Case Study – basement insulation

My father-in-law has recently added significant insulation to his basement windows and bulkhead. He created some great ways to plug the holes using bubble wrap and insulation in ways that also make it easy to install for the winter and store them away for the warm months.

He provided me with data from his oil bill, as well as the degree day information from his oil company for the years before and the year after this improvement.

One of the first problems I thought about in reviewing his data was that oil fill-ups don’t correspond well to the days that the oil was burned. I can see that there were 100 gallons put into the tank in March, for instance, but I can’t say how many of those gallons were used in the next week or the next month. The oil that goes into a tank in May may not get used until September.

The second problem to consider was that the oil company provided 9 months  of degree data — from September to April. So, to try to match this up to the months when oil was added to tank required a little guesswork. I ended up throwing out some gallons of oil, hoping that I was making good guesses.

In the end, I did the calculations and spreadsheets three different ways, each a little more precise than the first. Below is the summary of the first (simplest) and third (most complex). The middle one provided data closer to the third, but basically in the middle.

Simple Analysis:

In the simple case, I used the oil company degree data AND the oil fill up data for only the months of September through April. After looking up a couple of estimates of kWatt-hours per gallon of heating oil, I used 1 gal=41KWh (which doesn’t take into account the efficiencies of the oil burner). I found an average number of degree days from the 5 years given by the oil company, 6245, and used that to ‘normalize’ the kWh and gallons of oil.

Year Gal of Oil kWh Deg Days kWh/DD Norm kWh Norm Gal Savings
2004-2005 1169 47929 6487 7.4 46141 1125 -$33
2005-2006 1036 42476 6020 7.1 44064 1075 $93
2006-2007 1089 44649 6116 7.3 45591 1112 $ 0
2007-2008 972 39852 6042 6.6 41191 1005 $268

The first few columns are the numbers provided by the oil bills and the degree days provide by the oil company. The normalized kWh and normalized gallons are the amount of energy or gallons of gas your heating system would have used if there was the exact same number of degree days in each of these years. Now we can compare 2007-2008 against 2006-2007 and there is a savings of about 10%, which would be $268.28.

After going through these numbers I felt it would be much better if I could get a full year of data and more detailed degree days and see if the result was better. I used the degree day data from this website:, where I can set the base temperature and get monthly, weekly or even daily data. That way I can use the entire years worth of oil information as well. The only drawback is that for the zip code near this house, the degree data only goes back 2.5 years. So the monthly detailed analysis is only useful for the last two years.

Complex Analysis:

Year Gal of Oil kWh Deg Days kWh/DD Norm kWh Norm Gal Savings
2006-2007 1225 50221 6075 8.3 51626 1259 $ 0
2007-2008 1011 41467 5913 7.0 43796 1068 $477

These numbers indicate a 15% increase in efficiency (savings in gallons of oil) between 2007 and 2008, which translates into a savings of $477 in a ‘typical’ year. That’s pretty nice.

There is a big difference between the first ‘simple’ estimate and the final one. The differences in the calculations that lead me to believe the final savings number is a better estimate of the savings than the simple one are: 1) I used more sophisticated degree day data, which allowed me to set the proper base temperatures and work with monthly data; and 2) I used the full year of data for both the oil fill ups and the degree data and set the calendar year to go from June to June assuming that the oil in the tank during the summer months was not used quickly.

I expect to return to this case study next year to see if the numbers are consistent. If you want the more detailed spreadsheet of numbers for this case study, please write to me at kim at

Getting started in Solar

Many people think of ‘going solar’ as requiring a large investment, specialty installation, equipment on your roof and calculating the years required for payback.

But there is a way to get started on a lot smaller budget as soon as possible.

If you think about all the things you use every day that require electricity, and then rank these things by criticality for your use. For instance, on a scale of 1 (low criticality) to 5 (high), charging your Roomba or your hand-vac might rank as a 1. It doesn’t matter exactly when it gets charged, you probably have days or weeks between usage.

Charging your iPod might be a 2 or 3 depending on how critical those tunes are for your daily workout or your commute.

Running your computer might be a 4 or 5 if your business depends on it.

On a larger scale (requiring significantly more energy), running your washer and dryer might be a 2, if you are willing and able to wait until there is enough battery charge or bright sunshine.

So how about a solar panel that is hooked up to a few special outlets or a utility room where these less critical devices get recharged. Maybe in the future we will have ‘recharging’ rooms or ‘recharging’ outlets that are only expected to charge when the sun is shining.

In the mean time, I looked up a couple of portable and smaller scale solar chargers that can be used for devices around the house. I am working with the Solio so I will provide a review on that one in an upcoming blog.

Get your kids involved by making it a game to see how many things they can charge without using the household electricity — make sure the Nintendo DS is on the list!

