LED-640 — Karebo Systems will supply 12V, left, and 220V LED downlighters free of charge

Under ordinary circumstances, Wilmot Prusent only speaks about Eskom to complain. The electricity bill for his five-bedroom home in Summerset Estate, Midrand, has escalated to R2 500 in the average month. “All they ever do is raise our rates, raise our rates,” he grumbled.

Recently, though, Eskom-funded contractors visited his home and replaced the halogen downlights in his ceiling with state-of-the-art light-emitting diode (LED) lamps that use a fraction of the electricity. The hi-tech lamps were worth more than R10 000, but Prusent did not have to pay a cent. “I’m absolutely elated,” he said. “At this time of year it’s a very nice Christmas present.”

Eskom has begun replacing up to 40 halogen bulbs per household with LED bulbs that are worth close to R300 each. Eskom’s residential installation contractor, Karebo Systems, will have installed more than a million LED bulbs in South African homes by the end of 2012 and Eskom plans to extend the programme with more contractors from next year.

“We want these out and into homes as soon as possible in view of the power constraints we have,” said Andrew Etzinger, senior GM of integrated demand management at Eskom.

Bulb replacement is not an entirely new idea at Eskom or other utilities. The South African parastatal has distributed about 47m free compact fluorescent lamps. But fluorescent lamps were slow to catch on in the suburbs, where many houses have downlights built into their ceilings. The downlights — reflector lamps that typically use 50W each — were hampering Eskom’s efforts to control the spike in electricity consumption each evening.

It was obvious to any observer of lighting technology that a solution would be found in the same LED bulbs that consumers first saw in the green or red glow of calculator displays about 40 years ago. LED bulbs are incredibly efficient, using as little as a tenth of the power that incandescent lights need and are far more durable. They have gradually become brighter, whiter and finally more affordable — but just barely.

Readiness of consumers
The efficient replacements for 35W halogen downlights typically cost between R200 and R300 at retail prices. Discount-brand LED bulbs selling for less than R100 are usually less bright. More powerful and expensive LED bulb replacements for 50W halogens are nearly impossible to find. Philips recently stopped stocking Makro with the LED bulbs that Karebo Systems installs because of what Lorato Maphiri, marketing and communications officer for Philips Lighting, calls “the readiness of consumers”.

But for Eskom, LED bulbs are hitting the sweet spot. “We’ve followed this technology for the past five years,” said Etzinger, “and it’s just recently matured to a level of quality, price and performance where it makes sense to embark on a roll-out.”

Eskom’s calculations are based on its reliance on peaking-supply turbines fuelled by diesel to handle the evening spike. This power costs Eskom about R2/50/kWh, about eight times more than the running costs of existing coal stations.

Many foreign utilities that want to reduce their carbon footprint or stave off the construction of another power plant have offered rebates on LED bulbs to reduce their cost. A few have offered a small number of free LED bulbs to draw attention to the technology. But neither Etzinger nor Maury Wright, editor of the American publication LEDs Magazine, is aware of anything on the scale of Eskom’s free offer. The National Energy Regulator of South Africa allocated R5,4bn to Eskom over the past three years so the utility could control demand.

For efficiency programmes aimed at the evening peak in consumption, the regulator stipulates that Eskom should spend no more than R5m for each megawatt saved, or R5/W. Etzinger said free LED bulbs fell well below that limit, whereas subsidies for solar hot water heaters were more costly.

Consumers who do their sums carefully have begun buying LED bulbs on their own, especially for rooms where the lights are on for several hours a day. In addition to cutting bills, the expensive bulbs are made to last up to 25 years, saving on regular replacements. For the sake of his budget and the environment, Midrand resident Anthony Walley began phasing out his halogen downlights a few years ago, working room by room. He spent about R1 000 at each stage in the process.

Boggles the mind
So when Walley first heard that Eskom would install LED bulbs for free, he thought “there must be some catch”. Forty new bulbs later, Walley now tries to convince his friends and family to seize this gift while they can.

“It boggles the mind because I’m a client — indirectly — of Eskom and now they’re paying me to use less of what they are selling me.”

There are a few small catches to the free Eskom deal. Karebo Systems is contracted to replace only 50W halogens. Homeowners who have tried to cut their consumption by using 35W or 20W bulbs will find that the only way to participate is to swap them for new 50-watt halogens, only to see the new bulbs taken away for destruction.

Dimmable LED bulbs are a more expensive technology, so Karebo charges R25, a fraction of the full value, for each LED bulb to be placed on a dimmer. However, certain dimmers work poorly with these bulbs and homeowners may have to shell out another R250 for Karebo to install a suitable dimmer.

Most South African homes with halogen downlighters use 12V transformers, which add another layer of complication. Karebo offers pin-type, low-voltage LED bulbs made by Philips, but they have a few disadvantages over their 220V siblings.

Their wattage is a bit higher — 7W versus 5,5W for the 220V, non-dimmable version — in addition to the small amount of power that the transformer uses. And the low-voltage bulbs have a somewhat shorter lifespan — 30 000 hours instead of 40 000 hours.

Spike times
Karebo Systems director Ravi Govender said that each of the LED bulbs his company installed was rated to last at least 10 times longer than an ordinary halogen lamp. “You’ll probably move out of your house before you have to change it.”

Finally, a small percentage of transformers don’t work with the new technology. For all these reasons, Govender finds that his commercial customers, including Standard Bank and Sun International, have ditched their 12V transformers and retrofitted their downlights to take mains voltage LED bulbs.

The free LED bulb offer is only one part of Eskom’s mass residential roll-out programme. Karebo also offers homeowners compact fluorescent lamps, low-flow shower heads to reduce hot water consumption and timers for pool pumps and geysers. The timers are preset to stay off during the six-to-eight morning and evening spike times.

Etzinger hinted that Eskom might soon make the geyser timer mandatory for those who wish to enjoy the other freebies. He emphasised that geyser timers would work in the favour of consumers in the future, when electricity tariffs will be higher during peak hours.

The benefits of LED bulbs should start to show from the first utility bill. On average, 19% of residential electricity is used for lighting. So if 40 downlights make up most of a home’s lighting, consumption charges could fall by at least a 10%. Simple maths suggests that if those 40 lights are used four hours a day, LED bulbs will save more than R200 a month.