mechanical Completion) by the relevant building Authority (i.e Dubai Municipality, Trakhees, etc) before initiating
the electrical works. This will assure that the modules, layout and fixation comply with the applicable standards and
safety rules in Dubai. In case of a positive result, the Solar PV construction can proceed with the electrical works.
When the Solar PV is installed and all civil and electrical works are completed, the Applicant submits through DEWA
website an Inspection Application. This application has to be submitted for all plant sizes.
Revised/updated copy of a single line diagram with details on metering and protection system;
Undertaking letter stating that the load on each feeder shall not exceed 3MW (175A) in normal operation and
6MW (350A) in case ofcontingency if the adjacent feeder fails;
Real measurement of harmonics shall be conducted after full commissioning of the equipment and to be
submitted to DEWA for verification to ensure that the values are within prescribed limits;
Step by step relay setting calculations. The relay co-ordination shall be made on maximum fault
current and the grading margin shall be kept at 0.300 seconds between DEWA ends to private partys
panel end;
Owners undertaking stating Our equipment are suitable to energize in line with DEWA network system and
confirm that the relays are set as per DEWA approved setting;
HV cable Jointers list in details (approved by DEWA);
Names and telephone numbers of contact person for the project who should be available to contact on a 24 hour
basis;
Name of technical staff, competent in the switchgear operation and issuing of permit stating that cable is safe
for work and also ensure no one, will operate during test & repairing time.
Factory & Site test report for the transformer/breaker, MV cable, etc. and test result for the transformer inrush
unbalance current to be forwarded for verification;
Operation philosophy (interlocking details) -to be incorporated in the single line diagram; and
All catalogues for CT, VT, relay & motor.
In case of a positive result of the site inspection, DEWA installs the meter(s).
During this inspection, DEWA supervises the tests and the measurements on the installation made by a Test Engineer
appointed by the Contractor.
In case of construction of a new DEWA substation, the Substation Inspection Request is also sent through DEWA
website by the Applicant after completing the civil works of the proposed substation as per the Trench Layout drawing.
After the meters have been installed, the RRGP can be energized. For plants connected to the Medium Voltage
distribution network, it is particularly important that this operation be supervised by DEWA Engineers.The same
Engineers will take care of all the necessary provisions for the energization of the ring to which the plant is connected
(manoeuvres to be made on the DEWA Distribution Network), and eventually witness the closure of the RRGP main
circuit breaker.
After the plant has been connected to the network, a number of tests with the aim of verifying the correct behaviour of
inverters, protections as well as the electrical checks on the installation, need to be carried out.
For all the plants, these tests shall be carried out by a certified Test Engineer. The results of these tests will be collected
into a Technical Dossier to be submitted to DEWA for approval. In case of plants with PMC 100 kW or connected to
MV network, this approval is a prerequisite to the execution of the Performance Tests. For plants below 100 kW, no
further tests or inspections are required, so the Final Inspection Report will be prepared by DEWA and Connection
Agreement issued (see below). No DEWA supervision is needed during this testing stage.
For PV plants of Maximum Capacity larger than or equal to 100 kW, DEWA issues a Preliminary Authorization to let the
Applicant execute the performance tests as indicated in the Connection Standards. The tests will be carried out by a
Test Engineer or by an appointed system integrator engineer who has to be commissioned by the Applicant. Upon the
finalization of the tests, the Applicant submits a copy of the testing documents (As-Built Drawings and the Technical
Dossier) and applies to request the Post-Connection Inspection through the DEWA website.
In case of positive result of the inspection, DEWA Connection Services Department issues the Final Inspection
Report, which certifies that the installation is compliant with DEWA rules and that the electricity production can
start (after the signing of the Connection Agreement).
A regular Operation and Maintenance (O&M) Contract has to be provided by the Applicant.The Contractor and/or
Consultant will inform the Producer about the requirements of the plant in terms of O&M. An O&M manual shall be
made available to the Producer, in order for the Producer to correctly and safely operate the plant, if adequately
skilled, or to transfer the operating obligations to an appointed Contractor. As stated above, the Contractor services
The Producer also needs to provide DEWA with a statement stipulating that he is aware of the Operation and
Maintenance needs of the plant, indicating who will be responsible for the O&M.
