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Guideline E.2: Renewable Energy

Intent

To require a minimal use of onsite renewable energy and to encourage the broader consideration and use of renewable energy sources and cleaner forms of energy to reduce atmospheric pollution. This can provide a stimulus to the state’s economy through investments in local jobs and materials while reducing the state’s expenditures on imported fuel and power. The language of this guideline is intended to align with Minnesota legislation, which requires an economic analysis of onsite solar-and-wind-derived renewable energy systems sufficient to offset 2% of predicted energy demand (MN Statute §16B.32, Subd 1a). This legislation requires the installation of such systems unless explicit reasons are provided that rule out installation.

Required Performance Criteria

Guidelines apply to all projects designated New Buildings and are recommended for Major Renovations.

  1. Provide at least 2% of energy needs with onsite solar or wind renewable sources. Eligible wind and solar renewable sources may include:
      1. Photovoltaic solar panels which convert sunlight directly into electricity.
      2. Wind turbines that capture wind to turn rotors, which turns a generator and creates electricity.
      3. Transpired solar collectors that use sunlight to preheat air for heating purposes.
      4. Solar thermal systems that use the sun to heat water for heating or domestic hot water uses.

    Analyze at least two scenarios that include the environmental and economic impacts of supplying 2% of the building’s anticipated total energy use with onsite renewable generation systems. This is coordinated with Minnesota Statute §16B.32, which states 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]

    [1] Minnesota Statute §16B.32, Subd. 1a. www.revisor.mn.gov/statutes/?id=16B.32

    Evaluation of the feasibility of the 2% systems for projects shall be done 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 energy and carbon. The tool includes several generic values for costs at the predesign phase to streamline evaluation which are refined at later phases. Installation of a system meeting 2% of the anticipated energy need of the project is required if the evaluation determines that the levelized cost of energy from a proposed system is less than the combined price of grid energy and carbon.

  2. Design project to be solar-ready to facilitate future solar design retrofits or expansion of installed systems. Solar-ready considerations include planning for the location of solar systems in building orientation and massing, structure to support solar systems, electrical or plumbing chases, dedicated mechanical space, and planning for maintenance access to allow straightforward installation and operation.

Recommended Performance Criteria

  1. Provide 10% of energy needs with renewable and cleaner distributed generation systems. Consider the inclusion of all renewable and cleaner distributed generation approaches to meet 10% or more of the buildings energy needs. This goal may be achieved through the construction budget by paying for the design and installation of a renewable or cleaner distributed generation system or through the operating budget through a contract to purchase renewable or cleaner distributed generation.
  2. Provide 100% or more of energy needs with renewable and cleaner distributed generation systems. Consider the inclusion of all renewable and cleaner distributed generation approaches to meet 100% or more of the buildings energy needs. This goal may be achieved through the construction budget by paying for the design and installation of a renewable or cleaner distributed generation system or through the operating budget through a contract to purchase renewable or cleaner distributed generation.

Implementation in the Design Process:

Identify the potential investment value of onsite generation to offset 2% of predicted energy use during Predesign and site selection. Evaluate and adjust building geometry and orientation for solar-based energy solutions, and investigate the viability and potential of other onsite renewable and distributed energy options. Also evaluate the proximity to nearby renewable distributed energy generation sources and the transmission potential to the site and/or the investment potential for the project.

Two options must be investigated using the LCOE calculator to achieve compliance with E.2 Renewable Energy: a solar photovoltaic (PV) option, and either a solar hot water or small wind option. Transpired solar thermal collectors may be evaluated as an second option but are not supported by the LCOE calculator. If the design team wishes to pursue this option the B3 Guidelines Team may be consulted to assist in calculating levelized cost. 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.2.

During the Predesign phase 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 (>/= 2% of predicted total building energy use as determined by the SB 2030 Energy Standard Tool (E.1.c)) 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 either provided as defaults or assumptions built into the calculation cells. Input cells with default values should not be adjusted unless there is reason to adjust them. Calculation cells are locked so users cannot adjust them.

During the Design phase, locate renewable and distributed energy installation areas on plans, elevations and sections as appropriate. Investigate spatial and loading impact on site, architectural, mechanical and electrical systems and develop preliminary performance specifications for the selected technology(s). The Design and Final Design versions of the LCOE calculator require more detailed information than the predesign version, and should correspond to contractor refined performance characteristics, energy production, and cost. Outputs of the refined assumptions are uploaded in the B3 Guidelines Tracking Tool at the Design phase and updated with final estimates for Final Design phase. Identification of which system was installed will be verified at project Closeout.

Related Legislation:

There may be implications resulting from Minnesota Statute §16B.323, which states in part that the project may, “after the completion of a cost-benefit analysis, may include installation of “Made in Minnesota” solar energy systems of 40 kilowatts capacity on, adjacent, or in proximity to the state-funded building.” Additionally “The capacity of a solar system must be less than 40 kilowatts to the extent necessary to match the electrical load of the building or to the extent necessary to keep the costs for the installation below the five percent maximum…” Note that this limits the cost of “Made in Minnesota” solar that can be installed on site to no more than 5 percent of the appropriation.

Minnesota Statute §16B.326 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.

Predesign:

  • E.2A: Predesign plan for projects using state predesign process, Predesign LCOE calculator documenting two systems evaluated (including at least one PV) for meeting 2% of annual energy demand.

Design:

  • E.2A: Design LCOE calculator documenting two systems evaluated for meeting 2% of annual energy demand including contractor estimates of performance, energy production and cost.
  • E.2B: Verification of solar-ready design features included in project.
  • E.2C: Detail and verification of system meeting 10% of annual energy need.
  • E.2D: Detail and verification of system meeting 100% of annual energy need.

Final Design:

  • E.2A: Updated LCOE calculator documenting two systems evaluated for meeting 2% of annual energy demand, including updated contractor estimates of performance, energy production and cost, and selection of which system planned for installation.
  • E.2B: Verification of solar-ready design features included in project.
  • E.2C: Detail and verification of system meeting 10% of annual energy need.
  • E.2D: Detail and verification of system meeting 100% of annual energy need.

Closeout:

  • E.2A: Updated LCOE calculator documenting two systems evaluated for meeting 2% of annual energy demand, including updated contractor estimates of performance, energy production and cost, and selection of which system installed.
  • E.2B: Verification of installed solar-ready design features included in project.
  • E.2C: Detail and verification of system installed meeting 10% of annual energy need.
  • E.2D: Detail and verification of system installed meeting 100% of annual energy need.

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

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