Sunday, March 16, 2008

electric rates

I wrote about "My Carbon Footprint at Home" on an SAP SDN blog in January 2008 after getting positive reinforcement for an earlier blog on "CSR and me." In the former story, I tersely recounted my electric bill record keeping, mentioning an Excel spreadsheet, and then There were a couple comments on the blog, and more on Twitter, which alas, are fading into the woodwork. I know Eddy De Clercq said his use in Belgium is dramatically lower than ours (mine) here in the U.S.

I'd like to share a few threads in this blog:

  • How my electric bill looks, and what this means to consumer conservation
  • What I've done to control my energy use, and thus carbon emissions, and dollars out of my pocket
  • How to use the editgrid tool, and why this is important.

The Bill

Below are a bunch of graphics, most from scanned images of our home electric bill, but the later ones generated live from online data. The oldest bills that I have from BGE included a rolling 13 month chart, generated after our first bill. Starting in 1995, the bar charts switch from solid to outline shape, no doubt to save the cost of ink or toner.

The bill format has changed twice since this earlier one, so the visual feedback of energy use pattern went away on the first revision, in January 1997. The replacement was a 3 line comparison of the prior month, and the same month a year before. This Electric Usage Profile has remained to today. I am used to crunching numbers all day at work, so this is easy for me, but somehow I think most consumers are inclined to look at the number following the dollar sign.

Earlier versions listed temperature separately from the electric use; later versions show kWH and average monthly temperatures on the same line. The intent is to tell you whether you used more because it was colder (or hotter), or if you just weren't paying attention and left the iron on all month.

If you look at the average daily use charts, you might notice that the Y-axis, for maximum use, has been auto-scaled each month. Assuming this chart was still being produced, it would make it hard to see where changes in behavior, or in efficiency of furnaces or air cooling units had altered. That's part of the reason I am transcribing from the bills to online web pages.

Oh, yeah, the last chart below shows our electric rates in Maryland. Instead of our bills climbing with energy costs over the last decade, we had frozen, even reduced charges (no pun intended) from 1999 to 2005. Then, the rate caps came off and away we went. I'm not going to chart the amount of my bills. If you really want to know, you can probably do the math. Or, let editgrid take care of it.

Cutting back

Hopefully the big investment I made in a new heat pump in August 2007 is starting to show returns. It's either that, or pushing the thermostat down to 62 degrees F. for as long as Kathy can stand it.

I haven't been able to fool editgrid into reversing the chronological order on my charts, so as I add each new month's information onto the top row, it is charted on the left side, not the right. Now that I have the bill for February 2008, I can see a lowered peak for this past winter compared to prior years.

Is this lower because of the heat pump, pushing the thermostat, or a warmer winter? I thought I'd be able to tell more graphing average daily use against average temperature, but it is not so clear. I probably need a formula using "degree days", which BGE supplied a long time ago but probably abandoned to obscurity.

Edit grid

I found out about on Twitter. It isn't Google, but it seems to have a viable business model where you pay to share edit rights with others, but publishing single-owner pages is free. The interface works great from IE or Firefox, and there are innumerable great web features possible. As you can see below, I simply add a link to a generated image URL, and live data shows up on my web page.

For example:

<img src="" />

The data

Temperatures 1993 - 1996 (November readings, December bills)

Electric use per billing period (1994-1997, 2007)







Electric daily use (1993-1996)

I signed up for an online account at, but I have not found any useful features there, such as digital displays of my energy use, temperature charts, etc. I can get a copy of my bill, but it is in a crippled PDF format that does not allow copying. What good it that. Matthias Z.!?

Energy use by month from 2007 though the present (older data is to the right):

Electric use March (meter period roughly Feb 9 - Mar 11)

Electric use February (meter period roughly Jan 9 - Feb 9)

Recap of electric energy costs from BGE (Constellation Energy utility)

More details on electric use at my house:


eredux said...

Check out this US Carbon Footprint Map, an interactive United States Carbon Footprint Map, illustrating Greenest States to Cities. This site has all sorts of stats on individual State & City energy consumptions, demographics and much more down to your local US City level...

batticdoor said...

How To Reduce Your Energy Bills / Energy Conservation Begins at Home

Imagine leaving a window open all winter long -- the heat loss, cold drafts and wasted energy! If your home has a folding attic stair, a whole house fan or AC Return, a fireplace or a clothes dryer, that may be just what is occurring in your home every day.

These often overlooked sources of heat loss and air leakage can cause heat to pour out and the cold outside air to rush in -- costing you higher heating bills.

