#1208 PV Compliance Credit to offset Standard Solar Thermal Savings

[Scott Criswell]

The purpose of this enhancement would be to allow multifamily projects with all-electric central DHW system(s) and photovoltaic system(s) to get compliance credit for a portion of the proposed PV equivalent to the standard design solar thermal DHW savings.

Principal Question - how to quantify the standard design solar thermal (TDV) savings?
To calculate the most accurate savings value we would have to simulate the standard design model with and without its solar thermal system. To avoid simulation of a complete std model we could perform a secondary solar thermal sizing run w/ 0 and final solar thermal sizes and compute the TDV difference.
Another alternative would be to estimate the solar thermal DHW savings based on the final standard model SSF and fraction of dwelling units assigned to electric central DHW systems.

Implementation details:
The existing compliance enduse "Self Utilization Credit" will be renamed "Flexibility Credit" and the solar thermal PV adjustment will be added to the existing self-util credit (for PV-battery systems).
The user will need to specify when this PV-solar thermal credit is to be included in the Flexibility Credit results by activating a checkbox probably in the Building tab of the Project tabbed dialog (made available for all multifamily models but only calculated for those models meeting all criteria)
Once the total standard solar thermal TDV savings is calculated, an equivalent amount of PV TDV (not to exceed 100% of proposed PV TDV) and proportional kWh will be moved from the Proposed Photovoltaics enduse into Flexibility Credit.

[Scott Criswell]

Initial features implemented in SVN r1768 - from that commit statement:
executables and ruleset source implementing new Self Util/Flexibility Credit where a portion of Proposed PV can offset standard design solar thermal (DHW) in MFam models w/ all-electric central DHW (tic #1208) ... and a couple of other bug fixes

• new Std-NSLRTH (no solar thermal) CSE run performed to help determine solar thermal savings in std design run, then SU/Flex PV credit of lesser between StdSlrThrmlTDV savings & PropPVTDV (shifted from PV (below the compliance line) to Self Util/Flex credit (above the compliance line)
• new checkbox exposed in DHWSys dialog to take this new Self Util/Flex PV credit (only when it is available based on above criteria) - defaulting to no credit

[Scott Criswell]

report change needed - label "Self Utilization Credit" in Energy Use Summary needs to be chnaged to "Self Utilization/Flexibility Credit"

[Robert Scott]

This needs to be changed in the schema and the text will be reflected in the rendered document. Asssigning to Diane to make this change in the schema.

<xsd:element name="SelfUtilCredit" >
                              <xsd:annotation>
                                 <xsd:documentation source="FieldText">Self Utilization Credit</xsd:documentation>
                                 <xsd:appinfo source="CBECCresXML">
                                    <dtyp:CBECCresXMLterm>:</dtyp:CBECCresXMLterm>
                                 </xsd:appinfo>
                              </xsd:annotation>

[Diane Pepetone]

I have changed the display term for this element that appears in single and multiple orientation subsections of the Energy Use Summary. It will be in the next version of the schema that I post.

[Scott Criswell]

Self Util/Flex display term updated in XSD from Diane 6/28 (SVN r1854)
Report not yet reflecting display term update

[Robert Scott]

The report template was returning the value for the first field in the xml which has a different value for that line. This has been modified for this column to read from the schema. See attached.

[Dee Anne Ross]

On 8/4 Danny Tam said this is an internal calculation. There is nothing to put on the CF1R. It will be reflected in the PV size. I'm marking verified.