We’ve been in our new home for 24 months now. Around this time last year, we got our twelfth bill from Entergy at the new place. That meant a year’s worth of accumulated energy consumption data. This was a handy baseline, coming just days before we insulated underneath the house with closed-cell spray foam.
So here we are, one year later. As promised, here is the energy use data for the last twelve months.
|Month||kWh Used||Days Billed||Avg. Daily Usage|
Obviously the big question is how this compares to last year’s data. Crunch the numbers yourself if you’re so inclined. I’m simply going to put the average daily use side by side.
|Month||Avg. Daily Usage
|Avg. Daily Usage
On average, we used less energy after the house was insulated. More to the point, if we total up all the kilowatt hours for the respective years, we find we used 23,390 before the insulation and 16,544 after. That’s a drop of almost 7,000 kWh. Even accounting for the freakish cold snap of January 2009, it’s a substantial reduction.
Or so it seems. How much does a kilowatt hour of electricity really cost? It’s complicated. Our bill shows energy charges and fuel charges and lots of stuff I can’t quite figure. I appreciate that Entergy has some tools for analyzing your bill, but I don’t understand why they don’t retain data longer than one year. I do know that our November 2011 bill is $22.97 (31%) lower than our November 2010 bill. I assume our savings more than offset the $2000 we spent on insulation.
Caveats: I talked about energy consumption but this is actually only electrical usage. We have some gas appliances, most notably our upstairs furnace. However, the downstairs furnace and of course the air conditioning system runs on electricity.