Schools-2009 EAc2: On-Site Renewable Energy

  • NC Schools EAc2 Type3 Onsite Renewables Diagram
  • Lower cost strategies come first

    Capturing useful energy from natural energy flows like sunshine, wind, moving water is a great concept. The technologies to capture this energy aren’t cheap, however, nor do they work equally well in all locations. Typically, it’s hard to generate a significant fraction of total electricity we use onsite.

    Before investing a lot of time and energy into this credit, focus on energy efficiency and passive energy collection such as daylighting, natural ventilation, passive solar heating before investing in renewable energy systems. This work will probably pay off faster than renewable energy, and if you do invest in renewable energy, you’ll have a lighter load for it to carry.

    What types of systems count

    All electricity generated and heat used on site is counted towards the credit. Electricity and heat generated onsite but sold to the grid is not eligible. See table below

    Type of system and eligibility for EAc2 points

    LEED allows you to take credit for technologies that generate electricity from sun, wind, water flows, and waste biomass. It also allows certain thermal technologies, such as solar hot water, concentrating solar collectors, biomass, and geothermal (extraction of heat from within the Earth, not ground-source heat pumps).

    Of these, solar hot water systems are typically the most cost-effective. Small wind turbines have been found to not make sense on or near most buildings in urban areas because they need strong, steady winds, while the air around buildings is very turbulent. (See Resources for more.)

    PV panels on a buildingThese photovoltaic panels at Fossil Ridge School in Fort Collins, Colorado provide onsite renewable energy as well as shading.Depending on the features and location of your site and the expertise available, the technologies you can use are:

    • Solar photovoltaics (PV)
    • Wind turbines
    • Small hydroelectric generation
    • Certain types of biomass—untreated wood waste, agricultural waste and animal waste 
    • Landfill gas captured as fuel
    • Fuel cells if hydrogen is produced onsite without using fossil fuels
    • Solar-concentrated power for steam turbines
    • Solar-thermal hot water
    • Activity-generated electricity

    Follow the money

    The federal government and many states have a variety of incentive programs to encourage the use of renewable energy. These incentives can offset up to half of the costs in making systems cost-effective. Many states also have laws that provide for net-metering so that you can feed the excess electricity into the grid and get paid by the utility for that electricity. Some utilities will offer you above-market rates for feeding green electricity into their grid, but if you do that you’re selling the power’s green attributes as RECs, so you’re not allowed to use that energy to earn this credit.

    Start by analyzing the site’s resources

    The natural resources harvested by renewable energy technologies are site- and climate-specific. You can use both online databases and direct investigation of the site to figure out which technologies might be feasible. There are many factors to consider, so it’s wise to bring in an experienced consultant and/or technology vendors as early as possible in the design process to help with feasibility studies.

    Double dip with energy credits

    You can double-dip with onsite renewable energy. In addition to earning this credit, renewable energy helps to offset total annual building energy use, contributing to EAp2, and EAc1, if using Option 1, Whole Building Optimization Energy Modeling.

  • FAQs for EAc2

    We have a PV array installed on our campus, under the same ownership, but not on the building or within the LEED project boundary. Can we count that toward EAc2?

    Yes. Provide a letter from the owner allocating some or all of the solar power to this project. Make sure that the solar power allocated to the project is not already allocated to another LEED project, and won't be in the future. Also, be sure that the owner retains ownership of the power and the RECs being generated.

    Because of how our onsite PV system was financed through the utility, the project is selling the RECs associated with its solar energy production, even though we own the PV array and its power. Is there any way we can earn EAc2?

    Yes, as discussed in the LEED Reference Guide and reinforced by LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #10161 made on 04/01/2012, you can buy RECs for your project to make up for RECs for 100% of what you want to claim for EAc2. You may not apply these REC purchases toward EAc6: Green Power.

    Can I pursue this credit if I am using one of the prescriptive compliance paths for EAp2/EAc1?

    Yes. You can use the CBECSThe Commercial Buildings Energy Consumption Survey (CBECS) is a national sample survey that collects information on the stock of U.S. commercial buildings, their energy-related building characteristics, and their energy consumption and expenditures. Commercial buildings include all buildings in which at least half of the floorspace is used for a purpose that is not residential, industrial, or agricultural, so they include building types that might not traditionally be considered "commercial," such as schools, correctional institutions, and buildings used for religious worship. CBECS data is used in LEED energy credits. data as explained in the LEED Reference Guide or use the actual energy data from the facility.

    Can I really double-count onsite renewable energy in both EAc2 and EAc1?

