TariffsJudging by this I'd say the power is coming from the...

Tariffs
Judging by this I'd say the power is coming from the grid, which is more available in the south than the north. Or if not from the grid....this gives an indication of power production costs in Bolivia anyway.


"Electricity tariffs in Bolivia are far lower than average tariffs in Latin America. The average residential tariff in 2006 was US$ 0.0614 per kWh (compared to US$ 0.115 per kWh weighted averagein LAC), while the average tariff for the industry was US$ 0.044 per kWh (compared to US$ 0.107 per kWh weighted average in LAC)[8].

Electricity prices charged by the distribution companies to their regulated clients include energy costs (including generation and transmission costs) and all the distribution costs, including a specific return on investment. However, as it was mentioned before, some distribution companies resell electricity to communal organizations or rural enterprises. The price and conditions of those transactions are not regulated, which causes an important legal void in the sector. [2]
[edit] "

source:http://en.wikipedia.org/wiki/Electricity_sector_in_Bolivia