By Edison M Makwarela Pr Tech Eng, Senior Consultant, Industry Association Resource Centre

BACKGROUND
Recent generating capacity constraints in South Africa (SA) is undoubtedly fast ushering in a new way of energy metering in the country in an effort to save energy and manage consumer demand. Although the focus is presently more on saving electrical energy, the shortage of electrical energy could lead to either a shortage or increase in the price of other alternative energy sources available in the country. It is for this reason that utilities are now focusing on consumer energy-saving initiatives in addition to traditional metering. The focus is also on transparent metering, the reduction of non-technical losses and improved customer service. This has led to the advent of a new breed of advanced meters termed “Smart Meters” that give rise to advanced metering infrastructure (AMI).

In 2008, the South African Government gazetted that all consumers whose monthly electricity consumption is over 1,000 kWh must be on Time of Use tariff (TOU) in order to reduce demand. This immediately posed serious challenges for utilities as, by design, the current conventional and prepayment meters cannot be used with a TOU tariff. It is therefore not surprising that most utilities today in South Africa are either busy compiling a smart metering business case or are implementing smart meters.

POTENTIAL AND BUSINESS CASE
Approximately 3,000 MW of total SA suburban consumption can be reduced by smart meter functionality to reduce/ limit a customer’s supply capacity e.g. from 60A to 20A via a single wireless broadcast, and restored individually or in a group via a staggered comeback approach through an advanced, intelligent master station. The above saving is equivalent to the capacity of large power station such as the Eskom Kriel Power Station!

There is no magic business case for utilities to introduce AMI. An AMI business case is unique to different segments of the market (residential, commercial, agricultural, traction, etc) within a utility. For example, an AMI business case that makes sound economic sense in urban residential areas will not necessarily make economic sense in rural areas unless other variables such as the introduction of ancillary services (VOIP or internet access, alarms, etc) are brought into the equation of the business case.

COMMUNICATIONS NETWORK
The biggest threat to implementation of smart meters in South Africa is the availability of a cost-effective and reliable communications network. Communication is the backbone of AMI solutions and as such, a cost-effective and ubiquitous communication medium is required for successful implementation of AMI. There are a number of different communication medium options which can be used to meet the requirements of the AMI initiative. Some of the options are readily available while others are currently still under development but will be available in the near future. Some of the communication medium options support low bandwidth communications which are only suitable for pure AMI (metering) while others will allow for ancillary services (VOIP or internet access) in addition to the basic metering function. Due to the fact that not all the communication medium options will be available in all the areas as required, it is likely that the final communication medium solution will be a mix of different communication medium technologies. This also means that it may not be possible for all the metering customers to have access to the ancillary services immediately.

PILOT RESULTS
Although several pilot projects conducted by different utilities were in general successful and confirmed the viability of the smart metering system in South Africa, preliminary results indicated some challenges that need to be addressed to pave the way forward for smart meters. Among others, the challenges include:

  • The communication network needs to be improved. In most cases, the network is relatively slow and not available at times
  • There is a need to use standard protocols to enforce interoperability of different meters and systems as opposed to using proprietary protocols
  • The cost of smart meters is presently very high compared with current meters that utilities are using. Municipalities are finding it hard to implement smart meters without subsidy from the government. It is envisaged that, with time, the cost will go down
  • Where meters were installed inside customers’ homes, access into homes to install meters was not always guaranteed. Utilities need to seriously consider installing meters outside dwellings.

The implementation of smart meters in a way gives birth to a smart reticulation network and eventually a smart grid if smart breakers, sensors and switches are installed. Our power grid as we know it is a centralised grid that is supplier driven. The industry is gradually moving towards a decentralised network that is equipped with microprocessorbased equipment using two-way communications to facilitate interaction between the source and the user. South Africa is not immune from that trend. This trend is generally linked to the development of a future power grid / smart grid. There might be differences in defining what a smart grid is but the role players agree on its impact. In summary, it is expected that a smart grid will modernise the power grid and provide the necessary flexibility for the power grid to cater for current and future customer needs.

Like AMI, Smart Grid in South Africa will only be realised once a viable communication network is available. In other countries, governments paved the way for smart grids through legislation. South Africa should follow the same route.

If properly implemented and managed, smart metering together with other demand side management (DSM) interventions will ease the country’s energy constraints. Smart Meters will get us there quicker, but a combination of all DSM interventions is a sustainable long term option that involves a change in consumer’s behaviour and attitude on usage of electricity.