Solar terms
Solar & net metering.
NEM 3.0 (Net Energy Metering 3.0)
California's residential solar rate structure for systems interconnecting with investor-owned utilities (SCE, PG&E, SDG&E) after April 14, 2023. Export credits can be lower than retail electricity rates, so the design should account for self-consumption, evening usage, battery storage, and utility territory. LADWP customers operate under separate municipal utility rules that should be reviewed before assuming SCE-style economics.NEM 2.0 (Net Energy Metering 2.0)
Legacy net metering rate structure. Customers who installed solar with interconnection applications submitted before April 14, 2023 (and approved before April 13, 2024) maintain NEM 2.0 status for 20 years from PTO (Permission to Operate). NEM 2.0 credits exports at retail rate minus non-bypassable charges. Most LADWP customers operate under similar legacy terms.Federal Solar Tax Treatment (Investment Tax Credit)
For residential systems placed in service through December 31, 2025, federal tax treatment may apply, subject to eligibility and current law, on the installed cost of solar panels, solar-plus-battery systems, and stand-alone batteries (Tesla Powerwall, Enphase IQ Battery). Under current law this residential credit is no longer available for new projects placed in service in 2026. Confirm current eligibility with your tax professional; Home Upgrade Specialist is not a tax advisor.PTO (Permission to Operate)
The utility-issued certificate authorizing a residential solar system to interconnect with the grid and export power. LADWP and SCE both issue PTO after final inspection. Your NEM grandfathering date is the PTO date, not the install date.SolarAPP+
National Renewable Energy Laboratory's automated solar permitting platform. Cities that participate (Santa Monica, San Jose, Tucson, etc.) issue residential solar permits in 24-48 hours through SolarAPP+ vs the typical 2-4 week manual permitting process.kW DC vs kW AC
kW DC (direct current) is the nameplate rating of solar panels at standard test conditions. kW AC (alternating current) is the post-inverter rating that actually feeds your home and the grid. AC is typically 80-85% of DC. When a contractor quotes "7kW system" they usually mean DC.Self-consumption ratio
The percentage of solar production used directly in your home instead of exported to the grid. Under current net-billing rules, self-consumption can matter because export values may be lower than retail rates. A battery can increase self-consumption, but the best design depends on your usage, rate plan, and storage goals.Microinverters vs string inverters
String inverters convert DC from multiple panels at one point (cheaper, faster shutdown if one panel fails). Microinverters (Enphase IQ series) sit on each panel for panel-level optimization (more expensive, better shading performance, 25-year warranty). Tesla Powerwall 3 has a built-in solar inverter, eliminating the need for a separate string inverter.Battery storage
Battery storage.
Tesla Powerwall 3
Tesla Energy's 2024-2026 home battery. 13.5 kWh usable capacity, 11.5 kW continuous output, includes built-in solar inverter (97.5% efficient). LFP chemistry. 10-year warranty. Installed by Tesla Certified Premium Installers like Home Upgrade Specialist.Enphase IQ Battery 5P
Enphase's modular battery storage system. 5 kWh per unit, 3.84 kW continuous (7.68 kW peak). Stackable up to 80 kWh. LFP chemistry. 15-year warranty. Native integration with Enphase microinverter solar systems.LFP (Lithium Iron Phosphate)
The battery chemistry used in modern home storage (Powerwall 3, Enphase IQ 5P). Safer than older NMC chemistry (much higher thermal runaway temperature), longer cycle life (~6,000+ full cycles), more eco-friendly. Tradeoff is slightly lower energy density (larger physical size per kWh).SGIP (Self-Generation Incentive Program)
California's regular residential SGIP battery budgets are closed to new applicants. The remaining Residential Solar and Storage Equity pathway is limited to qualifying low-income customers and is currently waitlisted. A submitted or waitlisted application is not guaranteed funding, and no amount should be treated as project savings without written reservation approval.Whole-home backup vs critical-loads backup
Whole-home backup powers your entire electrical panel during an outage (requires battery with sufficient continuous output — Powerwall 3 at 11.5 kW handles most LA homes). Critical-loads backup uses a sub-panel to power only essential circuits (fridge, lights, WiFi, medical equipment), allowing a smaller battery.PSPS (Public Safety Power Shutoff)
Pre-emptive utility-initiated power outages during high fire risk weather (Santa Ana winds + low humidity + high temperatures). SCE territory experiences multiple PSPS events per year in fire-prone areas. Battery + solar is the primary defense.HVAC terms
HVAC & heat pumps.
