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Scientific Irrigation Scheduling Provisional Standard Protocol. Regional Technical Forum November 19, 2013. Scientific Irrigation Scheduling Measure Overview. Current Category: RTF Calculator (pre-Guidelines) Current Status: Under review for Guidelines compliance
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Scientific Irrigation SchedulingProvisional Standard Protocol Regional Technical Forum November 19, 2013
Scientific Irrigation SchedulingMeasure Overview • Current Category: RTF Calculator (pre-Guidelines) • Current Status: Under review for Guidelines compliance • Current Sunset Date: Unclear • Reason for Update/Review: Guidelines Compliance • Baseline Type: Current Practice • Subcommittee Review Yes
Staff Highlighted Areas • Findings from 2003 – 2005 Quantec study • Control group not consistent with Guidelines definition of baseline • Significant uncertainty in results • Significant subcommittee concerns about staff proposal • Reduction in savings percentage • Provisional data collection requirements • Use of AgriMet for evapotranspiration and precipitation data • Provisional data collection is limited to “simple systems” • Single crop • Pump or pumps on dedicated utility meter
Measure History • 2003 – 2005 – Quantec conducts 3-part study of baseline irrigation practices and SIS impacts for BPA. • Concludes that SIS is, on average, 10% more water-efficient than irrigation without water management. • January 2006 – RTF approves SIS Calculator • Uses 10% savings estimate from Quantec study • November 2012 – Cascade Energy, under RTF contract, proposes a Guidelines-compliant SIS Standard Protocol modeled after the SIS Calculator. • The RTF decides to table a decision until the Guidelines address parameter requirements for Standard Protocols. • July/August 2013 – RTF staff and Subcommittee revisit the SIS Standard Protocol. [see Findings upcoming slide] • November 2013 – RTF staff present Proposed Provisional Standard Protocol to subcommittee. [see Findings in upcoming slide]
Quantec Study – 2003 to 2005 http://rtf.nwcouncil.org/subcommittees/SIS/SIS%20Final%20Report%20Phase%20II%20(1).pdf
Quantec Study – Phase 1. Baseline Practices 43% of irrigated acres are irrigated efficiently • Survey of 776 farms across the PNW • Quanteccategorized farms according to irrigation decision-making practices • “Examination of reported water use and their deviations from known irrigation requirements indicated that, by and large, farms in practice level I tend to use less water than farms that use less sophisticated practices. Comparison of mean water use derived from a regression model of water use showed that application of the combination of methods used in practice levels I and II are likely to result in water savings of approximately 12% and 10%, respectively.”
Quantec Study – Phase 2. Impact Study The impact study compared growers known to use outside SIS services to growers known not to practice water management. I.e. – compare the best to the worst. “It was therefore decided to select the treatment group from among growers who received water management services through GWMA or IRZ Consulting, and to select the control group from farms in close proximity to the treatment farms. The main advantage of this approach was that it offered a more consistent basis for defining water management practices among the treatment group and significantly helped the recruitment and data collection processes. “To ensure comparability with the treatment group, each treatment field was matched with a local control field with the same crop grown by a farmer known not to practice water management.”
Quantec Study – Impact Study • Analysis • Meter irrigation water use - indirect measurement: log line pressure at point of delivery, multiply by sprinkler design flow rate • Estimate “ideal” water use – use water balance model specific to county-level weather, field soil type, crop type (evapotranspiration rates) • Ideal water use is the normalizing factor for all fields (control and treatment) • Findings • Control group used 12% more water than ideal • Treatment group used 2% more water than ideal • Based on this, a 10% water savings for SIS is proposed
Measure History • July/August 2013 – RTF staff and Subcommittee revisit the SIS Standard Protocol. Findings: • Application of results of Quantec study (savings = 10% of ideal) is not in compliance with the Guidelines, because baseline only considers the least efficient irrigators. • Significant uncertainty in the savings estimates: do not meet the rigor requirements of a Proven RTF measure. • Programs could collect pre-participation data to eventually specify the baseline. • About half of participants have simple enough systems (single crop, dedicated pumps, dedicated meter) to yield useful data for a baseline study. • There is no appetite for an experiment to observe the persistence of savings, which would require restricting participation. One year measure life must be imposed. • Broad range of regional experience on subcommittee: in some regions, SIS programs have been cancelled because everyone’s doing it anyway. In other regions, SIS would not be popular without programs.
