Performing LEED Green Power Calculations

Content Scope: 
Use Tabbed Form
Bird's Eye view

Green Power credits

To calculate your project’s required green power purchase quantity for the Green Power credit, choose one of the methods below according to your project type and calculation method. See these pages for more guidance on Green Power credits: NC EAc6 | CS EAc6 | Schools EAc6 | CI EAc4 | EBOM EAc4

For LEED-NC and Schools projects

Calculation Based on Design Energy Cost

Total Required Green Power Quantity = Design case total electricity usage  X  35%  X  2 years

  • The Design case total electricity usage may be obtained from EAc1 calculations or energy model results. If an energy model was used to document compliance with EAc1, the data from the energy model must be used as the basis for determining the electricity consumption for this credit.
  • Confirm accurate threshold percentage to achieve desired LEED points.
  • LEED-NC and Schools projects will calculation 35% of the electricity use to achieve EAc6.
  • Exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. will be achieved for all projects that purchase 100% of their electricity use from renewable sources.

Calculations Based on Default Electricity Consumption

Total Required Green Power Quantity = Size of project (sf)  X  default value electrical intensity based on building type  X  35%  X  2 years

  • Confirm accurate threshold percentage to achieve desired LEED points. Exemplary performance can be achieved for all projects that purchase 100% of their electricity use from renewable sources.

Actual Consumption Calculation

If a project’s utility bills for a year’s worth of electricity usage are available, project teams can use this information to calculate the total required green power quantity.

Total Required Green Power Quantity = Actual electricity consumption (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.)  X  50%   X   2 years

  • Exemplary performance will be achieved for all projects that purchase 100% of their electricity use from renewable sources.

For LEED-CI  Projects

Design Energy Cost Method

Total Required Green Power Quantity = Design case total electricity usage  X  50%  X  2 years

  • The Design case total electricity usage may be obtained from EAc1 calculations or energy model results.
  • Confirm accurate threshold percentage to achieve desired LEED points.
  • LEED-CI projects will calculation 50% of the electricity use to achieve EAc4.
  • Exemplary performance will be achieved for all projects that purchase 100% of their electricity use from renewable sources.

Default Electricity Consumption Calculation

Total Required Green Power Quantity = Size of project (sq)  X  8 kWh  X  2 years

  • Exemplary performance will be achieved for CI projects that double their purchase to 16 kWh.

Actual Consumption Calculation

If a project’s utility bills for a year’s worth of electricity usage are available, project teams can use this information to calculate the total required green power quantity.

Total Required Green Power Quantity = Actual electricity consumption (kWh)  X  50%   X   2 years

  • Exemplary performance will be achieved for all projects that purchase 100% of their electricity use from renewable sources.

For LEED-CS Projects

Using Default Electricity Consumption Calculation 

Step 1: Determine % of building that is CS: (Building Gross Square FootageSum of the floor areas of the spaces within the building including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft or greater. It is measured from the exterior faces of exterior walls or from the centerline of walls separating buildings, but excluding covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, chimneys, roof overhangs, and similar features. – Building Usable Square Footage) / Building Gross Square Footage  X  100

  • The calculation above uses ANSI / Building Owners and Managers Association (BOMA) Standard Z65.1-1996 to determine the CS electricity usage (based on square footage). 
  • If the calculation below is less than 15%, use 15% as the minimum input value. For example, if a project calculates the percentage of CS square footage as only 8%, you will need to run the calculations as 15% of the building. 

Step 2: Calculate Total Annual Electricity Consumption: Result from Step 1  X  default value electrical intensity based on building type  

  • Refer to the LEED Reference Guide table, copied at right, for default values based on building type.

Step 3: Calculate Required Green Power Quantity: Result from Step 2  X  35%  X  2 years

  • Confirm accurate threshold percentage to achieve desired LEED points. 
  • Exemplary performance will be achieved for all projects that purchase 100% of their electricity use from renewable sources.

