INNOVATIVE THINKING FOR THE REAL WORLD Advanced Grid Connection Workshop The Innovation Centre, Sci-Tech Daresbury, 16 th July 2013 Welcome and Introduction George Hall, Project Manager The Wind-Tech Project
Sep 05, 2014
INNOVATIVE THINKING FOR THE REAL WORLD
Advanced
Grid Connection Workshop
The Innovation Centre, Sci-Tech Daresbury, 16th July 2013 Welcome and Introduction George Hall, Project Manager The Wind-Tech Project
INNOVATIVE THINKING FOR THE REAL WORLD
Programme 9.00 Welcome & introduction Dr. George Hall, Wind-Tech Project, UCLan 9.10 Introduction to the workshop 9.20 Part 1: Variation in grid voltage and the need for DNO studies 9.50 Part 2: The rural grid in detail: Schematic diagrams for most rural connections 10.45 Morning Refreshments 11.00 Exercise 1: Completing a site survey for an example PV, hydro or wind project 12.00 Part 3: Larger grid connection projects and case studies Geoff Owen, Grid Connections 12.30 Lunch 1.30 Part 3: Larger grid connection projects and case studies (continued) 2.00 Part 4: Additional grid connection
2.45 Afternoon refreshments 3.00 Exercise 2: Completing the ENA application form for an example project Geoff Owen 4.30 Summary and surgery: one-to-one advice Geoff Owen, Dr. George Hall
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Today’s workshop • Following the energy and grid connection basics workshop, today
we will investigate in more detail the complexity of connecting to the grid;
• A more interactive workshop, with morning and afternoon group
exercises, with support from the Wind-Tech team;
• Follow-on support from the Wind-Tech team for companies interested in wind turbine technologies, or other forms of renewable technology, available after today’s workshop.
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Today’s workshop Please note: The information provided today is done so in an advisory capacity only. The supplier shall not incur any liability for any action or omission arising out of any reliance being placed on this information by any organisation or other person. Any organisation or person in receipt of this information should take their own legal, financial and other relevant professional advice when considering what action (if any) to take in respect of any grid connection, renewable strategy, initiative, proposal, or other involvement with any renewable technology, before placing any reliance on anything contained herein.
INNOVATIVE THINKING FOR THE REAL WORLD
Advanced
Grid Connection Workshop
16th July 2013 Geoff Owen, Grid Connections
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Level 1 review • Essential power terminology & application for renewable
generation projects
• G83 is under 16 amp per phase
• G59 is over 16 amps per phase
• One G83 project is allowed per customer
• Once a G83 project is fitted to increase or add another project will require a G59 application & permission from the DNO
• The function of the DNO grid and connections
• Application and upstanding grid connectivity for renewable energy projects
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LEVEL 2 Workshop Content
Part 1: Variation in grid voltage and the reason for DNO studies
Part 2: The rural grid in detail
Exercise 1: Completing a site survey
Part 3: Larger grid connection projects and case studies
Part 4: Additional grid connection considerations
Exercise 2: Completing the ENA application form for an example project
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Renewable power generation Essential considerations for projects
• If there is no consumer demand then there is limited justification to install a generation project
• The Availability of FIT support will not be there for long
• The installation of renewable power technologies enables consumers to take control of their energy costs and limit their exposure to future price increases.
• De-centralised power generation can reduce transmission grid losses.
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Part 1: Variation in grid voltage and the need for DNO studies
• For a generator to work and stay connected it must operate within design parameters
• G83 upper cut of voltage stage 1 (@51.5HZ) 262.2 volts in 90 seconds
• G59 upper cut of voltage stage 1 (@51.5HZ) 253 volts in 90 seconds
• The grid supply transformer is set at 250 volts at the source, this allows a head room of only 3 volts
• In periods of low customer load the grid volts are high through out the grid system, generation may increase the grid voltage resulting in invertors and protection relays operating with loss of generation, and Grid voltage pushed beyond statutory levels
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Why is the Grid connection process so complicated?
