There's a pressing need for us to cut back on our energy consumption: apart from global warming, the cost of electricity is set to climb in South Africa. We look at practical ways in which you can reduce your reliance on the national electricity grid.
Another electricity cut at home - your frustration with Eskom's unreliable power supply escalates another two notches. You reach for the Yellow Pages in search of a small, petrol-powered generator. Then, rather inconveniently, you remember Al Gore's award-winning movie and his message of cataclysmic climate change.
Some vague memories of alternatives present themselves. Idyllic visions of electricity-generating windmills and solar panels appear. Where are these technologies at? Are they still only the toys of a few scientists and the occasional long-haired, sandals-and-granola type, or is there financial and functional merit to them? What are the options for reducing your electricity consumption and unplugging yourself from the grid? Do any of these options have a financial payback? Let's find out.
First, a little more on the rationale for unplugging yourself: except for occasional technical hiccups, power cuts are mostly due to demand outstripping Eskom's ability to supply electricity. To remedy this shortfall requires a comprehensive, long-term strategy for increasing the electricity-generating capacity on the one side and improving the efficient use of electricity on the other. This process will take many years, and periodic load-shedding power cuts will, in all likelihood, remain a fact of life in South Africa.
Another reason for getting unplugged is that our era of cheap electricity is coming to an end. In a bid to finance its new capital expenditure and encourage more frugal energy use, Eskom is pushing for an 18-percent tariff increase (subject to regulator approval) for next year and 17 percent the year after.
A third rationale is, of course, climate change. Our human contribution to naturally occurring climate change is a fact; it is dangerous and is already starting to change life as we know it. The topic is increasingly dominating government, corporate and civil society agendas. Humanity quite suddenly finds itself in the 11th hour of a global emergency, yet it is an emergency that we can barely see or feel.
Emergencies such as this require us to take urgent remedial steps at all levels and to act altruistically by each of us "doing our bit".
So, not only would getting unplugged provide you with a satisfying independence from Eskom, it would also allow you to reduce your carbon footprint - your contribution to climate change.
Before we dive into reviewing the options for reducing our dependence on Eskom, it is useful to see how most of our electricity is consumed at home.
A study conducted by Eskom for a range of medium- to high-income residences reveals a number of interesting facts ( see diagram here). Your geyser gobbles by far the greatest amount of electricity. This is followed by lighting and then, very interestingly, losses due to electrical appliances left in standby or sleep mode - so switch off your electronic gadgets at the plug when they are not in use. Next are heating, cooking and refrigeration. The "Other" category refers to the electricity consumed by switched-on media devices (as opposed to being left in standby mode) and other appliances, such as toasters, kettles and hairdryers. Laundry appliances and swimming pool pumps consume the remainder.
Usage by category can, of course, vary immensely from household to household, depending on individual patterns of use. The largest variation is probably experienced in heating - households in colder cities are likely to consume more electricity to keep out the winter chill.
Finding consistent information on average household electricity use has almost proved to be mission impossible. But a mix of asking around, speaking to Eskom staff and energy researchers, and reviewing various studies indicates that a medium- to high-income home will on average consume somewhere between 800 and 1 200 kilowatt hours (kWh) a month. Note that prudent or small households can consume less, while large households and opulent users can consume significantly more.
Larger households will on average consume electricity more efficiently due to shared lighting, cooking, appliances and so on.
Winter usage will tend to be higher than summer because more heaters are used.
Some households qualify for 50 kWh (50 units) of free electricity, but this applies only to low-consumption (less than 450 kWh a month) and to low-income households. Note that the qualification criteria vary somewhat by region.
Now, given that the average medium- to high-income household consists of about 3.5 people, the above consumption range of 800 to 1 200 kWh converts to between about 230 kWh and 340 kWh a person a month. Since one unit of electricity equals one kWh, which at present in Cape Town costs about 45 cents a kWh (including VAT and service charges - but note that electricity costs vary by region, usage and service agreement), this equates to between R103 and R153 in electricity consumption a person a month.
With this handful of facts in mind, we are now ready to consider possible investment options for reducing electricity consumption.
