Building owners have more questions and requests on how to integrate renewable power into their buildings. And as the Smart Grid evolves, integration of renewable energy sources is increasing. Possible renewable power technologies include solar, wind, geothermal, and biomass. As the technologies that support increasing use of renewable energy mature, the codes and standards that define their use, interconnection, and interoperability with the grid must keep pace with them. Engineers involved with integrating renewable power into buildings must be aware of the applicable energy codes and standards and how to properly implement them into the building design. They must also evaluate the design objectives, materials, systems, and construction from all perspectives. It’s critical for designers to assess the design for cost, quality of life, expansion capabilities, efficiencies, impact on environment, creativity, and productivity.

1. Critical Power: Integrating
Renewable Power into Buildings
Sponsored by:
#CSErenewpower

2. Today’s Webcast Sponsor:

3. Learning Objectives:
1.The audience will understand the applicable codes: ASHRAE Standard
90.1: Energy Standard for Buildings Except Low-Rise Residential
Buildings; ASHRAE 189.1: Standard for the Design of High-Performance
Green Buildings Except Low-Rise Residential Buildings; and NFPA 70:
National Electrical Code, Article 705: Interconnected Electric Power
Production Sources
2.Attendees will learn about identifying specific renewable energy
technologies to be included in a new building or major retrofit project
3.Viewers will understand how to connect renewable energy technologies
to the grid
4.Viewers will learn how employing energy management techniques
reduce energy consumption and costs by driving efficiencies, improving
system reliability, and providing data to support energy sustainability.

4. Scotte Elliott, CEM, Electrical Engineer, NABCEP
Certified PV Installation Professional,
Metro CD Engineering LLC
Andrew Solberg, PE, CEM, LEED AP,
Director of Advanced Design and Simulation,
CH2M HILL
Moderator: Jack Smith,
Consulting-Specifying Engineer and Pure Power,
CFE Media, LLC
Presenters:

5. Scotte Elliott, CEM, Electrical Engineer, NABCEP Certified PV Installation
Professional, Metro CD Engineering LLC
Andrew Solberg, PE, CEM, LEED AP, Director of Advanced Design and
Simulation, CH2M HILL
Critical Power: Integrating
Renewable Power into Buildings
#CSErenewpower

6. Efficient Design

7. Energy Conservation
• Right Sizing
• Conservation
* Improvements at this level will result in
biggest reduction in plant energy use
Energy Efficiency
• Efficient systems
• Understanding and Documentation
• Control and system optimization
• New Technology
• Innovative Design
Renewable
Energy
• Integrate renewable energy only after the most energy
efficient process and building/facility are realized
• Take advantage of regional renewable resources
Energy Strategy
7

8. ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise
Residential Buildings
Minimum energy-efficient requirements for the design, construction, and a plan for operation and maintenance of
buildings and their systems.
Design requirements are divided into sections. The sections most commonly utilized Include:
A. Section 5: Building Envelope
B. Section 6: Heating, Ventilating, and Air Conditioning
C. Section 7: Service Water Heating
D. Section 8: Power
E. Section 9: Lighting
F. Section 10: Other Equipment
G. Normative Appendix D: Climatic Data
H. Informative Appendix G: Performance Rating Method
ASHRAE Standard 189.1: Standard for the Design of High-Performance
Green Buildings Except Low-Rise Residential Buildings
Minimum requirements for the siting, design, construction, and plan for operation of high-performance green buildings.
Minimum criteria to address site sustainability, water use efficiency, energy efficiency, indoor environmental quality (IEQ),
and the building’s impact on the atmosphere, materials, and resources.
Design requirements are divided into sections. The sections most commonly utilized Include:
A. Section 5: Site Sustainability
B. Section 6: Water Use Efficiency
C. Section 7: Energy Efficiency
D. Section 8: Indoor Environmental Quality (IEQ)
E. Section 9: The Building’s Impact on the Atmosphere, Materials, and Resources
F. Section 10: Construction and Plans for Operation
Design Standards – Efficiency First

