Whole-House Idle Loads - MAREA...Our “whole house” idle loads Notes: All electric house, w...

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TEKParkOctober 30, 2018

www.themarea.org

Whole-House Idle LoadsSurprising News & Info!

Whole-House Idle LoadsSurprising News & Info!

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Speaker Line UpSpeaker Line Up

Vera Cole Kurt Reinhart Bill Hennessy Jay Owen Phil Jones

Mid‐Atlantic Renewable Energy Association (MAREA) is a 501(c)3 nonprofit organization, dedicated to educating and engaging the public and advocating for renewable energy production, energy efficiency and sustainable living.

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Terminology—just to be sure!Terminology—just to be sure!

Energy and power are not the same thing. Electricity is a form of energy.

Energy is measured in kWh (“kilowatt-hours”). We transform energy from one form to another to do things we want. For example, a lightbulb transforms electricity into light and heat.

Power is measured in W or kW (Watts or kilowatts). The more powerful something is, the more energy it can transform. A100-W bulb is four times more powerful than a 25-W bulb.

Similarly, a solar array transforms energy from the sun into electricity. How much electricity it will produce depends on the array’s power rating (W or kW) and how much incoming energy it gets from the sun.

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Our StoryOur Story

Have solar, wanted batteries. How many would I need? Then…where on earth is all this energy going??

After years of efficiency efforts—– Home energy audit & performance improvements (sealed envelope,

insulation)– Major remediation projects (bilco doors, fireplace)– Managing thermostats, turning things off when not using, etc.

Did “experiment”…While we were away,

house used 0.59 kWh/hr, or 5,168 kWh per year. About 21% of our annual total electricity consumption,

for empty house loads.

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NRDC StudyNRDC Study

On average, nearly ¼ of electricity used by northern CA homes was for idle loads.

may cost Americans $19 billion a year equivalent to 50 large (500 MW) power plants study used smart-meter data to identify hours of

minimum power usage.

Home Idle Load: Devices Wasting Huge Amounts of Electricity When Not in Active Use

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Whole House “Home-Idle” LoadsWhole House “Home-Idle” Loads

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Our “whole house” idle loadsOur “whole house” idle loads

Notes:All electric house, w electric car, power wheel chair, stair lift, mowerAssuming 1 kW of PV produces 1,250 kWh per year in this region.(Roughly, one 300‐W panel for 0.042 kWh/hr of load.)

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Smart meter data from PPLSmart meter data from PPL

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Smart meter data from PECOSmart meter data from PECO

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What is using all that energy?What is using all that energy?

Used Kill-A-Watt meter to spot check loads throughout the house. Took these steps (so far!)

– Used extension cord to make it possible to unplug kitchen microwave when not in use (~50 kWh/yr)

– Put all living room a/v equipment, except cable box, on power strip with remote switch. Turned cable box power saver mode “On”. (~200 kWh/yr)

– Moved bathroom appliances to power strip: microwave, coffee maker, radio (~100 kWh/yr)

– Disconnected dorm-sized fridge (~300 kWh/yr)– Put plasma television on power strip (~200 kWh/yr)– Total, roughly (very) 850 kWh/yrWhole house loads, however, remain insufficiently

understood and addressed. Still figuring.

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Cablebox “Power Saver”Cablebox “Power Saver”

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To figure out next…To figure out next…

Refrigerator Hot water heater Well & sand mound pumps Volt charger Phone system Alarm system Dishwasher Garage door openers Stair lift battery charger Recent battery chargers in garage (EGO equipment) What else???

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From Jonathan…From Jonathan…

Home energy monitor (Smappee) was projecting an annual refrigerator consumption of 900 kWh (@ 0.13c/kWh = $117)

I found that the coil was very dirty, but after carefully brushing and vacuuming the dust and dirt away. Smappeenow projects an annual consumption of 347kWh (@ 0.13c/kWh = $49.00)

I’ve set a calendar reminder to perform a semi-annual cleaning.

Per monitor, whole-house always-on loads are 780 kWh per year.

