PV plant to help power Outeniqua Wastewater Works

GEORGE NEWS - The Outeniqua Wastewater Treatment Works (WWTW) which is situated in Pacaltsdorp, is the first service plant of the George Municipality to be powered with solar energy following the installation of a 400-kilowatt peak (kWp) PV plant, occupying an area of approximately 4 800m².

On Friday 30 June, George Mayor Leon van Wyk, accompanied by Portfolio Councillor for Electrotechnical Services & Fleet Management Nosicelo Mbete, Portfolio Councillor for Civil Engineering Services Jacqulique von Brandis and Municipal Manager Michele Gratz, visited the plant.

"We are thrilled to have this Solar PV plant installed and are working towards getting operational to provide electricity to our Wastewater Treatment Works by the end of July this year.

"Meanwhile, we are also busy finalising a tender process for roughly 4,8megawatt hours' (MWh) worth of battery energy storage that we are going to be implementing, and that 4,8MWh will be split between various installations and treatment works around George to compensate for load shedding and any other unexpected power outages," said Van Wyk.

"Once operational we will be able to power most of the wastewater treatment works electrical loads during the daytime. It is essential that we make use of renewable energy along with a battery pack, which will be added in due course so that we can have the power to operate our sewerage at all times."

Solar PV to reduce consumption from the grid and bulk purchases

The director of Electrotechnical Services, Bongani Mandla, said that this is among the multiple solar installations planned for the City of George, particularly for the essential facilities such as water and wastewater treatment works and other municipal buildings.

"The purpose of the installation of Solar PV is to reduce our facilities' consumption from the grid, which will reduce our bulk purchases," Mandla said. "The facility will mainly be supplied through the use of clean energy and a battery energy storage system will also be installed to further make the facility more resilient."

Plant energy, cost and lifespan

The department says the PV installation, supported by the battery system, will provide a more stable energy supply to the WWTW. According to Thabo Yiga, the municipal project manager, the system will comprise 738 panels, with each panel rated at 545W.

"Then we have the inverters that convert the DC power from the panels into AC electricity that's required by the loads. We have a total of eight inverters, with each inverter rated at 50kW, Yiga said.

"The system will be grid-tied with no storage. However, it will allow for the integration of battery storage to be installed in the next financial year. The power generated will be fed into the facility's main low-voltage distribution board where the loads (pumps and motors) required to operate the wastewater facility are connected."

The expected annual energy yield is 678 680kWh, and at a rate of R1,60 per kWh, the cost of the annual energy generated is R1 085 888. The calculated payback period of the system is seven years.

The lifespan of PV systems is 25 years. The system's total cost, including a 24-month operation and maintenance period and training of four municipal staff, is R7,8m (inclusive of Vat). The carbon emissions that will be avoided using energy generated from a clean and renewable source is 12 809 tons over the 25-year lifespan.

In addition, the PV system will have a weather monitoring station equipped with four sensors to measure parameters such as irradiance, wind speed and wind direction, humidity, ambient temperature, PV panels' temperature, etc.

This data, including the PV production date, will be sent to a cloud, and then pulled off from there and displayed on the Scada system, for remote monitoring in near real-time.

The PV installation will enhance service delivery. "The PV system will provide a more stable energy supply to the wastewater treatment works during periods of power outages and ensure power supply continuity is necessary to ensure quality compliance of the final effluent by not causing interruptions to the treatment process," said Lindsay Mooiman, Deputy Director of Infrastructure, Planning and Project Management.

The system will comprise 738 panels, with each panel rated at 545W.