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.
All electricity generated and heat used on site is counted towards the credit. Electricity and heat generated onsite but sold to the grid at a premium is not eligible. (See table.)
LEED allows you to take credit for technologies that generate electricity and heat 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.)
Centerbrook Architects in Centerbrook, Connecticut, supplies about 20% of its power needs with onsite photovoltaic power, including this 26.4 kW array. The Falls River, in the background, powers a small hydroelectric turbine supplying another 10% of the firm’s power. Both sources contribute to this LEED credit. However, many small installations like this find it financially important to sell RECs from the renewables, which would make the power ineligible for the credit. Photo – Centerbrook Architects and Planners, LLC Depending on the features and location of your site and the expertise available, the technologies you can use are:
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.
The Adventure Aquarium in Camden, New Jersey, features eight 400-watt and four 1000-watt parapet-mounted AeroVironment turbines. Photo – Jeff Titcomb
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.
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 Energy Simulation.
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.
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.
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.
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.
Yes, but don't push the timeframe too far. 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.
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 hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. with PV panels.
Yes, all the energy would qualify. Check the CHP guidance in the district energy systems modeling protocol.
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.
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.
The 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.
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:
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.
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.
A 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.
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.
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.
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.
Excerpted from LEED 2009 for New Construction and Major Renovations
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.
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:
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.
Charts showing total U.S. energy consumption and U.S. residential electricity prices.
Compilation of research and technological breakthroughs in BIPV.
Maps and data showing statistics, trends, and the availability of renewable energy resources throughout the United States.
Interactive map to help consumers find certified solar PV and solar thermal installers.
Helps non-experts to quickly obtain performance estimates for grid-connected PV systems.
Covers cost considerations for PV systems.
Links to multiple educational tools for examining cost and performance of various energy-efficient and solar energy technologies and products.
Provides guidance for determining renewable energy potential of residential and non-residential sites.
Resources on net metering laws, policies, and guidelines.
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.
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 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 is a tool available for a fee for design, calculation and optimization of solar thermal water systems.
A collection of renewable energy building analysis tools.
Detailed description of design considerations and installation instructions for PV systems.
Illustrates 16 case studies across U.S. that incorporate BIPV and prepares readers with common BIPV terminology, pitfalls, and design basics.
Free article explaining how third-party providers can install and maintain solar electrical systems on private property.
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.
Links to publications, workshops, courses, outreach programs and other renewable energy education opportunities.
A non-profit organization that supports a voluntary certification program designed to help identify and reward hydropower dams that are minimizing their environmental impacts.
Comprehensive listing of federal, state, local, and utility incentives that subsidize renewable energy use and energy efficiency.
A national trade association that provides resources and information about the domestic and international wind industry.
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.
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.
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.
Sample documents showing PV infrastructure and calculations with an onsite PV project.
Documentation for this credit can be part of a Design Phase submittal.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each NC-2009 EA credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictsions for these forms; for more information, visit LEED Online and click "Sample Forms Download."
Our project has two sources of energy (electricity, and natural gas).
We have already finished the simulation model, and its result was accepted by USGBC, when reviewed.
In addition we have already contacted our government for electric supply (maximum demand load) agreement.
At the moment we are thinking of having PV cells on the roof, though we are confused about;
whether the percentage of the cells electric energy production should be compared with the actual maximum demand load OR the simulation results of the proposed design electricity?
The renewable energy production is evaluated as a percentage of the total energy use from the simulation for EAp2/EAc1. You can also count the renewable energy for EAp2/EAc1.
Is "total energy" means ( electricity and natural gas) altogether?
Yes but I should have been more clear. It is a percentage of the total energy cost, not energy use.
I am doing a factory building in Dhaka Bangladesh. To offset the power outage, they are going to use gas generator. There is an option of using low em mission gas generators, which will be little more expensive.
Shall we qualify for EAc2 by using these generators along with solar panels?
IF the fuel source is gasoline or natural gas it does not qualify. If it is something like landfill methane then yes.
I need the criteria of biogas outside of United States (Germany). Are ther requirements?
International project must meet the same requirements as US based projects. The Reference Guide contains the best guidance on eligible renewables.
We have a Student Commons building going for certification on a campus. There is also a solar installation already on the campus and if there is a way to supplement the electricity for this Commons building with solar, can we still be eligible for this credit even though it isn't "on-site" and located in our LEED project boundary? The same university (owner) owns all buildings on the campus and solar installation.