9. ASHRAE 189.1
Mandatory to provide for the future installation of on-site renewable energy systems and
allocated space and pathways for installation of on-site renewable energy systems and
associated infrastructure.
Prescriptive option for building projects to contain on-site renewable energy systems that
provide the annual energy production equivalent of not less than 6.0 KBtu/ft2 (20 kWh/m2) of
conditioned space.
* Exceptions for buildings with poor solar resource, and for purchase of renewable electricity
complying with Green-e Energy National Standard.
Design Standards – Onsite Renewable Energy
ASHRAE 90.1
On-site renewable energy sources or site-recovered energy shall not be
considered to be purchased energy and shall not be included in the design energy
cost.

10. U.S. Green Building Council LEED - Leadership in Energy and
Environmental Design new construction standards evaluate environmental
performance from a whole-building perspective over a building's lifecycle.
Prerequisites and credits in the LEED Green Building Rating Systems
address 7 topics:
1. Sustainable Sites (SS)
2. Water Efficiency (WE)
3. Energy and Atmosphere (EA)
4. Materials and Resources (MR)
5. Indoor Environmental Quality (IEQ)
6. Innovation in Design (ID)
7. Regional Priority (RP)
* Integrated renewable energy is rewarded both in a reduction of
onsite energy use as well as onsite renewable energy
production.
Other International Green Building Programs:
BREEAM - UK, DGNB – Germany, ESTIDAMA – UAE, CASBEE - Japan
Green Building Programs and Renewable Energy

11. Owner Goals
Economic:
Balance financial objectives on a project lifecycle
basis. Good sustainability practices result in
measurable lifecycle financial savings.
Social:
Address community and stakeholder values
including health and safety of construction workers,
clients/owners, occupants and users of facilities
Environmental:
Reduced impact to and consumption of natural
resources throughout the lifetime of the building
11

12. Renewable Energy
Resources

13. Renewable energy is derived from natural processes that are replenished constantly. In
its various forms, it derives directly from the sun, or from heat generated deep within the
Earth. Included in the definition is electricity and heat generated from solar, wind, ocean,
hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from
renewable resources.
—International Energy Agency (IEA)
Renewable Energy Sources
Solar Wind Geothermal
Biomass
Biofuel
Ocean EnergyHydropower

14. Solar Resource Map

15. Wind Resource Map

16. Geothermal Resource Map

17. Biomass Resource Map

18. A Good Resource is Only Part of the Equation
The economic value of onsite renewable power generation will depend on:
1) Building electrical load (hourly load curve)
2) Renewable energy generation (hourly energy production curve)
3) Utility Rate Structure (flat rate, time of day pricing, demand charges, etc)
4) Incentives (rebates, tax credits, special improvement districts)
Regional power price is the
most important variable an
ROI analysis of PV system.
Building type and solar
resources impact are less
important.

19. Renewable Energy for
Buildings

20. Solar Photovoltaic (PV)
Rooftop
– Roof must support up to an additional 5 pounds/sq ft for a solar
array
– Need to consider structural integrity of roof in existing buildings
– New buildings (solar-ready buildings) must be designed to support
the additional load

21. Solar Photovoltaic (PV)
Ground Mount
– Requires open land adjacent to building
– PV Array electrical connections must be inaccessible, which may
require fencing

22. Solar Photovoltaic (PV)
Carports and Pavilions
– Multipurpose Structures
– Carports with EV Charging Stations for renewable-powered
transportation

23. Solar Photovoltaic (PV)
• Siting
– Orientation as close to south (180 degrees) as
possible for optimal energy production
• +/- 15 degrees of south has minimal impact to
production
• East and West orientations may result in significant
production degradation
– Shade-free location for optimal energy production
• Shade analysis tools (Solar Pathfinder, Solmetric
SunEye) can quantify shade impacts
• Microinverters or DC Optimizers can help mitigate
shade impacts by isolating losses to individual solar
panels rather than the entire array

