RENEWABLE ENERGY GENERATION OPTIMISATION AND INNOVATION

The energy landscape globally is changing fundamentally. The ongoing concerns about climate change, new possibilities with digital solutions and the economic efficiency of renewables are shaping the energy transition.

Involved players such as municipalities, local communities or metropolitan cities are adapting their strategies, but also new partners such as private businesses are rethinking their approaches.

Globally operating companies are developing initiatives which focus on reducing energy consumption, driving down energy costs and integrating wind & solar power in the overall mix. At the Siemens’ headquarters in Midrand,Johannesburg, a one-of-a-kind Distributed Energy Systems (DES) solution was installed during 2018 as a key measure to achieve carbon neutrality by 2030. Dubbed the ‘Siemens South Africa Distributed Energy System Project’, the system consists of a 1MW solar photovoltaic (PV) plant on the campus buildings as well as the parking area and is integrated with the diesel generator and a 140 KWh SieStorage energy system via the Siemens MicroGrid Controller. Consequently, the facility is not only able to charge its eCar fleet but is also capable of managing energy production and consumption.

PROJECT MILESTONES

The project design has achieved four noteworthy milestones: The DES was customised to matchthe requirements of the office park, which has enabled Siemens to shape local generation andconsumption in response to market price signals to achieve the lowest overall cost of energy. Coupled with other traditional energy conservation measures, the DES has improved system efficiency.

Integrated real-time data monitoring and multipoint controls at both building and network level have improved overall operations of assets. Additionally, the DES includes renewable and low carbon technologies and controls which enable the integration of such technologies into the network and reduction in the carbon intensity and local environmental impact of the system. The project took about 12 months from inception to operation.

PROJECT RESULTS

Since the system has been operating at full capacity, the results indicate 16 months of uninterrupted power. The company has saved 2,435,000 kWh (2.4GWh), which translates into 174,000 kWh per month, representing 50% of the office park’s normal consumption – enough to power 50 average South African households for a year. This represents exactly 50% of the baseline consumption – but the past few months have shown closer to 60% less consumption due to system optimisation and battery usage. In addition, Siemens has saved about 2,460 tonnes of CO2 since the system was opened.

The initial payback period calculated for the system was 11.1 years (capex, financing, maintenance, conservative power price inflation). However, despite there being adjustments to the tariff , after taking the actual production figures into consideration, Siemens is confident that the full payback will be achievable in under five years.The local, decentralised and controllable nature of DESgeneration and storage sources can be designed to provide the end user with local resilience or even full independence from the grid. The benefits accrue to grid operators as well: the DES can manage demand to reduce peak loads and maintain power qualitywhen infrastructure is nearing capacity, avoiding the risk of blackouts and postponing the need for major grid reinforcement investments.

The project can be replicatedand customised at any scale to match consumer requirements. Countries such as South Africa are heavily dependent on coalfor supply of electricity; this in combination with infrastructural challenges has led to an unreliable energy supply for South Africans.

Distributed Energy Systems present the opportunity to diversify the energy mix, thus contributing to a higher rate of energy security. The introduction of wind and solar power would enable residential areas, commercial and retail campuses, office buildings, hospitals and hotels to continue operations without any interruptions even when one source of energy fails.

DES presents the perfect solution to create resilience in energy systems for cities and communities. Rapid population growth is driving the urbanisation of increasingly dense cities with large energy demands. These trends coupled with large scale environmental changes make cities a priority for increased resilience to shock events. A distributed energy system is a potential solution to this problem as energy could be stored in small pockets within the affected areas.