You may be driven purely by financial concerns, or you may be motivated by altruistic reasons, or perhaps a combination of both. So in a bid to satisfy this range, in this article your options have been divided into three categories: first-rate investments, irresolute investments and altruistic investments.
First-rate investments
This category of investments is a "must-do". It will save you lots of money.
Energy-efficient lighting - the quick return
This is the foundation for reducing your energy consumption. Traditional incandescent light bulbs are shamefully uneconomical, with about 90 percent of the electricity converted to heat instead of light.
Compact fluorescent light bulbs (CFLs) are far more energy efficient.
Yes, they are not dimmable, their light can be a little cold and they take time to reach full brightness, but they save you money and you can use them with a warm feeling in your heart.
While CFLs cost about four times as much as incandescent light bulbs (R20 as opposed to R5), they consume about 25 percent or less of the electricity of an incandescent bulb and last about six times as long. This means they pay for themselves in a very short time (and their longer life reduces the number of times you have the hassle of replacing old bulbs).
Based on some back-of-the-envelope calculations using an all-in electricity cost of 45 cents a kWh, a 100 watt-equivalent CFL will pay for itself within a few months if you use it for just a few hours each day.
Your next step is to chuck out all your incandescent bulbs and replace them with CFLs. Some countries, such as Australia, are going as far as banning the sale of incandescent light bulbs.
The real downside of CFLs is that they contain low levels of mercury, and we do not yet have appropriate recycling systems in place. This means they end up in your local landfill, and the toxic mercury will eventually leach its way into our soil and groundwater. So keep your burnt-out CFLs until appropriate recycling processes are found and encourage your local retailers and municipality to put in place recycling systems.
Solar water heating - the big return
Solar water heaters are an old idea to reduce electricity consumption and greenhouse gas emissions. They harness the power of the sun to pre-heat water for residential or commercial use, using a roof-mounted, heat-absorbing plate.
The heated water is fed into a special solar geyser that stores and, when necessary, uses electricity to further heat the water to the desired temperature - typically when there is a succession of cloudy days or when much hot water is required.
Simply speaking, there are two types of solar water panels on the market:
- Flat-plate collectors. With this system, a thin, black metal sheet, covered by clear glass or plastic to improve heat retention, absorbs and transfers the sun's energy to the water.
- Evacuated tubes. This system consists of a set of heat-absorbing glass tubes, which have a vacuum inside that reduces heat loss.
More evacuated tubes are now sold globally than flat-plate collectors. The advantage of evacuated tubes is that they are marginally more efficient. The downside is that in hot areas they may overheat the water, which may activate the geyser's pressure-release valve from time to time, thus increasing wear and tear. The glass tubes are also more fragile, which may pose a problem in areas where hail is frequent.
This said, evacuated tube systems are modular, and if a tube or two are broken, they can be replaced.
If you would like to support local industry, a further consideration is that tube systems are imported from China, while flat-plate collectors are in many cases locally manufactured.
When switching to a solar water-heating system, you will in most cases not be able to use your old geyser. These systems require a geyser that has additional pipe fittings to attach to the solar panel. There are one or two providers that have developed designs that allow you to retrofit a solar heating system on to an existing geyser.
If you live in an area where temperatures can fall below freezing, such as Gauteng, it is important to install an indirect solar water-heating system otherwise the piping in the solar collector panels may burst when the water freezes. In a direct system, the water itself passes through the solar collector panels and is heated by the sun. In an indirect system, the solar panels are filled with an antifreeze mixture (glycol and water), which absorbs the sun's heat and then transfers this to the water by means of a so-called heat-exchanger.
Switching to solar water heating is a financial no-brainer. Although the cost of the system is fairly high - typically between R10 000 and R25 000 for residential systems - the payback period is typically between four and 10 years, although this depends on usage of the system.
Eskom will during October this year announce a solar water heating subsidy scheme. This means that as long as you opt for a system and an installer approved by Eskom, you will, depending on the system type and size, receive a subsidy of between R2 000 and R5 000.
Eskom's board has approved a total budget of R2 billion over five years for the subsidies.
