Transformer Sizing for PV and BESS: What Trips People Up<\/title>\n<meta name=\"description\" content=\"A field-engineering look at transformer sizing and selection for solar PV and battery storage plants \u2014 load basis, harmonics, cooling, grounding, and the mistakes that keep showing up on real projects.\">\n\n<script type=\"application\/ld+json\">\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@graph\": [\n {\n \"@type\": \"TechArticle\",\n \"@id\": \"https:\/\/haochengcompany.com\/transformer-sizing-for-pv-and-bess\/\",\n \"headline\": \"Transformer Sizing for PV and BESS: What Trips People Up\",\n \"description\": \"A field-engineering breakdown of transformer sizing and selection considerations for solar PV and battery energy storage plants.\",\n \"author\": { \"@type\": \"Organization\", \"name\": \"Haocheng Electrical\", \"url\": \"https:\/\/haochengcompany.com\" },\n \"publisher\": {\n \"@type\": \"Organization\",\n \"name\": \"Haocheng Electrical\",\n \"logo\": { \"@type\": \"ImageObject\", \"url\": \"https:\/\/haochengcompany.com\/wp-content\/uploads\/logo.png\" }\n },\n \"image\": \"https:\/\/haochengcompany.com\/wp-content\/uploads\/2026\/08\/Transformer-sizing-for-PV-and-BESS-some-things-that-trip-people-up.webp\",\n \"datePublished\": \"2026-08-12\",\n \"dateModified\": \"2026-08-12\",\n \"mainEntityOfPage\": \"https:\/\/haochengcompany.com\/transformer-sizing-for-pv-and-bess\/\",\n \"about\": [\n { \"@type\": \"Thing\", \"name\": \"Solar PV Transformer\" },\n { \"@type\": \"Thing\", \"name\": \"BESS Transformer\" },\n { \"@type\": \"Thing\", \"name\": \"Transformer Sizing\" },\n { \"@type\": \"Thing\", \"name\": \"Harmonic Derating\" }\n ],\n \"keywords\": \"PV transformer sizing, BESS transformer, harmonic derating, step-up transformer, K-factor transformer, renewable energy substation\",\n \"inLanguage\": \"en\",\n \"technicalAudience\": \"Electrical engineers, EPC contractors, solar and storage developers, substation planners\",\n \"proficiencyLevel\": \"Intermediate\u2013Expert\"\n },\n {\n \"@type\": \"Product\",\n \"name\": \"Haocheng Transformer Series\",\n \"description\": \"Transformer product line covering dry-type, oil-immersed, and amorphous alloy core transformers for solar PV, BESS, and distribution applications.\",\n \"brand\": { \"@type\": \"Brand\", \"name\": \"Haocheng Electrical\" },\n \"url\": \"https:\/\/haochengcompany.com\/transformer-series\/\",\n \"category\": \"Power Transformer\"\n }\n ]\n}\n<\/script>\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Sora:wght@300;400;500;600;700&family=DM+Serif+Display:ital@0;1&display=swap\" rel=\"stylesheet\">\n\n<style>\n:root {\n --hc-primary: #0A2540;\n --hc-accent: #E8A020;\n --hc-accent-light: #FFF4DE;\n --hc-teal: #1A7A6E;\n --hc-teal-light: #EAF6F4;\n --hc-text: #1C2B3A;\n --hc-text-muted: #5A7080;\n --hc-border: #D9E4EC;\n --hc-bg: #F7FAFC;\n --hc-white: #FFFFFF;\n --hc-rule: #C8D8E4;\n --hc-font-display: 'DM Serif Display', Georgia, serif;\n --hc-font-body: 'Sora', sans-serif;\n --hc-radius: 10px;\n --hc-shadow: 0 4px 24px rgba(10,37,64,0.09);\n --hc-shadow-hover: 0 8px 36px rgba(10,37,64,0.14);\n --hc-max-width: 860px;\n --hc-transition: 0.22s cubic-bezier(.4,0,.2,1);\n}\n\n.hc-article-wrap * { box-sizing: border-box; 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}\n .hc-featured-image-wrap { padding: 0 16px; }\n .hc-article-body { padding: 16px 20px 48px; }\n .hc-obs-grid { grid-template-columns: 1fr; }\n .hc-stat-grid { grid-template-columns: repeat(2, 1fr); }\n .hc-cta-card { flex-direction: column; align-items: flex-start; }\n .hc-table td:first-child { white-space: normal; }\n .hc-step-header { gap: 12px; }\n}\n<\/style>\n<\/head>\n\n<body>\n<div class=\"hc-article-wrap elementor-widget-wrap\">\n\n \n <header class=\"hc-hero\">\n <div class=\"hc-hero-inner\">\n <span class=\"hc-hero-eyebrow\">Field Notes<\/span>\n <h1>Transformer Sizing for PV and BESS: <em>What Trips People Up<\/em><\/h1>\n <p class=\"hc-hero-lead\">Sizing a transformer for solar or storage is never just picking a kVA number off an inverter datasheet. The load basis, the harmonics, the cooling class, and the grounding scheme all decide whether the unit runs cool for 30 years or gets replaced at year ten.