Ground-Mounted PV Measure¶ ↑
This measure is to add ground-mounted PV to a model. Renewable energy should be the last item added to a model.
Description¶ ↑
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The users’ inputs for the measure are PV module type, and total area and azimuth and tilt angles of PV panels.
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A json file has been created that includes a variety of PV modules options.
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It has been assumed that PV panel’s size is 5 ft x 2 ft as it seems to fit the racking system used for ground mounts as per Mike Lubun’s comment.
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Default PV panels’ tilt angle has been set as the latitude of the location.
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Default PV panels’ azimuth angle has been set as south-facing arrays.
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Default PV module type has been set as “HES-160-36PV 26.6 x 58.3 x 1.38” as assuming a typical panel is 5 ft x 2 ft, the closest standard type PV panel in the costing spreadsheet would be the 160W HES based on Mike Lubun’s comment.
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Only one PVWatts generator is created using the measure for simplification, however exact number of PVWatts generators (and inverters) are calculated for costing as per Mike Lubun’s comment.
Approach¶ ↑
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A new file in github.com/NREL/openstudio-standards/tree/nrcan/lib/openstudio-standards/standards/necb/ECMS folder called pv_ground.rb has been created.
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A method called apply_pv_ground has been added to the
ECMS
class. This is where the PV method logic has been writen. -
Since the PV modules has many options (i.e. type and capacity) a library in json format has been created in github.com/NREL/openstudio-standards/blob/nrcan/lib/openstudio-standards/standards/necb/ECMS/data. These properties align with the costing spreadsheet.
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The apply_pv_ground method has been added to the end of the ‘apply_systems_and_efficiencies’ method in necb2011.rb.
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The inputs have been set to ‘nil’ for the do nothing option, similar to what is done in the erv measure.
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The required arguments have been threaded up to the ‘model_create_prototype_model’ method in necb_2011.rb.
Testing Plan¶ ↑
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The tests were run in OpenStudio to ensure electricity is being generated and scales with changes in the PV panels area.
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In OpenStudio, it has been checked that net site/source energy is less than total site/source energy due to the installation of PV panels.
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Another output variable that can be checked in OpenStudio at different timesteps is Inverter AC Output Electric Power [W].
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A unit test has been developed.
Notes:¶ ↑
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“Total site energy is the ”gross“ energy consumed by the building site and Net Site Energy is the final energy consumed by the building site after accounting for any on-site energy generation (photovoltaics, generators, etc.).” (Ref: unmethours.com/question/25416/what-is-the-difference-between-site-energy-and-source-energy/)
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“Total Source Energy (=”represents the total amount of raw fuel that is required to operate the building. It incorporates all transmission, delivery, and production losses“ Source: EPA). In contrast, the Net Source Energy is the energy that you get after the losses of delivery and transportation.” (Ref: unmethours.com/question/19090/what-is-the-difference-between-total-source-energy-and-net-source-energy/)
Files Added/Modified¶ ↑
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Files have been modified:
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necb_2011.rb
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btap_pre1980.rb
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Files have been added:
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pv_ground.rb
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pv.json
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test_pv_ground.rb
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pv_ground.md