24. Solar Thermal – Hot Water, Absorption Cooling

25. Proven Energy 2.5 kW
Downwind Horizontal Axis
Swift 1.5 kW
Upwind Horizontal Axis
Windspire 1.2 kW
Vertical Axis
Helix
Vertical Axis
Other manufacturers:
• Bergey
• Evance
• Skystream
• Raum
• XZERES
Small Wind Turbine Types

26. Tower height is the most important factor in obtaining the
best wind resource and achieving economic viability. The
best wind turbine installation will be at the highest spot on
the property and will use a tower that is high enough so
the turbine is out of the turbulent region caused by
buildings and vegetation. This is roughly twice the height
of surrounding buildings and trees.
* American Wind Energy Association
* American Wind Energy Association
Small Wind Considerations

27. Prevailing
Wind
Prevailing
Wind
IV Complete Flagging
Often trees in the general vicinity of the
proposed wind turbine site will reveal the
prevailing wind direction and give and
indication of average wind strength.
II Slight to Moderate Flagging at tree top * American Wind Energy Association
Wind Indicators

28. Figure A
Model of Downtown Reno
Reno Wind Demonstration
Urban Wind Flow Patterns

29. 10 ft Above Grade – Wind Speed
(15 mph at 30 ft )
100 ft Above Grade – Wind Speed
(15 mph at 30 ft)
Wind Shadowing

30. Southeast peninsula has
relatively less Wind
Resource due to its
situation downwind of high
elevation topography
Northwest areas on the
peninsula have relatively
better Wind Resource due to
its situation upwind of high
elevation topography
NW
Prevailing
Wind
Wind Shadowing

31. Wind Frequency Distribution shows the number
of hours per year at a specific wind speed (i.e.
X hrs at 1 mph, Y hrs at 2 mph, etc….)
The Wind Rose shows the
percentage of the year the wind
is out of a certain direction, as
well as the percentage of time at
specific wind speeds. Wind
speed and direction is indicated
by the colored wind barbs
overlaid on the compass rose.
Percentage of time is shown in
concentric circles.
Wind Distribution vs. Average Wind Speed

32. Turbine Power Curve

33. Skystream 3.7 : 2.4 kW rating, 12 ft diameter, 3 Blade Horizontal Axis
Estimated Annual Power Produced per Turbine = 6,922 kWh/yr
Estimated Annual Power Produced for 8 Turbines = 55,380 kWh/yr
Proven 7 : 2.5 kW rating, 11.5 ft diameter, 3 Blade Horizontal Axis
Estimated Annual Power Produced per Turbine = 10,520 kWh/yr *
Estimated Annual Power Produced for 8 Turbines = 84,160 kWh/yr *
* Power curve has unrealistic power production at low wind speeds
Raum 3.5 : 3.5 kW rating, 13 ft diameter, 5 Blade Horizontal Axis
Estimated Annual Power Produced per Turbine = 9,470 kWh/yr
Estimated Annual Power Produced for 8 Turbines = 75,760 kWh/yr
Name Skystream Proven Raum
Rating (kW) 2.4 2.5 3.5
Tower 45 ft 36 ft 47 ft
Count 8 8 8
Turbine, Installation, & Maintenance $237,171 $331,410 $249,410
Tax $9,866 $13,787 $10,375
Simple Payback Period (years) 13.7 12.6 10.6
Internal Rate of return (20 year) 5.7% 6.7% 8.9%
Return on Investment (20 years) 77.0% 92.5% 130.3%
Expenses
Return Rate
Turbine Information
Example Return on Investment
Varying turbine manufacturers same wind resource

34. Renewable Energy Integration
Requirements

35. NFPA 70: National Electrical Code (NEC)
Articles
• Article 705: Interconnected Electric Power Production Sources
• Article 690: Solar photovoltaic (PV) Systems
• Article 694: Small Wind Electric Systems
Some key provisions to keep in mind
• Labeling
– At the point of interconnection: “Warning: Dual Power Supplies –
Second Source is Photovoltaic System”
– At the panelboard: “Warning: Electric Shock Hazard. Both Line and
Load Sides May Be Energized in the Open Position.”

