We monitor the total hashrate of course, but can we figure out the estimated power input for the network hashrate? One way is to assume the average wattage GH but that is a big assumption as there are many variations in mining hardware out there.

There's a couple reasons why I am interested.
1) It would be another cool chart to plot on blockchain.info, because data is cool.
2) It would give us an accurate depiction of the energy footprint of the bitcoin network. Personally I think any project endeavor business consumer in life should be conscious of its environmental footprint.
3) If we knew the historical power consumption in relation to bitcoin price and network hashrate, it would be easier to forecast the future difficulty for a given BTC price and chip efficiency. This would be useful for budgeting and forecasting future difficulty and BTC price when considering a significant investment in mining. For example if you look at the timeframe between January to September 2015, you see that the BTC price was relatively flat and stable around $260 USD and the network hashrate was also relatively flat and stable around 350,000 TH/s. I would assume that increase in difficulty slowed to a flatline because we reached an equilibrium here where mining operating costs was close to mining revenue. Investing in new hardware would have a very long payout period at this time. Of course, shortly after the BTC price started to increase and also new hardware which is more energy efficiency was introduced and so the network difficulty begins another growth period.

Can you think of any other reasons this information would be useful?
Cheers