Large-scale plants are out of the question in some areas

Two countries in particular - India and Nepal - are enthusiastically embracing the systems, albeit for very different reasons.

The mini-grid consists of a basic power-generation unit that stands alone from a national grid, and is able to supply power to a small community, regulated by adding and removing electric loads to respond to changes in demand.

In India, the scheme has been piloted in the Sundarbans islands, in the Ganges delta in the southern part of West Bengal.

"There are a large number of islands - 53 islands - with four million people without electricity," SP Choudhury, founder of the Rural Energy Cooperative Society, told BBC World Service's One Planet programme.

"I thought at that time it may be a good idea to set up a small power plant with a mini-grid in the local area - maybe 50 or 100 kilowatt - and we would get at the needs of one or two villages, say 400 or 500 families.

"They would get grid-quality electricity, similar to what we are enjoying."

Ownership

The project was an instant success.

The key to this was the feeling of ownership of the electricity, Mr Choudhury said.

People were happy to pay the cost because they felt that they owned it.

"'Yes, it is our power plant, we should pay', and it clicked - the idea clicked," Mr Choudhury said.

"In one village it was very successful. Immediately all the islands are asking.

Rural Nepal is one of the areas hoping to benefit from the mini-grids

"Already we have covered 11 islands of Sundarbans with this type of solar power plant, and I have now got 2,000 consumers."

This feeling of ownership has also been the reason for the project's success in Nepal - although there mini-grids are employed to supply power to remote communities.

"We deliver the required power at a certain point, we put a meter on this particular point - that means they will be responsible for the operation and maintenance of the system," said Dr Janak L Karmacharya, head of the Nepal Electricity Authority (NEA).

"The first thing that will happen is they will feel the ownership."

There had been additional benefits to the mini-grids giving people ownership of their power, Dr Karmacharya pointed out.

Firstly, the maintenance that the NEA would normally have had to pay could instead by spent on something else.

And further, it had totally eliminated electricity theft.

"The losses due to theft will vanish - people will not steal their own property," he insisted.

National grid failures

The mini-grids provide a marked contrast to the coal, gas and nuclear plants powering national grids.

Recent blackouts around the world have shown the problems with national grids

The failure of these grids has been graphically illustrated in recent weeks - in the UK, Italy, the US, and parts of Scandinavia.

"The mini-grid concept really only comes into its own when you are so far away from the main generators that it's no longer cost-effective to run a set of wires to that particular set of customers," stated Professor Nick Jenkins, a chief researcher at the High Voltage Research Centre in Manchester.

"It could work in isolated rural areas and the particular applications are clearly on islands."

He added that they could also help with supplying the estimated two billion people around the world currently without power.