Case Studies

Vital health Foods

The Background

Vital Health Foods (Vital) manufactures and markets pharmaceutical and health products. Its manufacturing plant, Head Office and distribution centre is based in Kuilsriver, Cape Town and occupies an area of approximately 11,110m2.

Given the recent and the anticipated future tariff increases as well as the company’s goal to reduce overall carbon emissions, Vital has embarked on an energy efficiency initiative in order to reduce operating costs whilst also reducing its impact on the environment.

The Objectives

The objectives of this project were to:

  • Benchmark the energy efficiency work already done at Vital;
  • Identify further interventions for energy savings;
  • Identify renewable energy opportunities that will assist the goal of carbon neutrality by 2015.

The Process

The following methodology was used in compiling this energy efficiency audit:

  • A detailed energy efficiency audit of all energy-consuming devices in the facility which included the following areas:
    • Lighting
    • Heating, Ventilation and Cooling (HVAC)
    • Office/IT Equipment
    • Water Heating
    • Air Compressor
    • Boiler
    • Equipment (heating, motors etc)
  • Analysis of historical consumption to establish a building performance baseline;
  • Logging and analysis of the main incoming feeder for one week;
  • Analysis of the data gathered during the energy efficiency audit and identification of energy management opportunities;
  • Evaluation and financial analysis of proposed interventions;
  • Development of an energy management action plan for the facility. In addition, pre-feasibility studies were conducted on the following renewable energy options:
  • the installation of a rooftop solar photovoltaic (PV) system;
  • a biomass to energy plant utilising a gasifier and bamboo (bamboesa balcooa) pellets.

The Results

The audited data, including a full inventory of energy-consuming devices in the facility was analysed with the following results:

  • The total energy consumption for the facility over the 12 months was 3,869,598 kWh.
  • As this is a strictly temperature-controlled environment with specified cooling and dehumidification requirements, the largest energy consumer was the air conditioning (HVAC) system (42%).
  • Factory equipment was also a significant energy consumer (30%), followed by lighting (17%).
  • The “Other” category includes water heating equipment, encapsulation machines and HVAC peripheral fans.
  • Current energy efficiency benchmark: Vital has already implemented certain energy saving interventions (Electro Flow device and a wasteheat recovery unit) that were modelled to have saved 698,919kWh (708 tonnes CO2e) over the past year.
  • A total of 753,248 kWh of electricity can be saved through energy efficiency, which is equivalent to 19.5% of the total bill (excluding the heat pump).
  • A rooftop solar photovoltaic (PV) system is currently not financially viable due to the lack of feed-in tariff as well as the high cost of PV panels in South Africa at present.
  • A biomass-to-energy plant is an excellent solution to Vital’s goal to be carbon neutral by 2015 and should be investigated further as it will allow Vital to use 100% renewable energy as well as to obtain carbon offsets through the sequestration of growing biomass (bamboo).

The Opportunities

The following energy management opportunities were identified and are summarised in the table that follows:

Lighting:

Vital is in the early stages of a demand-side management (DSM) project for lighting retrofits and is presently trialling LED tubes to replace the existing fluorescent fittings. These LED tubes produce a significantly lower level of light, and it is therefore recommended that Vital also trial T5 replacement fittings.

Vital should also:

  • upgrade the fluorescent T8 fittings to T5 fittings;
  • replace the 250W and 400W high bay fittings with fluorescent fittings.

After retrofitting, the installation of motion sensors should be further investigated as they can be a highly effective control intervention.

HVAC:

The facility’s HVAC system consists of numerous individual units, a water-cooled Daikin chiller plant and a dehumidification plant fed by the boiler and water chiller.

The individual units are energy-inefficient and should therefore be replaced with a more efficient variable refrigerant volume (VRV) system.

The chiller plant operates efficiently and incorporates a waste heat recovery unit. The waste heat is currently not being used, and it is recommended that it be used to supplement the hot water from the boiler, thereby reducing paraffin usage.

Office/IT Equipment:

Most office equipment consists of PCs with energy-inefficient cathode ray tube monitors. These should be replaced with LCD monitors or laptops.

Water Heating:

Vital is currently replacing the electrical geysers with solar water heaters which will give excellent energy savings.

Boiler:

It is recommended that the boiler be supplemented with a heat pump to preheat the water. Whilst this will increase electricity usage it will decrease overall energy usage as a result of a reduction in the paraffin used by the boiler.

Equipment:

The following interventions were identified as areas of potential energy savings:

  • Insulation of the package heater machines and removable insulation jackets for the portable heating cylinders.
  • Replace the existing standard-efficiency motors with higher-efficiency motors as they fail rather than rewinding them. This will reduce both heat loss and energy consumption, thereby reducing the air conditioning load.
  • Ensure motors are switched off when they are not needed.
  • Ensure motors are placed on a maintenance schedule that includes regular lubrication.
  • Begin a motor performance monitoring program with the motor operators recording the following:
    • Operating hours at 100%, 75% and 50% load
    • Condition of fans/drive belts

This will identify those motors that can either be replaced with smaller motors or be fitted with variable speed drives.

The graph below illustrates annual savings with the recommended lighting and IT investment only (other interventions excluded because system redesign is necessary to obtain an accurate costing).

The Future

Implementation of some or all of the opportunities presented above will not only lead to significant and ongoing cost savings, but will also position Vital as an industry leader in addressing climate change and assist in moving the company towards its goal of carbon neutrality.