Chris Lund Financial Consultant Utility Financial Solutions, LLC clund@ufsweb.com 231-342-9798
International consulting firm providing financial services to utilities across the county, Guam, Canada and the Caribbean Instructors for cost of service and financial planning for APPA, and regularly requested to present for organizations across the country including MMEA & AWWA APPA Hometown Connections Partner 2
Solar Primary Objectives • Value of solar valuation method to determine kWh credit • Long run, short run or blend? (typically short run for market based & full requirements utilities, typically long run for traditional self generation utilities) • Metering preference(s) • One or two meters? Digital or analog meters? • Billing preference(s) • Method to apply value of solar kWh credit? • Community solar strategy vs. rooftop • Project scope and future plans? • Solar with battery storage • Potential impacts of battery storage with solar – interactive case study example 3
Utility Financial Solutions works with utilities to conduct an avoided cost (marginal cost) determination for the value of solar per kWh The study is conducted using the respective utility’s load data and power supply resource mix Solar production profile is based on irradiance data obtained from pvwatts.nrel.gov (sample shown for the Escanaba MI area) Ultimate approach adopted should be based on potential State Utility Commission, local board / council directives and management preferences 4
Most inaccurate method of distribution (& fixed cost recovery) is through a kWh charge Distribution system is constructed to handle a customers peak demand or a classes peak demands and are not constructed to handle kWh’s 5
Rates based on kWh sales are high risk to utility for fixed cost recovery 6
(theoretical) 7
Many utilities are moving toward or considering demand / TOU rates for distribution & fixed cost recovery for all customers: • Send better price signals to customers • Promote electric vehicles (off peak charging) • Reduce subsidies for customers with distributed generation 8
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Short Run Avoided Cost (Marginal Cost) ◦ Savings in the short run ◦ Typically energy value weighted by solar production, plus predicted transmission savings, may include a demand or capacity value, no system loss savings for community solar ◦ (typically tracks with market et pricing) g) Solar weight hted ed hourly rly mark rket et avera rage (typic icall lly day ahead local node pricin ing) Distrib tribut utio ion system tem loss savin ings May includ ude a demand nd or capacity ty value lue Trans nsmission ion saving ings 10
Long Run Avoided Cost (Marginal Cost) ◦ Theoretical savings in the long run ◦ Theoretical value of avoiding installing the next generating unit ◦ Traditionally based on natural gas plant but many utilities are basing value on utility scale solar Avoid ided ed fuel el to run next xt plant nt (zero ro fuel cost for solar) r) Avoid ided ed capacity ty (ins nsta tall, ll, O&M for next xt plant nt) Distrib tribut utio ion system tem loss savin ings Avoid ided ed trans nsmis ission on Theo eoreti retical long run distrib tribut ution ion system tem savin ings (if any) y) Residential Rooftop Small Commercial Rooftop Community Solar Long Run $ 0.093430 $ 0.103770 $ 0.087170 Short Run $ 0.054510 $ 0.054510 $ 0.052890 11
Rooftop solar (behind customer meter) • Value of solar includes (increased by) system losses • Value of solar may include a long run distribution • savings, no short run distribution savings Community solar (solar garden in community) • Value of solar does NOT include system losses • Value of solar does NOT include long or short run • distribution savings 12
