Download - Denver: How to Become Both Solar and Tree-Friendly

Colorado’s First Solar (and TREE!) Friendly Community

January 8, 2013

Jessica Scott, Sustainability Strategist

Office of Sustainability

Office of Mayor Michael Hancock

Denver Designated As Gold Level Solar Friendly Community (1275 pts)

How Did We Do It?

Denver’s Score At A Glance

• Provide Checklists (200 pts)

• Solar Coordinator (50 pts)

• Website (25 pts)

Step 1(275/275)


• Use Standard Form (50 pts)

• One point of contact (25 pts)

• Authorize electronic communication (25 pts)

Step 2 (100/275)


• Electronic Submittal (150)—

in process, Accela launch slightly delayed

Step 3 (150/150)


• Same-day, electronic, or OTC permits (100 pts)

Step 4 (150/150)


• Cap residential permit fees at $50 for standard systems

(100 pts)

• P.E. Stamp exemption for standard systems (50 pts)

Step 5 (150/150)


• Accept NABCEP/no local req. (25 pts)

• Post Inspection Checklist

(25 pts)

• Post Changes to Code

(10 pts)

Step 6 (25/25)

Step 7 (35/50)


• < Two hr lnspection Window

(50 pts)

• One Inspection (75 pts)

• Allow Affidavit (15 pts)

Step 8 (50/75)

Step 9 (90/100)


• Work with Fire Officials (50 pts)

• Encourage Community Solar (25 pts)

• Adopt Balanced Written Goals (25 pts)

Step 10 (100/150)


• Employee group discount (50 pts)• Low-interest solar loan for Denver

Energy Challenge participants that achieve 15% energy savings (50 pts)

• Educational Solar Events (25 pts)

Step 11 (125/125)


• Denver Regional Solar Map (10 pts)• Encourage solar development as

stated goal for community (15 pts)• Running tabulation of solar projects

(50 pts)

Step 12 (75/75)

What is Denver Currently Working On?

• In process of launching online permitting (Accela)

• Launching 2nd round of Solar Group Discount (contact Jessica if your municipality or company is interested in participating)

• Solar Friendly (but still Tree Friendly!) Communities

Trees and Solar Collectors Working Together

• What is the urban forest? • Urban forest benefits• Governance• Solar conflicts• Solutions

The Urban Forest

• A collection of woody vegetation within a city or town

• Impacts every parcel in a city

• Essential to the well being of city residents

• Provides individual and community benefits

Urban Forest BenefitsEnhanced Quality of Life

• Promotes physical health and mental well being

• Walkablitiy• Reduced stress• Reduced hospital

stay length

Urban Forest BenefitsProperty value

A large healthy tree can increase a property’s value by 1% to 4%

Urban Forest BenefitsEnvironmental Service

• Clean air• Clean water• CO2 storage and sequestration

Urban Forest BenefitsUrban Heat Island

Urban Forest BenefitsEnergy Efficiency

• Evergreens buffer cold winter winds reducing heat heat loss

• Deciduous trees planted on the east and west block summer sun and reduce cooling needs but allow for winter heating

• Shading to the south by branch structures negatively affects winter heating

Metro Denver Urban Forest• 16.4% canopy cover (4.5% in Erie to 37.4% in Cherry Hill Village)

• 9.6 million trees• 4.8 trees per capita

• Denver canopy cover is 19.7%• 2.2 million trees• 3.7 trees per capita

• 182,000 MWh saved through cooling each year ($21.8 million)• 997 MWH per day during the cooling season

Ordinance, Rules & Regulations

• PROW are protected

- belong to the City • Private property

- no jurisdiction • Licensing

- insurance required

- no cuts over 4”

- no topping

- license revocation

Solar Conflict

• Current• NREL study – only 20-25% of residential roofs are

suitable for solar*• Due to shading and roof orientation

• Trees aren't static

* Denholm, P. and Margolis, R.M. 2008. Supply Curves for Rooftop Solar PV-Generated Electricity for the United States. NREL/TP-6A0-44073, National Renewable Energy Laboratory, Golden, CO, USA.

Solar Conflict

• Future• Trees are dynamic• Lack of knowledge:

• Growth rate • Size• Shape• Height control techniques (solar friendly pruning)

What Is A Relevant Conflict?

Trees As Solar Conflicts• Tree Shade Instead of Adequate Insulation

• Millions of $ in savings in every city on earth• Infrastructure Placement Paradigm

Solution Sets• Current

• Solar-friendly Arborists• Solar Gardens

• Future • Solar-safe Zones• Site Planning• Neighborhood Planning• Regional Planning

Current Solutions• International Society of Arborists (ISA) –Certified work

• Solar-friendly Analysis, Plant Care and Selection• Cost, repeat visits amortize into total cost of array• The urban forest is a managed landscape

Future Solutions

• The following can be voluntary, covenant, agreement, ordinance, recommendation.

• Solutions change across scales.• Trees can’t be pruned like a hedge, so species selection

is important.• Solar Safe Zone or Solar Access Zone is fundamental unit

of outcome (parcel scale, neighborhood scale, regional scale, city scale).

Parcel Scale Solutions• Solar Access Zones with species selection by location.

Street Scale Solution• Street Tree Species Selection by Defined Side of Street• Covenant, Ordinance

Street Scale Solution• Street Tree Size at Obstruction Only After Many Years

Recap: Solutions• Current Conflicts:

• ISA-Certified Arborist :: Solar-Friendly• Future Conflicts:

• Analysis needed for time• Species selection and restrictions in space• Ordinances: parcel, street, neighborhood level

• Most People Forget Trees are Dynamic, PV is Static• Trees and Solar are Good Partners

Solution

• Get an arborist• Educate the home owner

Questions?Sara Davis, Mile High Million Program Manager

Department of Parks and Recreation

[email protected]

Jessica Scott, Sustainability Strategist

Office of Sustainability

[email protected]

Dan Staley

DCS Consulting

Green Infrastructure Consultant

[email protected]

mailto:[email protected]