• Grid systems were never designed for multiple smaller generation connections, designed for power flow in one direction
• DNO’s have to guarantee to the customers the quality of supply and availability 24/7
• Increasing number of projects could result in a unstable Grid system, with undermining of network supply security
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DNO Responsibilities
These are the statutory obligations under the terms of their licence
• Secure operation and development of the network;
• Safe & reliable operation of the network;
• Ensure fair and equal access to the network;
• Least cost options for connection;
• Lifetime ownership of network not just your connection.
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Grid voltage variation
• The voltage level in the UK was standardised with the EU
• The DNO is responsible for the supply characteristics and is directly responsible for guaranteeing the supply quality to all customers
• The supply characteristics are declared as 400/230 volts (+10% to -6%), 50Hz damage to electrical equipment will result if the if the supply voltage goes outside of the stated range
• Customer switches on large motor
• G83 or G59 nuisance tripping Grid transformer output set at 250/433 volts
Maximum 253 volts
Minimum 216 volts
Low customer load
high customer load
Normal grid 240 volts
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DNO’s EXISTING ELECTRICITY NETWORK (LV grid)
Small single phase cable to house
Small 3 phase Commercial supply
3 C 300 mm W cable in pathway or road
Large 3 phase Commercial supply
DNO designs infrastructure connections to guarantee the supply quality
Cable joints in highway
Voltage at source set 250/433 volts
Supplying Sub station
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Voltage variation data with customer load for proposed G83 generation
Day 1 Day 2 Day 3
252 volts
244 volts
Peak 254 volts
Switching on of motor load
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Frequency variation data with customer load for proposed G83 generation
Day 1 Day 2 Day 3
50.3
50.18.
50.06
49.94
49.82
49.7
Hz
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Part 2: The rural grid in detail
Introduction to the complexity and schematic view of most rural connection arrangements
for projects < 50kW
Warning Excludes non-standard DNO supply systems that are awaiting a
system upgrade
Will the grid connection cost undermine the F.I.T/energy reduction investment return?
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Essential Information
Supplied by sustainable Energy Eystems
Installer of over 300 small WT’s in the last 5 years
What you must have
• Good healthy DNO supply
• Single phase or 3 phase
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Examples of poor connection capability
• More than one property run
from the transformer
• End of line connection
• Long distance to three phase line
• Low on site usage
• Old supply transformer
• High voltage tapings on the supply transformer
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Rural supplies • 70 % of rural areas have a single phase supply
system
• A technical assessment must be made before any applications are submitted to the DNO
• A project must initially have view of the likely GRID connectivity and costs
• Submit a budgetary request to the DNO for indicative costs
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Rural overhead line supplies & grid connectivity
HV 3 phase supply
Transformer HV to LV single phase
Single phase LV supply to a farm
• This supply arrangement provides single phase to the customer
• MCS generator project connectivity is 3.68kW
• Cost to upgrade for 3 phase if pole is suitable (£6k to £15k)
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70% of rural overhead line supplies are single phase only
HV 2 phase supply
DNO HV/LV transformer
• This supply arrangement can only provide single phase to the customer
• MCS generator project connectivity is 3.68kW
• Cost to upgrade to 3 phase, with a new pole transformer = £18k
• New lines and poles = £80 = £120/m
Single phase supply to customer
Substation name and pole number
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Connectivity for single phase rural grid supplies with one customer
1 Customer
Small LV grid cables
G 83
generator
• Installed under G83
• May require later DNO grid upgrade High voltage
lines
Proposed 3.68 kW single phase WT
Single phase LV grid cable
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Connectivity for single phase rural grid supplies to one customer
Customer no 1
Small LV grid cables
G 59
generator
High voltage lines
Proposed >11 kW < 50 kW single phase WT
• G59 application to DNO • Installed under G59 • DNO grid upgrade & costs to connect
Single phase LV grid Cable
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Connectivity for single phase rural grid supplies with more than one customer
Customer no. 1
Customer no. 3
Customer no. 2
Small LV 3 phase grid cable
G 83
generator
• Single phase installed under G83 maximum of 3.68 kW
• May require later DNO grid upgrade
High voltage
lines