Using EAc1, Option 1 Whole Building Simulation Data

Step 1: Determine % of building that is CS: (Building Gross Square Footage – Building Usable Square Footage) / Building Gross Square Footage  X  100

  • The calculation above uses ANSI / Building Owners and Managers Association (BOMA) Standard Z65.1-1996 to determine the CS electricity usage (based on square footage). 
  • If the calculation above is less than 15%, use 15% as the minimum input value. For example, if a project calculates the percentage of CS square footage as only 8%, they will need to run the calculations as 15% of the building.

Step 2: Calculate Total Annual Electricity Consumption:
Result from Step 1  X  EAc1 Energy Model results for total building’s annual electricity use  

Step 3: Calculate Required Green Power Quantity: Result from Step 2  X  35%  X  2 years

  • Confirm accurate threshold percentage to achieve desired LEED points. 
  • Exemplary performance will be achieved for all projects that purchase 100% of their electricity use from renewable sources.

Publications

LEED Reference Documents

The LEED reference guides contain more detailed information on the requirements and implementation procedures for the Green Power credit.

16 Comments

0
0
Shenhao Li Atkins
Jul 01 2013
Guest
512 Thumbs Up

Can green power used on another project?

We are doing a LEED submission for a project in china. Can we buy green power for this project to get the credit, but get some preferential policy for another project in USA? By the way ,these two projects have same owner.

1
4
0
Marcus Sheffer LEED Fellow, 7group Jul 01 2013 LEEDuser Expert 69130 Thumbs Up

Please be more specific about the situation and preferential policy you seek.

2
4
0
Shenhao Li Atkins Jul 02 2013 Guest 512 Thumbs Up

Our project is located in china as a branch office of an America company. we are going to get credit EA c6 by purchasing green power.
But the client want to know, if they are buying green power for the branch office in china.Is it possible they can get a discount or other preferential policy for their America company?

3
4
0
Marcus Sheffer LEED Fellow, 7group Jul 03 2013 LEEDuser Expert 69130 Thumbs Up

You would need to contact some suppliers and ask.

For a list of US-Based companies selling Green-eGreen-e is a program established by the Center for Resource Solutions to both promote green electricity products and provide consumers with a rigorous and nationally recognized method to identify those products. RECs go to http://www.green-e.org/base/re_products

I am not familiar with the Chinese green power market but I would guess that there is not a similar program to Green-e there since Green-e supports the voluntary market for green power. Any green power mandated is not equivalent.

4
4
0
Shenhao Li Atkins Jul 03 2013 Guest 512 Thumbs Up

Marcus Sheffer:
Thank you for you reply.

Post a Reply
0
0
Tristan Roberts LEED AP BD+C, Executive Editor – LEEDuser BuildingGreen, Inc.
Jun 22 2012
LEEDuser Moderator

EAc1 model and EAc6 calcs

Note that according to a 4/1/12 addendum from USGBC, "If an energy model was used to document compliance with EAc1: Optimize Energy Performance, the data from the energy model must be used as the basis for determining the electricity consumption for this credit." I assume most teams would do this anyway, but it's a useful clarification.

1
1
0
Tiffany Moore LEED Documentation Consultant, Built Kansas City LLC Jul 26 2013 Guest 1275 Thumbs Up

Tristan,

I'm curious about the tip sheet calculation above that illustrates taking the C&S square footage percentage x the annual energy use from the energy model to establish the energy use to calculate RECs. I don't see that particular strategy in the v2009 reference guide. Is it a modification of the original Option #2 that has become acceptable practice after the 4/1/12 addendum required the use of the energy model information?

I have received wildly different approaches from the REC brokers I contacted and want to validate the information before advising my client to make a purchase.

