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Dolce Verde Urban Homestead: 2013 Energy Use Wrap-Up

I keep track of my year-over-year electrical use so I can tell, in a general sort of way, which of my energy savings methods are working and which give the best return on investment (ROI). 

General background on my house:

  • 1,100 square feet

  • Single story

  • Built in 1939 out of bricks laid in a Flemish bond pattern

  • One human occupant, two cats

  • Central air conditioning (heat is gas)

The numbers:

  • 2011 is the baseline year:  6,813 kWh used – highest usage is in summer with the A/C running.

  • In March, 2012, I had additional insulation blown into the attic to bring it up to code (R38) and 5 roof vents put in. 

    • Project cost:  $1700

    • Energy savings over 2011:  407 kWh

    • Cost savings over 2011:  $52

    • Amount of time to see return on investment:  33 years

  • In May, 2013 dad put up three cheapo exterior blinds from Home Depot across my front porch which faces west.  It’s also the side of the house with my biggest windows – ugh!  I also started paying meticulous attention to my daily energy use by checking my account on aps.com.  I am on their 7PM to noon plan where energy is less expensive during those hours and more expensive during peak usage times from noon to 7 PM.  I found that by keeping the thermostat at 86° during peak times and 84° during the other times in the hottest months, I actually saved money over trying to sweat it out with NO A/C during the hottest part of the day and suffering through indoor temperatures often in excess of 92°. 

    • Project cost:  $40

    • Energy savings over 2012:  1536 kWh

    • Cost savings over 2012:  $115

    • Amount of time to see return on investment:  Immediate!

 

So the winner by a long shot is “exterior shades and paying attention to thermostat settings”!  I’m glad I insulated and vented the attic too – don’t get me wrong.  I can feel the difference the insulation has made especially in the really hot months when the heat build-up in the attic would make my interior walls warm to the touch.  That doesn’t happen anymore.

I’m still working on strategies to keep even more heat off my house in the summer to stop the bricks (thermal mass) from heating up. 

Here’s one of my strategies from a few years ago – use summer vines to shade the porch.  This worked pretty well and had the added benefits of being pretty and green.  Also, being a plant, it transpired thus adding a tiny bit of cooling.  But it wasn’t solid shade like the blind, and there was no way of covering the middle bay of the porch which leads to the front door.

Here’s the front of the house with the blinds – notice that all three porch bays have a blind on them.  They did an amazing job shading this western side of my house, especially in the evening when the sun was low enough to slide right under my tree canopy.

Plans for more energy savings in 2014

With our intense summer heat and with my biggest windows on the HOTTEST side of my house (West), I’m investing in a “hedge fund”.  What’s that you say?  Yes – a hedge fund – basically some tall shrubs placed strategically along the inside of the fence surrounding the front of my property.  These shrubs will ultimately grow to a height where they will act to block that low, setting sun in the summer, thus acting as another “solar baffle” to keep the heat off my house.  Here's a mockup of what I mean using SketchUp (which I am fabulously UNskilled at using).

Basic model of the west side of my house at 6 PM on June 22nd without tall “solar baffle” shrubs. Note the low sun angle in the evening allows the sun to shine right under my tree canopy and hit my house – including my windows.

Basic model of the west side of my house at 6 PM on June 22nd WITH an example of a tall “solar baffle” shrub. Note the shadow of this shrub (6 ft) now blocks out that low sun angle and shades my front porch. The idea is to plant a variety of “solar baffle” taller shrubs in the yard that will serve as another layer to protect against that low summer setting sun while simultaneously making the air around my house cooler with their evapotranspiration.

That's the plan....!

See more of my projects at:  Abundant Desert Blog

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Comment by Catherine, The Herb Lady on March 31, 2014 at 5:18am

Jennifer - what a great report on your project and goal.  I'm reposting your blog :-)

Comment by Heather Green on March 30, 2014 at 9:40pm

This was an inspiring post... It actually got me to research my electric usage and bills. Although my usage went down 699 kWh from the year prior, it's still higher than I would like. I'm actually going to attribute part of the reduction to a new low energy washer and dryer, refrigerator and stove. I rarely buy new things... but it was time. But my older A/C unit, little if any insulation and original windows are probably the main culprits of my energy usage. Only one room of the house isn't shaded... yet, and although the walkway overhang shades the front of the house quite nicely, the vine walkway project should add to it until the front yard replacement trees get bigger... At the end of the day, I think I need to find some window and insulation people- probably a better a/c unit too... 

Comment by Cynthia Carter on February 26, 2014 at 1:54pm

Hi, Jennifer. :)  Unfortunately the driveway opens onto the street, so there's no shade west of us for a whole block, and the hot wind just barrels down the road, straight at us during the summer.  Not much I can do about that, but I am going to install some "wind break" plants where I can to cut down on the wind and litter that comes with it (we are the neighborhood trash-landing, it seems. Grr!)  I've thought about putting pomegranates on the south, and keeping them trimmed short.  Two story house, so I probably won't have to worry about them getting up to eaves. :)  Putting in vines on trellises also sounds appealing, and likely easier, so I may go that route.  For now, my time is mostly spent just trying to get the back yard up and running with trees and developing the dirt and doing some gardening.  But, always dreaming of "the next phase"!  :-D

Comment by Jennifer Wadsworth on February 26, 2014 at 12:23pm

Thanks Cynthia - I think the building next to you is probably serving to shade that west side pretty effectively, right?  You could always grow vines over the top if you wanted overhead shade (cats claw vine will grow like a weed with very little water).

As for planting on the south side, it depends on what you want to do with that spot.  Some people use that area for a winter garden, so growing deciduous trees might be a great idea.  If you ever plan on installing solar panels, they usually make you remove any trees on the south side.

I'm looking to keep up with my savings this year - we'll see how it goes!  Good luck to you as well!

Comment by Cynthia Carter on February 24, 2014 at 10:10am

Wow, this is a great report, thanks for taking the time to share this with the rest of us!  Sad for me, our western side is a narrow strip that is barely larger than our driveway slab, so natural shade isn't possible there, but our south facing walls might benefit from some trees.  And your work tells me the shading where I can place it would be worth the bother of expanding the watering system and babying new trees/shrubs.  Hubby handles power stuff, but I will share this with him and see if we can tweak our A/C to minimize the bill.  

Best of luck on the coming year at your homestead! :D

Comment by Jennifer Wadsworth on February 16, 2014 at 2:51pm

Yep - I'd have to agree with you about trees!!  I have several trees in the front yard and they cool the property between 5-20 degrees in the heat of summer.  Plus they:

  • build the soil with their leaf drop
  • rehydrate the soil by acting as hydrological pumps
  • create more humid air through evapotranspiration
  • attract "nutrient dropping" birds (bird poop) - a nitrogen source
  • enhance soil life
  • bring up minerals from the subsoil
  • keep the sun from heating up the thermal mass of the house in summer and expose the thermal mass to the sun in winter
  • cleans air pollution
  • and.....trees are beautiful!
Comment by Patricia on February 16, 2014 at 2:34pm

Impressive!  Trees work wonders.  I have an African sumac that drops litter everywhere, but it's located on the west side of my house and provides a lot of shade on those hot summer days.  So worth it.

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