Air leaks are the largest source of heating and cooling loss in the home. Air leaks occur through the small cracks around doors, windows, pipes, etc. Most homeowners are well aware of the benefits caulk and weatherstripping provide to minimize heat loss and cold drafts.

But what can you do about the four largest “holes” in your home -- the folding attic stair, the whole house fan or AC return, the fireplace, and the clothes dryer? Here are some tips and techniques that can easily, quickly and inexpensively seal and insulate these holes.

Attic Stairs

When attic stairs are installed, a large hole (approximately 10 square feet) is created in your ceiling. The ceiling and insulation that were there have to be removed, leaving only a thin, unsealed, sheet of plywood.

Your attic space is ventilated directly to the outdoors. In the winter, the attic space can be very cold, and in the summer it can be very hot. And what is separating your conditioned house from your unconditioned attic? That thin sheet of plywood.

Often a gap can be observed around the perimeter of the door. Try this yourself: at night, turn on the attic light and shut the attic stairway door -- do you see any light coming through? These are gaps add up to a large opening where your heated/cooled air leaks out 24 hours a day. This is like leaving a window open all year round.

An easy, low-cost solution to this problem is to add an attic stair cover. An attic stair cover provides an air seal, reducing the air leaks. Add the desired amount of insulation over the cover to restore the insulation removed from the ceiling.

Whole House Fans and AC Returns

Much like attic stairs above, when whole house fans are installed, a large hole (up to 16 square feet or larger) is created in your ceiling. The ceiling and insulation that were there have to be removed, leaving only leaky ceiling shutter between the house and the outdoors.

An easy, low-cost solution to this problem is to add a whole house fan cover. Installed from the attic side, the whole house fan cover is invisible. Cover the fan to reduce heating and air-conditioning loss, remove it when use of the fan is desired.

If attic access is inconvenient, or for AC returns, a ceiling shutter cover is another option for reducing heat loss through the ceiling shutter and AC return. Made from R-8, textured, thin, white flexible insulation, and installed from the house side over the ceiling shutter with Velcro, a whole house fan shutter cover is easily installed and removed.


Sixty-five percent, or approximately 100 million homes, in North America are constructed with wood or gas burning fireplaces. Unfortunately there are negative side effects that the fireplace brings to a home especially during the winter home-heating season. Fireplaces are energy losers.

Researchers have studied this to determine the amount of heat loss through a fireplace, and the results are amazing. One research study showed that an open damper on an unused fireplace in a well-insulated house can raise overall heating-energy consumption by 30 percent.

A recent study showed that for many consumers, their heating bills may be more than $500 higher per winter due to the air leakage and wasted energy caused by fireplaces.

Why does a home with a fireplace have higher heating bills? Hot air rises. Your heated air leaks out any exit it can find, and when warm heated air is drawn out of your home, cold outside air is drawn in to make up for it. The fireplace is like a giant straw sucking the heated air from your house.

An easy, low-cost solution to this problem is to add a fireplace draftstopper. Available from Battic Door, a company known for their energy conservation products, a fireplace draftstopper is an inflatable pillow that seals the damper, eliminating any air leaks. The pillow is removed whenever the fireplace is used, then reinserted after.

Clothes Dryer Exhaust Ducts

In many homes, the room with the clothes dryer is the coldest room in the house. Your clothes dryer is connected to an exhaust duct that is open to the outdoors. In the winter, cold air leaks in through the duct, through your dryer and into your house.

Dryer vents use a sheet-metal flapper to try to reduce this air leakage. This is very primitive technology that does not provide a positive seal to stop the air leakage. Compounding the problem is that over time, lint clogs the flapper valve causing it to stay open.

An easy, low-cost solution to this problem is to add a dryer vent seal. This will reduce unwanted air infiltration, and keep out pests, bees and rodents as well. The vent will remain closed unless the dryer is in use. When the dryer is in use, a floating shuttle rises to allow warm air, lint and moisture to escape.

If your home has a folding attic stair, a whole house fan, an AC return, a fireplace, and/or a clothes dryer, you can easily, quickly and inexpensively seal and insulate these holes.

Mark D. Tyrol is a Professional Engineer specializing in cause and origin of construction defects. He developed several residential energy conservation products including an attic stair cover, an attic access door, and is the U.S. distributor of the fireplace draftstopper. To learn more visit

EditGrid said...

Great use of tracking your electricity usage in EditGrid and publishing them using our blog widget.

By the way, we are finally on Twitter now, so follow us at to get the latest on what's going on.