Yes you can. Provide a letter from the university allocating some or all of the solar to this project. They just cannot double count it for another project on the same campus.
Great! Thanks for the fast reply, Marcus. Just to clarify, they wouldn't be able to garner points on this particular Commons building if it was counted on any previous LEED certified buildings (i am not sure if the campus has any other LEED projects, I need to confirm) and/or this means that any future LEED projects on the campus won't be able to count it either? Thank you!
Yep it is a matter of allocation to individual projects.
Again, thanks. LAST question, the university would have to own and operate the system, correct? But is there anyway for solar PV to count if the system is being installed through a power purchase agreement? I highly doubt it, but the third party can utilize advantages that the university can't because they are tax exempt. Its really the only way solar makes economic sense being that tax credits don't apply to them. Please advise. Thanks again!
It is really a matter of who owns the power output and the SRECs not who owns and maintains the system. If the University owns the power and the SRECs then it can be allocated.
Our project will support a PV array capable of supplying 15% of the building's electrical needs. There will be a small battery bank to provide power for some DC loads such as chargers and a few lights. The bulk of the power will be fed to the grid, net metered. In this state, there is a feed-in tariff imposed by the state: all renewable power must be purchased by the utility at $.06 over the retail rate for power.
I've read conflicting statements, and am unsure; does this meet the requirements for the credit under EAc2?
Who owns the array? If you facility is basically a rack for a solar system feeding into the grid side of your meter then it is my understanding that you cannot claim the renewable energy under LEED.
The building owner is also the array owner. The building is a public educational demonstration project, containing some offices, developed and owned by the electric utility company. So the array, the building and the grid all all owned by the same entity.
So if it is all owned by the same entity and is a demonstration project for customers why feed the PV into the utility grid side of the meter (assuming there is one)? If the PV feeds the building circuits then it will count, no questions. If not then you will have to provide a justification and explanation for why it should count given your circumstances.
Thanks, Marcus. Turns out it won't be net metered, just feed the building. Any excess supplies the grid.
My client has installed a large solar array on top of the parking garage. The output is 160kWh annually. Based on the whole building energy model we can max out the possible points in EAc1 and EAc2 with 100kWh of the energy produced by the array. Can the client sell RECs for the additional 60kWh to help offset the cost of installation? If so, should this be explained in a narrative and submitted to the reviewer or should we run the models based on the 100kWh production required and leave out the 60kWh they plan on using for the RECs? I believe this is an appropriate path to pursue and fulfills the intent of the credits while provided a funding source to help offset the cost of the array.
In addition; does anyone know of 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 that deals with this issue? Thanks!
Sure I do not see why not. Yes it should be explained to the reviewer.
I do not know the number but there is an Interpretation that requires the replacement of sold RECs.
My personal opinion is you should be able to sell all the RECs and still count it for your LEED project. Why should LEED discourage the use of a viable funding stream that enables renewable energy projects? It shouldn't IMO.
Thank you for the follow-up Marcus. I aggree and will pursue this strategy. In addtion: I will try to dig up the 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, but please let me know if you remember the number. As always: thank you for the help!
We are certifying a Positive Energy Building, that will produce 130% of its energy consumption with solar PV.
All the energy produced with the PV will be sold to the grid.
I was wondering if we could get any credit for the PV, considering that the building produces 30% more energy than it consumes, and, thus, this "extra" 30% needs to be sold to the grid, since the building cannot consume it.
Does anybody know how to treat cases like this?
Check the interpretations on this issue. I recall that the PV power must be fed into the building, not the grid, in order to count at all. It is possible that has changed. If my recollection is correct the fact that it produces 30% is moot.
IMO if the PV is just feeding to the grid then your building is just a big PV rack not a net positive building.
If the project is district cooled with option 1 where the cooling energy consumption is determined by adding chilled water meter in the energy model for EAc1, in calculating the capacity of the PV array, is it right to convert then add the BTUA unit of energy consumed by or delivered to a building. A Btu is an acronym for British thermal unit and is defined as the amount of energy required to increase the temperature of 1 pound of water by 1 degree Fahrenheit, at normal atmospheric pressure. Energy consumption is expressed in Btu to allow for consumption comparisons among fuels that are measured in different units. reading from the chilled water meter to the total annual energy use to show compliance?
