Scientific Irrigation SchedulingProvisional Standard Protocol

Ryan FirestoneRegional Technical Forum

February 18, 2015

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Presentation OutlineToday’s Objective: Approve the SIS Standard Protocol measure as Provisional, Active measure

• Measure Overview• SIS Background• 2015/2016 Bonneville SIS Study• Provisional Standard Protocol Proposal

– Provisional Savings Number– Standard Protocol– Calculator– Research Plan

• Staff Highlighted Areas • Proposed Recommendation

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Measure OverviewMeasure Developers RTF Staff

CAT Review Yes (Ryan Firestone and Team)

Tech Sub-Com Review Yes

R&E Sub-Com Review Some – research plan has been fleshed out since

Notes Long history … most recent changes:• Jun 2014: RTF postponed decision on SIS until Oct.

2014 with the guidance: BPA to provide a research plan to estimate inefficient to efficient savings and to estimate baseline prevalence of efficient irrigation practices

• Oct. 2014: RTF set to OOC with sunset date in Dec 2014.

• Dec 2014: Set sunset date to Feb. to allow more time for research plan development

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SIS Background

[for additional background, see the June 2014 RTF presentation]

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What is SIS?

• Information on when/how much to irrigate to satisfy crop water requirements and avoid plant moisture stress

• Tools – soil moisture monitoring

– evapotranspiration model specific to crop type, soil type, and local meteorology

• Traditional methods rely more on look/feel of soil and crops, predetermined watering calendars, and water availability

• Water savings from irrigation management translate into electricity savings from reduced pumping

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What is the SIS measure?• Application of SIS in irrigation decision-making• Can be applied by either a consultant or by the grower• Service is provided for a single growing season

– soil moisture meters are removed at end of season– crops may rotate from season to season– climatic data will vary from year to year

• Framed as a Current Practice measure – growers shop for an irrigation strategy each year– no infrastructure left in field from year to year– Baseline = population average– Measure Life = 1 year

• Water savings expressed as a percentage of Water Requirement– This is a means of normalizing water consumption across crops,

weather, and soil type

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What do we know about SIS savings?

2003-2005 Bonneville SIS Study*

• 2003: Phone survey of ~800 growers in NW regarding irrigation practices– 43% of irrigated acreage using efficient management practices

• Caveats: self-reported and at farm level, not field level

• 2004: Field study of 38 fields– 19 that didn’t use SIS– 19 that did– Fields not randomly selected– 10% average difference in normalized water usage, not

statistically significant

*referred to in previous RTF presentations as “The Quantec Study”

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2015/2016 Bonneville SIS Study

• Bonneville developing– plans to implement in 2016– hoping for other utilities to buy in to study

• The objective of the research is to characterize baseline (population) irrigation efficiency levels.– Not to estimate savings– Although the study will collect all elements needed to estimate

savings, it may not have a large enough sample size to demonstrate statistically significant savings.• Keep in mind: this study will be, by far, the best data we have, and a

larger study would be too expensive. So the RTF will need to weigh best possible against low precision.

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Bonneville Study – Key Design Elements

Objective: At least 90/10 confidence precision on water consumption (as a percentage of Water Requirement)

• Stakeholder intensive - This study will be open and transparent, with a high-level of review and input from diverse experts across the region

• Geo-spatial sampling – SIS consultants and utilities review coordinates and identify growers for contact– Random selection at the field level. This will reduce participant bias and has never

been done before.• Sample stratification

– Two regions: Columbia Basin, Southern Idaho – these regions have water management services.

– Two crop groups for Columbia Basin• High Water Management• Low/Medium Water Management• Categorization based on expert survey on typical water management levels, by crop type

– Eligible fields – all crop types, pressurized irrigation

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2015/16 Bonneville Study – Key Design Elements (cont’d)

• Leverages existing data - Bonneville will attempt to utilize existing data wherever possible (i.e., sampled sites with SIS services) to decrease costs and increase sample

• Apples to apples – same data collection and analysis methodology for baseline and program fields

• Study may include a phone survey – selected sites would be contacted by phone and asked questions about farm characteristics and irrigation practices, in addition to being asked to participate in the field study– Larger sample size than field study – may be able to answer questions about varying

levels of irrigation management at a more granular level than the field study (e.g., specific to crop, farm size)

– Concerns that phone survey would not reach the right person to answer these questions, and that respondents could overstate efficient practices