Single phase LV grid cables
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Connectivity for single phase rural grid supplies with more than one customer
Customer no 1
Customer no 3
Customer no 2
Small LV single phase grid cables
G 59
generator
• G59 application to DNO with technical details
• With DNO’s agreement installed under G83
maximum output 3.68 kW
• May attract DNO grid upgrade costs
High voltage
lines
Proposed 5 kW WT limited to ( 3.68 kW output)
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Rural Case Study Grid upgrade costs for exceeding 16 amps
• Evance 9000 installed in Rossendale
• Planning submitted and passed
• Application submitted to DNO for connection of 5 kw
• Grid costs excessive £ 20,000
• Technical agreement with DNO to cap turbine output to 3.6kW – nil cost
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New S/S for
customer no 2
Connectivity for single phase rural grid supplies
Customer no 1
Customer no 3
Customer no 2
G 59
generator
• G59 application to DNO
• installed under G 59
• DNO grid upgrade & costs to connect
High voltage lines
Proposed 10 kW to 50 kW single phase WT
Single phase LV grid cables
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Connectivity for split phase rural grid supplies with more than one customer
Customer no 2
Customer no 1
Has 2 x 1 phase supplies
Small LV grid cables
G 83
generator
• 1x3.68 kW project installed under G83
• A second project will require G83 stage 2 application to DNO
High voltage
lines
Proposed 3.68 kW single phase WT
Split ( single) phase LV grid cable
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Single (split) or three phase ?
• In a rural area if there is any doubt
• Competent electrician to carry out voltage test a the source of the supply on the customers side
• Contact the DNO
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Overhead supply with three phase transformer
HV 3 phase supply
Transformer HV to LV 3 phase
Overhead LV 3 phase supply to customer
• Maximum rated capacity 50KVA (approx 70 amps per phase)
• MCS generator project connectivity is 11kW
• Exceeding 11 kW will require connection approval from the DNO
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Connectivity for 3 phase rural grid supplies to one customer
Customer no 1
G 83
generator
High voltage lines
Proposed 11 kW 3phase WT
3 phase LV grid cable
Installed under G83 May require later DNO grid upgrade
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Connectivity for 3 phase rural grid supplies to one customer
Customer no 1
G 59
generator
• G59 Application to DNO
• Installed under G 59
• Grid upgrade & costs to connect
High voltage lines
Proposed >11 kW <50kW 3phase WT
3 phase LV grid cable
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Connectivity for single/3 phase rural grid supplies with more than one customer
Customer no 1
Customer no 3
Customer no 2
G 59
generator
• G59 Application to DNO
• Installed under G 59
• Grid upgrade to connect
High voltage lines
New S/S for
customer no 2
Proposed >11 kW < 50 kW 3 phase WT
3 phase LV grid cable
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Connectivity for single/3 phase rural grid supplies with more than one customer
Customer no 1
Customer no 3
Customer no 2
Small LV grid cables
G 83
generator
• Installed under G83
• May require later DNO grid upgrade
High voltage
lines
Proposed 3.68 kW single phase WT
3 phase LV grid cable
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Connectivity for single/3 phase rural grid supplies with more than one customer
Customer no 1
Customer no 3
Customer no 2
3 phase LV grid cable
G 83
generator
• Request to DNO to upgrade supply customer supply
from 1 phase to 3 phase ( from £1,500 to £ 4,500)
• Installed under G83
• May require later DNO grid upgrade to transformer
High voltage
lines
Proposed 11 kW 3 phase WT
Single phase grid service cable to
customer
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Connectivity for single/3 phase rural grid supplies with more than one customer
Customer no 1
Customer no 3
Customer no 2
G 59
generator
• G59 Application to DNO
• Installed under G 59
• Grid upgrade to connect
High voltage lines
New S/S for customer no 2
Proposed >11 kW < 50 kW 3 phase WT
3 phase LV grid cable
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Larger rural supplies The H pole
Maximum size of grid transformer 200kVA feeding • Dedicated customers •Several costumers in one area • MCS generator project connectivity is 11kW ( or 3.68kW for single phase supplies) •Exceeding 11 kW will require connection
approval from the DNO
Larger generator projects will require permission from the DNO to connect
11KV DNO grid
240/415 volt LV grid to customers
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Firm grid connection quotation • Will include:
– Connection permission
– Terms and conditions specific to the project
– Any connection costs
– Legal work if required
• On acceptance, the project work can commence
– You can install the project to the submitted design
– You must follow G83 & G59 Compliance stages
– You must complete the test and commissioning stages.
