Monitoring My Energy Use

Every time I get a utility bill, I record the amounts used each month (electricity, natural gas, and water).  I've been doing this for more than three years now and have plotted up the trends.  Here's my electrical energy use over the last 3.3 years.  Each year is plotted as a different color.  After my solar power system was installed, I plot the amount produced each month on the top plot.  In the bottom plot I show how much energy was consumed after subtracting the solar production (negative numbers mean putting energy back on the grid).

There are a few things to notice here, that I think are interesting.

1. Our baseline energy use for the household, without air conditioning, is ~6 kWh/day, or an average of 250 watts at all times.  If I want to identify places to be more efficient, I have to be able to chip away at that number.  If I have to do/spend a lot and it only buys me a few watts, it's not really going to help.

2. About 2/3rd of our energy is that baseline load and about 1/3rd is air conditioning.  I could spend many thousands of dollars to change my air conditioner and reduce the electricity use from the AC by ~30%, but it would only reduce my electricity usage by about 10%.

4. It is WAY more efficient to have multiple people living in the same house.  I lived alone in my home in 2012, but my wife lived in it with me in 2013 & 2014.  Focus on the time between March-May since those times aren't susceptible to weather variations (as we don't use heat or AC then).  You can see that the energy use went up by ~15%, when the number of people in the home went up by 100%.  Get roommates people. It's efficient.

5.  March through June, my house is a gift to the environment.  There's a lot of sunlight and we don't need AC, so we put a lot of energy onto the grid in the spring (and a bit less in the fall).

6.  Every month last year except September, I put energy onto the grid.  That's pretty cool.