Critical Power: Integrating Renewable Power into Buildings

Critical Power: Integrating Renewable Power into Buildings

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#CSErenewpower

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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.

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:

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

Efficient Design

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

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ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential BuildingsMinimum 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 EnvelopeB. Section 6: Heating, Ventilating, and Air ConditioningC. Section 7: Service Water HeatingD. Section 8: PowerE. Section 9: LightingF. Section 10: Other EquipmentG. Normative Appendix D: Climatic DataH. Informative Appendix G: Performance Rating Method

ASHRAE Standard 189.1: Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential BuildingsMinimum 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 SustainabilityB. Section 6: Water Use EfficiencyC. Section 7: Energy EfficiencyD. Section 8: Indoor Environmental Quality (IEQ)E. Section 9: The Building’s Impact on the Atmosphere, Materials, and ResourcesF. Section 10: Construction and Plans for Operation

Design Standards – Efficiency First

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 90.1On-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.

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

Owner GoalsEconomic: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

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Renewable Energy Resources

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

BiofuelOcean EnergyHydropower

Solar Resource Map

Wind Resource Map

Geothermal Resource Map

Biomass Resource Map

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.

Renewable Energy for Buildings

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

Solar Photovoltaic (PV)Ground Mount

– Requires open land adjacent to building– PV Array electrical connections must be inaccessible, which may

require fencing

Solar Photovoltaic (PV)Carports and Pavilions

– Multipurpose Structures– Carports with EV Charging Stations for renewable-powered

transportation

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

Solar Thermal – Hot Water, Absorption Cooling

Proven Energy 2.5 kWDownwind Horizontal Axis

Swift 1.5 kWUpwind Horizontal Axis

Windspire 1.2 kWVertical Axis

HelixVertical Axis

Other manufacturers:• Bergey • Evance• Skystream• Raum• XZERES

Small Wind Turbine Types

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

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

Figure A

Model of Downtown Reno

Reno Wind Demonstration

Urban Wind Flow Patterns

10 ft Above Grade – Wind Speed(15 mph at 30 ft )

100 ft Above Grade – Wind Speed(15 mph at 30 ft)

Wind Shadowing

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

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

Turbine Power Curve

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/yrEstimated Annual Power Produced for 8 Turbines = 75,760 kWh/yr

Name Skystream Proven RaumRating (kW) 2.4 2.5 3.5Tower 45 ft 36 ft 47 ftCount 8 8 8Turbine, Installation, & Maintenance $237,171 $331,410 $249,410Tax $9,866 $13,787 $10,375Simple Payback Period (years) 13.7 12.6 10.6Internal 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 InvestmentVarying turbine manufacturers same wind resource

Renewable Energy Integration Requirements

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.”

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

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

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

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

Utility RequirementsMost 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

Utility RequirementsNet 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

Utility RequirementsNet 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

Project Examples

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

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

Slide courtesy of David Perron, CH2M HILL

Wind Turbine Integration at Landfill

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)

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

High-Efficiency Data Center

Putting Waste Heat to Good Use

Energy Balance

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

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

Solar Thermal on Dining Hall

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)

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

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

Tools and Reference Information

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

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 T

ests

12.Utility External Disconnect Switch - Practical, Legal, and Technical R

easons to Eliminate the Requirement

References

13.Utility-Interconnected Photovoltaic Systems: Evaluating the Rational

e 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

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:

Thanks to Today’s Webcast Sponsor:

Critical Power: Integrating Renewable Power into Buildings

Sponsored by:

#CSErenewpower