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From Ray…From Ray…

Unoccupied cabin in the Poconos Breakers/Circuits ON: crawl space sump pump, septic

system dosing pump, refrigerator, two 9-W LED outdoor front night lights on a timer, television, crawlspace dehumidifier

Breakers/Circuits OFF: hot water heater, well pump, stove, electric heat, internet modem and router

Hourly idle load, 0.40 kWh/hr. Annual idle loads, 3,504 kWh.

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From Bill…From Bill…

Known-on loads: charging two phones and one tablet; one night light; two land lines; two computers and a printer Over two 7-hr periods, reading of 1 kWh. However,

1 kWh is smallest increment on meter. Based on 1 full kWh per 7 hours…idle loads are

0.14 kWh/hr or 1,250 kWh per year

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From Mark…From Mark…

1.2 kWh for hours of midnight to 5 am Total idle loads…0.24 kWh per hour, or 2,100

kWh per year

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Summary of Shared ObservationsSummary of Shared Observations

Hourly Idle Loads (kWh/hr)

Annual Idle Loads (kWh/year)

300-W Solar Module Equivalence

0.37 3,241 9

0.59 5,168 14

0.09 780 2

0.40 3,504 10

0.14 1,250 3

0.24 2,102 6

IDLE LOADS

Kurt ReinhartOctober 30, 2018 

PASSIVE/ACTIVE SOLAR DESIGN• Ranch style• Orientated 15° East of true South• Air tight construction (as much as possible)• Heat recovery ventilation ‐ HRV• Highly Insulated:

– Subslab ‐ R20; 4” styrofoam under slab– Walls ‐ R40; 6” SIPs with urethane foam– Ceiling ‐ R80; 24” blown in cellulose

• 8.4 kW solar array on roof:  33 panels @ 255W ea• Triple glazed, argon filled windows north and west• Double glazed windows south with Cardinal 181 coating• Approaching Net Zero performance

METHOD

• I don’t have a Smart Meter so I can not download data from MET‐ED• I recorded my meter readings 3 ways:

– Took readings before and after a one week vacation in August; turned off everything I normally turn off when leaving for an extended period;

– Took readings before and after a one month period while we were home; and,

– Took readings while away for a weekend but turned off everything I could think of.

CALCULATIONS

• Solar generation = ending solar meter reading minus starting solar meter reading from solar meter;

• Consumption = ending consumption reading minus starting consumption reading from utility meter; 

• Excess solar generation = ending excess reading minus starting excess reading from utility meter; and,

• Actual consumption = Consumption + Solar Generation minus Excess Solar Generation

• Hourly Consumption = Actual consumption ÷ hours in period

IDLE LOAD SOURCESALWAYS ON OPTIONALLY OFF

Refrigerator Well & rainwater pumps

Freezer Septic system pump

Heat pump water heater

Radon fan Computer modem/router

Home Security System TV, TV modem, stereo

Plant lights and fan Printer

Microwave

Clock radios

Night lights

Computer

Echo Dot

ITEMS TURNED OFF WITH EACH TEST

OCCUPIED ‐ 36 days NOT OCCUPIED1 – 5+ days NOT OCCUPIED2 – 2 days

NONE Heat Pump Water Heater Heat Pump Water Heater

Heat Recovery Ventilator Heat Recovery Ventilator

TV

Stereo & Modem

Computer

Microwave

Clock Radios ‐ 3

Printer

Night Lights

1What we normally turn off when we’re not home.2With additional things turned off/unplugged.

RESULTSOCCUPIED NOT OCCUPIED NOT OCCUPIED1

Solar Generation 816 226 34

Consumption 560 23 11

Excess Generation 523 197 24

Hours in Period 860 124 50

Actual Consumption 853 52 21

Consumption/Hour 0.99 0.42 0.42

1Long weekend with additional items turned off.

CONCLUSIONS• My idle load is 42% of my total usage – YIKES!• My occupied usage at 0.99 KWH/hour extrapolates to 738 KWH per 

month.  MET‐ED shows a 780 KWH monthly average.• Interestingly, I saw no difference in the two unoccupied tests – Slide 8.• Also these tests were performed in August & September with no heat 

running and very little air conditioning.  Results could be very different if repeated in January/February.

