Peak demand occurs in the mornings and evenings when most people consume electricity for functions such as lighting, water heating and space heating (during winter). “The building of a peaking load station that runs for short periods during the day and only for a few months a year would have severe cost implications for all end-users,” declares Eskom DSM manager Albert Africa.
However, an alternative to satisfying this peak demand, which is being seriously focused on by Eskom, is the demand side management (DSM) strategy.
About half-a-billion rands will be spent implementing this programme in 2003, which includes marketing and advertising the DSM strategy across income groups.
“The Eskom DSM strategy is an intervention that will seek to influence the time, pattern and amount of electricity that is consumed.
“This, in turn, will affect positively the cost of electricity infrastructure, the environment and, most importantly, customer satisfaction,” indicates Africa.
The bulk of South Africa’s electri-city is generated using coal, a non- renewable fossil fuel.
In addition to the finite reserves of coal remaining, its combustion generates carbon dioxide, which in turn causes pollution.
DSM is a programme whereby the man in the street can claim a role in afffecting these issues through the effective use of energy.
Eskom implemented the DSM programme last year after nearly a decade of research and pilot studies into various technologies. Demand side is being managed by the virtual power station (VPS), which is situated at Eskom’s Megawatt Park.
The role of the VPS is unlike that of any other power station in that its job is to remove megawatts from the system.
It is expected to remove some 5 600 MW over the next 25 years, which is a huge amount considering an average South African power plant has a capacity of 2 500 MW.
The VPS allows for Eskom customers, such as large industrial plants, to curtail their energy use in expensive peak periods and to rather increase use, should they need to, during less-expensive periods. This is done through various Internet-based technologies that are able to control the operating hours for certain high-consumption electricity items, such as boilers, turbines and geysers, resulting in savings for electricity users.
After a successful pilot project in Tableview, in Cape Town, in which 10 000 geysers are now cycled from the VPS in Johannesburg, the concept of geyser cycling is to be rolled out to a further 13 areas across the country, including Pretoria, Nelspruit and Worcester.
Geyser cycling is different from geyser control, in that the affected communities give input into the process and have a choice in how their geyser is to be cycled.
Numerous factors are taken into consideration, including how many people live in the household, what their lifestyle habits are and what time of the day they bath, with their geyser cycled accordingly.
The customer can choose from 40 different control regimes, which can be changed immediately by dialling a toll-free number.
The resultant saving is obviously beneficial to the consumer, and Eskom is able to reduce demand.
“Electrification presents a great opportunity to implement energy-efficient technology,” observes Africa.
“Implementing the right technologies to begin with is much easier than going back and retrofitting,” he continues.
Part of the DSM strategy is to give people building new homes advice in how to do so in a manner that will make the most efficient use of energy.
Advice is given as to where windows should face and how large they should be, how large roof overhangs should be and what type of ceilings to use.
People are also encouraged to use door stoppers and geyser blankets, which are available at cost price from Eskom offices across South Africa.
“Building a house correctly could mean the difference between having to turn a heater on at 6 pm in winter or at 9 pm, which makes a significant difference to peak demand,” remarks Africa.
The DSM programme also assists people in drawing up lighting plans.
Africa feels energy-efficient lighting can make the biggest saving in reducing peak demand. Eskom DSM works closely with Bonesa to realise this.
Bonesa is a joint venture between Eskom and the Global Environmental Forum through the World Bank to promote efficient lighting and ensure the latest technologies are available in South Africa.
Energy-efficient lights are now available in most large retail outlets in the country and Eskom has ensured that the most rural areas have access to them by making them available at all of the utility’s offices.
These compact fluorescent lights use 80% less electricity than ordinary lights and last for up to ten times longer.
They are, however, more expensive than ordinary lights and were retailing for between R80 and R90 when they first reached the South African market.
Bonesa has since succeeded in bringing the price down to R15, which is what they are selling for at Eskom offices.
Another focus of Eskom DSM is to promote efficient energy use and load control in commercial and industrial buildings.
Through the National Electricity Regulator, Eskom DSM is in a position to make funds available to companies wanting to improve their building energy efficiencies, and works with energy service companies (Escos) in this regard.
An Esco will go into a company, do an audit, that is look at the technologies used for energy, and establish where electricity use can be better managed.
The Esco then presents Eskom DSM with a proposal highlighting how many megawatts can be saved by introducing energy-efficient load-management technologies and, if it meets Eskom DSM’s criteria, Eskom will make funds available and take a certain portion of the savings for an agreed period.
Such interventions are able to ensure significant cost savings for business owners.
As part of the pilot programme, this process was carried out at Megawatt Park, which has managed to save Eskom 34% of its yearly electri- city bill there.
There are now a number of companies which have expressed interest since the implementation of the programme. “We have found Eskom to be a world leader in certain areas of DSM, such as our VPS.
“However, until South Africans start realising the worth of electricity, which is still very cheap in this country in comparison to other countries, energy-efficient technologies will not take off to the extent they should,” concludes Africa.