Pema's house sits on the north side of the valley and loses the sun early. For years the family burned kerosene in a tin lamp, about a litre a week. The lamp lit one corner of one room, and the smoke stayed in the rafters.

Before

Homework stopped at dusk. Pema's daughter Yangchen is eleven and walks forty minutes to school. In winter she got home with half an hour of light left. Cooking, mending and anything that needed eyes had to fit into the same half hour.

The day

The crew arrived at noon with two panels, a battery and three lamps. Two of the four were technicians from Dhorpa itself, trained the summer before. By four the panels were on the roof. By six the kitchen was lit.

• Two 40-watt panels on the south slope of the roof
• One battery in a box by the door
• Three lamps: kitchen, the big room, the doorway
• A socket that charges a phone

After

The kerosene money, about nine dollars a month, now buys salt and school notebooks. Pema charges two neighbours' phones for a small fee, which she pays into the village repair fund.

What it cost

The kit cost $118 fitted. Pema's family gave two days of labour carrying panels up from the road head, and pays a few cents a month into the fund that will replace the battery in about six years.