{"schema_version":1,"revision":"research-library-1","reviewed_on":"2026-11-07","scope":"Targeted buying explainers and a claim-based task screen; not a systematic review, measured performance ranking or installation design.","rights":{"creator":"Original illustrations prepared for SolarCompare","usage":"Original site illustrations authorized for SolarCompare publication; no third-party artwork is reproduced. Source documents and publisher media retain their own rights.","figure_basis":"Conceptual diagrams and explicitly hypothetical arithmetic. No illustration is a measured curve or manufacturer drawing."},"sources":{"battery-life":{"title":"SAM help: battery life","url":"https://samrepo.nlr.gov/help/battery_life.html","scope":"Battery Life Options, Cycle Degradation and Calendar Degradation; model-specific assumptions, not a measured lifespan for a catalog product.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:10.330251+00:00","capture_sha256":"12656c4efc305aebf414651352a9e25c424b5f27deca1c4f273cf34acf45143c"},"battery-results":{"title":"SAM help: battery results","url":"https://samrepo.nlr.gov/help/battery_results.html","scope":"Battery Storage Results: charge/discharge energy, temperature and separately modeled ancillary and converter losses.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:10.867215+00:00","capture_sha256":"ef91e5d1d4d69173f3135b3767c78571fe44ebd43bd409dfbdfbe9bba39ff4cd"},"pv-module":{"title":"SAM help: PV module models","url":"https://samrepo.nlr.gov/help/pv_module.html","scope":"Module Characteristics at Reference Conditions and Bifacial Specifications; reference ratings and rear-irradiance inputs.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:11.193156+00:00","capture_sha256":"0fd67f74f4fe5c3d506eeda3bf675cf17bcb4b9fc4cbca7c75110ca75aef5aaf"},"pv-inverter":{"title":"SAM help: PV inverter models","url":"https://samrepo.nlr.gov/help/pv_inverter.html","scope":"DC-to-AC conversion, part-load curves and weighted efficiency; no universal inverter efficiency is assumed.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:11.503925+00:00","capture_sha256":"5951a1ca3156eb556662c336798386d7557884a26acb62c0a1c8ca12561bb19f"},"pv-efficiency":{"title":"US Department of Energy: PV performance and efficiency","url":"https://www.energy.gov/cmei/systems/solar-photovoltaic-performance-and-efficiency-basics","scope":"Conversion efficiency, temperature and reflection; not a forecast for a particular roof.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:11.720205+00:00","capture_sha256":"89a3646b7e351a22092b9ecbbd24e681fa0d42481256254457ccbae6ea50688e"},"pv-design":{"title":"US Department of Energy: PV system design","url":"https://www.energy.gov/cmei/systems/solar-photovoltaic-system-design-basics","scope":"Modules, mounting, conversion and storage are different parts of a complete system.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:11.824103+00:00","capture_sha256":"a49ebe3d8b3c3e71794eb8c974698516e5b41f7272450c27915db54688f61207"},"battery-basics":{"title":"Australian Government: battery technology","url":"https://www.energy.gov.au/solar/get-know-solar-technology/batteries","scope":"Nominal/usable capacity, power and backup configuration concepts only. Australian incentives, installation rules and product approvals are not applied to US projects.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"official_indexed_text","access_note":"Official-page indexed text reviewed; two direct requests timed out. No local body capture or hash is claimed.","captured_at":null,"capture_sha256":null},"electricity-units":{"title":"US EIA: measuring electricity","url":"https://www.eia.gov/energyexplained/electricity/measuring-electricity.php","scope":"Power and energy units and their relationship over time.","reviewed_on":"2026-11-07","published_on":null,"publication_note":"Publication date not established; review date is not a publication or experiment date.","access":"direct_capture","access_note":"Direct source captured.","captured_at":"2026-11-08T01:51:42.568179+00:00","capture_sha256":"6b899b9e0f18deabfa94eaef1e631a879b97c4a10e0b57113861ed224c91d440"}},"articles":[{"id":"battery-energy","title":"Why two 1 kWh batteries can deliver different runtimes.","summary":"Trace the energy boundary before comparing the number on the box.","figure":"energy","published_on":"2026-11-07","reviewed_on":"2026-11-07","revision":1,"applicability":"Conceptual buying guidance. Numerical examples are explicitly hypothetical; no exact product or installation is approved by this article.","sections":[{"title":"Name the boundary first.","text":"Nominal battery energy, usable battery energy and energy delivered at an AC outlet answer different