    Yes. You could theoretically offset an inefficient building with a lot of renewables. As a matter of best practice, and of cost-effectiveness, you should start with efficiency measures, however.

    Our PV system is being installed after the building is occupied. Is that okay?

    Yes, but don't push the timeframe too farFloor-area ratio is the density of nonresidential land use, exclusive of parking, measured as the total nonresidential building floor area divided by the total buildable land area available for nonresidential structures. For example, on a site with 10,000 square feet (930 square meters) of buildable land area, an FAR of 1.0 would be 10,000 square feet (930 square meters) of building floor area. On the same site, an FAR of 1.5 would be 15,000 square feet (1395 square meters), an FAR of 2.0 would be 20,000 square feet (1860 square meters), and an FAR of 0.5 would be 5,000 square feet (465 square meters).. The credit form asks the owner to verify its installation. It would be a good idea to provide a purchase order or contract and installation schedule as documentation.

    Our project will have a PV system onsite, but it will be installed, operated, and owned by a separate entity that is paying for the system through a premium price per kWh paid by the utility, per state regulations. Is there any way to count this toward the project, in EAc2 or EAc1?

    Probably not. LEEDuser's experts have not seen this attempted, even though it comes up from time to time. You would need to make your case via a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide or LEED Interpretation. The only LEED benefit you are likely to get here is through SSc7.1—shading your hardscapeThe inanimate elements of the building landscaping. It includes pavement, roadways, stonewalls, wood and synthetic decking, concrete paths and sidewalks, and concrete, brick, and tile patios. with PV panels.

    A biofuel-based cogenerator is being used to produce both electricity and heat (CHP). Can I consider all the energy produced, or just the electricity?

    Yes, all the energy would qualify. Check the CHP guidance in the district energy systems modeling protocol.

    Can a backup generator qualify, if it runs on biofuels?

    If it is only used for backup—no. It might be able to contribute if it is run regularly run, for peak shaving, for example.

Legend

  • Best Practices
  • Gotcha
  • Action Steps
  • Cost Tip

Pre-Design

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  • Analyze the site to find out what renewable energy resources it offers. See Resources for help on this. 


  • Identify relevant technology options for the available resources. 


  • Incentives of various kinds often mean the difference between pursuing this credit and not. Identify tax rebates, subsidies, cost-sharing, long-term leasing, net metering opportunities, and other incentives available from local, regional and national authorities as well as utilities. See Resources for help on this. 


  • Consider the location, available space, structural and maintenance requirements of possible renewable technologies, bringing your focus to the most applicable. 


  • Stillwell train stationThe Stillwell Avenue Train Station of the New York Metro Transit Authority used RWE/Schott PV glazing for the 76,000 square-foot curved roof; these custom ASI THRU panels provide 20 to 25% light transmission and are expected to produce 250,000 kWh per year. Photo – Schott North AmericaBuilding-integrated installations can work even if space is tight on the site. Consider wall-mounted PV panels, vertical terrace-mounted solar thermal, or PV integrated into the glazing, for example. These technologies often sacrifice some efficiency for convenient placement. 


  • Start by reducing the building’s energy load. The smaller the load, the less renewable energy you have to generate to meet the credit thresholds, which saves money and might expand the options you can use. For example, a 100-MMBtu/year building needs to produce 1 MMBtu/yr to reach the 1% credit threshold, while an 80-MMBtu/year building needs only 0.8 MMBtu/year. 


  • Conduct a preliminary cost-benefit analysis to determine the first cost and life cycle payback. Most teams use LEED point thresholds as a way to frame the analysis. For example, what is the cost and the payback of meeting the 1% threshold?


  • Contact an experienced renewable energy provider who can provide generation capacity for solar, wind or hydro systems installed onsite in a pre-feasibility study and identify potential obstacles. It is easiest to locate the providers through the trade organizations or manufacturers. For example, a wind turbine manufacturer should be able to provide names of qualified vendors who can visit the site and provide a written feasibility report based on the site specific wind speed, hourly generation capacity, and major obstacles like neighboring buildings. If a systems provider is not available, get names of electrical engineering firms who can do the analysis. Look up NREL and trade organizations to obtain the directory listed in Resources.  


  • Cost is a huge issue for renewable energy installations. In initial assessments from the renewable energy provider, look for generation capacity estimates and a cost-benefit analysis for long-term operations. Some providers may offer an initial assessment at low or no cost. 


  • If your project is located in the U.S., consult wind and solar maps developed by the Department of Energy (see Resources). 


