linear regression with "partitioned" data
It is due to the fact that the 6th predictor is a linear combination of the other 5. You can write:

electricity = 100%-kerosene-candle-generator-solar-other


Linear regression models do not handle linear combinations at all. However the solution is easy, since the 6th variable is embedded in the first 5, you can just drop a column since it is implied by the other 5.