SURNA Grow Facility: Systems Comparison - IEA

Transcription

1 SURNA Grow Facility: Systems Comparison - IEA May 2016

2 SURNA Grow Facility This analysis provides the projected energy and associated cost comparison between the Surna proposed facility in comparison to an otherwise identical indoor facility with conventional systems for its operation. Provided in the sections below are a summary of input assumptions for the simulation as well as a discussion of the analysis approach and resulting output from the simulations. Grow Facility Model Shown below in the figure below is the model representation of the SURNA Hybrid Grow Facility with inputs and assumptions as noted in the Appendix. Figure 1 - SURNA Hybrid Facility Boulder, CO

3 Grow Facility Loads Summary Provided in the tables below are the peak building loads for the facility operating as described in Boulder, CO. For this analysis only the production areas have been modeled and include interior lighting and HVAC enduses. Loads for humidity control have not been included in this analysis as expected water use watering loads and schedules are not known. The peak coincident load on the facility is summarized in Table 2. As can be seen, the peak loads in the facility are driven by solar gain to the space through the glazing for cooling and through glazing conduction for heating. The lighting load with daylighting controls as described represents approximately 27% of the peak load components with a total glazing load representing 72%. Shading and controls are not included in this analysis. Table 1 Peak Building Load Components

4 The peak load for each production area is summarized in Table 3. The total load offset for both facility scenarios are provided with system capacities based on design conditions as shown. The total supply air is calculated on a constant supply air temperature (SAT) and constant chilled water supply (CHWS) temperature with no temperature reset controls. Table 2 Grow Facility System Summary Qsens (kbtu/hr) Transpiration Cool SAT Supply (CFM) System Indoor Hybrid (gal/day Qlat (kbtu/hr) (F) (F) Indoor Hybrid Flower +1, NA ,100 41,800 Veg NA ,100 10,100 Balance unconditioned The predominant equipment loads in the facility is attributed to lighting as described in the table below with associated lighting schedules shown in the figures that follow. Table 3 Zone Lighting Load Summary Zone Fixture (kw) Count Total (kw) Indoor Hybrid Schedule On Daylight Ctl Indoor Hybrid Flower NA NA a-6p NO YES Veg NA NA a-10p NO NO Balance not included Figure 2 Lighting Schedules

5 The annual energy enduse for the Indoor Grow Facility along with monthly energy use is summarized in Figure 3. As shown, lighting energy is the dominate energy enduse in the facility, representing 73% of annual energy use. Cooling energy represents approximately 24% with the balance of energy being contributed to ventilation fans. Note there is no (0.0%) heating energy use energy required under operating conditions as described. Figure 3 Grow Facility Enduse Summary The total annual energy use for the production areas of the Indoor Grow Facility is 2,812,300kWh with an associated cost of $247,400.

6 The annual energy enduse for the Surna Hybrid Grow Facility along with monthly energy use is summarized in Figure 4. As shown, lighting energy is the dominate energy enduse in the facility, representing 72% of annual energy use. Cooling energy represents approximately 23% with the balance of energy being contributed to ventilation and pump energy. Note there is no (0.0%) heating energy use energy required under operating conditions as described. Figure 4 Grow Facility Enduse Summary The total annual energy use for the production areas of the Indoor Grow Facility is 965,600kWh with an associated cost of $101,200.

7 Energy Conservation Measures DAYLIGHTING CONTROLS Opportunities to utilize daylight in the space in conjunction with appropriate lighting controls for reduced energy use and associated energy cost savings has been evaluated. They typical measurement for lighting control is foot-candle (FC) which is measure of light within the visible light spectrum of humans. For plants, the metric of interest is the daily light integral (DLI) which is a measure of the amount of light received over the course of a day; the amount of Photosynthetically Active Radiation (PAR) per unit area. Based on this information, lighting controls are shown to offset a total of 69 hours of required artificial light throughout the flower area resulting in a facility electrical energy use reduction from 1,828,100kWh to 965,691kWh and a peak demand reduction from 667kW to 340kW with a resulting energy cost savings of $53,175. Additional incentives may be available through the local utility for energy efficiency measures implemented as part of this project and should be investigated. Utility Summary As shown in Figure 4, the facility end uses for the operation of this facility is primarily comprised of ventilation and lighting with specific load and equipment information provided. Humidity control, process cooling, and operational support office energy is not included in this analysis. The simulated peak electrical demand for this facility is 338.6kW. A representative time of use (TOU) utility rate schedule has been used to capture the impact of billing demand and availability for opportunities for reduced TOU costs as shown in Table 4. Table 4 - TOU Utility Rate Summary Season Dates $/kwh $/kw Monthly Summer Jun-Sep $ $16.02 Winter Jan-May / Oct-Dec $ $14.67 $28.59 From this information, the estimated monthly and resulting annual energy cost is provided in Figure 5. As shown, the total estimated energy use for operating this is 951,854 kwh with an associate cost of $100,308. The Surna Hybrid Grow Facility system is projected to save over $147,100 when compared to the energy use of the facility with conventional DX HVAC systems, shown below for comparison.

8 Figure 5 - Grow Facility Energy Use Indoor Grow Facility Surna Hybrid Grow Facility

9 Appendix Building Component Baseline Surna Comments General Parameters Weather Data Boulder, CO Building Type Metal building Building Area 8,000ft 2 +/- Above-Grade Floors 2-floor facility with high-bay process areas S: Jun-Sep $ /kWh $16.02/kW Energy Cost W: Jan-May / Oct-Dec $ /kWh $14.67/kW Building Orientation Plan North Zoning Pattern By activity Perimeter Zone Depth NA Floor to Floor Height 12 ft Floor to Ceiling Height 10 ft Roof Construction R-30 Roof Pitch 27⁰ WallConstruction Steel framed R-19 Batt Floor 6 concrete Infiltration-Core/Perimeter 0.001/0.003 cfm/ft2 Door Type Opaque, insulated with thermal break Space Parameters Total Vegetation Area Flower Area 8,000sf 1,500sf 6,200sf 8,000sf 1,500sf 6,200sf Lighting Power Density (kw) 56.1kW veg 56.1kW veg 387.5kW flower 387.5kW flower Daylighting NO YES Occupancy Sensors NO NO Exterior Lighting 0.0kW 0.0kW HVAC System Packaged Single Zone DX Surna Fan Coil Unit Supply Fan Control Constant Volume Constant Volume Office area included in model, but not regularly conditioned. Production area includes vegetation and grow areas as shown.

10 Building Component Baseline Surna Comments Zone Minimum Airflow NA NA Outdoor Air (OA) 0.00 CFM/sf 0.00 CFM/sf Analysis for production systems only. Production systems modeled as recirculation only, no OA. Infiltration 0.001/0.003 cfm/ft /0.003 cfm/ft2 Core/Perimeter Preconditioner NO NO Evaporative preconditioner not included in model. Heat Recovery NO NO Heat recovery not included in model. Plant Parameters Boiler NA NA Hydronic heating not included in model. Simulated with electric heat. DX Chiller NA 12 EER/0.280 EIR Air cooled compressor Baseline DX system modeled with a cooling EIR of No Economizer WC Chiller NA NA Domestic Hot Water Loop NA NA DHW not included Design Temperature - - Flow Control - - Loop Head - - Space Hot Water Loop NA NA HW not included Design Temperature - - Flow Control - - Loop Head - - Chilled Water Loop No CHW in Baseline Model Design Temperature NA 44F, 10F dt Flow Control - Variable Speed