  • The owner and team establish goals for onsite renewable energy based on the initial assessment. Include goals in the Owner’s Project Requirements developed during early design for Fundamental (EAp1) and Enhanced (EAc3) commissioning.


  • Find out if net-metering is available in your area. Net metering allows you to feed power that your system generates into the electrical grid and get paid for that power. This allows you to use the grid as a battery, which saves the cost and hassle of installing and maintaining a battery system. (Without batteries, however, you won’t have back-up power to use in a power failure or idle periods). Typical PV, wind and other on site systems generate DC current which has to be stored for future use and converted to AC current for onsite application. This is one of the biggest barriers to generating onsite electricity as battery storage is expensive, inefficient and hazardous. Now, many utilities allow excess electricity to be supplied into the grid, thus eliminating the need of an onsite battery. Confirm whether if your project site is connected to a utility or grid-tied where net metering is available. 


  • Onsite generation can reduce peak utility loads, reducing utility costs and need for electricity generation capacity. Utilities often encourage onsite generation and support it with subsidies and incentives.


  • Account for inflation and increases in utility costs over the next few years to obtain a realistic cost-benefit analysis, as ROI and payback are highly dependent on utility charges for conventional energy. Look up the costs of electricity in your state and projected price for the calculations. Also obtain the actual inflation rate current at the time of the ROI analysis. Retail residential electricity prices increased an estimated 8% during the first quarter of 2009 compared to the first quarter of 2008 according to a June 2009 report by the U.S. Energy Information Administration. (See Resources.) 


  • Look for partnerships with local utilities and other groups who can purchase excess electricity. Some utilities are looking to encourage more existing facilities to generate electricity from renewable sources to increase their renewable portfolio. Also, they may be short on space to install their own system or need an experimental site for net metering. 


  • Allocate space on or around the building for solar arrays or wind turbines, and include this early in site plans and budget considerations. 


  • Roof mounted or on-site generation technology is considered a mechanical system so the area it takes up is excluded from calculations for the heat island reduction credits, SSc7.1 and SSc7.2.


  • Consider standalone systems that are easier to install. Electrical vehicle charging stations can be easily hooked up to PV panels, for example. Standalone solar-powered site lighting (in which a small PV panel is integrated into each fixture) can be solar powered throughout the year and reduces the infrastructure requirements of wiring and maintenance. These systems are not likely to add up to enough energy to earn the credit, though.


  • It tends to be easier to earn this credit on low-rise buildings with relatively large roof areas, because they often have large unobstructed areas for installing solar panels.


  • Onsite electricity generation is one of the most visible ways to demonstrate a building owner’s commitment to green building and a conscious attempt to reduce the building’s carbon footprint. A visible solar panel or wind turbine on the building rooftop is a strong statement in public and occupant relations.


  • When selecting a specific technology, consider the long-term operation and maintenance requirements. Some PV systems come with a 20-year warranty while wind turbines often require annual oiling and checkups. Solar thermal may require glass replacement in case of some accident.


  • Geothermal energy, which uses heat generated deep within the Earth, is considered renewable by LEED. But technologies that use the surface of the Earth as a heat source and sink for heating and cooling with heat pumps, are also commonly called “geothermal” or “geo-exchange,” and these don’t count.


  • You can double-dip with onsite renewable energy—in addition to this credit, it helps to offset total annual building energy use, contributing to EAp2, and EAc1, if using Option 1, Whole Building Optimization Energy Modeling.


  • Excess energy beyond the building energy demand can be sold using net-metering, but only at market electricity rate. The building owner cannot charge a premium for the renewable energy. If the excess energy is sold at a price higher than market rate because it carries a green premium, it cannot be counted towards this credit, because you’re selling the environmental attributes of the power as RECs for someone else to claim. Although a bit convoluted, you can claim that electricity by purchasing RECs from a Green-e certified source (similarly to EAc6: Green Power). These RECs can be generated by any energy source, such as solar, wind, or biomass, and doesn’t have to be same as the LEED project fuel source.


  • Fuel cells are often touted for renewable energy systems, but they consume hydrogen as fuel, usually from natural gas. They are only considered renewable if their hydrogen is generated by renewable sources.  


  • Energy from solid-waste incineration, also known as “waste-to-energy,” does not contribute to this credit. 


  • Cogeneration with natural gas as a fuel is not renewable energy.


  • Transportation energy use is not a factor in this credit. For example, biofuels generated onsite from waste cooking oil is not eligible if used for vehicles and not buildings. 