The EAc2 calculation is based on energy cost. Energy cost includes the cost of all energy end uses.
We've just learned from "Treatment of District or Campus Thermal Energy in LEED V2 & 2009" reference page 15, that our project cannot earn EAc2 points using option 1 but option 2 could. Can someone enlighten us why is that?
Is there 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 that we should be aware about?
Option 2 accounts for the effect of the DES and any connected renewables. Option 1 does not. So if you are not going to account for the DES effects then the renewables connected to the DES don't count either.
Even if the renewable energy supplies energy only for the project?
If the renewables feed into the building and not the DES then it can count.
I am working on a project with two large solar arrays on a parking garage, both are separately metered. Array #1 is providing in excess of 20% of the total building’s energy consumption; qualifying the project for the maximum EAc2 points and an ID credit. The owner wants to sell SREC's based on the second array’s (Array #2) output to off-set the cost of installation. Array #2’s output is not needed to satisfy EAc2. Has anyone attempted this strategy? It would seem to satisfy the LEED requirement while providing a way to off-set the cost, therefore, making the installation of on-site renewables more feasible. Thoughts?
So basically array #2 would not be included in the LEED submission right? If so that would probably work.
You are correct Marcus, we will not be including the energy produced by array #2 in the LEED submittal. I plan on moving forward as descibed, thank you for the response.
We have a few schools from the same district being built at the same time, and we are considering adding PV to some/all of them. If we can get a larger array on one school, can we split the credit for the renewable energy with another school? Ex: If both schools need a 14kW system to reach the 3% threshold, and one school can hold a 30kW system, can half be earmarked for one school, and half to the other? That way, it is one larger array (vs two smaller ones) and both schools would gain renewable energy credit.
Renee, I would say that you can only do this if you undertake a campus/multiple building LEED certification.
Our building project is a methane pumping facility located at landfill that is the source of the methane. Most of the methane generated by the landfill will be "cleaned up" and pumped to another facility for power generation. Additionally, during the methane "cleaning" process (prior to pumping)there will be waste methane that will be used as fuel for the HVAC units in the methane pumping facility instead of piping in natural gas from the local utility.
Is this project a candidate for the On-Site Renewable Energy credit?
A second question: Considering that we are capturing a "waste" product (waste methane) and reusing it, can the "waste" methane be regarded as a material and be considered for the Material Reuse credit?
Yes it will count as an on-site renewable.
I think the materials need to be solid, not gaseous, to even be considered as salvaged materials.
I'm working on a project where the owner has interest in adding a roof mounted PV system that is connected to the facility and the grid in the LEED project/boundary and in the associated construction contract. However the 50kW array (approx. 33% of facility consumption) will be provided, installed, and maintained by a subcontractor who will own the system for a period of time and pay for the system through savings, participating in the local utility program that will pay a premium per 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. for onsite generation. Obviously, and regrettably, we cannot claim EAc2 credit under 2009, however is it acceptable to include the onsite generation capacity in the energy model?
I have not seen this attempted. There is not a clear link between EAc2 and EAc1 in the Reference Guide. You could always give it a try and see if it makes it through the review process. Otherwise it sounds like a 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.. You might check there to see if this issue has been raised before.
Marcus, Thank you for your quick reply, I'll report the results for others.
Hi Ken. I am curious of the outcome, as we have the same situation. Please do keep us posted!
For an upcoming project we are proposing using a metal wall system that acts as a transpired solar collector to bring preheated air into the building. Preheating the air will offset energy being used by the building systems to heat the building in the heating months. Would this strategy be considered "passive" solar or could it be considered an onsite renewable energy technology that would be applicable to this credit?
Those systems typically use fans and other mechanical devices to operate making them an active solar system. So they can be counted. Make sure you provide thorough documentation of the calculation of the savings.
My project is LEED NC version 2009, and consists of two buildings. One, the Lodge, is the building pursuing LEED Certification. The second building on our site is a parking garage, not pursuing certification, which will house the projects 250KW PV system.
Currently the project does not feed the energy produced from the PV system directly into the Lodge, but rather straight into the grid. The Lodge will most definitely be consuming more energy than is produced by our PV system, but since the energy isn't directly feeding our building can we count it towards EAc2 and EAc1?