Average annual solar production forEscanabaMI Residential Rooftop fora Standard Fixed (roof mount) 1KW Unit Array Tilt (deg): Average from: 18.4349, 26.5651and 45. Irradiance datafrom NREL and compiled by UFS kWh Non Capacity Production Theoretical Snow kWh Produced factor Monthly Monthly at time of Average Snow Days - Capacity Days reduced by reduced by Production Production Monthly Marquette MI kWh Produced factor factor Snow Days Snow Days Percent Rank Solar Peak 2017 KW Unit Days Hours Possible kWh 1 20.05 1 31 744 744 61 8.15% 35.34% 21 2.88% 1.96% 12 0.2413 2 13.21 1 28 672 672 73 10.88% 52.83% 39 5.75% 3.52% 10 0.3990 3 8.49 1 31 744 744 121 16.30% 72.61% 88 11.84% 8.03% 7 0.6051 4 2.95 1 30 720 720 132 18.30% 90.17% 119 16.50% 10.83% 5 0.7514 5 0.12 1 31 744 744 145 19.48% 99.62% 144 19.41% 13.17% 2 0.8117 6 0.00 1 30 720 720 144 20.04% 100.00% 144 20.04% 13.16% 3 0.8235 7 0.00 1 31 744 744 150 20.10% 100.00% 150 20.10% 13.64% 1 0.7610 8 0.00 1 31 744 744 133 17.86% 100.00% 133 17.86% 12.12% 4 0.7651 9 0.00 1 30 720 720 112 15.62% 100.00% 112 15.62% 10.26% 6 0.7392 10 0.59 1 31 744 744 83 11.15% 98.10% 81 10.94% 7.42% 8 0.6638 11 6.84 1 30 720 720 54 7.47% 77.20% 42 5.77% 3.79% 9 0.4786 12 16.86 1 31 744 744 50 6.77% 45.61% 23 3.09% 2.09% 11 0.2713 69.10 365 8760 8,760 1,258 14.36% 81.07% 1,096 12.52% 100.00% Average annual kWh kWh production production per KW of loss due to installed solar snow 1,096 -12.85% 13
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Buy All Sell All with Digital Meter (two meters) Buy All Sell All with Analog Meter (two meters) Net Metering with Additional Charge (single meter) Net Billing with Digital Meter (single meter) Net Billing with Analog Meter (single meter) Net Metering (Traditional) (single meter) 16
Buy all Sell all – Digital Revenue Meter, Solar is Metered 17
Buy all Sell all – Analog Revenue Meter, Solar is Metered 18
Net Metering with Additional Charge – Analog or Digital Revenue Meter Solar not Metered 19
Net Billing – Digital Revenue Meter Solar not Metered 20
Net Billing – Analog Revenue Meter Solar not Metered 21
Net Metering (traditional) – Analog or Digital Revenue Meter Solar not Metered (Worse for accuracy & utility fixed cost recovery. However, some states still require net metering) 22
Preferred valuation method (long run, short run or blend?) • System Metering and Billing Capabilities (how to apply value of solar ) • • May be different based on Community solar, rooftop and solar array size Current and Future Rate Structures (Demand, TOU…) • Right Sizing – Many Utilities are implementing guidelines that specify the • allowable size of distributed generation resource(s) the customer is allowed to install. Examples of how a utility may want to consider this for future customer solar installs: • Allow solar install up to greater of : 110% of a customer’s peak demand “before solar” Or 100% of a customer’s average annual kWh usage “before solar” (net zero) ◦ Utility may specify maximum customer allowed solar install (example up to 20 KW array allowed within right sizing, installs above 20 KW by negotiation) System Verification – May consider procedures to ensure installed size and • future additions to a distributed generation resource. Periodic Review – Utility should review and update the value of solar credit • and implementation methods as significant assumptions change. • This will typically mirror general rate making timing (usually annually) . • Some utilities calculate value of solar credit monthly. 23
Rate “Smart Export Program” (Source: puc.hawaii.gov) Solar + Battery + Smart Inverter TOU value of solar credit for excess pushed to grid 24
Rate “Grid Supply+ Program” (Source: puc.hawaii.gov) Solar + Smart Inverter (controlled by utility) Fixed value of solar credit for excess pushed to grid, excess curtailed by utility to maintain a stable grid 25
Battery storage justification ◦ Financial (optimize time value of energy) ◦ Backup (provide backup power to grid power) ◦ Power quality (maintain more consistent power) Financial value dependent on time value of energy ◦ TOU energy rate ◦ Demand / capacity peaks ◦ Transmission peaks Loss of energy when batteries are charged (typical 11% loss ~ 89% efficiency) 26
Chris Lund Financial Consultant Utility Financial Solutions, LLC clund@ufsweb.com 231-342-9798
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