1

Raphael HerzManager, Green Affordable

Housing Initiative

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Next up:PV Technology Basics

• Why Solar photovoltaics (PV)?• How PV works• “Grid-tied” and “net-metering”• Good solar sites

Then• Rebate Programs

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Do Energy Efficiency First!!!!!New or Existing property owners should:• Determine a baseline of recent energy usage, on a

British Thermal Unit (BTU) / foot2 / degree-day basis,• Model energy efficiency and renewable energy

improvements, • Implement, through new construction, renovation or

rehabilitation of the property, the maximum amount of energy efficiency improvements possible,

• Have a 3rd party measure and verify the energy efficiency and renewable energy improvements, and

• Commission any larger building or system improvements, energy efficiency and renewable energy improvements.

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Cost of Energy Generation\Energy Avoidance

Equipment cost to deliver 1 kWh per year (The energy is free.)

Passive Solar, Daylighting $0.50

Passive Cooling $0.25

Solar H20 $2.00

Solar Electric Power $8.00

Wind $6.00

Efficiency Improvements $0.10 - $1.00

Envelope Improvements $0.50 - $2.00

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Leverage Utility Energy-Efficiency Incentives!

At a minimum, get existing home or business audited:– Residential customers:

http://www.masssave.com/

– Other customers (go to utility website):• http://www.nationalgridus.com/masselectric/business/

• http://www.nstaronline.com/your_business/

• http://www.gasnetworks.com/efficiency/applications.asp

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7

Solar Electric Energy

• In one hour, the sun sends energy to this planet to meet all of our energy needs for an entire year

• Solar Photovoltaic (PV) cells convert some sunlight energy into electricity

• Combine with NE’s high traditional electricity costs…

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Cost of PV ($/W)

Cost of Electricity

($/kWh)

Rebate Required ($/Watt)

$8.50 $0.40 $0.62$7.50 $0.35 $0.59$6.50 $0.30 $0.57$5.50 $0.25 $0.54$4.50 $0.20 $0.52$3.00 $0.15 $0.16$3.00 $0.15 $0.00

Scenarios for Solar Electricity

Nominal Cost of Installed PV mapped against the Cost of Electricity and a Rebate to achieve a Internal Rate of Return of 10% (used in typical project investments).

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Converting Sunlight to Electricity

• Photons strike silicon sandwiches, dislodge electrons

• Electrons freed by solar energy travel an electrical circuit

• Creates Direct Current (DC) electricity

• Has to be inverted to 60 Hz AC – household power

Thanks to Terry Dupuis, Solar Works Inc. for the slides

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Utility-Connected PV Systems means “Grid-Tied”

• PV systems parallel the electric utility service – house usually runs on both solar and utility electricity

• PV Power will either:– supply home electrical needs, and/or– flow to the grid when PV power exceeds household

demand.

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Net Metering Changes Everything

• Sun shining – your home draws power from the array; at night, utility supplies power.

• When making more power than using, electric meter “spins” backwards– “netting” power

• “Net metering” effectively sells excess PV electricity to the utility - and at retail prices(it’s the law)

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• Lots of Sunlight – minimize shading from trees, roof elements, other buildings during solar window: 9am -3pm

• Newly covered, structurally sound, roof facing near south

• ~40° Roof pitchor PV system pitch (flat roofs OK, too)

Decent PV Installation Characteristics

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No Shade on Panels!

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A Tough Roof

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Urban Flat Roof, Tilted Mounting

2.6 kW; 20¢/kWh energy cost; $800/yr annually avoided

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Ground-Mounted Solar Array

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Residential PV System

Commonwealth Solar – 2.4 kW PV system

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$2.56Average Award - $/watt

$9,935Average Total Award

$9.73Average $/watt cost

3890Average Capacity (watts)

$37,795Average Installed Cost

578Systems Rebated by MTC

PV System Costs 2001 - 2007

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PV Project Economics

http://www.masstech.org/cleanenergy/cando/howto.htm

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PV Project Economics

Assumes MTC rebate and grant plus adders.