  • In the case of generating onsite electricity and waste heat with a renewable source, e.g. biomass generator, all of the generated energy may be considered as on-site renewable energy. Use the latest LEED Combined Heat and Power guidance to determine credit.


  • If a PV vendor purchases and installs system on the project site, then the project does not have ‘ownership’ of the renewable system. To obtain LEED credit, the project must get into a ‘power purchase agreement’ where the building buys the electricity from the PV vendor at or lower than market price. The electricity has to flow into the building. The PV vendor may not retain the Renewable Energy Credits (RECs) of the system. If they are retaining the RECs then the LEED project can’t claim credit under EAc2. This is done to avoid any double counting of renewable energy by one plant.


  • If a system is owned and operated off-site by the project owner with the project receiving the energy generated, then the project may be able to count that renewable energy towards LEED EAc2.


  • Energy produced by wood pellet stoves from untreated wood waste would qualify as renewable energy.


  • Wood harvested from a project site is considered ineligible as a fuel source for non-renewable energy and doesn’t count under EAc2.

Schematic Design

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  • Consider building design and optimized energy performance before finalizing renewable energy calculations. Use estimates of the project’s annual energy use and costs to help determine what percentage of onsite renewable energy will be required to meet the credit threshold. 


  • The key factors in implementing renewable energy for onsite generation include:

    • envelope optimization and efficiency;
    • studying feasibility; 
    • selection of appropriate technology;
    • optimizing the mechanical and onsite systems; 
    • integrated design development;
    • space and resource allocation;
    • budget allocation;
    • Identifying available incentives.

  • Consider space requirements and access. For PV, look for shadows, evaluate for optimal solar radiation and the angle of incidence during peak generating season. If possible, consider solar tracking system that follows the sun during the day and throughout the year. This would allow more electricity generated from the same area, though with more infrastructure cost. (See Resources.) 


  • For possible wind generation, consider any obstruction like nearby buildings or future planned developments. 


  • Many PV panels are very sensitive to shading, so shade on even a small part of the panel reduces its output significantly. Discuss the structural requirements with a qualified vendor and structural engineer. Some types of PV, such as thin-film, are less sensitive to shading, but are also less efficient overall. 


  • Initiate the process for financial support and subsidies. Some programs require applications early in the design period and designate only approved vendors. 


  • Compare the various available renewable energy technologies for cost, capacity, and project goals. 


  • Consider the onsite environmental impact of the technologies. Will wind turbines affect migratory birds? Will solar panels cause unwanted glare?


  • Determine an annual energy-cost estimate using your energy model, if developing one for EAc1: Optimize Energy Performance, or by basing it on the estimates of average building energy usage developed by CBECS—see the LEED Reference Guide.


  • Conventional developer-driven projects do not allow room for long payback. It is helpful to run a long-term cost-benefit analysis to estimate the savings after the first ten years of the installation, presenting onsite renewable system as a cost-effective investment to the future occupants. Spec projects can still pursue this credit and install renewable energy with the promise of lower utility bills and future energy freedom to the occupants of the building. The cost can be transferred to the occupant either in the form of higher rent or fees, or an escrow account where the occupant pays monthly dues for the cost of installation over a period of time. It’s also possible to purchase the system on loan and transfer the loan to the future owners. Work creatively to reduce the financial impact and allow as much energy generation as possible. 


  • Current technologies for generating small-scale renewable energy systems have two major barriers: low efficiency and high installation expense. The expenses consist of the actual generating technology (photovoltaic panels, wind turbine, or a hydro plant) and the “balance of system” components: inverter, battery or grid-interface, and wiring. System components and wiring is often a major cost element. 

Design Development

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  • The renewable energy designer provides layout, sizing, electrical load requirements and other design parameters to the design team. Integrate these into the overall project design and check for impacts on structural design and mechanical system sizing. 


  • Solar thermal systemA solar thermal installation provides hot water at the Snowmass Recreation Center in Snowmass, Colorado.Backup power may be needed. For example, solar-thermal hot water may be combined with a hot water tank and a boiler. This will require integrated controls. A building management system can track which fuel is used when to optimize efficiency. 


  • If you are considering building-integrated systems that have PV integrated into windows, skylights, canopies, parking shades, or roof tiles, have the manufacturer and contractor do a constructability review. Some glazing manufacturers provide the technical input and work with the team to develop a custom product like BIPV glass laminate panels. (See Resources for more on BIPV.)


  • Include all renewable energy systems within the scope of commissioning when writing the RFP for a commissioning agent. 


