Progress in making off grid lighting affordable

Through the International Year of Light and Light-based technologies (IYL 2015), the UN is raising global awareness about ‘how light-based technologies promote sustainable development and provide solutions to global challenges in energy, education, agriculture and health.’

Poor-quality light holds back all aspects of development. Imagine trying to do homework by the light of a single kerosene lamp shared with all your family. Or imagine the midwife delivering your baby by the light of a candle. In both cases the light is dim and smoky, and there’s an ever-present fire risk. But these examples are a daily reality for most of the 1.5 billion people who lack access to grid electricity.

But how does improved lighting technology help if you don’t have the electricity to use it? The answer is that improved light technology has helped to made off-grid electric lighting much cheaper.

A new barber benefiting from clean electricity. Credit: Ashden.

A new barber benefiting from clean electricity. Credit: Ashden.

Making off-grid lighting cheaper

Take the ‘solar-home-system,’ which has sold in millions in countries like Bangladesh, India and Kenya. Installed in an individual home, the system uses a small photovoltaic (PV) panel to run one or more lights, along with small appliances like phone chargers and radios. It also needs a rechargeable battery so that power is still available even when the sun is not, and an electronic charge controller to manage the battery.

An example is the ‘Connect 600’ system from previous Ashden winner Barefoot Power, which has a 6.6 Wp PV panel and 48 Wh battery, and comes with four 75-lumen bright LED lamps and two USB sockets for charging phones. Performance measurements by Lighting Global show that, after a typical day of charging in the sun, this system will provide 300 lumens of light for eight hours. That’s twenty times the brightness of a kerosene wick lamp! It’s a versatile system to fit the needs of different households.

So how has improved technology made lighting cheaper? The system above currently retails for US$142 in Uganda. You’d need about double the PV and battery capacity to get the same amount of light from compact fluorescent lamps (CFLs), so the system would cost about US$250. And to provide the same amount of light from incandescent bulbs it would over US$1,200! That’s a staggering difference in the cost of lighting, and all down to efficient LED lamps.

LEDs have also made solar-based lighting much cheaper than kerosene. Using a kerosene wick lamp for eight hours per day burns about 70 litres of kerosene in a year, which at current prices would cost about US$70 in Uganda. Thus replacing four kerosene lamps with four LED lamps saves a household US$280 per year on kerosene, or twice the retail price of Connect 600 system. (On a lumen-equivalent basis the saving is even more impressive: about US$1,400 per year!)

But ‘cheaper’ doesn’t necessarily mean ‘affordable’. Despite the significant financial savings on kerosene, US$142 is simply too high an upfront cost for most off-grid households. Both financial and technical approaches – and sometimes a combination of both – are being used to tackle the problem of affordability.

Making off-grid lighting affordable

One approach is to provide a suitable form of credit for purchasers of solar-home-systems. Microfinance schemes of this type have worked well in South Asia, in particular in Bangladesh where multilateral funds, managed through the Infrastructure Development Company, have led to the sale and installation of over 3 million solar home systems by installers like Grameen Shakti, Rahimafrooz and 2015 Ashden Award finalist, the Bright Green Energy Foundation.

An obvious technology route to increase affordability is to make solar systems smaller. The smallest solar lighting system is a single PV-powered lamp. 2015 Ashden finalist Greenlight Planet produces a great entry-level model that, from Lighting Global tests, provides 27 lumens of light for eight hours from one day of solar charging. That’s twice as bright as a kerosene wick lamp for an upfront cost of just US$11, less than two months’ expenditure on kerosene. And individual lamps can provide flexibility: many households start with an entry-level lamp then buy a more powerful model when they can afford it. The top model in the Greenlight range gives a light output of 160 lumens and also includes two USB charging points.

Another technology option is to provide electricity to homes from PV-powered mini-grids, rather than individual systems, and allow customers to pay-as-they-go per kWh, as with mains electricity. A 6 kWp PV system can supply not just lighting but larger power demands like household appliances and electric tools, for 100 customers or more. But someone still has to pay the upfront cost of a mini-grid system, and investors are cautious at present. One challenge is the difficulty in controlling and monitoring the use of electricity on a mini-grid, collecting payments and troubleshooting – particularly if the mini-grid is in a remote area.

2015 Ashden finalist SteamaCo has developed innovative hardware and software to manage all these functions on a mini-grid remotely. One of the functions of the software is to process money transfers made via mobile phones. Customers can make pre-payments for micro-grid electricity at the amount and frequency they can afford, and micro-grid owners can collect large numbers of small payments very efficiently.

Other innovators are using mobile money to make ‘cheap’ become ‘affordable’ in different ways. For example, M-Kopa  in Kenya sells solar-home-systems on credit, with repayments made through mobile money. Off Grid Electric in Tanzania uses mobile payments in a slightly different way with a ‘pay-to-use’ scheme for solar-home systems.

What challenges remain?

Off-grid electric lighting has come a long way in the past five years. Lamp technology and solar PV technology has become significantly better and cheaper. The Lighting Global initiative has brought in independent performance tests and quality certification, so that purchasers can have confidence in the products that they buy, although many countries are still plagued by poor quality, un-certified, products.

Back in March we asked a number of Ashden Award winners what they thought was still needed to make off-grid lighting more widely available. Ned Tozun, CEO of d.light, said: “I’d love to see further drops in price of long-life/high quality batteries. For entry-level solar lamps, the industry is moving towards lithium polymer batteries with a 5+ year lifetime. However, these battery technologies are not as affordable when looking at … solar home systems”.

Ned also noted that “Developments in the electric vehicle industry in battery technology are continuing to push lithium polymer battery prices down and quality up, and we would like to see that trend continue and accelerate!”

And there are optimistic signs. At the end of April, Tesla Motors announced that it is “amplifying its efforts to accelerate the move away from fossil fuels to a sustainable energy future” by unveiling a new generation of lithium batteries, designed for electricity storage in grid-connected homes.

Nowhere is the need to move away from fossil fuels greater than for the 1.5 billion people who don’t have access to the mains grid, and depend on fuel-based lighting (kerosene and candles).  Let’s hope that the innovation in this new generation of batteries will soon become available to them.


Anne Wheldon - AshdenAnne Wheldon is Ashden’s Knowledge and Research Advisor, as well as being an Ashden Awards assessor and judge for both the international and UK Awards. Anne is an expert on sustainable energy technologies and on how these can be used to help mitigate climate change and increase resilience to its impacts. She is particularly knowledgeable about energy access in developing countries, including solar electricity and clean cookstoves.

This year’s Ashden Awards Ceremony is on 11 June. Find out more and book your place at Ashden Award week events here.

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