The whole PV system is being funded by our project and is within our LEED Project Boundary. From my understanding, as long as you are not selling the power, produced from the onsite renewable energy source, back to the grid you are allowed to count the energy created by the PVs towards offsetting your building's overall energy load.
The amount of net energy used from the grid to power our building will be the same whether or not we route it through the Lodge or directly into the grid. But I need to know if the grid option precludes us from pursuing the EA credits 1 & 2.
Thanks for your help.
There is a potentially big difference between a generator connected to the grid and a customer who happens to have some generation capabilities. The rules in most utility service territories are very different between a generator and a facility with net metering. The rules also vary widely across the country so maybe there is a good reason in your case.
Why would your project feed the power to the grid and not through the building? Is the power metered? How does your facility get credit from the utility? Grid connections raise many questions.
The primary issue is ownership of the renewable power. There are requirements for retaining RECs, etc. Feeding into the grid will raise considerably more questions than feeding into the building. As long as you have good explanations it might work. Check the LEED interpretations for some guidance too.
It is an interesting situation. The Lodge originally had solar hot water and a PV system located on top of the roof. But throughout the design process the team realized that only one of the two systems would fit on top of the Lodge roof. So it was decided to put the PVs on the parking garage. And of course, there was no extra money to run a cable and a duct bank from the parking garage to the Lodge to feed to power generated by the system directly into the facility.
I raised this as a concern I while ago saying that if we didn't feed the building with the power, it would be difficult to claim the onsite renewable energy for our building. This project is funding the construction of the system, and I am unsure if this has any affect on LEED. The Lodge will be the owner of the PV system, and responsible for its maintenance throughout its lifecycle. But the power from the PVs is being fed straight into the grid for the base. Which would obviously be offsetting any number of other buildings on base and not specifically our building.
A member of our project team has interpreted the LEED credit to mean that as long as the system is on our LEED project site, which it is, and we aren’t producing more energy than we are using, which we aren’t. Then according to the credit verbiage we should be able to count the energy from the PV system towards the energy reduction of our building.
Please advise, thanks for your help.
What I did not get from your original post was that the power is not feeding the utility grid, but a local campus grid. Extremely big difference there. That situation is fine. All you will need is a letter from the owner allocating the power to the lodge project.
There are interpretations that address this specific situation.
We are doing LEED Volume under NC-Retail for a gas station chain that sells E-85 at all locations. Does E-85 qualify as On-Site Renewable Energy?
In my opinion it does not. To count under EAc2 it would need to be used by the facility not purchased at the facility.
I am looking at the on-line form for EAc2 On-Site Renewable Energy. (LEED 2009 for New Construction) The asterisk occurs after each of two Required Signatory boxes. Path selected: Option 1 Whole Bulding Energy Simulation.
Under the Additional Details check the special circumstances box and a narrative space opens. Enter your explanation there for how the owner was informed about the ownership of the RECs and the installation of the system. If any documents would assist in this task, upload them.
For a NC manufacturing project we have been aproached by a company who would mount pv-modules on the building roof and sell them to building owner at no cost premium.
My question is if these modules would achieve the credit intent despite RECs deriving from the module output being sold to someone else.
I could not find any specification on this, but remember having read about this issues when preparing for the LEED BD C exam.
Thank you very much for your feedback.
I do not necessarily agree with this but if you sell the RECs you cannot count the system output for EAc2 or EAc1. You can replace the RECs with other RECs and then count the output of your on-site system for EAc2 and EAc1. See page 293 in the Reference Guide. If you have an older version it may say that a 2 to 1 replacement is necessary but that was changed to a 1 to 1 replacement.
In my opinion renewable projects that sell their RECs should still be able to count the output for EAc2. While technically you have sold the environmental attributes, you still managed to get a renewable energy system on your facility. If selling the RECs enabled the financial transaction that allowed you to do that then LEED should not be discouraging this type of arrangement. So I think that if you have renewable energy flowing through your building you should be able to count it for LEED.
I have a project with a similar situation where a 2nd party will own the PVs and install on the owner's site. The 2nd party will sell the electricty back to the owner at a reduced cost. While our project may not consume all power, it is part of a larger facility that will consume 100% of the solar power produced 100% of the time. We don't have a situation where we would be selling RECs. Would this count in EAc2?