  • Submeter renewable energy systems so that energy use is recorded and verified. Compare it with the rated capacity of the system. Include this within the scope of EAc5: Measurement and Verification


  • Be sure to design for adequate access to the systems, for maintenance and inspection after the project is completed.

Construction Documents

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  • Include the renewable energy systems in the specifications and construction documents. 


  • Make sure elements that are needed to attach the systems, such as anchors or flanges, are clearly called out in the appropriate drawings and specs because workers who aren’t installing the actual systems might not have experience with them. 

Construction

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  • Discuss the system with the construction team during bidding, and address any potential conflicts in construction issues and scheduling. 


  • Coordinate the project schedule to account for installation and connection requirements of the renewable energy systems. Often, when unfamiliar with the system, the construction team does not account for the additional time and interaction required with steel, electrical, mechanical and plumbing subcontractors. For example, the vendor, electrician, window contractor, and façade consultant all have to coordinate on the installation of glass-laminated PV. 


  • Schedule the installation to be completed before final commissioning, both to allow ample time for commissioning and for any changes or adjustments. 


  • Make final calculations of the estimated building energy loads. Confirm that renewable energy generation capacity is 1% of building energy, at minimum for the LEED credit, or that the project’s goals are met.


  • Double-check that you will earn any incentives or rebates you are counting on.

Operations & Maintenance

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  • Obtain warranty information and a maintenance contract with the system installer for future visits. Some of the technologies such as hydroelectric and wind include moving parts that will need regular maintenance. Solar panels need to be cleaned of bird droppings and snow to operate at highest possible efficiencies. Incorporate these measures into the facility maintenance manual.

  • USGBC

    Excerpted from LEED 2009 for Schools New Construction and Major Renovations

    EA Credit 2: On-site renewable energy

    1–7 Points

    Intent

    To encourage and recognize increasing levels of on-site renewable energy self-supply to reduce environmental and economic impacts associated with fossil fuel energy use.

    Requirements

    Use on-site renewable energy systems to offset building energy costs. Calculate project performance by expressing the energy produced by the renewable systems as a percentage of the building’s annual energy cost and use the table below to determine the number of points achieved.

    Use the building annual energy cost calculated in EA Credit 1: Optimize Energy Performance or the U.S. Department of Energy’s Commercial Buildings Energy Consumption Survey database to determine the estimated electricity use.

    The minimum renewable energy percentage for each point threshold is as follows:

    Percentage Renewable Energy Points
    1% 1
    3% 2
    5% 3
    7% 4
    9% 5
    11% 6
    13% 7



    Pilot ACPs Available

    The following pilot alternative compliance path is available for this credit. See the pilot credit library for more information.

    EApc95: Alternative Energy Performance Metric ACP

    Potential Technologies & Strategies

    Assess the project for nonpolluting and renewable energy potential, including solar, wind, geothermal, low-impact hydro, biomass and bio-gas strategies. When applying these strategies, take advantage of net metering with the local utility.

    Schools should contact their local utilities and state energy offices to identify potential financial incentives that can pay for some or all of the renewable energy system. In addition, some companies offer design, construction, maintenance and financing of renewable energy systems if the school buys all the energy output of the system for a set fee and time period.

Publications

Energy Information Administration Electricity Consumption and Price Data

Charts showing total U.S. energy consumption and U.S. residential electricity prices.


National Renewable Energy Laboratory (NREL)—Building Integrated PV Research (BIPV)

Compilation of research and technological breakthroughs in BIPV.


U.S. Department of Energy, Energy Efficiency and Renewable Energy, Renewable Energy Maps and Data

The maps and data section of DOE’s EERE website provides information on regional distribution of 
renewable energy sources and technologies in the United States. 


Energy Information Administration Electricity Consumption and Price Data

Charts showing total U.S. energy consumption and U.S. residential electricity prices.

Web Tools

U.S. Department of Energy—Energy Efficiency and Renewable Energy Maps & Data

Maps and data showing statistics, trends, and the availability of renewable energy resources throughout the United States.


North American Board of Certified Energy Practitioners (NABCEP) Installer Locator

Interactive map to help consumers find certified solar PV and solar thermal installers.


PV Watts Performance Calculator for Grid-Connected PV Systems

Helps non-experts to quickly obtain performance estimates for grid-connected PV systems.


U.S. Department of Energy—Energy Savers: The Economics of a Small Solar Electric System

Covers cost considerations for PV systems.


PV Watts Solar Calculator

Links to multiple educational tools for examining cost and performance of various energy-efficient and solar energy technologies and products.


