Sarah Weatherhead, TNEI, talks through problems solar installers can face with connecting systems to the grid and how to overcome them.

1. Grid Connections for Solar
How to get connected and current issues
Thursday 7th August
Sarah Weatherhead, TNEI Services Ltd

2. TNEI Services Ltd
• Two core-groups
– Power Systems & Technology
– Planning & Environment
• Manchester, Newcastle and Glasgow
– 60 Staff - 15 nationalities
– Predominantly UK and Europe footprint
– Increasing international workload
– Expanding range of design and technical site services
• Acquired by Petrofac in June 2010
• Solar Energy UK Conference and Exhibition
NEC, Birmingham 14 – 16 October 2014

3. Why are TNEI relevant ?
Development Pipeline
Site Selection Design Consenting Build
• GIS sieving (including
topology, aspect, flood
risk and Global Horizontal
Irradiance)
• Environmental
Constraints mapping
• Grid Feasibility
• Power System Design
• Layout Design
• Grid Connection
Applications
• Planning Applications
• Community Consultation
• Environmental Impact
Assessments
•Planning Appeals,
Enquiries and Hearings

4. Power Systems & Technology
• Key Markets:
– Electrical Transmission and Distribution
Utilities
– Renewable Industry
– Oil & Gas Industry
• Services:
– Strategic Infrastructure Planning &
Technology Assessment
– Regulation, Technical Strategy & Due
Diligence
– Specialist Power Systems Analysis
– Grid Connection & Compliance
– Project Development – Design
– Software/Application Development
Established Client Base
• Transmission and Distribution
• Generation Manufacturers
• Oil and Gas Industry
• Renewable Developers
• Government & Regulator
(Scottish Enterprise, Scottish
Government, Ofgem, DECC...)

5. Grid Connections
1. The transmission and distribution networks
2. Where to connect and common issues
3. The grid connection process

6. Source: SP Electrical Awareness
Transmission
Distribution
Distribution (Transmission
in Scotland)

7. • Moves bulk power around the country
England & Wales:
• Operates at 400kV and 275kV
• Owned and Operated by National Grid
Scotland:
• Operates at 400kV, 275kV and 132kV
• Network is owned by:
• Scottish Power Transmission (SPT)
• Scottish Hydro Electric Transmission (SHET)
• National Grid are still the System Operator
The Transmission Network

8. The Distribution Network
• Takes power from transmission
system to end users
• 14 licence areas
• Operated by 6 Distribution
Network Operators (DNOs)
• Complex networks with LOTS of
assets
• Frequent changes to the network
every week
2 license
areas
-North East
-Yorkshire
4 license areas
-East Midlands
-West Midlands
-South West
-South Wales
3 license
areas
-London
-Eastern
-Southern

9. Grid Connections
1. The transmission and distribution networks
2. Where to connect and common issues
3. The grid connection process

10. Where to connect?
Transformer
Load
Busbar
Grid Infeed

11. Thermal Constraints
Where would you
connect a 10MW
solar farm?
A

12. Thermal Constraints
Where would you
connect a 35MW
solar farm?
A
B
C

13. Voltage Rise

14. Fault levels

15. Available Information
• Long Term Development Statements
• Heat maps / capacity maps

16. Active Network Management Schemes

17. Grid Connections
1. The transmission and distribution networks
2. Where to connect and common issues
3. The grid connection process

18. > 16A per phase
i.e. >3.68kW for a
single phase generator?
YES
Apply to DNO for
grid connection
NO
Connection Applications
No grid connection
agreement needed.
Inform the DNO
after connection.
For multiple
installations in the
same area, discuss
with DNO first and
get approval.

19. Submit
Application
90 days Receive
Offer
Up to 90 days
Accept
Offer
Acceptance feeFree
Connection Applications

20. • Occurs if multiple generators apply for the same capacity
• DNO will issue interactive offers
Substation:
20 MW
Wind Farm 1
Applies for
15MW
DNO
issues
Offer
Interactive Offers
Wind Farm 2
Applies for
10MW
DNO issues
interactive
Offer
DNO issues
letter stating
interactivity.
Wind Farm 1
is 1st in
Queue
Wind Farm 2
is 2nd in
Queue
10 day Moratorium
period starts
Priority depends on
Queue position

21. Does my
generation
cause
problems?
28 days
How to
address
this
problem?
Up to 90 days
Variation
Notice
Project
Progression
£4.5k - £17.2k
Request for
Statement
of Works
£1000-£3000
Statement of Works
Costs to
secure works
?

22. Studies and Design
• Harmonics
• P28 – transformer inrush, voltage step change, flicker
• Load flow
• Fault Level

23. Financial Support
• Solar over 5MW won’t be eligible for ROCs if commissioned
after 31 March 2015
 will need Contract for Difference
• CfD application window 14th – 27th October.
• Sealed bid submissions 26th Nov- 3rd December
• Need planning permission and signed grid connection offer.
• Strike price (theoretical maximum) £120/MWh.

24. Thank You
Any Questions ?