Potomac Region Solar Energy Association

--Reading your electric bill

--Conservation and efficiency

--Solar hot water

--Solar electricity

--Kilowatt-hours used

--Transmission cost

--Cost per kilowatt-hour

--Fuel adjustment charge

Total cost per KWH: 12.9¢(increased by 30% in last 5 years)

69 kWh

69 x o.o260300

69 x 0.0551500

69 x 0.0474500

--Rate increases alreadyapproved in VA, MD, DC

--Carbon tax and/or cap-and-trade policy will increasefuel costs

Electricity Cost Trends

Upgrade to efficient “Energy Star” appliances-refrigerator-clothes washer-dehumidifier

Insulation, sealing

Heating/cooling Front-load washer

Energy-star refrigerator

www.energystar.gov

Upgrade to efficient appliances

Insulation, sealing-attic insulation 15” minimum-attic door cover-storm windows

Heating/coolingInsulated attic door cover

Upgrade to efficient appliances

Insulation, sealing

Heating/cooling

--Annual maintenance

--Difficult to retrofit

--Ductless heat pumps

--Radiant barrier

--Use less air conditioning— programmable thermostat

--Whole house fan

--Lower hot water heater temperature setting

--Use fans for spot cooling

--Use less air conditioning

--Whole house fan

--Lower hot water heater temperature setting

--Use fans for spot cooling

From: Extremehowto.com

--Use less air conditioning

--Whole house fan

--Lower hot water temperature setting to 130 F--Add insulation blanket

--Use fans for spot cooling

1. Turn off circuitbreaker

2. Remove covers

3. Set thermostats

4. Turn on breaker!

--Use less air conditioning

--Whole house fan

--Lower hot water heater temperature setting

--Use fans for spot cooling—Turn off when you are not nearby

--Buy things that don’t use energy when turned off

--Eliminate “phantom” loads

--Turn stuff off!

Coffee pot with clock/timer

--Buy things that don’t use energy when turned off

--Eliminate “phantom” loads “Kill-a-Watt” meter

--Turn stuff off!

Entertainment center with Power strip

Kill-a-Watt meter

--Buy things that don’t use energy when turned off

--Eliminate “phantom” loads

--Turn stuff off! (printers, monitors, coffeepots, security lights, etc., etc.)

Your personal smart grid can reduce “peak” energy usagePut hot water tank on a timer to avoid peak

hour operation (12:00 pm-7:00 pm).Use timers on other major appliances

(dehumidifier, possibly freezer/refrigerator)

--How does it work?

--What does it look like?

--What are the requirements?

--What are the cost/benefits?

Diagram courtesy of Standard Solar, Inc.

Back up heat

1. Evacuated tube--more efficient--smaller footprint--angle tolerant

2. Flat panel

www.sssolar.com

1. Evacuated tube

2. Flat panel--simple, effective,

durable--heavy!--angle steeper than

many roofs

www.heliodyne.com

--Unshaded, south facing roof or other location near house

--Angle should be optimized for winter; summer will have plenty

Shed mounted

Ground mount near house

1. Typical usage (family of four) = 4700 kwh/year @ 15¢ per = $700

2. SHW system displaces ~70% of usage= $500

3. SHW system cost after tax incentives = $5000--

Basic assumptions

Three ways to look the benefits:

1. Simple payback --$5000/$500 per year savings = 10 year s

2. CD comparison --$5000 invested to get $500 per year = 10% interest rate. Actually about 13% effective rate considering taxes.

3. Refinance $5000 @ 5% rate costs $322 per year. You saved $500-$322 = $178 per year. No large out of pocket expense.

And don’t forget!

--How does it work?

--What does it look like?

--What are the requirements?

--What are the cost/benefits?

Diagram courtesy of Standard Solar, Inc.

Single crystal, polycrystalline, extruded thin-film—all are functionally very similar.--cost/watt approximately $3.50-4.00--panels represent about half the total system cost of ~$7.00-8.00 per watt.

Single crystal

Polycrystalline

1. Off-grid2. Grid-tied with net metering3. Grid-tied with net metering and battery backup

--DC electricity generated by your solar panels is converted to AC by an inverter that feeds the power back to the grid.

--You receive a power “credit”. In essence, your utility meter runs backwards if you are generating more electricity than is being used within the house.

--The grid becomes like a giant battery—saving your excess solar energy for later use.

--Solar panels

--Charge controller (battery backup systems only)

--DC -> AC Inverter

--External shut-off

External shut-off

System with battery backup

Simple grid-tie inverter

--Need southern exposure with no shading for most of the day.

--Roof mount or ground mount; fixed or adjustable.

--Can be located away from house (inverter near panels so that power is transmitted as high voltage AC.

--Modular design is possible

Assumptions:

1. Price for a one kilowatt grid-tied array after incentives: $7000

2. Annual kilowatt-hours produced : 1250

3. Value of electricity produced: $188 @ 15¢ per kwh

$376 @ 30¢ per kwh

4. Annual cost to finance at 5% rate: $451

www.dsireusa.org

Picture is changing rapidly—You can influence the outcome!

Website provides information about incentives for each state:

A few other resources:www.prsea.org (our website)Homepower.com (home power magazine)Solartour.org (DC area solar homes tour

website)

The 7 stages towards acceptance of a new idea, such as solar power generation, by entrenched interests:1. Idea is dismissed out of hand.2. Idea is described as quixotic and impractical,

for various reasons3. Some lip service is paid, but grudgingly4. Keen interest expressed, but mainly a

marketing ploy5. Control of changing public attitudes and

political trends becomes difficult.6. Idea is mainstream and treated seriously.7. Corporations must adapt or become extinct!