Heat pump
A reversible refrigeration system that moves heat in either direction — cooling in summer, heating in winter. Modern heat pumps (Daikin Fit, Bosch IDS, Mitsubishi M-Series, Trane XV20i) deliver 200-400% efficiency (vs gas furnace ~85-95%) because they move heat rather than generate it.SEER2 (Seasonal Energy Efficiency Ratio 2)
The updated 2023+ cooling efficiency rating for residential HVAC systems. Higher = more efficient. Minimum allowed in California is SEER2 15. Premium heat pumps reach SEER2 21-26. Each SEER2 point increase reduces cooling cost roughly 7%.HSPF2 (Heating Seasonal Performance Factor 2)
The updated 2023+ heating efficiency rating for heat pumps. Higher = more efficient. Premium heat pumps reach HSPF2 9-11. HSPF2 is essentially "BTU heat delivered per kWh consumed."Variable-speed compressor
A compressor that modulates output (typically 30%-100%) rather than running full-blast or off. Result: lower energy consumption, better humidity control, quieter operation, longer equipment life. All premium heat pumps use variable-speed compressors.Manual J load calculation
The ACCA-certified room-by-room heating and cooling load analysis used to right-size HVAC equipment. A proper Manual J considers home insulation, window count/type, climate zone, infiltration rate, and occupant count. Most LA contractors skip Manual J and oversize by 30-50%. Home Upgrade Specialist runs Manual J on every install.Ductless mini-split
A heat pump system where the outdoor unit connects to wall-mounted indoor units via refrigerant lines (no ductwork). Ideal for room additions, garages, ADUs, or homes without existing ducts. Mitsubishi M-Series and Daikin Quaternity are leading mini-split brands.Coastal-rated HVAC
HVAC equipment specifically engineered for salt-air corrosion environments (Santa Monica, Pacific Palisades, Manhattan Beach, Redondo, Malibu). Includes marine-grade aluminum coil coatings, stainless hardware, and powder-coated cabinets. Standard equipment lifespan in coastal LA drops 20-30% without coastal-rating.Roofing & EV
Roofing & EV charging.
Tesla Solar Roof
Solar-generating roof tiles (vs panels mounted on a conventional roof). Comparable cost to premium asphalt + premium solar installed together. 25-year tile warranty + 25-year power warranty. Installed by Tesla Certified Premium Installers.Cool roof
Roofing systems with high solar reflectance (typically >0.65 reflectance) that reduce attic temperatures and HVAC load. Required by California Title 24 on most new residential roofs. Certainteed Landmark Solaris and Owens Corning Duration COOL are leading cool-roof shingle options.Solar-ready roofing
Roofing installed with future solar in mind: properly spaced rafters, electrical conduit pre-run from attic to electrical panel, and a structural rating that supports the additional load. May reduce rework compared with retrofitting solar onto an existing roof, depending on roof condition, electrical path, and final design.Level 2 EV charger
240V residential EV charger that adds 25-40 miles of range per hour of charging. Tesla Wall Connector (Tesla cars) and Universal Level 2 chargers (J1772 plug for non-Tesla EVs) are the two common types. Installation typically requires 40-amp circuit and panel capacity verification.Panel upgrade
Replacement of an electrical service panel (typically 100A or 125A) with a larger panel (typically 200A or 225A) to support EV chargers, heat pumps, and battery interconnection. Many pre-1985 LA homes need a panel upgrade before they can install EV + solar + heat pump.LA-specific terms
LA agencies & permitting.
LADWP (Los Angeles Department of Water and Power)
The municipal utility serving the City of Los Angeles (most of central, west, and northeast LA). LADWP customers operate under their own net metering rules (more favorable than IOU NEM 3.0) and have access to LADWP solar incentives, EV charger incentive programs, and heat pump water heater incentive programs.LADBS (Los Angeles Department of Building and Safety)
The City of LA's permitting authority for residential construction, including HVAC changeouts, solar installations, panel upgrades, roofing, and battery storage. LADBS operates an expedited fire-rebuild permitting track for homes affected by the Palisades and Eaton fires.SCE (Southern California Edison)
An investor-owned utility serving many Los Angeles County and Orange County addresses outside municipal utility territories. SCE solar customers may operate under Net Billing rules. Regular residential SGIP battery funding is closed, while qualifying low-income customers may be reviewed for the currently waitlisted RSSE pathway through the applicable administrator.PWP / GWP / BWP
The three municipal utilities serving specific LA cities: PWP (Pasadena Water and Power), GWP (Glendale Water and Power), and BWP (Burbank Water and Power). Each runs its own net metering rules and incentive programs separate from LADWP and SCE.SoCalGas
The natural gas utility serving much of the Los Angeles area. Some heat pump water heater incentive options may be available for qualifying customers, subject to current SoCalGas program rules, equipment, funding, and eligibility.Title 24
California's Building Energy Efficiency Standards. The 2022 edition (effective 2023) requires new residential roofs to meet cool-roof reflectance standards and new homes to be "solar-ready." The 2025 edition further tightens HVAC efficiency requirements and pushes heat pump adoption.How to use this glossaryTurn definitions into a better project plan.
- 1Confirm your utility territory before comparing solar, battery, heat pump or EV charger incentives.
- 2Ask whether the estimate includes permit coordination, inspection steps, equipment model numbers and written warranty terms.
- 3Use terms such as Manual J, NEM 3.0, SGIP, critical-load backup and cool roof to compare proposals more clearly.
- 4Confirm rebate, financing and tax questions with the relevant program, lender or tax professional before signing.
Ready to start?Now apply this to your home.
Start with a quick estimate and eligibility review for your equipment, address, utility territory, roof, HVAC load, and battery goals. Tesla Certified Premium Installer.