questions. A capacity in kWh also does not specify the maximum output in kW. Ask whether reserve, conversion and auxiliary consumption are already included before applying another allowance.","source_ids":["battery-basics","battery-results"]},{"title":"Work one explicit example.","text":"Hypothetical arithmetic: 1,000 Wh nominal × 90% usable share × 80% remaining after reserve × 90% conversion = 648 Wh at the AC boundary. At a constant 100 W, that is 6.48 hours before any additional unmodeled consumption. These percentages are exercise assumptions, not defaults for a chemistry or model. If a test already measures delivered AC energy, do not subtract the same conversion loss again.","source_ids":["electricity-units"]},{"title":"Match the load and conditions.","text":"Temperature and separately accounted equipment losses can change available energy. A test at a different load or stopping rule is context, not a promised runtime for your appliance. Keep measured output and manufacturer capacity in separate fields; carry unknowns into the runtime tool.","source_ids":["battery-results"]}],"takeaways":["Identify the boundary before multiplying by an efficiency.","Review continuous and starting power separately from energy.","A measured AC result applies to its reported test conditions."],"tools":[{"url":"/tools/runtime/","label":"Explore runtime assumptions"},{"url":"/research/#task-fit","label":"Screen a portable-power task"},{"url":"/learn/battery-boundaries/","label":"Practice battery arithmetic"}],"corrections":[{"date":"2026-11-07","kind":"initial_publication","note":"Initial publication. No subsequent correction is recorded in this revision."}]},{"id":"battery-degradation","title":"What a cycle-life claim cannot tell you.","summary":"Put age, cycling and the test endpoint beside a lifespan claim.","figure":"aging","published_on":"2026-11-07","reviewed_on":"2026-11-07","revision":1,"applicability":"Conceptual buying guidance. Numerical examples are explicitly hypothetical; no exact product or installation is approved by this article.","sections":[{"title":"Time and use are different exposures.","text":"Battery capacity can change through calendar aging as well as cycling. SAM’s lifetime documentation treats age, temperature, state of charge and cycle depth as model inputs or drivers. A published cycle count without its remaining-capacity endpoint and test conditions cannot establish a calendar replacement year for your installation.","source_ids":["battery-life"]},{"title":"Read the conditions, then the contract.","text":"For a buying decision, record the exact model and document revision, cycle definition, depth of discharge, charge/discharge conditions, temperature and retained-capacity endpoint. Read the warranty separately: record its term, throughput or cycle limits, exclusions and remedy from the actual contract. Missing conditions remain missing; a marketing cycle claim is not itself a warranty document.","source_ids":[]},{"title":"Keep the lifetime estimate conditional.","text":"A model is a calculation under assumptions, not a new endurance test. SAM offers different degradation models with different ways to combine mechanisms; the diagram does not add two curves or predict a universal decay rate. Our current portable-power evidence collection contains no reviewed long-term cycling or calendar-aging experiment. The absence is a coverage gap, not evidence of zero aging.","source_ids":["battery-life"]}],"takeaways":["Cycle counts need conditions and a retained-capacity endpoint.","Chemistry alone does not establish years of service.","Keep warranty terms, modeled replacement years and observed aging separate."],"tools":[{"url":"/projects/binder/","label":"Keep warranty and service documents"},{"url":"/tools/ownership-costs/","label":"Model a conditional replacement cost"},{"url":"/performance/","label":"Inspect current measurement coverage"}],"corrections":[{"date":"2026-11-07","kind":"initial_publication","note":"Initial publication. No subsequent correction is recorded in this revision."