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Case Study Small Hydro G59 connection
Small 15kW hydro project in a remote valley
• Refer to site map for further information
• Large valley with no 3 phase grid supply
• A technical solution agreed with the DNO
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Case Study Rural location: 10kWp School project
The Project • Grid supply looks like it is 3 phase • Installation has 3 phase TP/N switch fuse • Sales person secured a 10 kWp PV array contract • PV panels and inverters were installed • Electrician was sent to complete the connection
to G83 standards The issue • The electrician discovered that the supply was
actually 3 x single phase supplies • The incoming overhead grid lines to the grid
distribution transformer only have 2 cables. • There is no 3 phase supply in the area The Solution • They submitted G83/2 application requesting
permission to connect multiple projects.
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Case Study Two incoming HV lines supplying village
No 3 phase supply
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Case Study Two incoming HV lines supplying village
No 3 phase supply
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Do’s • Have a view of what is involved
• Carry out a detailed site survey
• Understand the potential connection costs
• Make the right decisions, at the right time
Dont’s • Ignore grid connection
• Leave it to the last minute
• Make assumptions
• Request a firm grid connection offer until you are in a position to accept
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Break time
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Exercise 1: Completing a site survey Group exercise with feedback and discussion
• You are going to a site, to undertake a survey for a renewable energy project.
• Maximum of three groups
• List what you think you need to consider when undertaking this site survey…
1. 50kW hydro 3 phase generator
2. 150 kW peak PV solar
3. G83 or G59 WT generation
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Site Survey 1 Proposed 50kW Hydro project: The Weir
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Site Survey 2: Burnley College 150 kW peak PV solar
Proposed PV 150 kWp project
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Site Survey 3 Proposed 2 x 11 kW Gaia turbines
The project:
Green Farm
Existing supply
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Part 3
large power connections
Have a view of what is involved
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The UK Grid layout Provides a network of cables and substations to transport power
to customers
National grid transmission 400kV
Bulk supply
point to DNO
132 kV
Primary Grid
supply into areas
33kV 66kV
Area
distribution
6.6kV11kV
Automatic connected network
Power Station
Manual connected network
Large
customers
supplies
Domestic and small industrial supplies
Power
stations
network
connected
240/415 volts
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Other considerations • Network capacity issues
• Connection capacity race
• Technical, design for firm grid application, correct choice of generator , thermal limits, voltage limits, reverse power flow, switch gear rating and fault levels, protection arrangements, power quality , earthing stability ,
• Competent design /experienced consultants
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Grid connection project planning
1. Planning information phase
2. Detailed design phase
3. Construction phase
4. Compliance and commissioning stage
Budgetary/indicative quotation from DNO
Permission and costs to connect Identifying a suitable site
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New NHS build Ashton
Case study
Non contestable & contestable Grid costs
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The I.C.P?