• I would like to think the idle load is high because the house is very efficient and doesn’t use much electricity even when occupied

In areas requiring a ground‐fault interruption circuit (GFCI), a combination switch with receptacle offers more outlets, but single GFCI combo switches are 

available if space is limited.

Wiring options for GFCI combo receptacle

Extra requirements for 240v appliancesYou’ll need to use a double‐pole switch that can handle the voltage and amperage of the appliance.

Most dryers and  built‐in  ovens require a double‐pole, 240v circuit rated at 30 amps. It’s a little easier to wire if you use a two‐gang box.

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Home Electricity Conservation Kits (for libraries)Home Electricity Conservation Kits (for libraries)

Each kit includes: “Kill-a-Watt” meter extension cord book, “Consumer Guide to Home Energy Savings” (New

Society Publishers, 2007) book, “Pennsylvania Homeowner’s Guide to Solar

Electricity” (MAREA, 2009) directions for “Kill-a-watt” meter use worksheets for results and calculations five postcards for evaluation returns

Materials are contained within a sturdy carrying bag.

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Conservation Kit Workshop GoalsConservation Kit Workshop Goals

Participants will: understand “phantom load” learn watt-meter use calculate appliance operating costs learn to complete a home electricity audit identify strategies to reduce electricity consumption be introduced to the benefits of solar electricity

Nolde Forest Environmental Education Center 2910 New Holland Road, Reading PA 19607-9448

Phone 610-796-3699 FAX 610-796-3698NoldeForestProgramStaff@state.pa.us

Phantom LoadsThings that Go Bang in the Morning

https://myelitedetail.us/clipart/drawn‐bat_1631877.html

Philip Jones

Radon Fan• 24/7/365• Unit installed 12 years = 81 Watts • 706 kWh/year (0.6 solar panel)• New unit ECM• Unit = 45W• 395 kWh/year (0.3 solar panel)• Savings = 311 kWh/year  ($37/year)• Fan cost = $140 • 4 (7) yr payback ‐ self‐install (or not)

Context• No solar generation• All‐electric (no gas or oil)• Heat Pump heated and cooled• Heat Pump‐hybrid water heater• 87% LED/CFL/FL Lights • Mostly ENERGY STAR Appliances• Two adults, no pets

Method

• PPL Smart Meter (combo of 15 min, Hourly)• Minimum Intervals• Average at mid‐day(s) of vacations• Follow‐up Kill‐A‐Watt measures of Individual Loads

Idle Load Consumption

Lowest Hourly Usage, from Smart Meter Data

Average Hourly Usage on Vacation (excl. start, end)

Hourly idle loads (kWh/hr) 0.130 0.217Annual idle loads (kWh/yr) 1,139 1,901Percent of total usage 7% 11%PV Equivalent (kW) 0.9 1.5

“Always-on” Loads• Refrigerator: 1W / 140W   65W (no access)  

75W (typical access)556W (Defrost) 

• Radon Fan: 45W• Clock: 1W• Standby 22W

Total 133W  (~ minimum metered)

“Standby” Loads• Cable Modem 7W• Cable‐TV converter 5W• Internet Router  4W• Garage Door Opener 4W• Microwave (clock) 2W• HDMI Switch for TV input 2W• PC Speakers 1.5W• Internet Radio 1.5W• TV 1W• Sound Bar 1W• Inkjet Printer 1W – don’t power this off• Dehumidifier 0.6W

• Total 30.6W  (21.6W on vacation)

“Automatic Intermittent” Loads

1. Heat Pump2. Water Heater3. Refrigerator4. Dehumidifier5. Attic Fans

99952978

657360

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kWH/Yr62.6%18.6%

4.1%2.3%0.3%

% Total

“Active” Loads

1. Stove2. Lights3. Dryer4. Heating Pot for coffee, tea, etc.5. Garage Door Opener6. TV7. Microwave8. Dishwasher9. Toaster Oven10. Laptops11. Washer

411394104

8044444223202015

kWH/Yr2.6%2.5%0.7%0.5%0.3%0.3%0.3%0.1%0.1%0.1%0.1%

% Total