36. NFPA 70: National Electrical Code (NEC)
Some key provisions to keep in mind
• 20% Backfeed Rule
– Generation backfeed cannot exceed 20% of the bus rated ampacity
of a panelboard
– For example, for a 200 A panelboard, 40 A of generation can be
backfed
– Backfeed amount can be increased by reducing the main breaker
size
• Arc Fault Circuit Protection
– Required for PV systems 80+ Vdc with conductors installed on or in a
building
• Grounding and Bonding
– Generation systems treated as separately derived systems
– Equipment grounding for safety in the event of a line fault

37. NFPA 70: National Electrical Code (NEC)
2014 NEC
• A significant number of Solar related code updates are
forthcoming
– Provisions for systems up to 1000 Vdc for locations other than one
and two-family dwellings
– Rapid Shutdown of PV Systems on Buildings, which covers
conductors more than 10 ft from the array or 5 ft within the building
– Chapter VIII (Battery Systems) Reinstated

38. Building Department / AHJ
The Building Department / Authority Having Jurisdiction
dictates the requirements for integrating renewable power
into buildings
– In general, national codes such at those from NFPA and the
International Code Council are adopted
– It is important to find out which code versions are in effect before
designing a project
– There may also be local/regional requirements
– Permitting and Inspection requirements vary widely

39. Fire Protection Requirements
• Fire protection concerns have become a major issue in
many jurisdictions
• While renewable generation systems are considered safe
when designed an installed in a code-compliant manner, if
a building is on fire they are potential hazards to firefighters
– When solar panels are exposed to light the PV circuits remain
energized on the DC conductors even after AC power has been
disconnected
– Roofs covered by solar panels may impede firefighter’s ability to
ventilate roofs during a fire
• The National Association of State Fire Marshals and SEIA
have developed recommendations for fire safety and solar

40. Utility Requirements
Most utilities have standard requirements and procedures for
interconnecting renewable generation sources to the
electrical grid
– For small systems (10 kW and under) system studies are typically
not required as long as equipment is listed and complies with
applicable safety standards
– For mid-size systems (up to 1 MW) there is typically a streamlined
screening process
– For large systems (1 MW+) detailed studies are usually required
• The system owner is responsible for costs incurred by the utility for
system upgrades that may be needed (larger transformers, larger
conductors, protective equipment, metering and monitoring, etc.)
– Some utilities require a Utility-Accessible External Disconnect
Switch

41. Utility Requirements
Net Metering
– The most common and often the most favorable way to
interconnect
– Typically available for systems that generate less energy on an
annual basis than what is used by the facility
– The generated energy offsets the energy that would otherwise be
purchased from the utility
– At times when generation is greater than the building loads, the
excess energy is exported to the grid and the utility meter “spins”
backwards providing a bankable credit for later use
– Most states have laws requiring investor-owned utilities to offer net-
metering to their customers
– Public Power utilities (i.e. Municipal Utilities, Rural Electric Co-ops)
may not be required to offer Net Metering but many still do

42. Utility Requirements
Net Metering
– Sites that produce more energy than what they consume may not
be eligible for net metering
• Other options include interconnecting with the Utility as a PURPA
Qualifying Facility and selling the excess energy to the Utility at their
avoided cost of generation; or interconnecting with the Regional
Transmission Organization as a wholesale generator and selling all of
the system output on the wholesale market
• Neither of these options are as desirable as net metering from
implementation or financial perspectives

43. Project Examples

44. Alvarado Water
Treatment Plant, San
Diego, CA; 1 MW atop
water reservoirs; PPA
with Sun Edison
West Basin Municipal
Water District, El
Segunda, CA
North Hudson
Sewerage
Authority,
Hoboken, NJ
Photos courtesy of Kurt Lyell, CH2M HILL AUS
PV Integration at Water Treatment Facilities