There is usually not a significant difference in price between the flat-plate and evacuated tube systems. The cost of the system depends on the size and type, and on your house and roof configuration. The panels need to have a northward angle, so as to maximise heat absorption.
Ideally, the geyser should be placed higher than the panels, which is possible in most roofs, including flat roofs. Where this is not possible, a circulation pump has to be installed, which will cost an additional R2 000 to R3 000. Solar-powered pumps are available. For a typical three- to four-person residence, a 200-litre geyser with a panel of three to four square metres is recommended.
The system lifespan is between 20 and 25 years, and sometimes longer. There is little you can do to improve the lifespan of the panels - there are no moving parts. Some plumbers suggest you have the system professionally checked every few years or so, specifically the pressure valves and vacuum breakers. The solar panels don't need to be cleaned, but if you do notice significant dust accumulation, it won't do any harm to hose or wipe them down once in a while.
Low-cost, low-pressure water-heating systems can be bought and installed for as little as R5 000, but these do not make for an immensely satisfying showering experience and are generally installed only in low-cost housing projects.
Variability in water consumption and the availability of sunlight makes calculating a payback period for a solar water installation rather confounding. A solar water heater can save as much as 30 percent to 40 percent of a residential energy bill. A Namibian residential study last year demonstrated that a break-even point was reached in about five years or sooner, depending on the usage pattern.
Because of the relatively fixed initial investment, the higher the water consumption, the quicker the payback period. If financed as part of a mortgage bond over 20 years, a solar geyser could immediately be cheaper to operate than an electric geyser.
A study in 2005 estimated that a two-by-two-metre solar water panel can recover R700 a year (R1 225 for a four-by-two-metre panel) assuming an electricity cost of 35 cents a kWh. (The study, "Economic and Environmental benefits of Solar Heating in South Africa", by Willi Sureman and John Ledger, appeared in Energize in June 2005.)
The efficiency of solar water heaters can be further improved by installing a timer switch that activates the geyser's electrical element for only an hour or two a day.
If the economic rationale fails to justify a solar heating system for you, consider that for every 2 000 kWh of electricity saved (the saving that is likely every year for a medium- to high-income household), you prevent 1 080 kg of coal being burnt and the release of 1 956 kg of climate-change-causing carbon dioxide and 17.9 kg of acid-rain-causing sulphur dioxide.
Other savings options
There are a number of other cost- and electricity-saving ideas to implement, irrespective of whether or not you opt to go the solar-heating route.
You can wrap your geyser and the inlet and outlet pipes in a geyser blanket and insulation material. Some high-end geysers may not require wrapping - check this with your geyser supplier or plumber. A geyser blanket will cost you only about R200 and will pay for itself within a few years.
Turn down the thermostat on your geyser to about 55°C. This will cost you a short, if daring and dirty, climb into your ceiling and will save you many rands a month. Remember to switch off the electricity at the mains before you fiddle with the thermostat.
Install a geyser timer switch that activates your geyser for only a few hours each day. This means the geyser element is not switched on every time you wash your hands with warm water. A timer switch plus the installation should not cost you more than R1 000. (I was quoted R700.)
Also install a water-saving shower rose, which fragments the water into smaller droplets and can reduce your hot water consumption by an impressive 50 percent (thus saving you electricity). The impact on your daily showering experience is virtually non-existent. The cost of such a rose is between R150 and R350.
Solar cookers
Solar cookers use reflectors to concentrate and trap the sun's energy to cook food. While these cookers were designed for communities without reliable access to electricity or fuel sources, they are also suitable in most other home environments.
Although a solar cooker can cost anything from a few hundred to over a thousand rand, it does not require any fuel and thus costs nothing to operate.
Depending on the sun's intensity and the type of stove, impressive temperatures of over 200°C can be achieved for some parabolic cookers.
A compact solar cooker, which costs under R300, is ideal for slowly cooking lentils, rice and stews, and even for baking bread. If used regularly, it is likely to save you a rand or two every few days and can thus pay for itself within a year or two of regular use.
