Village-scale mini-grids can serve tens or hundreds of households. Traditionally, mini-grids in remote areas and on islands have been powered by diesel generators or small hydro. Generation from solar PV, wind, or biomass, often in hybrid combinations including batteries and/or a supplementary diesel generator, is slowly providing alternatives to the traditional model, mostly in Asia. Tens of thousands of mini-grids exist in China, primarily based on small hydro, while hundreds or thousands exist in India, Nepal,Vietnam, and Sri Lanka. The use of wind and solar PV technologies in mini-grids and hybrid systems is still on the order of a thousand systems worldwide, mostly installed in China since 2000. China’s "Township Electrification Program" from 2002–2004 electrified one million rural people in one thousand townships, about 250,000 households, with electricity from solar PV, wind-solar PV hybrid systems, and small hydropower systems. During 2002–2004, almost 700 townships received village-scale solar PV stations of approximately 30–150 kW (about 20 MW total). A few of these were hybrid systems with wind power (about 800 kW of wind total). India, the other main location for village-scale power systems, has 550 kW of solar/wind hybrid systems installed, which serve on the order of a few thousand households in several dozen villages.[N41]