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Guideline E.2: Renewable Energy

Intent

To facilitate the implementation of onsite renewable energy and promote the development of offsite renewable generation to satisfy project energy demand. Greater use of renewable energy reduces atmospheric pollution from fossil fuel-derived energy and can provide a stimulus to the state’s economy through investments in local energy jobs and manufacturing. Greater use of renewable energy also reduces the state’s expenditures on imported fuel and power.

The language of this guideline is intended to align with existing Minnesota legislation, which requires an economic analysis of onsite solar- and wind-derived renewable energy systems sufficient to offset two percent of predicted energy demand (MN Statute §16B.32, Subd 1a). This mandates the installation of such systems unless explicit reasons are provided that rule out installation.

Required Performance Criteria

Guideline E.2A and E.2B apply to all projects designated New Buildings. For projects designated Major Renovations, E.2A is recommended. E.2B is required for Major Renovations to the extent that the scope of the renovation aligns with the scope of the requirements.

    1. Provide at least two percent of the project’s energy needs with onsite solar or wind renewable sources:
      Eligible wind and solar renewable sources may include:

      • Photovoltaic (PV) solar panels
      • Wind turbines
      • Transpired solar collectors for heating air
      • Solar thermal systems for heating water

      Analyze at least two scenarios that include the environmental and economic impacts of supplying two percent of the project’s anticipated total energy use with onsite renewable generation systems. This is coordinated with Minnesota Statute §16B.32, which states in part that this analysis “must include an explicit cost and price analysis of complying with the two-percent requirement compared with the present and future costs of energy supplied by a public utility from a location away from the building site and the present and future costs of controlling carbon emissions. If the analysis concludes that the building should not meet at least two percent of its energy needs from renewable sources located on the building site, the analysis must provide explicit reasons why not.”[1] The feasibility of meeting this requirement for B3 Guidelines projects shall be determined using the B3 Levelized Cost of Energy (LCOE) Calculator to determine if the levelized cost of wind or solar is less than the combined price of grid and/or fossil fuel-supplied energy and carbon. The tool includes several default values for costs at the Predesign phase (including the accepted social cost of carbon) to streamline evaluation. These costs are refined at later phases. Installation of a system meeting two percent of the project’s anticipated energy need is required if the evaluation determines that the LCOE from a proposed system is less than the combined price of grid and/or fossil fuel-supplied energy and carbon.

    2. Ensure project design is renewable-energy ready:
      Solar-Ready Roof Requirements
      The building must be designed and built to facilitate future installation of solar systems on the building’s rooftop. Solar-ready roof planning begins with consideration for location, orientation, height, and massing of the building on the site, with the goal of maximizing exposure for solar systems mounted on the roof. At a minimum, a solar-ready building shall include:

      • Space on the roof that has unrestricted solar access to the south, is free of obstructions such as rooftop equipment, utility poles, plumbing vents, or other shading elements, and is structurally designed with attachment points, if necessary, to accommodate the weight, wind, and additional snow loads imposed by the system.
      • Roof material with sufficient durability and lifespan to withstand later solar installation and maintenance activities. Ensure that the warranty of the selected roof system will not be voided by future installation of a typical solar system.
      • An internal chase (or chases) with rated conduit and/or other means for connecting solar panels on the roof to the components and controls located within the building.
      • Space within the building that is conveniently located, readily accessible, and reserved for the installation of controls and components such as electric inverters, meters, disconnects, and hot-water storage tanks.
      • Solar-Ready Roof Plan, documenting location and extent of area dedicated for panels, chase location(s), electrical interconnection availability, roof structural capacity, and pertinent roofing product or system information.

      In some cases, these solar-ready roof requirements may be replaced with requirements for a renewable energy-ready site. Please contact B3 Guidelines Administrators at guidelines@b3mn.org to determine if project constraints permit this alternative. The following project constraints are permissible reasons to pursue the alternative renewable energy-ready site requirements:

      • Shading: If the project’s roof area is substantially shaded and reasonable massing and siting options for the building cannot remediate this condition.
      • Prohibitions against solar panels: If the project is located in a historic district or other zone that prohibits the use of solar panels on the building rooftop.
      • If project funding included proceeds from bonds that restrict the use of the building’s rooftop for third-party solar leases and the two-percent renewable requirement (part A) is met with onsite ground-mounted renewable energy.

