Six projects supply energy into eThekwini Municipality’s grid

Submitted by: Amanda Botes, Monday, August 6, 2012

<p>The Dew Catcher wind turbine is one of six energy projects in eThekwini Municipality that are connected to the grid (Image supplied by Dew Catcher).</p>

The Dew Catcher wind turbine is one of six energy projects in eThekwini Municipality that are connected to the grid (Image supplied by Dew Catcher).

“Six energy projects, with an installed capacity of 9.185MW, are currently connected to the eThekwini Municipality’s grid with twenty more in the pipeline, undergoing feasibility studies” says Roy Wienand Deputy Head of eThekwini Municipality’s Electricity Department.   The six projects that are connected to the eThekwini grid and are being remunerated for exported energy are summarised below:

Name

Method of generation

Approximate Generation Capacity

Dube Tradeport

Solar PV

675 kW

Soitec Solar Farm

Solar PV

500 kW

eThekwini Bisasar Road Landfill Site

Landfill gas to energy

6.5 MW

eThekwini Mariannhil Landfill Site

Landfill gas to energy

1 MW

NCP Alcohols

Steam driven turbine

500 kW

Dew Water

Wind Turbine

10kW

Safety and quality of supply

“The eThekwini Municipality’s electrical grid is well maintained and can cope with embedded renewable energy”, says Wienand.  However the Municipality has established a formal process for renewable energy connections to guarantee safety and quality of supply.  Wienand explains that if energy is placed onto the grid without the municipality knowing about it, the quality of the electricity cannot be tested and the quality of the electricity supplied by the municipality can be affected. In particular the municipality will only approve connections from generators, provided that they meet safety and quality standards.  Wienand warned that “it is of paramount importance that anyone synchronising to the grid only does so with the prior permission of the Municipality, failure to do so will be in breach of the bylaws and it may affect the integrity of the grid as well as jeopardise the safety of technical personnel when carrying out repairs and maintenance.”

Limitations

Certain projects may not be permitted to generate energy onto the grid due to network constraints and network saturation.  In the eThekwini Municipality’s case, the City’s Bisasar Road landfill gas to energy project in the industrial area of Springfield Park provides 6.5MW of energy and very little more can be absorbed by the grid in that area. When considering embedded energy generation applications, the Municipality investigates the ability of the surrounding customers to absorb the generated power from each application it receives.

Wienand also points out that applications from very small scale projects are unlikely to be worthwhile because the costs associated with the application will be greater than any potential income. 

Application process

eThekwini Municipality is the first municipality in South Africa to establish a formal application process for grid tied energy generation. The Municipality has set up a system where developers are required to complete an application form and sign a Purchase Power Agreement (PPA) with the eThekwini Municipality in order to benefit financially from generating energy onto the grid. The forms require details on the type of energy generated, energy conversion process and the technical/protection philosophy of grid connection.

Once the PPA has been signed, any excess energy produced by the renewable energy generator can be exported to the grid and eThekwini Municipality will pay the applicant for that energy at the applicable tariff rate that the Municipality buys electricity from Eskom.  On average this rate is approximately 50c/kWh but can vary considerably depending on time and season of generation.

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Amanda Botes