is this true? i found this explaination while giving a practice test..and i couldnt find any errata sheet which says something like this!

SOS!

I think its B, because A deals with the solar energy heating the water, not offsetting building energy costs. Though it does reduce energy costs, I think it is too indirect to county.

I passed today with a score of 190!! Good luck to everyone else who will be taking the test!

Joy

First of all geothermal systems come in different forms and have different applications.

For LEED, eligible geothermal systems are those that utilize DEEP earth water or steam to GENERATE electricity.

The most obvious examples would include systems that have deep wells drilled into the earth to harness the power of steam to turn turbines thus creating electricity.

A not so obvious example would be using deep earth hot water to initiate boiling of liquids with a lower boiling point than water. This creates steam, which turns turbines and creates electricity yay.

Another example would be pumping water down into the earth so that it boils and creates steam and turns a turbine and creates electricity. Seeing a pattern yet?

Another eligible system could utilize hot water closer to the surface to help with heating a building.

Now lets talk about what the USGBC will not allow as eligible for eac2; GEOEXCHANGE systems that use heat pumps. Geoexchange isn’t technically geothermal energy because most of the thermal energy generated doesnt actually come from the earth. These systems will usually have a network of pipes just beneath the ground. A liquid will pass through these pipes and underground and heat exchange will take place (ie. if the liquid is colder than the earth than it will absorb heat energy, if the liquid is warmer than the earth the earth will absorb the heat and cool down the liquid… equilibrium at work here).

These network of pipes however are part of a vapor compression system which does most of the heat transfer.

Without getting into too many details, a geoexchange system uses the liquid in our underground piping to change the state of the refrigerant gas in a heatpump (after the refrigerant has been compressed). The water then carries the resulting heat energy away. In the mean time the refrigerant is reduced in pressure which reduces its temperature and passed into an evaporator where it removes heat from the warm air circulating through the system. The refrigerant evaporates and gets compressed again and the cycle repeats. As you can see, the refrigeration cycle is what is really doing all of the work.

So when you think pumps, think heat pumps and vapor compression. These will not be eligible because they don’t serve the intent of the credit well.

I see in the reference guide that anything that involves the following is not eligible:
- ‘ground-source’ heat pumps,
- energy from the earth’s surface and
- vapor compression

However, how are you supposed to get the deep earth source energy that LEED allows out of the ground without pumps? Does LEED distinguish between ‘ground-source’ heat pumps and other kinds of geothermal pumps? Any thoughts on this?

The important distinction about EAc2 Renewable Energy is that it is calculated based on percentage of energy COST and the question refers to energy USE or “NEEDS”. LEED distinguishes between cost and use for this credit. Interestingly, EAc4, Green Power, IS based on energy energy USE, instead of cost. Tricky!

A project team in southern Utah is implementing an on-site renewable energy plan that will offset normal building energy costs by 17.5%. How many points would this project earn under EA Credit 2, On-Site Renewable Energy?

A-1 point
B- 2 points
C- 3 points
D- 4 points
E- 5 points

Solution:

The maximum number of points that can be awarded to a project for EA Credit 2, On-Site Renewable Energy, is three points. One point is awarded for 2.5% savings off the building annual energy cost, two points for 7.5% savings, and three points for 12.5% or greater savings. With energy cost savings of 17.5%, this project team qualifies for three points.

The answer is C.

Thanks!!

The calculation for EA 2 should be based on EA 1’s simulation (Building Performance Rating Method) or, in not performed, DOE’s EIA 2003 Commercial Sector Average Energy Costs by State, in conjunction with the CBECS.

Another thought, is hydroelectric generation eligible for EA on-site renewable energy. I cannot tell from page 204, Reference Guide.

Anyone has other input?

In order to ensure continuous operation of the assembly line, a manufacturing facility in Oregon seeking LEED certification installs backup generators powered by corn-based biodiesel, with capacity to provide 50% of the facility’s electricity needs. Accding to EPA’s Emissions & Generation Resource Integrated Database, an average of 60% of the facility;s utility electricty comes for hydroelectric generation. The facility is eligible for how many points in EAc2, On-site Renewable Energy?
A.0
b.1
C.2
D.3

Answer is A. Is that becasue they say it talks about 60% of the elecricity rather than the actual cost %?

The answer is b and e. I am OK with b and e, but why isn’t d correct?

A mechanical engineer is the only decision maker for b (EQ 1), d (EA 2), and e (EA 4) in Design Submittal phase.

Could someone please provide your input? Thanks.

also, this site is truly wonderful, it has helped me so much, thank you!

22. Using rooftop photovoltaic panels supplying 17.5% of a building’s energy needs
would help a project comply with EA Credit 2, On-Site Renewable Energy, and
which other credit?
A) ___ ID Credit 1, Innovation in Design, for exemplary performance under
EA Credit 2
B) ___ EA Credit 1, Optimize Energy Performance
C) ___ EA Credit 6, Green Power
D) ___ SS Credit 7, Heat Island Effect

why is the answer not a? it is 17.5 which gives the extra credit point, but the answer is b, I get where the b comes from, just wondering why it cant be a