}]},{"id":"solar-module-fit","title":"Is a higher-watt panel better for your roof?","summary":"Compare module area, electrical limits and the actual resource.","figure":"panel","published_on":"2026-11-07","reviewed_on":"2026-11-07","revision":1,"applicability":"Conceptual buying guidance. Numerical examples are explicitly hypothetical; no exact product or installation is approved by this article.","sections":[{"title":"Watts and efficiency are different views.","text":"Module efficiency relates electrical output to incident sunlight and area under stated conditions. A higher watt rating can come from greater area. Hypothetical modules at 1,000 W/m²: 450 W over 2.0 m² is 22.5%; 500 W over 2.5 m² is 20%. Those invented examples illustrate the ratio; they do not identify products. Temperature and reflection also affect conversion.","source_ids":["pv-efficiency"]},{"title":"Reference ratings need a production model.","text":"Nameplate power is specified at reference conditions. It does not provide annual kWh. For a roof, inspect dimensions, layout constraints, resource and temperature assumptions, then the exact electrical data and compatible equipment. A cheap price per nameplate watt does not resolve the cost or output of the installed array.","source_ids":["pv-module"]},{"title":"Treat bifacial construction as its own field.","text":"Cell polarity or technology labels and bifacial construction are separate catalog fields. Rear contribution requires rear-side light. SAM’s bifacial model uses rear irradiance, bifaciality, ground reflectance, row spacing and clearance. A tightly backed roof and a raised open array need different assumptions; a title does not justify a fixed extra-energy percentage.","source_ids":["pv-module"]}],"takeaways":["Compare watts, area and quantities on an equivalent basis.","Do not convert a watt rating directly into annual energy.","Rear contribution requires a resource and layout assumption."],"tools":[{"url":"/equipment/solar-panels/","label":"Compare panels and price per watt"},{"url":"/tools/solar/","label":"Estimate seasonal production"},{"url":"/tools/system/","label":"Check documented electrical limits"}],"corrections":[{"date":"2026-11-07","kind":"initial_publication","note":"Initial publication. No subsequent correction is recorded in this revision."}]},{"id":"conversion-efficiency","title":"Which efficiency number am I comparing?","summary":"Write the input and output boundary beside every percentage.","figure":"conversion","published_on":"2026-11-07","reviewed_on":"2026-11-07","revision":1,"applicability":"Conceptual buying guidance. Numerical examples are explicitly hypothetical; no exact product or installation is approved by this article.","sections":[{"title":"The denominator matters.","text":"PV conversion compares electrical output with incident solar input. An inverter’s DC-to-AC efficiency uses another boundary. A charge/discharge energy ratio uses yet another. Similar percentage signs do not make these measurements interchangeable.","source_ids":["pv-efficiency","pv-inverter","battery-results"]},{"title":"Use a matched energy accounting window.","text":"For a hypothetical AC round-trip test, 1,000 Wh measured entering and 800 Wh leaving would give 80% only when the accounting window, starting/ending storage state and included loads are defined consistently. Rated battery capacity divided by recharge input does not substitute for measured discharge output. The figure is invented arithmetic, not a measured product result.","source_ids":["battery-results"]},{"title":"Peak, weighted and operating efficiency differ.","text":"SAM supports part-load inverter curves and separately displays weighted efficiency. One quoted value does not describe every load point. For a buyer, ask for the load, voltage, temperature, boundaries and method. Keep standby energy visible and avoid applying a modeled conversion loss to an output that already includes it.","source_ids":["pv-inverter"]}],"takeaways":["Keep PV, inverter and round-trip boundaries separate.","A nominal-capacity ratio is not measured round-trip efficiency.","Use each loss once, at its documented boundary."],"tools":[{"url":"/performance/","label":"Inspect energy observations and conflicts"},{"url":"/tools/runtime/","label":"Set explicit runtime boundaries"},{"url":"/learn/battery-boundaries/","label":"Practice the conversion example"}],"corrections":[{"date":"2026-11-07","kind":"initial_publication","note":"Initial publication. No subsequent correction is recorded in this revision."}]},{"id":"review-task-fit","title":"Does a good review fit my load?","summary":"Separate what was observed from confidence in applying it.","figure":"evidence","published_on":"2026-11-07","reviewed_on":"2026-11-07","revision":1,"applicability":"Conceptual buying guidance. Numerical examples are explicitly hypothetical; no exact product or installation is approved by this article.","sections":[{"title":"Begin with the actual task.","text":"Specify continuous watts, duration, starts, electrical region and whether charging occurs. The checker below uses battery-only, steady AC loads without charging. A cycling refrigerator, motor start or medically critical use needs additional requirements that this simple screen does not establish.","source_ids":[]},{"title":"Read the protocol before borrowing the result.","text":"The reviewed GearLab observations