Susan, are you sure the 2nd party isn't retaining the RECs? That is usually why the 2nd party is willing to keep ownership and responsibility (for a period of time) of the PVs - they are gaining the RECs generated by the PVs. If that is the case, then the project owner has to balance that by buying RECs from some other source.
If the electricity flows into your facility on your side of the electric meter and the RECs have not been sold then it can count for EAc2. If the power flows into the grid side of the meter then probably not.
Renee - At this time, I am not sure but it is a good question. Marcus - Your answer seems to clarify/refine Renee's answer. Thanks!
thanks for your feedback.
Susan: our project is the same. The 2nd party sells the power to the user at reduced cost. Further he will not retain the RECs. The project is within a subsidary sheme for PV in China.
Marcus: thanks for the reference to the Reference Guide.
I guess all thats left is to make sure the requirements are specified in the contract and to make sure the contract covers the entire lilfespan of the PV modules.
From my reading of the Reference Manual for this credit it seems that Bio-fuel can only be used to generate electrical power on-site, and not to power bio-fuel boilers for water heating or space heating. Is this interpretation correct? In that case only something like a mini-CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source. unit burning bio-fuel is eligible going the bio-fuel route. And even then you are restricted in the bio-fuel you can use, ie. it pretty much needs to be ethanol produced from food waste - is this correct? I don't know of any bio-gas or wood chip CHP systems...
While the language in the Reference Guide has not been changed, it is in error. Eligible bio-fuels can be used directly and do not have to be converted to electricity. The list of eligible bio-fuels includes untreated mill residues, agricultural waste/crops, landfill gas and animal/organic waste.
There is a long history in LEED allowing the improtation of landfill gas to be burned and used for heat not just electricity.
Thanks Marcus, the Reference Guide is definitely misleading on this point so your clarification is very useful.
If an energy model has been reviewed during design phase submission and PVs are added during construction but were not included in the model, can the model be rerun and resubmitted during the construction review? Is there a cost associated with this?
It probably could be added to EAp2/EAc1 at no charge just indicate that the design credit (EAp2/EAc1) changed during construction and add the PV.
Help Please! Our GBCI reviwer is asking us to: Provide screenshots or output calculations from a simulation program showing how the annual energy savings was determined for the photovoltaic system.
They suggest using PV Watts, however PV Watts seems to be not usable for our project located in the Carribean as it says "No PV Watts data at mouseclick". Any suggestions? Is there another software we can use?
Whoever engineered the system must have some basis for estimating electricity output--it should be enough just to share their calculations. You'll want to to factor in climate data (solar insolation), orientation and slope of the panels, and their generation efficiency, as well as an estimate of losses in the balance of system components (such as DC to AC conversion).
PVWatts has pretty sophisticated algorithms for doing this, but there are simpler estimates you can use. Check with a local engineer with solar experience if your provider can't do it.
Hi, a company will be working with provisional natural gas boilers, but in a year's time two boilers will be replaced by a biomass boiler whish will be working on sawdust. The fase out of the provisional boilers is already planned, but the LEED project will finished before this replacement, in consequence the commissioning of this equipement is not possible to be performed within the LEED prpoject timeframe. Is it possible to commit the commissioning in order to include this renewable energy source? and is this saw dust boiler eligible since the sawdust comes from untreated wood waste?
I think the only way to include those boilers would be to delay applying for LEED certification until they are installed--but be careful that it doesn't take too long, as there is a limit to how long after construction you can apply.
Alternately, you could forego LEED certification from new construction, and, after two years, apply for EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. certification.
Hi, I have the following question: a company that is pursuing LEED certification. Owns a low impact renewable energy plant, but this plan, that is a pass hidraulic plant on a river, is off-site. This cannot be declared as Green Energy since its is owned by the company, but it is not on-site energy so it is not on-site renewable energy. Could we account for this energy on this credit? it meets the intention but is not part of the project even though it will provide all its energy to the LEED building making the proyect offset its energy costs.
The best way to approach a situation like this, in which you don't meet the requirements literally but could argue that you meet their intent, is 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 and see if you can get a favorable ruling.
Jose, there are ways to use assets outside your LEED boundary to help earn LEED credits—review the LEED Minimum Program Requirements Supplemental Guidance Document. However, you don't specify how far off-site you mean. There may be a limit to what is going to easily pass muster, but that doesn't mean you shouldn't try.
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