Connecting Low Carbon Generation Clive Goodman Primary System Design Engineer

Western Power Distribution Wholly owned subsidiary Pennsylvania Power & Light ( PPL) 4 UK Distribution Licences incl. former CN since April 1 st 2011 Serves 7.6 million homes + businesses 55,000 sq km Largest length UK network – roughly 1/3

Renewable Generation Wind Photovoltaic Hydro Wave Biomass Geothermal Other?

Growth of Distributed Generation 240% increase in DG connection (2009/10) Ofgem Feed-in-Tariffs were introduced on 1 April 2010 & provide incentives for small-scale generators to to 5MW

What is Driving Distributed Generation ? Environmental Concerns – Greenhouse Gas Emissions from Fossil Fuels Technological Innovation- Wind, Wave, Solar & Biofuels New Government Policy – Secure, Low Carbon, Competitively Priced

Feed in Tariffs (FITS) Introduced on 1 April 2010 Provide financial incentives for small-scale generators up to 5MW Most installations are Photovoltaic and Wind South West & South East accounting for almost 40% of the total installations Total Installed Capacity Breakdown of FIT installations by technology: 81 % Photovoltacic 11% Wind 5% Hydro 3% Anaerobic digestion

Renewable Resource

Small Scale Embedded Generation (SSEG) Low Voltage 230/400V Up to and including 16A per phase, single or multiple phase 3.68kW (Single-Phase) 11.04kw (Three-Phase)

Small Scale Embedded Generation

Utilities Act 2000 It shall be the duty of an electricity distributor – (a)To develop and maintain an efficient, co- ordinated and economical system of electricity distribution (b)To facilitate competition in the supply and generation of electricity

Connection Process G83 Stage 1 – Single Installations of SSEG – Legal Obligation for installers to notify the DNO within 28 days of commissioning G83 Stage 2 – Multiple Installations of SSEG (eg. Housing refurbishment in the same street or New Housing Development)– Application to the DNO required + test certification. Application considered and costs/implications advised G59 – Larger applications for generators in excess of 16A per phase (3.68KW)

Electricity Network Challenges Reverse Power Flow Voltage Rise Equipment Ratings Power Quality Voltage Disturbances (flicker) Voltage Distortion (harmonics) Fault Levels Equipment short circuit ratings

Traditional Network Power Flow

Renewable Generation Reverse Power Flow Power Flow

Voltage Rise Theory Assumes lightly loaded Voltage rise pu = V1 -Vo

Voltage Rise Ohms Law V = I x R

Voltage Rise Solutions: Reduce resistance (impedance) of the network. Improve network utilisation (i.e. ensure we get the most out of the network) Limit the connection of generation

Voltage Rise Improve Network Utilisation: Improve network modelling Increase monitoring on the LV network (Smart Meters and Smart Networks) Improve voltage regulation at 132kV and 33kV substations Reduce voltage on HV and LV networks Introduce load / generator control Introduce automatic voltage regulation on our LV networks

Power Quality Voltage Disturbance: Sudden increase or reduction in current / power causing voltage to dip or rise Causes flickering lights Solutions: Improve equipment design Reduce resistance (impedance) of the network Changes in lighting technology may help (e.g. compact fluorescent lighting)

Power Quality Voltage Distortion (harmonics): Caused by non-linear load / generation (power electronics, inverters, motor drives, fluorescent lighting etc.) High levels of harmonics can cause capacitors / power supplies to fail, transformers to overheat, cables to overheat and metering inaccuracy Solutions: Improve equipment design Reduce resistance (impedance) of the network

Low Carbon Networks Fund £500 Million Funding Tier 1 £80 Million for small scales projects across all the DNOs Tier 2 £320 Million for ‘Flagship Projects’ where DNOs compete for funding £100 Million discretionary fund Accelerate development of Low Carbon Electricity System Impact on DNO network performance Delivered benefits to customers expected to exceed cost of project Generate new knowledge to be shared

Low Carbon Networks Fund WPD Projects Include: Network Templates Project (monitoring 1000 distribution substations and associated LV network) Melin Homes - 20 PV installations (38kW) 11kV Voltage Regulation (use of STATCOM systems)

Low Carbon Network Fund Tier 2 Projects 2011 FALCON (Western Power Distribution East Midlands) Facilitate the installation of low carbon technologies by avoiding traditional reinforcement Use of real time network data in inform network decisions Development of a scenario investment model using data from the trials Control network tests in an area with about 200 distribution and primary substations centred on Milton Keynes

Low Carbon Networks Tier 2 Projects 2011 Buildings, Renewables, Integrated Storage To Overcome Limitations (BRISTOL) 30 Houses, 10 Schools and an Office with Solar PV and Battery installation Solar PV Battery connected using DC connection DC Lighting Circuits + Small appliances run on DC direct from solar PV and battery Battery ‘shared’ between Customer and DNO Tariff to encourage electricity use at times of high PV generation and use battery when network is heavily loaded Focused on social housing in Bristol in conjunction with Bristol City Council Solar PV, Heat Pumps & Electric Vehicles require network reinforcement – Project will provide data on how the existing capacity may be better utilised

The End