Tables below and corresponding Energy-Savings to Investment Ratio (E-SIR) were prepared using with data from a little-known report for the U.S. Department of Energy; summarized below. The complete report, except for Appendices D & E, may be downloaded via these links:  Title & Index (50 kB)  1-27 (820 kB)  28-45 (406 kB)  46-73 (947 kB)  74-82 (351 kB)  83-102 (643 kB)  App-A,B,C,F (546 kB)

This report is consistent with the 152-page GFX-Grant evaluation for DOE’s Office of Energy Related Inventions (OERI). Its first two parts may be downloaded from these links:

Grant Approval Letters (300 kB) & M. Pravda (421 kB)

Water Heating in Europe is much different; particularly in Germany, which has 7.2 million households with instantaneous systems and only 4 million households that use electric storage water heaters as their main hot water source; according to a report by the Austrian Energy Agency that may be downloaded from these links: Summary (59 kB)  Report (541 kB)

Although dated December 6, 1996, this report became available to the public in February of 2000. It presents results for many computer simulations of several water heater systems in all 5 U.S. Climate Zones under a variety of conditions. [See Table Rows A,B,C,D,F,G]

To demonstrate how bundling "Green" water heating systems can lead to improved payback and energy savings, these computer simulation results were combined with results from other GFX studies to generate the information in Table Rows E, GB#1, GB#2, GB#3, GB#4, GB#5, GB#6, GB#7.

The following list summarizes a conservation program quashed by DOE in 1997. It’s summarized on page 82 and called for the installation of various numbers of 5 types of Green water heating systems per year, as follows:

1. 125,000 hi-efficiency electric storage water heaters x 310 to save 38.8 million kWh/yr @ $75/installation = $9.375-million, or 4.13 kWh/$-invested.
2. 50,000 ad-on DHR systems x 1280 to save 64 million kWh/yr @ $400/installation $20-million, or 3.2 kWh/$-invested.
3. 25,000 multi-function heat pump water heaters (HPWH) x 2500 to save 62.5 million kWh/yr @ $1000/installation $25-million, or 2.5 kWh/$-invested.
4. 100,000 add-on HPWHs x 2070 to save 207 million kWh/yr @ $860/installation $86-million, or 2.4 kWh/$-invested.
5. 25,000 solar water heating systems x 2420 to save 60.5 million kWh/yr @ $2750/installation $68.75-million, or 0.88 kWh/$-invested.

Estimated savings are averages over 5 U.S. Climate Zones for medium residential annual consumption of 3764 kWh/yr. Savings can be much higher for heavy [6618 kWh/yr] residential users. The total "Site Energy Savings" would be about 0.43 billion kWh/yr at a total first incremental greening cost of about $210 million for these 325,000 systems. The latter represents about 8% of the annual replacement rate of 4 million electric storage water heaters [e.g. 1.6 million for households with 3 or more occupants and 1.3 million for single family homes]. "Primary Energy Savings" are higher by a factor of 3.2.

Heavy Residential User of 6618 kWh/yr Costing $562.53 @ 8.5¢/kWh¹

System

Type

Annual Savings kWh/yr

Greening Cost

Payback In Years @ 8.5¢/kWh

NAECA Standard

66 gal.
Tank Cost: $275

Consumption
6618 kWh/yr

Installed Cost
$500

N/A

A

Multifunction

HPWH

4100

$1000

2.9

B

Add-On HPWH

3510

$860

2.9

C

Solar [Thermal]

3080

$2750

10.5

D

GFX Model

G3-60 or S4-60

2250
PP&L: 2347

$400

2.1

E

Tankless

1280

$500

4.6

F

Desuperheater

1020

$600

6.9

Green-Bundle

CDE

Solar/GFX/

Tankless

6610

$3150
New Construction

5.6 vs. 10.5
(Solar Only “C”)

CD

Solar/GFX

5330

$3150

6.9

CE

Solar/Tankless

4360

$2750

New Construction

7.4

ED

GFX/Tankless

3530

$400

1.3 vs. 4.6 (“E”)

BD

GFX/HPWH

5940

$1260

2.5

AD

GFX/MF-HPWH

6350

$1400

2.6

FD

GFX/Desuperheater

3270

$1000

3.6 v. 6.9 (“F”)

Medium Residential User of 3764 kWh/yr Costing $318.75 @ 8.5¢/kWh

System

Type

Annual Savings kWh/yr

Greening Cost

Payback In Years @ 8.5¢/kWh

NAECA
Standard

66 gal.
Tank Cost: $275

Consumption
3764 kWh/yr

Installed Cost
$500

N/A

A

Multifunction

HPWH

2500

$1000

4.7

B

Add-On HPWH

2070

$860

4.9

C

Solar [Thermal]

2420

$2750

13.4

D

GFX Model

G3-60 or S4-60

1280
PP&L: 1660

R-2000 Credits:

Electric: 1760 kWh

Gas: 96 Therm

$400

3.7

E

Tankless

1280

$500

4.6

F

Desuperheater

610

$600

11.6

Green-Bundle

CDE

Solar/GFX/

Tankless

4980

$3150

New Construction

7.4 vs. 13.4

(Solar Only “C”)

CD

Solar/GFX

3700

$3150

10

CE

Solar/Tankless

3700

$2750

New Construction

8.7

ED

GFX/Tankless

2568

$400

1.8 vs. 4.6 (“E”)

BD

GFX/HPWH

3350

$1260

4.5

AD

GFX/MF-HPWH

3780

$1400

4.4

FD

GFX/Desuperheater

1890

$1000

6.2 v. 11.6 (“F”)

FOOTNOTE

1.        Estimates for whole-house On-Demand (Tankless) water heaters were substituted for Point-of-Use units because they also eliminate standby loss and have lower installed costs as compared to EEI/DOE estimates of $1800 & $1100 for multiple Point-of-Use units for heavy users & medium users, respectively.” (See Final Report for DOE/EEI Joint Water Heater Initiative, “Electric Water Heating Situation Analysis”, Reference #31186, Final Report to EEI/DOE December 6, 1996 by A.D. Little, Inc., Acorn Park, Cambridge, MA 02140-2390)