used a relative load near 80% of each unit’s rated output; actual load watts are not reported. Their delivered-Wh values can be shown together as a descriptive cohort, but cannot establish efficiency or runtime at your selected watts. The separate Notebookcheck Anker record reports about 250 W on European 230 V hardware. It does not verify a US offer. Conditions, held source conflicts and disclosure details remain in the original evidence records.","source_ids":[]},{"title":"Appraise applicability separately.","text":"An observed number answers what the publisher reported. Evidence confidence asks how well the identity, method, conditions, repeatability and independent coverage support your question. Unreported details are unknown, not zero. Our checker exposes those gaps instead of assigning a numerical confidence percentage or a universal best-product score.","source_ids":[]}],"takeaways":["Claims, measured observations and applicability are three separate views.","A similar model name does not prove the same tested hardware.","An unsupported task remains unverified even when a claim-based screen passes."],"tools":[{"url":"/research/#task-fit","label":"Try the explained task screen"},{"url":"/performance/","label":"Read exact observations and conditions"},{"url":"/guides/creator-reviews/","label":"Explore creator review videos"}],"corrections":[{"date":"2026-11-07","kind":"initial_publication","note":"Initial publication. No subsequent correction is recorded in this revision."}],"evidence_links":[{"url":"/performance/","label":"Reviewed GearLab and Notebookcheck records, methods, publication dates and conflicts"}]},{"id":"backup-system","title":"What makes a battery a backup system?","summary":"Look beyond the battery module to the complete operating configuration.","figure":"system","published_on":"2026-11-07","reviewed_on":"2026-11-07","revision":1,"applicability":"Conceptual buying guidance. Numerical examples are explicitly hypothetical; no exact product or installation is approved by this article.","sections":[{"title":"Energy storage is one component.","text":"Modules, mounting, conversion and storage have different roles in a PV system. Outage operation depends on an appropriate configuration; the presence of a battery alone does not establish backup capability. The drawing shows questions to resolve, not a wiring arrangement.","source_ids":["pv-design","battery-basics"]},{"title":"Keep certification scopes exact.","text":"Our source-linked certification guide distinguishes battery-module evidence, listed system combinations and fire-test documents. For example, a reviewed module certificate does not approve every inverter pairing. Match the exact model, document edition, quantities, configuration and remaining installation conditions. A standards number in a retailer title is not an exact-system match.","source_ids":[]},{"title":"Turn gaps into a project checklist.","text":"Record intended backed-up loads, operating modes, controls/transfer equipment, protection, mounting, utility process and local authority questions. Use the system builder for documented interfaces and the permit planner for the actual project context. This conceptual article does not set conductor sizes, protective-device ratings or installation instructions.","source_ids":[]}],"takeaways":["Capacity, outage operation and system certification answer different questions.","Use exact model and configuration evidence.","Carry unresolved requirements into the project rather than assuming compatibility."],"tools":[{"url":"/tools/system/","label":"Explore documented equipment combinations"},{"url":"/guides/equipment-certifications/","label":"Read exact certification scopes"},{"url":"/tools/permits/","label":"Build a local project checklist"}],"corrections":[{"date":"2026-11-07","kind":"initial_publication","note":"Initial publication. No subsequent correction is recorded in this revision."}],"evidence_links":[{"url":"/guides/equipment-certifications/","label":"Exact-model certificates and registry source links"}]}],"assessment_method":{"version":1,"scope":"Battery-only steady AC load; no charging, no starts, no duty-cycle or temperature simulation.","confidence":"Qualitative applicability reasons are shown separately from manufacturer claims and publisher observations. No probability, numerical confidence or universal product score is computed.","identity":"Explicit marketed-model references only; tested ordering SKU, hardware revision and US electrical identity remain unverified.","unknowns":["Exact-load measured runtime","Starting/surge capability for the task","Temperature and aging behavior","Sample SKU, revision and firmware equivalence","Repeated-run variability"]}}