Not for Profit 20+ yearsResidential* 8 to 18 yearsPublic 15+ yearsTaxable Business* ~5 years*Assumes ability to use Federal and State Tax Incentives

Examples of Solar PV Project Simple Paybacks

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Background to MTC and the Trust

• Massachusetts Technology Collaborative (MTC) administers the Renewable Energy Trust, created in 1997 by the Legislature to: – increase supply & demand for electricity from clean

sources, and – promote development of a vibrant Massachusetts

renewable energy industry.

• Over $250 million in awards; $40+ MM in FY2007• Support for over 1300 clean energy projects,

companies, and related activities.– Over 450 solar electric projects installed; ~5 megaWatts– Plus wind, small hydro, fuel cells, biomass, landfill gas

• 175+ cities and towns with installations

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Some Towns Aren’t Eligible for Funds• Source of funds is a surcharge $25 million/yr• Only customers in investor-owned utility service territories:

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Initiatives support commercially available technologies that useat least 25% of electricity onsite:

Commonwealth Solar or Small Renewables Initiative

Large Onsite Renewables Initiative

Solar PVWindHydro

Solar PVWindHydro

BiomassFuel Cells

Eligible Renewable Technologies

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Commonwealth Solar:More Clean Energy and Jobs

• Executive Administration Goal – Achieve the Governor’s 250 MW by 2017 goal– 4 Year Target: 27 MW by end of 2011

• Make it easy…– Non-competitive, rolling rebate application

process for all solar projects– Continuous, predictable PV incentives thru 2011– Ample Funding Available!

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Commonwealth Solar Funding

• $68 million over ~4 years– $40 million from the Renewable Energy Trust – $28 million from Div. of Energy Resources

• Minimum Reservations– $16 million through 2011 for state and municipal

buildings, including schools– $8 million thru 20111 for residences, including

low and moderate-income households.– 1st funding block:$8.5 million, of which $1

million reserved for residences.

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Commonwealth SolarResidential Benefits

+ Special incentives for moderate-income households

Cost Coverage 20% to 60% of typical residential PV System

Estimated payback 8 to 18 years

Return on Investment 4.3% to 13.7%

System size cap at 5.0 kW

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Commonwealth SolarInitial Residential Incentive Levels

-- So, what’s the rebate???

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Calculating PV Rebate - 1

• Is it in a Municipal Lighting Plant district?

• Does the residence have adequate:– Roof Space? – Structural Roof Strength– Access to sunlight

• Or can it be ground-mounted?

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Calculating PV Rebate - 2

• Determine PV Incentive (Total $ & $/watt)• Start with Base Incentive ($2/watt)• Are you using inverter or panels made in

Massachusetts?– YES: Add $0.25/watt

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Calculating PV Rebate - 3Does the residence meet the Moderate Home Value criteria?

≤ $400,000Barnstable, Duke, Essex, Middlesex, Nantucket, Norfolk, and Plymouth

≤ $350,000Bristol, Suffolk, and Worcester

≤ $300,000Berkshire, Franklin, Hampden, and Hampshire

Moderate Home Value

County

YES: Add $1.25 per watt

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Calculating PV Rebate - 3Does the Property Owner meet the Moderate Income criteria?

Add $1 per watt

Between $76,296 and $91,552 (up to 120 of MA median household income)

Add $2 per watt

Less than or equal to $76,296 (MA median household income)

Rebate AdderHousehold Income Criteria

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Sample Rebate Calculation

$4.50Rebate ($/watt dc) ‏$16,200Rebate ($)

$1.00Moderate Household Income $1.25Moderate Home Value$0.25MA Company Components$2.00Base Incentive ($/watt)3600Total System Size (watts)

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$3.62$0.55Average Award - $/watt$21,598$28,000Average Total Award

$6.13$1.77Average $/watt cost5.9650.1Average Capacity (watts) ‏

$36,531$89,981Average Installed Cost992Number of Systems

WindHydro

Small Hydro and Small WindSystem Costs 2001 - 2007

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For more information…• Commonwealth Solar and Other Rebate Programs:

www.masstech.org/rebateswww.masstech.org/solarKelly Brown, 508-870-0312, x1602

• MTC Affordable Housing website:http://www.masstech.org/

renewableenergy/afford_housing.htm

• Green Affordable HousingRaphael Herz at MTC:

(508) 870-0312 x1205herz@masstech.org

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Clean Energy. It’s Real. It’s Here.

It’s Working.