A Modest Result: The Continuing Benefit of the Dollars and Cents of My Home Energy Audit

Costs

My wife, Sheryl, and I have a townhouse at Crown Harbor in Alameda, California. In a series of blog posts, I outlined the process we followed in 2011 to make some energy improvements to our home:

In 2013, we signed up for green energy supplied by the city of Alameda.

I entitled the modest proposal blog posts based on the fact that we wanted to spend a modest amount of money in exchange for modest savings. As the years have passed, I shared the monetary results. If I wanted to be really accurate, I could have expressed the energy reduction in terms of units of energy (e.g., kilowatt hours) instead of dollars. I mention this because by signing up for Alameda Green, Sheryl and I volunteered to pay more for our energy in exchange for not polluting the planet. Had we not done that, our dollar savings reflected in the calculations that follow would have actually greater than what is shown; however, for the sake of simplicity, I am just using the dollar amounts.

Here is what we spent in 2011:

Item Cost
Building envelope sealing $1,409
Attic insulation $1,249
Building Permit Processing $250
BPI Safety Compliance Test $499
Duct replacement and airflow balancing $1,550
Return duct sealing $473
Total $5,430

Here are the incentives we took advantage of:

  • From Pacific Gas & Electric (PG&E), we received a rebate of $1,216.
  • With the help of Advanced Home Energy who performed the work, we also filed a rebate request with the Alameda Municipal Power Company. We received a check for $2,300 from Association of Bay Area Governments.
  • In addition, as part of filing 2011 taxes, taxpayers could get a credit by completing Form 5695 — the Residential Energy Credit Form. The Federal Tax program limited the credit to $500 per residence, and since we had already received $450 for the installation of our tankless hot water heater in 2009, we got a $50 credit that time.
  • In June 2012, we received another rebate from PG&E for $201.
  • In July 2012, we received another rebate from Alameda Power for $82.

When I combine our expenses with our incentives, I get:

Item Cost / Savings
Out of pocket $5,430
1st PG&E rebate -$1,216
Federal Residential Energy Credit -$50
1st Alameda Power Rebate -$2,300
2nd PG&E rebate -$201
2nd Alameda Power Rebate -$82
final total $1,581

Our condo is 1,977 square feet. We have been watching our electric and gas costs since we first moved in, particularly since the work was completed in April 2011.

Electricity_data

Gas_data

Various factors affect our results like: average daily temperature, price increases from year to year (particularly for the green energy), how much company we have, and how long our showers are. Variations aside, we have seen reasonable savings and have now come out ahead.

Year Electrical Savings Gas Savings Total Savings
2011 $184 $2 $186
2012 $270 $171 $441
2013 $127 $138 $265
2014 $200 $239 $439
2015 $243 $224 $467
2016 $391 $400 $791
To Date $1,415 $1,174 $2,589

Given our $1,581 out-of-pocket expenses, we have more than recouped our investment by accumulating $2,589 of savings and are actually $1,008 ahead.

If you look at our minimum and maximum payments, you can see what the best case scenario would look like for the years to come.

Electricity_before_after

Gas_before_after

As I noted in my original blog post, we undertook this project, not for the money, but because we felt our house was broken. When you borrow money to pay $646,000 for a townhouse, another $1,581 to make it right doesn't seem all that wrong. From now on out, it's all additional savings of between $265 to $791 per year, so it makes sense from both an environmental and financial standpoint.

Measurement of home energy savings is alive in the lab.