Thanks

Post a Reply
0
0
Chen Shalita B. Arch., LEED AP BD+C Alfa Sustainable Projects Limited
May 03 2012
LEEDuser Member
152 Thumbs Up

Purchasing REC's for international projects

We're doing a LEED 2009 NC submission for an over-seas university dormitory project. We're not familiar with a local RECA Renewable Energy Certificate (REC) is a certificate representing proof that a given unit of electricity was generated from a renewable energy source such as solar or wind. These certificates are able to be sold, traded, or bartered as environmental commodities, where an electricity consumer can buy the renewable energy attributes of electricty to support renewable energy, even if they are consuming generic grid-supplied electricity that may be supplied by nonrenewable sources. purchasing service. Can our project buy RECRenewable energy credit: a tradable commodity representing proof that a unit of electricity was generated from a renewable resource. RECs are sold separately from electricity itself and thus allow the purchase of green power by a user of conventionally generated electricity.'s from a US supplier, and will it be accepted for LEED credits?

1
2
0
Marcus Sheffer LEED Fellow, 7group May 03 2012 LEEDuser Expert 69130 Thumbs Up

Yes you can and it should be accepted.

2
2
0
Chen Shalita B. Arch., LEED AP BD+C, Alfa Sustainable Projects Limited Jul 07 2012 LEEDuser Member 152 Thumbs Up

Markus, Thanks for your reply.

Post a Reply
0
0
Christopher McArdle Mechanical/Energy Engineer Genesis Engineers, Inc.
Nov 17 2011
Guest
78 Thumbs Up

can i take a credit for on site renewable energy for green power

I have PV panels on my project building. Can i deduct the annual energy produced from the pv panels when calculating the amount of Green Power to purchase?

1
2
0
Marcus Sheffer LEED Fellow, 7group Nov 17 2011 LEEDuser Expert 69130 Thumbs Up

If you have sold your RECs then you use the total electric consumption of the building. If you own the RECs (and agree not the sell them during the two year purchase period) then you can subtract the solar output from the total electric consumption.

2
2
0
Lana Carmichael Director of Business Development- Green Building Team Leader, Renewable Choice Energy Jul 07 2012 Guest 1318 Thumbs Up

We've provided Green Power to hundreds of international LEED projects - please let me know if I can help! lmalone@renewablechoice.com

Post a Reply
0
0
John Albrecht Director of LEED Services Sieben Energy Assoc.
Aug 30 2010
Guest
2605 Thumbs Up

Green Power and on-site renewables

Can a project pursuing this credit reduce it's green power RECA Renewable Energy Certificate (REC) is a certificate representing proof that a given unit of electricity was generated from a renewable energy source such as solar or wind. These certificates are able to be sold, traded, or bartered as environmental commodities, where an electricity consumer can buy the renewable energy attributes of electricty to support renewable energy, even if they are consuming generic grid-supplied electricity that may be supplied by nonrenewable sources. purchase by the amount of green power to be generated on site via a new solar array? If so, does this calculation occur automatically within the referenced LEED Online EAc1 template, or is this an additional manual subtraction after the EAc1 template (Table 1.8.2(b) - Energy Cost and Consumption by Energy Type - Performance Rating Method Complianceresult)? The template language ('subtracted from model results to reflect Proposed Building Performance') is not perfectly clear to me. Thanks. John

1
2
0
Marcus Sheffer LEED Fellow, 7group Aug 31 2010 LEEDuser Expert 69130 Thumbs Up

Yes. The renewable energy inputed in section 1.6 of the template shows up in table 1.8.2b. If you have an all electric building you could uise the Total value at the bottom of this table, but if you have gas consumption you would need to factor that out. The total electricity purchased for EAc6 would be the modeled 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. minus the renewable kWh.

2
2
0
John Albrecht Director of LEED Services, Sieben Energy Assoc. Sep 06 2010 Guest 2605 Thumbs Up

Marcus, that helped, thanks,. John

Post a Reply

Start a new LEED comment thread

Mar 26 2017
Type the characters you see in this picture. (verify using audio)
Type the characters you see in the picture above; if you can't read them, submit the form and a new image will be generated. Not case sensitive.

Copyright 2017 – BuildingGreen, Inc.