Degree Day

If the outside temperature is 30 degrees F, and your thermostat inside is set to 68 F, than how much  work did you heating system do and how much did you just pay for that days heat?

A “Degree Day” (DD) is the term used in energy performance measurements to describe the number of degrees your heating or cooling system had to work against in order to warm or cool your house.

In the example above, the outside temperature is 30F (on average) for the day, and the inside is 68F, so the DD for that day is simply 68-30=38. When the outside temperature is 60F and the inside is 68F, the DD for that day is only 8 and much less energy would being used by your heating system.

Sounds simple, right?

Well, as I read more and more into the pitfalls, assumptions, discrepancies, and calculations, it quickly moves into the engineering level of ‘complex’. To get some of the details follow this link: DegreeDays, Handle with Care!

But the concept is important — because if you have the heating bills in front of you from last year and this year and try to compare the costs, you realize that  you can’t make a direct comparison because last year it might have been colder over all than this year.

But, if you made a significant change in your heating system or you plugged up the holes or added insulation, you really want to know if it made a difference. You need to be able to justify paying for improvements and the best way to do that is to run some numbers.

That’s why the ‘Degree Day’ was invented. If you know that there were 6232 degree days last year and only 6002 this year (a warmer year), then you can ‘normalize’ the data, which then lets you compare costs or gallons of oil over two different time periods. You would be able to say “if I had exactly the same winter as last year, I will save $435 on my heating bill”.

I am working on a case study right now where the homeowner has provided me with his data for gallons of oil purchased each month over the last few years and wants to know if the improvements he added in insulating the basement have made a difference.

I will post the data and details over the next few days in a Case Study.

In the meantime, if you have a set of data associated with your heating bill and would like some help comparing costs from year to year, please send it to me and I’ll give it a try. Posting some case studies (anonymously, if you like) might help inspire others to plug up some holes or change out that ancient oil burner for something much more cost efficient!

Also, the easiest way to get the Degree Day data for your area is from this website:

Your local gas or oil company might have Degree Day information as well.

No more paper (step 1)

I opened a bank account yesterday for Energy Emporium. I shopped around a bit, but really for small business banking they are all pretty much the same. The ones I looked at offer electronic banking and bill pay, which is important to me. I hate to write checks. I tell myself that e-bill payments save paper — which it probably does, but really I just hate to write checks.

If I really want to save paper that comes from the bank I need to take the plunge and sign up for electronic statements. I tried this with one credit card account a few years back. I got the email that says “your statement is ready” and I pretty much ignored it like I do with the other hundred emails I probably got that day.

Then I forgot to pay it until it was late and I got late fees and they raised my interest rate. I was very annoyed.

But, I’m going to do it again because it is important to my business that I do what every I can to avoid wasting paper. I’ll set up calendar reminders for when bills need to be paid and use an incoming mail rule that puts all the bank and credit card statements into their own folder.

The other thing I want to be much better about is backing up data. It is great to keep everything electronically, but if a hard disk goes on a computer… you can lose it all. After decades of using personal computers and depending on them for many things, I only bought my first back up hard drive last year.

From my mac, with Leopard, it is really easy to plug in a hard drive via USB and the ‘time machine’ takes over backing things up. That’s helpful.

Ok…no paper statements for The Energy Emporium. Have you chosen electronic statements? Has it worked for you?

Wind power for the home

Something I found out recently – Jay Leno is very involved in alternative energy solutions. He has this enormous garage to house his collection of cars and antique steam engines. The garage is powered by wind and solar!

My cousin Kaelin sent me a link about a new wind turbine that uses magnetic levitation to allow the blades to rotate without friction. This is a house mountable device. Here is a video of Jay Leno talking to the manufacturer:  Jay Leno’s Garage

EnviroEnergies, Maglev wind turbine

EnviroEnergies, Maglev wind turbine

Here is a tree hugger review of a similar product.

Everwind Maglev wind turbine

Everwind Maglev wind turbine

The cool thing about this technology is that it addresses some of the biggest problems we have with harnessing the wind: the mechanical moving parts fail after a while, you need to mount traditional blades away from other structures, the amount of wind should be fairly constant and fairly high.

This mag-wind turbine will start turning with winds of only 5Mph and does not make noise.

I want one! As soon as I figure out how to be a distributor or rep, I’ll get some for my store.

I’m very excited about the new products we are starting to see now that the ‘green revolution’ is underway. Did you see Obama’s interview on CNBC last night? He stated that we need to ensure that the money spent on the economic stimulus package is spent wisely. Some examples he noted of good spending include: “making sure that we are doubling alternative energy, and creating much more efficiency in our buildings and in our transportation systems,…”

If you come across interesting links for alternative products, please send them to me or add them to the comments!  Thanks!