      Alternative Renewable Energy-Ready Site Requirements
      The project’s site must be designed and built to facilitate future installation of renewable energy systems. At a minimum, a renewable energy-ready site shall include:

      • A designated area on the site that stays clear of required setbacks and planned building expansions, and has unrestricted solar access to the south, and/or unrestricted access to the prevailing wind directions.
      • Buried conduit sized sufficiently to conduct power from the designated area to components and controls located within the building.
      • Space within the building that is conveniently located, readily accessible, and reserved for the installation of controls and components such as electric inverters, meters, disconnects, and hot-water storage tanks.
      • Renewable-ready site plan, documenting location and extent of area dedicated for renewable systems, the unrestricted solar or wind access window, buried conduit location, and electrical interconnection availability.
      • Verification that local zoning regulations permit the construction and use of renewable energy systems on the building grounds.

      If both the building roof and nonbuilding site area are substantially shaded, not conducive to wind turbine placement, or prohibited from constructing renewable energy systems, please contact B3 Help at guidelines@b3mn.org to determine if these renewable energy-ready requirements (roof and/or site) can be considered out-of-scope.

[1] Minnesota Statute §16B.32, Subd. 1a.

Recommended Performance Criteria

    1. Achieve 2025 SB 2030 target with additional renewable energy:
      Provide sufficient renewable energy to achieve the building’s SB 2030 Energy and Carbon Standard for the year 2025. The renewable energy provided to meet this criteria may be supplied using any combination of the following approaches:

      • Onsite or on-campus systems
      • Offsite directly owned “portfolio”-based systems
      • Offsite renewable energy purchases including, but not limited to:
        • Community solar gardens
        • Renewable energy investment funds
        • Utility renewable energy programs
      • Purchase of Renewable Energy Credits (RECs)

      Note that the SB 2030 program requires prioritization of renewable energy resources in the order listed above. Once the required SB 2030 target is met, compliance with this recommended guideline permits any of the above to be used. Note also that offsite purchases including RECS must meet minimum contract requirements set forth in the Meeting the Guidelines section below.

    2. Achieve net-zero energy with additional renewable energy:
      Provide adequate renewable energy to achieve net-zero energy use for the building’s energy consumption using any of the resources outlined under E.2C.
    3. Achieve net-zero energy with additional onsite renewable energy:
      Provide additional onsite renewable energy to achieve net-zero energy use for the building’s energy consumption using only onsite or on-campus systems.[2]
    4. Provide resilient power infrastructure capacity by installing either: [3]
      • Grid disconnection capability and photovoltaic system with battery storage.
      • Grid disconnection capability and permanently installed efficient dual-fuel or cleaner-fuel generator and fuel storage.
      • Grid disconnection and electrical connection point to permit portable generator use.

      These systems should be sized to provide emergency power for the project’s identified critical loads for a period of three days. If the building is located within the 500-year flood plain, resilient power infrastructure and equipment above the flood elevation should be installed, if building height permits. Also note that if generators are deployed, dual-fuel or cleaner-fuel (such as natural gas) generators are recommended to reduce airborne pollution.

[1] Compliance with this guideline is similar to meeting National Renewable Energy Lab Net Zero Options 1-4.

[2] Compliance with this guideline is similar to meeting National Renewable Energy Lab Net Zero Options 1 or 2.

[3] These requirements are aligned with RELI, HA Requirement 2 and Enterprise Community Foundation, 2015 Green Communities Criteria 5.8a and 5.8b.

