Shake, rattle and charge: Harnessing the power of music
The British musician and drummer Sudha Kheterpal is proudly cradling her new creation. Called a Spark, it's the size and colour of a peeled mango and when shaken gently, it makes a noise a bit like a maraca.
Sudha made her name bashing out trance-like rhythms with electronic band Faithless and with other artists including Dido, Kylie Minogue and The Spice Girls.
But now she has decided to adapt her percussive skills to create what she believes is the world's first energy-generating musical instrument.
Proudly she describes the moment that triggered her new career as a social entrepreneur.
"It came to me at a gig in 2009," she says.
"The crowd stamped their feet so hard in time to the music that they created an earthquake measured on the Richter scale."
This seismic event at the Forest National Stadium in Belgium prompted Sudha to wonder whether so much raw human power could be harvested and used.
The technology is simple. As you shake it, a magnet moves backwards and forwards through a coil to generate power and this power is stored in an in-built battery.
You then have the option to press a button at the back providing either light, or the option to plug in your phone for a small recharge.
"It's a simple, musical way to help power off-grid Africans and Indians. I've used it in concerts already, and we're encouraging other musicians to do the same," says Sudha.
She is developing Spark through her own social enterprise, and she's teaming up with other renewable energy companies and groups to try to coordinate more off-grid solutions for energy-deprived parts of India and Africa.
It's important, she says, in poor countries where hundreds of millions of people have no reliable access to power or artificial light, with serious consequences for their source of income and education.
The entire African continent, despite its huge oil, gas and renewable reserves, still generates less electrical power than Spain.
"No region has more abundant or less utilised renewable energy potential", says Caroline Kende-Robb, of the Africa Progress Panel, an advocacy group promoting African development.
She says decentralised power generation can open up new possibilities for reaching populations currently bypassed by national grids.
There are already a range of similar small-scale companies and charities offering small-scale renewable solutions for local power generation across Africa, where there remains a massive energy deficit.
Take PEG Ghana, for example. PEG is private company offering hire purchase contracts to individuals and businesses, so that locals can buy small solar panels. At a cost of about 60 cents (40p) a day, a purchaser can buy this kit in just a year or so.
Nate Heller, the company's chief operating officer, says demand in Accra where he works is expanding rapidly.
"About 40% of our customers are not even off-grid. [But] the power-cuts here are so frequent and so bad, they need auxiliary power just to get by".
Other solutions include wind and even small-scale water turbines.
Micro-hydro power has been embraced by a number of companies and charities especially in the more mountainous regions of east and southern Africa, and south-east Asia, where there is more reliable access to falling water.
Dipti Vaghela is the Indian representative of the Hydro Empowerment Network. She says that small, decentralised systems can earn revenue for a village, bringing it out of poverty and at the same time generating renewable energy for a wider population in the region.
However, critics point out that companies aimed at bridging this gap have tended to be small-scale.
So far Sudha Kheterpal, for example, has made only about 1,000 of her Sparks, hardly enough it could be argued to light a Christmas tree, let alone launch an energy revolution.
Neither this technology nor the other small scale solutions on offer are capable of generating energy on the scale needed to power even a fridge, stove or a basic computer.
Critics say that until more substantial investors can see the profits to be made in their mass-production and roll-out, these off-grid solutions are unlikely to reach a large population or do much to resolve power problems.
For Sudha Kheterpal, though, it's mostly about raising awareness for now, and generating the infrastructure required to deliver all the renewable power that poor communities require.
She's also open to a wider range of ideas around ways local people could harness this technology to generate more power.
"During our Kickstarter campaign, one man suggested we could harness hundreds of Sparks around the necks of cows, to be generating power through the day," she says.
"There are many ways we scale this up. The important is to make a maximum impact."