Energy Basics – a tonne of rain

I was trying to work out how much energy is stored in the rain falling on the roof and dripping down the gutters.  Say a tonne of water for every 10 mm of rain.  We had 65mm last week and it’s raining hard now.

A tonne falling a metre gives about 10,000 joules or 7.8 kwh.

I used Wikipedia for the equation but I came across this good primer: Basic energy concepts from Energy for sustainable rural development projects – Vol.1: A reader

Enjoy!