• Details of field measurements and ET estimation TBD

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Provisional Standard Protocol Proposal

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Proposed Standard Protocol• Standard method for estimating evapotranspiration (ET)

– Function of crop type, planting schedule, soil type, weather– TBD - Bonneville currently working with experts to select best method

• Best Practice Method– Determine Water Requirement

• Estimate ET• Measure rain

– Measure Applied Water• TBD – field protocol

– Normalized Usage = [Applied Water] / [Water Requirement]– Normalized Water Savings = [Population Usage] - [Site Usage]– Energy Savings =

[Normalized Water Savings] x [Water Requirement] x [Water to Energy Conversion]

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Proposed Standard Protocol

• Simplest Reliable Method– Determine Water Requirement

• Estimate ET• Estimate rain from local weather

– Water savings = [Savings %] x [Water Requirement] – Energy Savings =

[Water Savings] x [Water to Energy Conversion]

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Calculator

[see Calculator]

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Provisional Savings Estimate• CAT/Staff has previously advocated for 5.7% of Water Requirement. This the

10% savings estimate produced by the 2003 – 2005 Bonneville SIS Study, adjusted for current practice (at the time of the study)

• Bonneville advocates for 10% of Water Requirement– Weighting 2003 – 2005 Bonneville SIS Study results by crop type can produce a value

close to this– There is risk that lowering the savings leads to …

lower Bonneville willingness to pay, which leads to …lower participation, which could …influence the baseline and reduce the number of program sites to collectdata from.

• CAT/Staff and Bonneville agree:– 2003 – 2005 Bonneville SIS Study data is of limited use: old, small sample size, not a

random sample– Relatively low risk from getting this wrong: 2-3 years of ~5 aMW, 1 year lifetime savings

• CAT/Staff has no technical recommendation

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Research Plan

• CAT/Staff developed a brief research plan to reflect RTF needs for estimating energy savings.– Primarily references the 2015/2016 Bonneville SIS Study– More detail on what analysis is needed after the

Bonneville Study to estimate savings for the RTF (see next slide)

– CAT/Staff identified limitations of the analysis

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Analysis

• Simplest reliable method should, on average, estimate electricity savings within 10% of best practice method

• Candidate approach will be to – 1) estimate average water savings as a percentage of site-specific water

requirement – 2) convert this to site-specific electricity savings– Water savings value may need to be adjusted if it leads to bias in energy savings:

• E.g., if there is correlation between site water savings and lift/pump type/irrigation system type

• Other models may be considered for a better fit to the data– This will depend on what the data looks like

• If available, examine survey data for significant differences in irrigation practice by crop type, farm size, etc.– Does self-reported irrigation practice correlate to measured water

consumption? – If so, consider measure identifiers where differences in irrigation practice exist

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Limitations of the Analysis• What precision can we expect to get on our savings estimate?• We don’t expect much precision, but it will be much better

than current data and not financially feasible to do more

Precision of savings estimate

Assumes Program average is precisely 1.00

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Limitations of the Analysis

• Quality Assurance– multiple consultants – possible conflict of interest

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RTF Staff encourage a phone survey

Objectives • Capture self-reported irrigation practices and basic farm characteristics• For those fields subject to both phone and field study, look for correlation

between self-report information and Water Consumption• I.e., look for variables in the phone survey that explain some of the variability in

the field study data

Benefits• Low cost – growers are already being contacted for recruitment. It’s mostly a

matter of asking them some questions while you’ve got them on the line.• Potential to increased precision of savings estimates – if variable(s) from the

survey are able to explain any of the variation in the field study• Potential to increase the granularity of the savings estimates – programs would

have the information necessary to target crop types, field sizes with most savings potential

• Low-cost repeatability – current practice baseline (mix of low/medium/high water management) could be updated periodically

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Sunset Date

• CAT/Staff recommendation: January 31, 2016• Expect to extend sunset date for provisional

savings number 1+ years at that time, provided– details of research plan have been fleshed out– Bonneville (and others) still plan to conduct

research for 2016 growing season

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Proposed Motion

“I _________ move that the RTF approve the research plan, standard protocol, calculator, and 10% of Water Requirement provisional water savings estimate for the SIS Standard Protocol measure. Set the sunset date to January 31, 2016, the category to ‘Provisional’, and the status to ‘Active’.”