Implementation in the Design Process:

Project teams should be aware that there is a distinction between the allowable locations for renewable energy installed to meet the SB 2030 Energy Use Intensity (EUI) targets (discussed as part of the SB 2030 Energy and Carbon Standard), and the allowable installation locations to meet the requirements of Guideline E.2A discussed here. This is due to the different legislation that governs each set of requirements. To fulfill the SB 2030 Energy and Carbon Standard, onsite and on-campus renewable energy installations are considered equivalent. Either location is acceptable, and together they form the first tier in a hierarchy of installation locations that can be used to meet the SB 2030 Energy Standard. However, only renewable energy that is installed on the building site may be used to comply with Guideline E.2A. This guideline requires that two percent of the predicted total project energy consumption (including space heating, water heating, and natural gas consumption) must be met by renewable energy generated onsite.

Furthermore, Guideline E.2B requires that all new projects constructed under the B3 program are “renewable ready,” in support of E.2A. Solar-ready roofs are prioritized, but a solar-ready site may achieve compliance as well under certain circumstances.

Therefore, project teams may find themselves in a scenario where installing or acquiring renewable energy from an on-campus renewable energy system is the most cost-effective way to meet the SB 2030 Energy and Carbon Standard for the building, but an installation on the building’s solar-ready roof or site is still required by the legislation referenced in this guideline. In that case, the project team may decide to provide all of the renewable energy on the building site, or install just enough renewable energy onsite to meet the two-percent requirement, while providing the rest with a campus-based (or even portfolio-based) approach.

Meeting the two-percent renewable energy requirement mandated by this guideline is only necessary if it is found to be cost effective. The cost effectiveness must be determined using the B3 LCOE Calculator. Two options must be investigated using the LCOE calculator to achieve compliance with E.2A: a solar photovoltaic (PV) option, and either a solar hot water or small wind option. Each of these three technologies has its own tab in the LCOE tool. Note that ground source (geothermal) heat pumps, air source heat pumps, and passive solar energy may be desirable for the project, but do not qualify to meet the requirements of E.2A. Also, transpired solar thermal collectors may be evaluated as a second option, but are not supported by the LCOE calculator. If the design team wishes to pursue transpired solar collectors as a second option, please consult the B3 Guidelines Administrators at guidelines@b3mn.org to assist in calculating levelized cost.

During predesign, the LCOE calculator requires a small number of inputs to perform the levelized cost of energy calculation. These inputs typically include the required yearly energy production (of at least two percent of predicted total project energy use as determined by the SB 2030 Energy Standard Tool (E.1A)) and the yearly average fuel/electricity costs at the site (including any demand charges, delivery charges, surcharges, and fees). All other necessary inputs are generally provided as either defaults or assumptions built into the calculation cells. Input cells with default values should not be adjusted unless there is documented justification. Calculation cells are locked so users cannot inadvertently adjust them.

If in the Predesign phase, the LCOE calculator shows that solar or wind may be cost effective, then project teams must advance to the Design phase calculator. At this phase, the LCOE calculator requires cost inputs from a contractor estimate. Note that for new projects, the additional structural costs for a solar-ready roof should not be included in the cost estimate since solar-ready roofs are required regardless of whether renewable energy is immediately installed. Using the refined costs from the contractor estimate, upload outputs from the Design phase LCOE calculator to the B3 Guidelines Tracking Tool. If the calculator shows that renewable energy is cost effective at this phase, then a renewable energy system capable of providing at least two percent of the building’s projected total energy consumption must be installed. Identification of the installed system will be verified at project closeout.

For renovation projects that are not renovating the roof, the solar-ready roof requirements are considered optional, as is the installation of a renewable energy system to meet the two-percent requirement. However, renovation projects that do require renovation or replacement of the roof will be required to make the roof solar-ready, to the extent made possible by the scope of work. For those projects, the addition of a renewable energy system is still optional but is recommended. A site is required to be made renewable-ready only when a solar-ready rooftop is not viable—determined in coordination with the B3 Guidelines Administrators as discussed above—and the renovation scope significantly impacts the site.

Because photovoltaic system pricing has achieved cost-parity with utility-generated electricity for many systems and throughout most of the state, and because solar-ready roofs are required for most B3 projects, project teams should budget for these expenses for all new construction projects.