Wisconsin Focus on Energy—Renewable Energy Site Assessment

Provides guidance for determining renewable energy potential of residential and non-residential sites.


U.S. Department of Energy—Green Power Network: Net Metering Policies

Resources on net metering laws, policies, and guidelines.


U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy

This website is a comprehensive resource for U.S. Department of Energy information on energy efficiency and renewable energy and provides access to energy links and downloadable documents. 


U.S. Department of Energy—Energy Savers: The Economics of a Small Solar Electric System

Covers cost considerations for PV systems.


National Renewable Energy Lab Tools

This comprehensive website provides energy data and tools that can assist in learning more about our main renewable energy technologies and their uses. Evaluate solar and wind potential with the listed tools under the Technology Analysis Models and Tools.


RETscreen

RETScreen 4 is an Excel-based clean energy project analysis software tool that helps decision makers quickly and inexpensively determine the technical and financial viability of potential renewable energy, energy efficiency and cogenerationThe simultaneous production of electric and thermal energy in on-site, distributed energy systems; typically, waste heat from the electricity generation process is recovered and used to heat, cool, or dehumidify building space. Neither generation of electricity without use of the byproduct heat, nor waste-heat recovery from processes other than electricity generation is included in the definition of cogeneration. projects.


Transol

Transol is a tool available for a fee for design, calculation and optimization of solar thermal water systems.


U.S. Department of Energy—Other Renewable Energy Tools

A collection of renewable energy building analysis tools.

Technical Guides

California Energy Commission—A Guide to Photovoltaic (PV) System Design and Installation

Detailed description of design considerations and installation instructions for PV systems.


Building-Integrated Photovoltaic (BIPV) Designs for Commercial and Institutional Structures: A Sourcebook for Architects

Illustrates 16 case studies across U.S. that incorporate BIPV and prepares readers with common BIPV terminology, pitfalls, and design basics.


California Solar Center—Solar Power Purchase Agreement Guide

Free article explaining how  third-party providers can install and maintain solar electrical systems on private property.


ENERGY Guide

This website provides information on different power types, including green power, as well as general information on energy efficiency and tools for selecting power providers based on economic, environmental, and other criteria.

Organizations

Solar Energy International

Links to publications, workshops, courses, outreach programs and other renewable energy education opportunities.


Low Impact Hydropower Institute

A non-profit organization that supports a voluntary certification program designed to help identify and reward hydropower dams that are minimizing their environmental impacts.


National Center for Photovoltaics

NCPV provides clearinghouse information on all aspects of photovoltaic systems. 


Database of State Incentives for Renewables and Efficiency (DSIRE)

Comprehensive listing of federal, state, local, and utility incentives that subsidize renewable energy use and energy efficiency.


American Wind Energy Association

A national trade association that provides resources and information about the domestic and international wind industry.

Articles

Low Emissions, Quick Energy Payback for Thin-Film PV

A BuildingGreen.com article about a 2008 study showing that all current photovoltaic technologies offer at least an 89% reduction of air emissions compared with conventional electricity while also offering an energy-payback time of less than three years.

Photovoltaic (PV) Calculator

Use of photovoltaic (PV) electricity is the most common way to earn LEED points. This spreadsheet helps you analyze how much PV you need to earn LEED points, what it will cost, and how much it will reduce your project's carbon emissions.

Renewable Energy Feasibility

Careful analysis of renewable energy feasibility is required for most projects. The example shown here was for a 20-kW system on a commercial building.

LEED Online Forms: Schools-2009 EA

Sample LEED Online forms for all rating systems and versions are available on the USGBC website.

Design Submittal

PencilDocumentation for this credit can be part of a Design Phase submittal.

Photovoltaic Project Work

Sample documents showing PV infrastructure and calculations with an onsite PV project.

24 Comments

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Michael Trzcinski Project Engineer Hesnor Engineering Associates, PLLC
Aug 07 2012
Guest
133 Thumbs Up

Annual Energy Cost Escalation

If a project includes a 3rd party PV system, and the electric rate increases each year after the 1st year (under the PPA), what rate must we use in calculating the dollar savings?

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Marcus Sheffer LEED Fellow, 7group Aug 07 2012 LEEDuser Expert 69427 Thumbs Up

This calculation for LEED is typically based on the virtual rate from the energy model if you are pursuing Option 1 for EAp2/EAc1. This is based on the rate used without any escalation. Technically the PPA does not even enter into the equation as the "savings" are solely based on avoided energy cost.

