Electricity usage

Managing your basic energy principles

Modern electric meter close up view

With load-shedding being almost a daily occurrence, energy security has become vitally important. Energy security, or the availability of energy, is important to everyone, but especially for hospitals, airports

However, the process used to address the challenge is usually not ideal and often leads to inappropriate decisions and unnecessary capital expenditure. Energy security is, and should be seen as, part of energy management.

The revised National Energy Efficiency Strategy (NEES), published for public comment earlier this year, includes guidelines when making any energy management decisions.

Energy essentials

  • Energy conservation:  Stop energy wastage or as defined ‘Reducing the Consumption of Energy without impacting on the production and/or Safety’, e.g. turn off the hot water in office building toilets (everyone has finished washing their hands by the time the hot water reaches the tap anyway).  These measures are often the no-cost or low-cost solutions!
  • Energy efficiency:  Next replace inefficient with more efficient technologies or processes, e.g. change CFLs with LEDs. Scientifically the equation ƞ = input/output applies. This option would usually be slightly more expensive than stopping wastage, but less expensive than the rest of the steps. Research by the International Energy Agency (IEA) found that the opportunity for energy efficiency, and therefore carbon related emission reduction, is more than double that of any other energy management measure. Energy efficiency should therefore always be a primary consideration.
  • Renewables:  Now that wastage has been stopped and the most efficient technologies have been installed, renewable solutions can be considered to provide for energy security to the level required. Renewables could serve as an energy substitution or for energy security. Doing so at this stage will ensure that the investment will be aligned to the actual requirement without providing for wastage or inefficient equipment and/or processes, as would have been the case if it was the first or only consideration!
  • Fuel switching: At this stage investigations can be undertaken to identify energy sources which could be replaced with more efficient alternatives. This would also be a consideration if energy security is a concern and where a switch could be made to energy sources which are more freely available. South Africa’s very low electricity prices of the past led to electrical processes or technologies being chosen, while the best practice(s) for the same in the rest of the world were often another energy source, for example the use of gas heating for spray booths which often use electrical energy in South Africa.
  • Co, Tri, and regeneration: Only at this stage should generation options be considered. This step includes solutions such as connecting a diesel generator to the facility or process infrastructure, using waste energy as is or converting waste heat from a process to a more useful energy source such as electricity (or vice versa). It should be noted that these solutions are different to those mentioned in step one as it is not about merely stopping wastage but converting it where it cannot be stopped, e.g. using the heat from diesel engines to drive electrical generators. These solutions are often much more complex and therefore often have the highest capital requirements and sometimes  high operational costs too.

This evaluation and decision making process may be dependent on the individuals or the type of facility or processes involved. Individual(s) may not have an appetite for a specific application while some facilities or processes may provide the ideal opportunities for any or all of the steps. Hence, if any step(s) of the evaluation or decision making process is found not to be applicable – after it has been checked for significance – it may be ignored.

Note that, as with any improvement process, this evaluation and decision making process should ideally be undertaken at regular intervals to check and confirm that bad practices have not crept in over time.

Too often sales driven individuals focus purely on that which they sell without considering its application as part of the larger energy management process. It would be expensive and provide little to no benefit to install a PV system on a facility which ’wastes’ more than half of its energy by leaving all inefficient lights on, even if not needed. The PV system would need to provide for this ‘wastage’ while it could possibly be half the size (and cost half the price) if the correct decision making processes were followed.

Knowledgeable energy managers or energy auditors, not linked to specific technologies or processes, would typically be the ideal individuals to use for identifying opportunities and providing suitable solutions. It should, however, be noted that these individuals would usually not be specialists in a specific technology or process and this speciality may need to be incorporated after the opportunities have been identified.  

Karel Steyn, president, Southern African Association for Energy Efficiency (SAEE)



High voltage substation Electricity Meter High voltage substation Glowing led bulb
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This edition

Issue 39