<\/p>\n <div class=\"hc-hero-meta\">\n <span class=\"hc-meta-tag\">\n <svg width=\"13\" height=\"13\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><circle cx=\"12\" cy=\"12\" r=\"10\"\/><polyline points=\"12 6 12 12 16 14\"\/><\/svg>\n 8 min read\n <\/span>\n <span class=\"hc-meta-tag\">\n <svg width=\"13\" height=\"13\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M12 20h9\"\/><path d=\"M16.5 3.5a2.121 2.121 0 0 1 3 3L7 19l-4 1 1-4L16.5 3.5z\"\/><\/svg>\n Haocheng Electrical Technical Team\n <\/span>\n <span class=\"hc-meta-tag\">\n <svg width=\"13\" height=\"13\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M4 19.5A2.5 2.5 0 0 1 6.5 17H20\"\/><path d=\"M6.5 2H20v20H6.5A2.5 2.5 0 0 1 4 19.5v-15A2.5 2.5 0 0 1 6.5 2z\"\/><\/svg>\n Updated August 2026\n <\/span>\n <\/div>\n <\/div>\n <\/header>\n\n \n <div class=\"hc-featured-image-wrap\">\n <div class=\"hc-featured-image\" role=\"img\" aria-label=\"Transformer sizing considerations for solar PV and battery energy storage plants\"><\/div>\n <p class=\"hc-image-caption\">A PV or BESS step-up transformer sees a very different duty cycle than a standard distribution unit \u2014 sizing has to reflect that.<\/p>\n <\/div>\n\n \n <main class=\"hc-article-body\" itemscope itemtype=\"https:\/\/schema.org\/TechArticle\">\n\n \n <div class=\"hc-intro\">\n <p>Transformer selection is one of those areas on solar and storage projects where a lot of people get burned early on. There isn't a lot of plain-language material out there on this, since most vendor datasheets assume the reader already knows what they're doing. The sections below cover what actually matters \u2014 from load basis and harmonics through grounding, cooling, and the mistakes that keep showing up on real projects.<\/p>\n <\/div>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s0-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">At a Glance<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s0-heading\">The Numbers That Usually Decide It<\/h2>\n <div class=\"hc-stat-grid\">\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>1.2\u20131.4<\/span><\/div>\n <div class=\"hc-stat-label\">Typical DC\/AC ratio \u2014 why sizing off inverter nameplate overshoots reality<\/div>\n <\/div>\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>15\u201330%<\/span><\/div>\n <div class=\"hc-stat-label\">Extra capacity typically gained by adding an ONAF fan stage over plain ONAN<\/div>\n <\/div>\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>0.95<\/span><\/div>\n <div class=\"hc-stat-label\">Common lagging power factor requirement at the POI \u2014 eats into kVA margin<\/div>\n <\/div>\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>20\u201330<\/span><\/div>\n <div class=\"hc-stat-label\">Years over which loss evaluation usually outweighs sticker price<\/div>\n <\/div>\n <\/div>\n <div class=\"hc-callout\">\n <p>The transformer that fails early was almost never undersized on paper. <em>It was sized to the wrong load basis in the first place.<\/em><\/p>\n <\/div>\n <\/section>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s1-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">01\u201308<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s1-heading\">The Factors That Actually Matter<\/h2>\n <p>These are worked through roughly in the order they tend to come up during design \u2014 starting with what defines the load, then what the transformer has to survive, then what protects it long-term.<\/p>\n\n <div class=\"hc-step-list\">\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">1<\/span>\n <div class=\"hc-step-title\">Load Basis, Not Nameplate<span>The most common first-project mistake<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Sizing off the sum of inverter nameplate ratings overshoots the real requirement, since DC\/AC ratios of 1.2 or higher mean the inverter rarely pushes full nameplate outside a handful of clipping hours. Realistic continuous AC output \u2014 based on site irradiance data, plus whatever power factor the utility requires \u2014 is the number that matters.<\/p>\n <p>BESS is different again, since power flows both directions and, depending on the application (arbitrage, frequency regulation, peak shaving), the unit can sit near rated power far more often than a PV plant ever would.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Load-profile dependent<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">2<\/span>\n <div class=\"hc-step-title\">Harmonic Loading<span>The most underrated failure mode<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Inverters and PCS units are switching devices, and harmonic current still flows into the transformer regardless of how clean the filtering looks on paper \u2014 driving extra eddy current and stray losses that a plain 60 Hz sine-wave design never accounted for. Actual THD data at partial load, not just rated output, matters more than most vendor sheets suggest.