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Michael Trzcinski Project Engineer, Hesnor Engineering Associates, PLLC Aug 07 2012 Guest 133 Thumbs Up

We take the savings to be the net difference between the virtual rate and the rate included in the PPA, since the owner will be charged a (reduced) rate for the electricity generated by the PV. Is this not correct?

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Hernando Miranda Owner, Soltierra LLC Aug 07 2012 Guest 14105 Thumbs Up

In PPA part of the cost that is not reflected in the rate paid is the land use agreement. The seller/owner is required to maintain land rights to allow operation, access and use of a PPA project.

Use the virtual rate as suggested by Marcus Sheffer. That is the only option that, more or less, accounts for costs that are not obvious in a PPA.

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Hernando Miranda Owner, Soltierra LLC Aug 07 2012 Guest 14105 Thumbs Up

I should note, that for a recent project, certified as LEED NC GOLD, a few months ago, we used TOU (Time of use) for renewables rather than virtual rate for electricity.

You should only spend the effort on figuring out TOU for on-site renewables, if you are just below the threshold to earn an additional energy efficiency point. Otherwise, claiming TOU does not make a significant difference. In the case of the project needed the extra point because the LEED review was exceptionally onerous.

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Marcus Sheffer LEED Fellow, 7group Aug 07 2012 LEEDuser Expert 69427 Thumbs Up

If you don't use the virtual rate you will need to make the case to the reviewer that another rate is more appropriate to your situation as Hernando suggests. If you feel that another rate is more appropriate I would suggest that you calculate it both ways and if it makes a substantial difference, justify the deviation. This way the reviewer can see the calculation based on the virtual rate and will not ask you to redo the calculation if they do not agree with your justification for another rate.

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Sara Curlee Project Architect BWBR
Mar 23 2012
LEEDuser Member
1067 Thumbs Up

'installed by substantial completion of construction'

The letter template has a sign-off for the owner/agent to declare that the renewable energy source (in my case PV solar thermal) is 'installed by substantial completion of construction.' We will be cutting it very close. Does anyone know how GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). really reads this? Does installed mean operational? Do the renewable energy systems need to be substantially complete for the overall project construction to be considered complete?

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Marcus Sheffer LEED Fellow, 7group Mar 23 2012 LEEDuser Expert 69427 Thumbs Up

Have the owner sign the form and also upload a narrative explaining the actual situation. It should be fine if the system is not fully operational since the credit is calculated based on a projection. The purpose of that sign off is to make sure that the system will be installed. The timing is not critical.

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Renee Shirey
Aug 31 2011
LEEDuser Member
4170 Thumbs Up

Buying & selling RECs

If the RECs are sold (solar RECs) is there a requirement that the RECs HAVE to be solar, or can they be any kind of RECs (wind)? I am asking, because there seems to be a large difference in price for wind RECS vs solar RECs. Anybody out there attempt this credit in this manner?

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Marcus Sheffer LEED Fellow, 7group Dec 09 2011 LEEDuser Expert 69427 Thumbs Up

The RECs just need to be qualifying RECs not from the same energy source.

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Kerrie Kannberg
Aug 03 2011
Guest
44 Thumbs Up

Can we involve PPA's?

Is there any way to involve a PPA (Power Purchase Agreement) or similar funding mechanism for EAc2? The language in the guide is not specific, as they mention a "energy system owner". If so, how?

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Renee Shirey Aug 23 2011 LEEDuser Member 4170 Thumbs Up

I would like an answer on this as well, because I am trying to understand how this would work within the requirements of LEED. If I understand correctly, the PPA would own the equipment, and then sell the school the energy, for the length of the contract. After the contract, the school can buy the equipment. If the PPA can't sell the generated RECs without buying the same amount back, (or this negates the ability to go for this credit) what is the incentive for a PPA to do this?

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Jessica Jones Project Consultant, Sustainable Design Consulting Dec 07 2011 Guest 222 Thumbs Up

@ Kerrie: I am researching this option for one of my projects now as well and I came across the 11/1/11 addenda for EAc2 which states (the portion after the "OR"): “To qualify as an eligible on-site system, the fuel source must meet one of the following conditions: the fuel source must be wholly contained/produced on-site; the project team must demonstrate full ownership of the fuel source, including ownership of all its environmental attributes; OR, if the fuel source is not owned, and in cases where use of a substitute, non-renewable fuel is possible, projects must enter into a 2-year contract for purchase of the renewable fuel source, with an ongoing commitment to renew for a period of 10 years total.” I'm not sure if this helps you with the project you were initially referencing but I hope this helps you in future projects that are considering a PPA.

