Author: Menno Sulsters, Design and Operations Manager at SEM Solutions

The City of Cape Town has been working hard to achieve the goals laid out in their Energy Climate Action Plan (ECAP) that was adopted in 2001 and officially approved in May 2010. One of the objectives laid out in the plan was that Council (local authority) operations reduce energy consumption by 10% by 2012. 

SEM Solutions, a company specialising in sustainably engineered energy and water solutions for the commercial- and industrial building sectors was involved in the first round of energy efficiency audits that needed to be done to work towards the objectives of the ECAP to make Cape Town a city with low energy consumption. 

SEM Solutions was also awarded the fourth round of energy efficiency audits that was for four complexes that the City of Cape Town had chosen. The project ran from July 2016 until July 2019.

Objectives

The project consisted of conducting energy audits, indicating the feasibility of various energy efficiency interventions and a full lighting retrofit using high efficiency LED light fittings with Digital Addressable Lighting Interface (DALI) controls in the four selected municipal building complexes. 

Besides the energy savings, the other objective was to ascertain/prove that local procurement and manufacturing was of the exceptional quality required to make this work. 

The complexes were the Parow Civic Centre, Bellville Civic Centre Complex (Hall, Civic Centre, Administrative Buildings, Workshops, Stores, Fire Department, Traffic Department, Roadworthy Centre, and Occupational Health Service Offices), Brackenfell Civic Centre Complex (Administrative Building, Community Hall, Law Enforcement, Clinic and Library) and Fish Hoek Civic Centre Complex (Administrative Building, Hall, Library, Disaster Risk Management, Fire Station and Clinic).

Challenges

Establishment of a baseline was the biggest challenge. Lighting usually accounts for 20%-40% of a building’s energy consumption, but in the building complexes; except for Parow, the lighting portion was a lot less due to other activities taking place at the facilities. This meant that the effect of the savings from lighting retrofits was in some cases less than 10% of the building’s total energy consumption. This made the measurement of savings on a building level problematic. Instead, as per International Measurement and Verification Protocol (IPMVP), representative portions of the building were chosen to measure the savings and extrapolate those savings for the entire complex. The saving per light fitting measurements exceeded 50%.

Another challenge was that the installation had to be maintained and guaranteed until the end of the three-year contract period. A performance guarantee had to be ensured, so that the calculated savings would be achieved, minimising the City of Cape Town’s risk. This meant that if the guaranteed electricity reduction per building was not met, SEM Solutions would have to cover the monetary shortcoming of the savings. This factor also ensured that only an Energy Service Company (ESCO’s) of the highest standard was used. 

Achievements

The proven benefit of local production was showcased during the installation, where very short, almost on demand lead times were achieved, allowing for a very dynamic installation process.

The work specifications stipulated that one-for-one light fitting replacements was required. Due to the degradation of old fluorescent tubes and fittings, the City of Cape had added more lights to maintain legislative compliant light levels. This meant the new LED lights provided had light levels that were 50% brighter. The advanced DALI control gear allowed for the fittings to be dimmed and set to a lower level, further increasing the savings.

Although the project was completed in July 2019, the lighting retrofits have a design life of about 15 years and will have long-term savings and benefits to these complexes for many years to come.