Hi All,
I am a little stuck on an approach and wanted to get some guidance from the
eQUEST greats. I have a project that is installing a cogeneration plant (CG)
that will use landfill gas from a nearby landfill.
The cogeneration plant is installed on site and all energy generated by the
plant is used on site. However, the operator / owner of the cogeneration
plant, a third party, sells the energy to the building owner.
On the documentation side, would one use the exceptional calculation method
or the renewable energy section (LEED Online Template v2.2)? Usually, the
renewable energy does not have a "purchased" component as in a utility.
How would one go about getting credit for the amount of energy used from
this landfill gas cogeneration plant when that energy is purchased?
Thanks for your help.
Regards.
Jeffrey G Ross-Bain, PE, LEED, BEMP
Energy that is purchased from a third party is EA credit 6 Green Power and
the third party needs to be able to prove that they have REC's (renewable
energy certificates) in order for it to count. Renewables go toward the
project be it building or whatever and have to be purchased by the building
owner. What I was told is that you are not allowed to profit off your
renewable energy if you are going to use it toward LEED for a project. In
order for it to count as renewable I think that the owner of the site would
have to give it to the building owner for free. Call USGBC and ask them to
interpret it for you to see. I usually call the USGBC if I have questions
and I do not understand. I do the same with building code because you never
know how the official interprets it versus one of us that is doing the
project.
In order to get EA credit 6 you have to purchase at least 35% of your
annual electrical consumption from this third party and it is calculated
from the energy model you made in EA credit 1 or you have to go to the US
department of energy commercial buildings energy consumption survey database
to determine the estimated electricity use.
This is how I have interpreted the LEED manual.
Thanks,
PETER HILLERMANN
After posting my previous comment I realized we should probably keep LEED
questions to a minimum because this is an eQuest forum. If you have LEED
questions I would go to LEED user it is a great resource.
Thanks,
PETER HILLERMANN
Jeff,
The CG plant has implications for both LEED EAc1 and the renewables
credits EAc2 and EAc6. For EAc1, you will need to determine how much
energy the CG plant will provide to the project. You will also need to
figure out the utility rate. Preferably, the owner/operator of the CG
plant will break up the billing into fuel and other costs. (Maintenance
and capital costs should not figure into the fuel cost for EAc1
calculation.) You will then have three utility rates (and three eQUEST
meters) - grid-provided electricity, landfill gas, and backup heating
fuel. Your baseline energy cost will use the rates for grid electricity
and backup heating fuel only.
I would try doing everything for the EAc1 calculation in eQUEST. Create
an electric generator of type "engine generator", assign it to a new
fuel meter, and assign it to the building electric meter. Electric
meters have a COGEN-TRACK-MODE that you use to set the control mode for
the CG plant. You can also assign a HW, WLHP or DHW loop to recover
exhaust heat. All of the electric end-use consumption provided by the CG
plant will show up as fuel consumption on your new fuel meter in the
eQUEST reports (such as BEPU).
For the renewables question, I disagree with Peter and think credit
should be taken for EAc2 - On-Site Renewable Energy, not EAc6. The
energy is produced on site, and landfill gas is an eligible renewable
source. You just need to account for the cost of the fuel as described
above for EAc1. Note, however, that I have not yet tried claiming this
for a LEED submission.
Best regards,
Bill
William Bishop, PE, BEMP, LEED(r) AP