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Jeff Ross-Bain, PE, LEED Fellow Principal Ross-Bain Green Building
May 16 2011
LEEDuser Member
242 Thumbs Up

Annual building energy determination

Does this credit require the sum of ALL energy uses (electricity, gas, etc.) for the proposed building be the basis for determining the renewable energy percentage or is it just the electricity use component? Thanks.

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Tristan Roberts LEED AP BD+C, Executive Editor – LEEDuser, BuildingGreen, Inc. May 19 2011 LEEDuser Moderator

Jeff, it's total annual energy cost that you are offsetting, so yes, it would include all of those uses.

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Gendel Metlitsky Sustainability Project Manager NYC SCA
May 02 2011
LEEDuser Member
342 Thumbs Up

How to keep birds away from PV panels

How to keep birds away from PV panels on the roof - any suggestions?

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Ward Miller Chief Environmental Officer, Alpenglow Advisory May 03 2011 Guest 891 Thumbs Up

Do proper conditions exist to integrate a few miniature wind turbines around the array or between panels?

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Bill Swanson PE, LEED AP, Integrated Architecture May 03 2011 LEEDuser Expert 23759 Thumbs Up

I've never heard of this as an issue before. You could try using those spikes that line ledges to keep birds off. I'd keep the spikes at the perimeter of the solar panels. Anything you put over the panels will block more light then the birds would block.

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James Geers Architect, LEED AP, Director of Sustainable Design SFA Architects Inc.
Mar 01 2011
LEEDuser Member
111 Thumbs Up

PV & SRECS

If a project installs a PV system but sells a SREC for that system can it still qualify for EA c2?

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Tristan Roberts LEED AP BD+C, Executive Editor – LEEDuser, BuildingGreen, Inc. Mar 01 2011 LEEDuser Moderator

Yes, but there is a special clause that you need to buy additonal RECs. This is outlined in the LEED Reference Guide, if you have a copy. If not, we can probably paste it in here, or I think you can find it being discussed in the NC 2009 forum for this credit.

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Ward Miller Chief Environmental Officer Alpenglow Advisory
Jan 14 2011
Guest
891 Thumbs Up

Feed in tarriffs and EAc2

In LEED energy savings seem to be calculated not only as an energy unit amount, but also and more specifically in EAc1 and 2 in monetary amounts. As solar PV panels would contribute to savings in kWhA kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu. the calculation for EAc2 would provide one number using this as the basis, but in the EU most countries have feed-in-tarriffs, which reimburse the owner for energy produced at a higher rate than the cost of energy. This would therefore provide a more favorable calculation for EAc2 when "using the building's annual energy cost". Does anyone know if feed-in-tarriffs can be used in the calculation?

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Shillpa Singh Senior Sustainability Manager, YR&G Jan 24 2011 LEEDuser Member 1993 Thumbs Up

Use the energy cost of electricity bought from a utility on site, not the feed-in tariff rate for EAc1 and EAc2 calculations

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April Ambrose Territory Manager Viridian
Mar 25 2010
LEEDuser Member
3223 Thumbs Up

Does PV on another campus roof count?

I have a school building that is doing LEED Schools 2009. It wants to incorporate solar-PV into the design, but also wants to take advantage of a recently released state incentive. This incentive is only available once the panels are installed and the building is occupied. In addition, it is a set amount of funding that is available only until it is all used. Since this project may not be occupied until Spring 2012, it cannot expect that the funds will still be available.

They could get the incentive if they placed panels on another already-existing building nearby on the same campus. In this case, they would choose the number of panels such that it produced 1% of the new building's energy, per LEED requirements. However, I'm not sure if this qualifies as "on-site" renewable energy. I've looked at the "LEED-NC Application Guide for Multiple Buildings and On-Campus Building Projects", but it is vague at best.

Can you assist?

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Shillpa Singh Senior Sustainability Manager, YR&G Apr 02 2010 LEEDuser Member 1993 Thumbs Up

Hello Brittany

Unfortunately, from what it seems, it is a little unlikely that the project can achieve EAc2.
The campus approach is applicable only if the existing building on which PV may be installed, is pursuing LEED certification by itself or through campus approach. If not, then the PV installed on the existing roof cannot be counted as on-site renewable energy for the new building pursuing LEED EAc2.
You may be able to try to get some guidance if you want to submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide.
Hope this was helpful and the project can find a way to get the credit and the incentive.

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