Grid Connection Issues Micro Hydro Projects Rachel Hodges

Where, and how suitable is the ‘Grid’? Tend to be in awkward locations Consider during initial feasibility Can be a go/no-go decision maker Look at: Distance Single / 3 Phase Voltage Local Loads Switchgear and Ratings Accommodation

Synchronising Synchronous Machine –Need inverters and controllers to match frequency of the grid –Need to consider harmonic content –Can operate in islanded system Asynchronous or Induction Machines –Automatically match frequency of the grid –Need power factor control (switchable capacitors or DFIG)

G83 versus G59 G83 For up to 16A per phase (6kW at Low Voltage) Equipment G83 Certification Notify the Distribution Network Operator (DNO) G59 For up to 5MW at 20kV Connection application, connection offer and witness testing required.

Connection Application DNO will look at: –Transformer and connection capacity –Abnormal feed conditions –Fault Levels –Voltage Rise (P28) –Voltage Step Change, Flicker and Harmonics (G5/4) –Loss of Mains (Islanding) Protection and Earthing (G59)

Connection Offer Can take up to 90 days Connection offer will indicate: –Non-contestable work and costs (to be undertaken by DNO) –Contestable work (undertaken by accredited 3 rd party or DNO) –Constraints –Timeframes

G59 Protection Under and Over Voltage Under and Over Frequency Loss of Mains (ROCOF, Vector Shift, Intertripping)

Metering ROCs Import / Export Export MPAN from Supplier Power Purchase Agreements Benefits of Onsite Generation

Grid Connection Issues Micro Hydro Projects Rachel Hodges