Measure History • July/August 2013 – RTF staff and Subcommittee revisit the SIS Standard Protocol. Findings: • Application of results of Quantec study (savings = 10% of ideal) is not in compliance with the Guidelines, because baseline only considers the least efficient irrigators. • Significant uncertainty in the savings estimates: do not meet the rigor requirements of a Proven RTF measure. • Programs could collect pre-participation data to eventually specify the baseline. • About half of participants have simple enough systems (single crop, dedicated pumps, dedicated meter) to yield useful data for a baseline study. • There is no appetite for an experiment to observe the persistence of savings, which would require restricting participation. One year measure life must be imposed. • Broad range of regional experience on subcommittee: in some regions, SIS programs have been cancelled because everyone’s doing it anyway. In other regions, SIS would not be popular without programs.
Staff Conclusions • Savings estimate should reflect current (as of 2003 Quantec study) practice: • 57% of acres irrigated without water management (10% savings) • 43% of acres irrigated with water management (0% savings) • Results from study are not rigorous enough for a proven measure • Research is feasible and could lead to a proven measure • Research could achieve the following • More certain regional savings estimate • Estimate of the impacts of measure identifier including • Location • Farm size • Water source • Irrigation system type • Explore the relationship between AgriMet-based and service-provider reported results
Measure History • November 2013 – RTF staff present Proposed Provisional Standard Protocol to subcommittee. • Findings: • Concerns • Reduced savings in the proposal threatens program cost-effectiveness • Additional cost of provisional data collection will further hurt programs • Ability to collect provisional data may be hampered by low cost-effectiveness of the provisional measure
Best Practice Method Proposal: • Develop a model that predicts water consumption – relative to gross water requirement (i.e., ideal water consumption) – based on factors such as • Use of SIS services • Crop type • Location • Farm size • Soil type • Total dynamic head • Collect pre and post data from existing participants to inform the structure of the model, and to calibrate the model
Best Practice Method • For pre and post years, determine water consumption relative to gross water requirement. • Pump kWh – from billing data if pump is isolated, otherwise metered • Irrigation system specifics – from interview with participant • Evapotranspiration (as function of crop type, soil type, location, year) – from AgriMet Collect three years of pre data where possible Service provider may recommend a different data source than AgriMet • Build a database of this information • Because of crop rotation, pre-data from a single participant is not sufficient to determine savings. • Post-data must be lined up with pre-data of the same crop • Use regression techniques to estimate the impact of program participation, holding all else constant (crop type, evapotranspiration, irrigation system, location, farm size) • Impact will be in percentage point difference of ideal water • Water savings (acre feet) = [SIS Impact] x [Gross Water Requirement] • Energy savings (kWh) = [water savings] x [kWh/acre foot for irrigation system]
Best Practice Method • For pre and post years, determine water consumption relative to gross water requirement. • Pump kWh – from billing data if pump is isolated, otherwise metered • Irrigation system specifics – from interview with participant • Evapotranspiration (as function of crop type, soil type, location, year) – from AgriMet Collect three years of pre data where possible Service provider may recommend a different data source than AgriMet • Build a database of this information • Because of crop rotation, pre-data from a single participant is not sufficient to determine savings. • Post-data must be lined up with pre-data of the same crop • Use regression techniques to estimate the impact of program participation, holding all else constant (crop type, evapotranspiration, irrigation system, location, farm size) • Impact will be in percentage point difference of ideal water • Water savings (acre feet) = [SIS Impact] x [Gross Water Requirement] • Energy savings (kWh) = [water savings] x [kWh/acre foot for irrigation system]
Best Practice Method • For pre and post years, determine water consumption relative to gross water requirement. • Pump kWh • Irrigation system specifics • Evapotranspiration (as function of crop type, soil type, location, year) Actual water consumption Gross water requirement Pump kWh Irrigation system Crop type Location Soil type Year Field(s) size Irrigation energy model Water ratio: Actual to Ideal / Evapotranspiration model
Best Practice Method • Build a database of this information • Because of crop rotation, pre-data from a single participant is not sufficient to determine savings. • Post-data must be lined up with pre-data of the same crop This table is for illustrative purposed only, it does not contain real data
Best Practice Method • Use regression techniques to estimate the impact of program participation, holding all else constant (crop type, evapotranspiration, irrigation system, location, farm size) • Impact will be in percentage point difference of ideal water • Water savings (acre feet) = [SIS Impact] x [Gross Water Requirement] This function will not be known until the database is constructed and analyzed. where This is the product of a water balance model.