45. MASDAR 10 MW PV Abu Dhabi, UAE
• 5 MW thin film, 5 MW crystalline
• Differences in panel efficiency are
evident in the area required for each
5 MW array
Enviromena llcEnviromena llc
Photo by Enviromena LLC

46. Slide courtesy of David Perron, CH2M HILL
Wind Turbine Integration at Landfill

47. Melink Inc. Net Zero Energy Corporate
Headquarters, Milford, Ohio
• 20,000-sq-ft building
constructed in 2006
• Energy Use Intensity
(EUI) of 18.8 kBtu/sq ft/yr
• RE systems include
Geothermal, PV (rooftop,
ground mount, carport),
Wind Turbine, and
Biomass (wood pellet
stoves for space heating)

48. Star Peak Energy Center
Geothermal + Solar + Wind + Energy Storage

49. High-Efficiency Data Center

50. Putting Waste Heat to Good Use

51. Energy Balance

52. Ohio State University Stone Laboratory Biological
Research Station, Gibraltar Island, Lake Erie
• Island predominantly
covered in trees
• Extensive field surveys to
evaluate suitable locations
for Solar (shade analysis,
building conditions)
• Solar used to meet
environmental goals,
reduce energy costs, and
as an education tool for
7,000+ students,
researchers and visitors
annually

53. Ohio State University Stone Laboratory Biological
Research Station, Gibraltar Island, Lake Erie
Solar Thermal on Dining Hall

54. Ohio State University Stone Laboratory Biological
Research Station, Gibraltar Island, Lake Erie
• Facility Operational
Spring – Fall (closed
during Winter)
• Solar Access during the
operating months
sufficient to provide
nearly all the hot water
needed at the dining hall
(primarily for dish
washing)

55. Ohio State University Stone Laboratory Biological
Research Station, Gibraltar Island, Lake Erie
Solar Pavilion
• Installed over an
abandoned water filtration
sand pit
• Previously the site was
unusable
• Now the site is utilized for
education and as a
gathering place for
students and visitors

56. Ohio State University Stone Laboratory Biological
Research Station, Gibraltar Island, Lake Erie

57. Tools and Reference
Information

58. 1.DOE Office of Energy Efficiency and Renewable Energy
2.California Power Grid
3.NREL Energy Analysis Models and Tools
4.NREL Renewable Resources Maps and Data
http://www.nrel.gov/renewable_resources
http://www.nrel.gov/rredc/wind_resource.html
http://www.nrel.gov/rredc/solar_resource.html
http://www.nrel.gov/rredc/geothermal_resource.html
References

59. 5. Star Peak Energy Project
6. Update to the 2014 NEC – Changes for PV
7. Database of State Incentives for Renewables and Efficiency (DSIRE)
8. EMerge Alliance, Standards for DC Power Distribution
9. Bridging the Gap: Fire Safety and Green Buildings Guide
10.Fire Safety and Solar
11.Economics of Solar Electric Systems: Payback and other Financial
Tests
12.Utility External Disconnect Switch - Practical, Legal, and Technical
Reasons to Eliminate the Requirement
References

60. 13.Utility-Interconnected Photovoltaic Systems: Evaluating the
Rationale for the Utility-Accessible External Disconnect Switch
14.PVWatts Calculator for Energy Production and Cost Savings of PV
Systems
15.Interstate Renewable Energy Council (IREC)
16.American Solar Energy Society (ASES)
References

61. Scotte Elliott, CEM, Electrical Engineer, NABCEP
Certified PV Installation Professional,
Metro CD Engineering LLC
Andrew Solberg, PE, CEM, LEED AP,
Director of Advanced Design and Simulation,
CH2M HILL
Moderator: Jack Smith,
Consulting-Specifying Engineer and Pure Power,
CFE Media, LLC
Presenters:

62. Thanks to Today’s Webcast Sponsor:

63. Critical Power: Integrating
Renewable Power into Buildings
Sponsored by:
#CSErenewpower