Resilient Power Infrastructure

If pursuing recommended guideline E.2F, the project team should consider how the facility could function during a disaster event that disrupts grid electrical supply, above and beyond any code-mandated emergency power systems. When selecting the critical loads that will be supplied during a disaster event, first determine the intent of the facility’s operation and assess which installed systems will be crucial in supporting the operation during a disruption. These may include: heating, cooling, ventilation, in-building transportation, lighting and/or emergency lighting, communications, appliances or equipment, and miscellaneous plug loads for things like charging cell phones. When evaluating disaster scenarios, it is important to consider the needs of vulnerable populations, such as those who may not have the capacity to evacuate or who are dependent on building systems such as refrigeration for medication. The energy demands of the selected loads should be determined by energy modeling, and the resilient power infrastructure should be sized to accommodate these loads for a period of at least three days.

Requirements for Offsite Renewable Energy Purchases:

Offsite renewable energy is not permitted to be used to meet the requirements of E.2A. However, a variety of options including the purchase of RECs are available to meet the E.2 Recommended Guidelines E.2C and E.2D. In order for the offsite renewable energy procurement methods to offset the annual energy consumption of the building, they need to meet the following minimum requirements:[1]

  1. The building owner shall contract to procure qualifying offsite renewable energy with a term of not less than 10 years.
  2. RECs and other environmental attributes associated with the procured offsite renewable energy shall be assigned to the building project for the duration of the contract. (Note that this may prohibit renewable energy purchases from most types of community solar gardens as these often separate RECs from produced energy).
  3. The renewable energy generating source shall be photovoltaic systems, solar thermal power plants, geothermal power plants, and/or wind turbines.
  4. The offsite renewable energy producer shall maintain transparent accounting that clearly assigns production to the building. Records on power sent to or purchased by the building shall be retained by the building owner.

Related Legislation:

There may be implications resulting from Minnesota Statute §16B.323, which states in part that, “a project for the construction or major renovation of a state building, after the completion of a cost-benefit analysis, may include installation of solar energy systems of up to 300 kilowatts capacity on, adjacent to, or in proximity to the state building.” Additionally “The capacity of a solar energy system must be less than 300 kilowatts to the extent necessary to match the electrical load of the building,” and “The cost of the solar energy system must not exceed five percent of the appropriations from the bond proceeds fund for the construction or renovation of the state building.”

Minnesota Statute §16B.326 also states that “when practicable, geothermal and solar thermal heating and cooling systems must be considered when designing, planning, or letting bids for necessary replacement or initial installation of cooling or heating systems in new or existing buildings that are constructed or maintained with state funds. The Predesign review must include a written plan for compliance with this section from a project proposer. For the purposes of this section, ‘solar thermal’ means a flat plate or evacuated tube with a fixed orientation that collects the sun’s radiant energy and transfers it to a storage medium for distribution as energy for heating and cooling.”

This section does not provide a comprehensive list of potentially relevant legislation or the full text of those statues cited. Please reference the Revisor of Statues of the State of Minnesota for full legislation text.

[1] These requirements are generally aligned with the Architecture 2030 Zero Code for Off-Site Procurement of Renewable Energy

Predesign:

  • 2A: Predesign plan for projects using state Predesign process; Predesign LCOE calculator documenting two systems evaluated (including at least one PV) for meeting two percent of annual energy demand.
  • 2B: Site plan delineating areas with the most feasible solar (or wind) access, accounting for planned site and building development.

Design:

  • 2A: Design phase LCOE calculator documenting two systems evaluated for supplying at least two percent of annual energy demand, including contractor estimates of performance, yearly energy production, and cost.
  • 2B: Documentation of renewable-ready design features included in the project design.
  • 2C: Documentation of project’s predicted 2025 SB 2030 EUI target and yearly total energy consumption.
  • 2D: Documentation of project’s predicted yearly total energy consumption, showing guideline met.
  • 2E: Documentation of project’s predicted yearly total energy consumption, showing guideline met.
  • 2F: List of identified critical electric loads to be served and their associated power demand (kW), and 3-day energy consumption estimate (kWh).