• Independent connection provider
• Lloyds registered to carry out contestable grid works that will be finally adopted by the DNO
• May be able to carry out design work for you project and project manage on you behalf
• Will apply for a Point of connection form the DNO and the non contestable costs
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Grid connection options Grid connections are split into two
• Non contestable work – the work only the DNO or his registered contractor can do
• Contestable work – The work that is open to competition that any Lloyds registered I.C.P can do, on completion will be adopted by the DNO
Choice • Use the DNO for all the Grid connection work and an experienced
Grid engineer for the testing and compliance stages of the project
• Use an I.C.P to complete the contestable work and project manage all the other requirements
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Non contestable & contestable works
DNO existing 11kV cable
Non-contestable Work
Final HV joint
Network study and all design approvals
Contestable work
New DNO HV S/S
New HV cable
Customer s HV cable
To next substation
This one cable connection to the existing grid is called a TEE or unsecured connection
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Non-contestable & contestable works
DNO existing 11kV cable
Non-contestable Work
Final HV joints
Network study and all design approvals
Contestable work
New DNO HV S/S
Customer’s HV cable
This cable connection to the existing grid is called a LOOPED or secured firm connection
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Larger single turbine –225kW The project:
• In pre-planning stages
• 1 x ASCA 225kW turbine
• Hub height 32m / Blade diameter 28m / Tip height 46m
The Benefits:
• F.I.T. payment
The grid connection process:
• Rural location
• Grid connection point - 450m from preferred turbine location
• In file - Grid connection budgetary quote - £168K
• Final – Grid connection £ 168,000
• Update – delayed due to planning consents
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Site layout
Proposed site of turbine
Incoming 6,600 volt overhead
Grid line
Incoming 6,600 volt overhead Grid line
Brown cables are low voltage
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Extract from Electricity Northwest’s
budgetary quote This shows the proposed
connection plan
• The Map shows the proposed route to connect the turbine to the grid
• A new substation and
cables would be required
• Cables would follow the road rather than cross agricultural fields
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2.25 MW turbine project 3 x 750 kW turbines
The project:
• 3 Turbines on farm near Chorley
• Total project installation costs - approx £2.5M
The Benefits:
• F.I.T / R.O.C payment
The grid connection process:
• Rural location
• Grid connection point 1.2km from site
• Need to access 3rd party land to reach grid connection
point
• Grid connection cost £227k (approx 10% of installation
cost)
• DNO non–contestable - £26,000
• DNO–contestable - £201,000
• I.C.P- contestable - £119,000, excludes legal costs
• Delays caused by ongoing negotiations with 3rd party
land owner land access payment
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Connection options
Difficult negotiations with 3rd party
landowner
Project considered connecting to the
passing 33,000 volts system .
DNO non contestable estimate £345,864
DNO contestable estimate £387,803
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Greenacres Farm 300kW AD plant
Greenacres Farm 300kW AD plant
18 months of planning and investment commitment
Agricultural consultant involved
Option no 1 for 300 kW of AD generation
• Initial budgetary Grid quote of £100,000
• non-contestable cost of £10,000
Option no 2 for 600kW of AD generation
• The connection cost remained the same but the extra upgrade works on the system to allow more generation were estimated at £251,000
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The basic Grid connection issues
for each Project
• Is there a Grid connection at a cost that the project can afford ?
What other issues do I have to consider? • Site location of new DNO Substation • Permission & cost to lay new DNO cables on 3rd
party land • Grid connection options
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Connections have commercial risk
• Actual connection capacity can only be secured when accepting a firm offer, and is subject to terms and conditions
• Outstanding offers can become interactive
• Grid systems are dynamic
• In some areas larger projects >5MW may be in a queue or waiting for connection room on the grid to become available.
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Approximate Connection delivery times
• 415 volt ( 3-phase) 2 months
• 11 kV 6 months
• 33 kV >12 months
• 66kV/132kV > 18 months
• 132kV upwards & NGT level
Legal works can take 3 to 12 months to complete
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Part 4: Additional grid connection considerations
1. I.D.N.O & mpan no’s
2. Power factor
3. 3 phase power calculation
4. Fault levels
5. Likely grid connection costs
6. G59 testing & Commissioning
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MPAN numbers Identifying the DNO
• MPAN (Meter Point Administration Number)
• This is found on the electricity bill issued by the supplier
• The full MPAN is 21 digits and should be printed in the format as shown on a recent electricity bill
www.energylinx.co.uk/mpan.htm
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The Distribution Network Owner
•Establishes and maintains Electricity Distribution connections to its customers – first for load, and more recently generation • Does not make, own, buy or sell electricity, though other parts of the groups may
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From electricity board to DNO’s Takeovers, mergers and acquisitions
MPAN ID Previous name Recent name 11 East Midlands Electricity Central Networks E.ON
14 Midlands Electricity
12 London Electricity
19 The SEE board EDF now UK Power Networks
10 Eastern Electricity
13 Manweb Scottish Power SP Energy Networks
18 Scottish Power
16 Norweb (UU) Electricity North West
17 Scottish Hydro Electric Scottish & Southern Energy now
20 Southern Electric SSE Power Distribution
21 South Wales Electricity Western Power Distribution
22 South western Electricity
15 Northern Electricity CE Electric (YEDL NEDL) now
23 Yorkshire Electricity Northern Power Grid
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IDNO Independent Distribution Network Operators
They own cables and substations inside of a DNO’s geological area
ID Name Licensee
24 Envoy Independent Power Networks
25 ESP ESP Electricity
26 Energetics Global Utilities Connections (electric)Ltd
27 GTC The Electricity Network Company Ltd.
28 EDF IDNO UK Power Network (IDNO) Ltd
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What is power factor and kVar?