Best Practice Method • Energy savings (kWh) = [water savings] x [kWh/acre foot for irrigation system] where
Candidate Simplest Reliable Method Proposal: • Estimate water savings as a percentage of the gross water requirement. • Gross water requirement would be specified by the SIS service provider. • Savings percentage would initially be based on the Quantec study. Once a reliable model of savings has been developed, the savings percentage would be determined by using the model.
Candidate Simplest Reliable Method Baseline • The current SIS standard protocol uses a 10%-of-ideal estimate of savings. • This assumes a baseline comprised entirely of inefficient irrigators. • This is not consistent with the RTF Guidelines • “The current practice baseline defines directly the conditions that would prevail in the absence of the program (the counterfactual), as dictated by codes and standards or the current practices of the market.” Guidelines – Roadmap – Section 1.3.2 Savings • The baseline is comprised of • 57% of acres that are not irrigated efficiently • 43% of acres that are irrigated efficiently Estimated 10% savings from SIS Estimated 0% savings from SIS
Candidate Simplest Reliable Method • Annual Water savings = [gross water requirement] x [SIS Δ% of ideal] • [gross water requirement] = either AgriMet-based or consultant report (to be determined) • [SIS Δ% of ideal] • For now, = [10%] x [ 1 – baseline SIS saturation] • 10% savings was estimated by Quantec (2003 – 2005) as the savings of going from inefficient irrigation practices to SIS • [ 1 – baseline SIS saturation] accounts for some participants already using efficient irrigation practices before subscribing to SIS services • 57%, estimated by Quantec (2003- 2005) studies • So, for now, the Simplest Reliable Method would be : Annual Water Savings = [Gross Water Requirement]*[10%]*[57%] = [Gross Water Requirement]*[5.7%] • Once provisional data has been collected, [SIS Δ% of ideal] will be determined from the regression analysis used in the Best Practice Method
Data Collection Requirements • Participant (survey) • Static data • Location (county, state) • Soil type • Irrigation system type • Farm size (acres) • Pump station information • Annual data (3 years pre, plus participation years) • Crop type • Modifications to irrigation system (e.g., change in acres irrigated, VFD installed, different sprinkler system) • # of acres subject to SIS • Utility • Annual pump kWh • SISConsultant • Cumulative evapotranspiration • Cumulative precipitation • Water applied
Review Documents • Standard Protocol • Calculator • Research Plan
Staff Proposal • Approve the SIS Standard Protocol as a provisional measure. • Set the measure status to “Active”. • Set the sunset date to June 30, 2015. • Estimate water savings as 5.7% of the gross water requirement. • Approve the proposed research plan. • Approve the proposed calculator.
Decision “I _______ move to: • Approve the SIS Standard Protocol as a provisional measure. • Set the measure status to “Active”. • Set the sunset date to June 30, 2015. • Estimate water savings as 5.7% of the gross water requirement. • Approve the proposed research plan. • Approve the proposed calculator.