It is also strongly recommended to have an insurance for the PV system as specified in chapter 4 (the system can be
included in the Building insurance or a specific insurance may be stipulated for the PV system).
Once the Final Inspection Report has been issued, the Connection Agreement will be signed and submitted to DEWA
by the producer.
The Connection Agreement encompasses both the technical and commercial aspects of the connection, addresses
the Standards and Minimum Technical Requirements and specifies the Terms and Conditions including the constraints
on quality of supply, in accordance with the defined rules.
The DRRG connection conditions apply. The official production start date and time that will be utilized for Net
Metering purposes, is thus the date of the Connection Agreement.
4 This may also be different from whom has constructed the plant
The purpose of this Chapter is to define a list of obligations and entitlements that each one of the parties involved in
the building and PV plant network connection has to comply with.
DEWA;
the Customer/Producer (as owner of the plant);
the Consultant of the Producer;
the Contractor (as appointed by the Producer); and
the Manufacturers of Solar PV equipment.
Please note that the Applicant may be either the Consultant or the Contractor. The limits of liability, as specified
for the Consultant, may then apply also for the Contractors, if they are also involved in the design of the plant.
4.1 DEWA
DEWA shall be responsible for:
operating and maintaining a secure, reliable and efficient electricity distribution network, in order to be able to
receive the power produced by the Renewable Resources Generating Plants;
granting the connection to the network to the Producers, by any possible and economical means of network
reinforcement.
conducting the site and plant inspections as defined above;
undertaking any possible provisions to clear a fault in the distribution network in the shortest time, within the
limits indicated in Table 4 of the Standards5. DEWA shall not be liable for the loss of production that the RRGPs
connected to the Distribution Network will undergo in case of disconnection following the intervention of the
Interface Protection 6.
Ownership Boundaries:
the boundary between DEWA and the Producer is the Connection Point as indicated in the connection schemes
in Appendix A;
the respective ownership of Plant or Apparatus shall be recorded in the Connection Agreement between DEWA
and the Producer in the form of a diagram.
5 The Producer must be aware that these clearing times may be higher than the time setting in the Interface Protection and in the disconnection
area of the LVRT curve, which means that the plant may disconnect from the network. This is because the purpose of the Interface Protection
settings and inverters LVRT feature is to permit the RRGPS to effectively ride through faults occurring in the High Voltage network, because of the
detrimental effects that a disconnection of these plants would have in this case.
6 In order to allow the automatic re-connection of the plant to the Distribution Network once the disturbance in the network has been cleared,
proper automatic re-closure schemes may be found in the Standards.
The Producer shall indemnify DEWA and accept liability for safety and supply quality issues that occur when the
PV Plant is operating.
4.3 CONSULTANT
Consultants responsibility and liability are defined by the laws in force.
carrying out the application process on behalf of the Producer as described above;
the correct choice of equipment;
correct consulting of the producer regarding all technical aspects.
4.4 CONTRACTOR
Contractors responsibility and liability are defined by the laws in force.
applying a safe system of work in the PV Plant construction, in compliance with all applicable standards,
regulations and statutory requirements;
proposing to the Producer adequate and certified PV equipment;
building the installation in compliance with all applicable technical standards7;
appointing a Test Engineer to perform tests on the plant.
As stated above, the limits of liability as specified for the Consultants apply also for the Contractors when their
services extend to include consultancy services and the design of the plant.
4.5 MANUFACTURERS
Manufacturers responsibility and liability are defined by the laws in force.
The manufacturers shall in particular be liable in case of delivery of false certificates of compliance for the PV products
(modules, inverters, cables, protections, and so forth).
7 The Contractor will have to deliver a declaration of compliance of the plant to these standards.
Note:
Note:
Note:
Note:
General switch separated from Interface switch where the former acts as a back-up of the latter; and
Interface switch separated from Generator switch.
Note:
Note:
Distributed
SHAMS DUBAI Renewable
- DRRG Connection
Resources Guideline
GenerationVersion
Program1.1 31
Dubai Electricity & Water Authority