The hotbox
This is a must. A hotbox is a well-insulated box - often made from two non-flammable, insulated bags (like mini beanbags) - in which you can place semi-cooked, hot food that will then finish cooking. You can also use it to keep food warm for many hours.
A hotbox works amazingly well for rice, pulses, stews, porridges and many other dishes. To cook plain rice, for example, you heat the pot and let it boil for a minute or two before transferring it to the hotbox, where the cooking process is completed without any additional heating being required. As a result, hotboxes can save you more than half of the electricity required for cooking a particular dish. A hotbox will set you back a mere R150.
Media devices
Your media devices, such as your television, hi-fi, computer and DVD player, when left in standby mode, continue to draw significant amounts of energy and can collectively consume between five and 15 percent of your electricity use.
In the United Kingdom it was calculated that media devices left on standby consume the equivalent output of about two power stations. Save money by switching off your devices at the plug.
When you buy new gadgets, compare energy efficiencies before deciding which one to purchase.
The washing line
Yes, you read correctly: your washing line can save you electricity if you use it instead of your tumble drier. In South Africa we are generally blessed with good weather. Whenever possible, dry your clothes on a washing line outside or a clothes horse inside when the weather is bad.
Irresolute investments
This category of investments does not always present an obvious return on your investment and each option must be evaluated on a case-by-case basis, taking payback periods and some environmental considerations into account.
Appliances
Appliances such as fridges and washing machines are large energy consumers, and South Africans do not have a tradition of insisting on energy-efficient appliances. In many developed nations, manufacturers are encouraged to improve efficiencies, and in Europe appliances are graded according to the European Union energy label. An A-rated fridge, for example, can be many times as efficient as an older fridge and thus less costly to operate.
Working out the cost-benefit of replacing your appliance is not an easy task in an article such as this, because it depends entirely on the efficiency of your old appliance and the efficiency of the desired new appliance. And replacement can range from a few thousand to tens of thousands of rands, so before you chuck out or redistribute your old washing machine or fridge, compare its energy consumption per cycle or hour to that of the product you desire. If it is marginal, keep the old appliance.
Studies have shown that washing dishes by hand requires more water and electrical energy (to heat the warm water you use) than modern, efficient dishwashers. However, these studies are rarely clear cut. Do they consider the lower cost of electrical energy for warming the water if you have a solar water heater? From an environmental perspective, do they consider the materials and the energy required to manufacture and distribute the dishwasher? From a financial point of view, do they consider only the cost of the actual washing process, or do they also factor in the cost of purchasing the dishwasher?
My simplified, rule-of-thumb suggestion is that if you feel you need a dishwasher, buy a machine that is highly efficient. If you are undecided, stick to manual washing, but work on ways to reduce your consumption of water and dishwashing liquid.
Heating and air conditioning
Heating can rapidly become a large user of electricity. Most of our heating is inefficient because of our poorly insulated houses. Placing insulation in your ceiling is probably the most cost-effective strategy - it will help keep your house cooler in summer and warmer in winter. Curtains also help to prevent heat loss through your windows.
The best way to reduce heating costs - and this suggestion won't be popular - is to put on a few layers of warm clothes.
If you are about to have a house or office built, ensure that you apply green design principles. Even in very cold climates it is possible to build super-insulated houses - so-called passive houses - that maintain a comfortable temperature without requiring any central heating or air conditioning whatsoever. These houses will typically also better use natural lighting to reduce the need for artificial lighting.
So, if you are about to build, explore using new materials and designs in such a way that less energy is required to build, heat, cool and light the building.
Cooking with gas
Those who enjoy preparing meals will know that cooking on gas is a far more satisfying experience - you are able almost instantly to adjust the heat to suit your needs.
Not only is burning gas more environmentally friendly (gas burns more cleanly than the coals Eskom burns), it is supposedly cheaper too, although gas prices have increased quite significantly over the past year. Working out a return on investment will depend entirely on how much you cook and what type of stove you purchase. Stoves can cost anything from a few hundred to a few thousand rands.
- See second half of this story as 'related article' below.
This article was first published in Personal Finance magazine, 4th Quarter 2007. See what's in our latest issue