The grid supplies the customer
with 500 kVa = 721 line amps
Customers peak
consumption 400kW
= 557 Line amps Reactive energy
300 kVar
= 443 Line amps
Pf = 400/500
= 0.8 = 36 degrees
Increase the Pf to 0.9
= 25 degrees
500kVa reduces to
444kVa and line
current reduces to
640 amps
Pf angle
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Three phase
FORMULA TRIANGLE
POWER
VOLTS AMPS 1.732
x
Power = volts x 1.732 x amps Amps = power
volts line x 1.732
Line
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Three phase calculations
• Calculating kW power for small three-phase supplies
• Power = line Voltage x line amps x PF x 1.732
(for small supplies assume PF as 1)
• (K)Watts = Line volts x Line amps x 1.732
• Line (phase) Amps = Power (K)Watts
line volts x 1.732
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Calculating phase line current for three-phase project
• PV array is rated at 11.4 kWp (11,400 watts)
• What is the maximum line current output in amps if the line voltage is: (assume PF as 1)
• Line voltage is 415 volts
• Line voltage is 400 volts
• Formula is amps = power kW / line voltage x 1.732
Answer
• 15.86 amps line current
• 16.45 amps line current
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Fault level current
This is the maximum fault current that a generator can deliver to a short circuit fault
• For inverter driven generation
The maximum fault current = output +5 %
• For rotating generators
This will require power engineering expertise with technical details of the rotating generator and calculations
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Likely grid connection costs • Turn the voltage down at PMT = £2,500
• Isolation and safe working on O/H lines = £ 2000
• Turn the voltage down at S/S = £1,500
• HV DNO Grid network Study from = £2,000
• New PMT and transformer = (£10,000 to £32,000)
• New ground mounted HV S/S = £40,000
• New ground S/S with transformer = £65,000
• HV cable laying = £100 to £200 / m
• LV cable laying = £80 to £150 / m
• New O/H lines and poles = £80 - £120 / m
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Testing and commissioning & compliance
• Refer to Technical notes supplied
• G59 Testing & commissioning and compliance with DNO’s requirements
Outsource to a competent experienced engineer
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Break time
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Exercise 2: Completing the ENA form for an example project
• Complete and submit to ENW using the ENW form for a 150 kWp PV solar project.
• The customers supply is 946 kW with a power factor of 0.95
• The estimated weekend base load is 145 kW
• Firm quotation is required
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Generator customer grid assessment Required on the standard EA form
Questions A2 A3 A4
Power
Station
Power
Station
Customers
SITE
Customers
SITE
Customers
intake load
In KW
Customers
intake load
In kW
Grid supply
meter & fuses
Grid supply
meter & fuses
Import Power Kw
Import Power Kw
Customer
generator
Diagram no 1 (A2)
Diagram no 2 (A3)
The Grid supply
The Grid supply
Power
Station
Customers
SITE
Customers
intake load
In kW
Grid supply
meter & fuses
Import Power zero Kw
Customer
generator
Diagram no 3 (A4)
Export power in Kw
The Grid Supply
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Group Exercise Repeat using the ENA form
• Complete and submit to ENW a ENA form for 150 kWp PV solar project.
• The customers supply is 946 kW with a power factor of 0.95
• Estimate the weekend base load
• Firm quotation is required
INNOVATIVE THINKING FOR THE REAL WORLD 84
INNOVATIVE THINKING FOR THE REAL WORLD
Advanced
Grid Connection Workshop
16th July 2013 SSummary and surgery
Geoff Owen, George Hall