Final Design:

  • 2A: Updated Design phase LCOE calculator documenting two systems evaluated for supplying at least two percent of annual energy demand, including updated contractor estimates of performance, yearly energy production, and cost, and selection of the final system for installation.
  • 2B: Documentation of renewable-ready design features included in the project including the Solar-Ready Roof Plan or Renewable-Ready Site Plan.
  • 2C: Documentation of onsite renewable energy system and energy production estimate or offsite renewable energy purchase to achieve the 2025 SB 2030 EUI target.
  • 2D: Documentation of onsite renewable energy system and energy production estimate or offsite renewable energy purchase to achieve net-zero energy.
  • 2E: Documentation of onsite renewable energy system and energy production estimate to achieve net-zero energy.
  • 2F: Documentation of resilient power system to be installed, including any dual- or cleaner-fuel generators and fuel storage, and grid disconnect. Updated list of critical electric loads to be served and their associated power demand (kW) and three-day energy consumption estimate (kWh).

Closeout:

  • 2A: Verification of installed renewable energy system and final yearly energy production estimate.
  • 2B: Verification of installed renewable-ready design features included in project.
  • 2C: Verification of installed renewable energy system and final yearly energy production estimate, or contract for purchase of offsite renewable energy adequate to achieve 2025 SB 2030 EUI target. Contract must specify minimum quantity and type of renewable energy, term of contract (years), location of renewable energy source, and must clearly assign associated RECs to the B3 project.
  • 2D: Verification of installed renewable energy system and final yearly energy production estimate, or contract for purchase of offsite renewable energy adequate to achieve net-zero energy. Contract must specify minimum quantity and type of renewable energy, term of contract (years), location of renewable energy source, and clearly assign associated RECs to the B3 project.
  • 2E: Verification of installed renewable energy system and final yearly energy production estimate adequate to achieve net-zero energy.
  • 2F: Verification of installed resilient power systems, including any dual- or cleaner- fuel generators and fuel storage, and grid disconnect.

Appendix E-2a: User Guide – Levelized Cost of Energy Calculator, Predesign Phase

Appendix E-2b: Levelized Cost of Energy Calculator, Predesign Phase

Appendix E-2c: Levelized Cost of Energy Calculator, Design Phase

Minnesota Renewable Legislation: MN Statute §16B.32, Subd 1a: www.revisor.mn.gov/statutes/?id=16B.32

Minnesota Legislation: Solar Energy in State Buildings: §16B.323 Solar Energy In State Buildings: www.revisor.mn.gov/statutes/?id=16B.323

Minnesota Legislation: Geothermal Energy in State Buildings: §16B.326 Heating And Cooling Systems; State-Funded Buildings: www.revisor.mn.gov/statutes/?id=16B.326

The Database of State Incentives for Renewable Energy (DSIRE): http://www.dsireusa.org/

RETScreen Software: www.retscreen.net

The Minnesota Department of Commerce Guidance Documents and Model Solar-Ready Specifications: http://mn.gov/commerce-stat/pdfs/solar-ready-building.pdf and http://mn.gov/commerce-stat/pdfs/solar-ready-construction.pdf

US Green Building Council (USGBC) Rules of Thumb for Solar Readiness: https://www.usgbc.org/articles/making-all-buildings-solarready-7-rules-thumb

National Renewable Energy Laboratory Solar-Ready Technical Considerations: https://www.nrel.gov/state-local-tribal/blog/posts/solar-ready-building-design-a-summary-of-technical-considerations.html

Energy Trust of Oregon Solar-Ready Commercial Design and Construction Requirements: https://insider.energytrust.org/wp-content/uploads/nb_solarready_comm_design_construction_req.pdf

National Renewable Energy Laboratory—Valuing the Resilience Provided for Solar and Battery Energy Storage Systems: https://www.nrel.gov/docs/fy18osti/70679.pdf