<\/p>\n <p>A K-factor rated unit, or a derating calculated per IEEE C57.110, is the difference between normal insulation life and replacing it ten years early.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag oil\">Requires vendor THD data<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">3<\/span>\n <div class=\"hc-step-title\">Oil-Filled vs. Dry-Type<span>Fire code usually settles it<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Most ground-mount utility-scale sites still run oil-filled, pad-mounted units \u2014 cheaper per kVA, better overload handling. BESS sites increasingly push toward dry-type or ester-fluid transformers even at a cost premium, mainly because it simplifies the fire protection conversation with the AHJ when the unit sits next to battery enclosures. Rooftop and carport PV is almost always dry-type given the installation location.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Site and code dependent<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">4<\/span>\n <div class=\"hc-step-title\">Cooling Class and Overload Margin<span>Cheap insurance, frequently skipped<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>On sites that run hot, or where the load profile sits near rated output often, ONAN\/ONAF instead of plain ONAN is usually worth the extra cost \u2014 the fan stage buys roughly 15\u201330% more capacity for a small fraction of total transformer cost. Ambient temperature and altitude correction factors are worth double-checking too; this gets missed constantly on desert and high-elevation sites.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag oil\">Favors ONAF in hot\/high-load sites<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">5<\/span>\n <div class=\"hc-step-title\">Impedance and Grounding<span>Not a default vendor setting<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Impedance should be worked out with a protection engineer before finalizing anything \u2014 too low and downstream fault currents get nasty, too high and voltage regulation problems show up, which matters more on PV because of cloud transients and on BESS because of fast power swings during cycling. Vector group matters too: Dyn11 (or Dyn1, region dependent) is the usual choice for step-up transformers, since it provides a grounded reference point that most inverters and PCS units need on their side.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Coordinate with protection engineer<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">6<\/span>\n <div class=\"hc-step-title\">Tap Changers<span>DETC covers most projects<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Unless there's a specific requirement for active voltage regulation as a grid service, an on-load tap changer usually isn't worth the added cost and maintenance burden. A de-energized tap changer, set once at commissioning based on measured site voltage, is sufficient for the large majority of PV and BESS installations.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag dry\">DETC sufficient in most cases<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">7<\/span>\n <div class=\"hc-step-title\">Hybrid PV + BESS on a Shared Transformer<span>Nameplate addition overstates the real load<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Nameplate ratings shouldn't just be added together. The actual coincident power flow needs modeling, since PV generation and BESS charge\/discharge rarely peak in the same direction at the same time \u2014 and the real ceiling is usually the POI interconnection limit, not the sum of equipment nameplates.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Model coincident load, not nameplate sum<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">8<\/span>\n <div class=\"hc-step-title\">Losses Over Project Life<span>Rarely the deciding factor upfront, always one in the end<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>A loss evaluation \u2014 no-load losses and load losses, capitalized \u2014 is worth requesting before picking a transformer on price alone. Over a 20\u201330 year project life, losses can outweigh the purchase price difference between two otherwise similar units. Utilities usually have their own loss evaluation formula available on request.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag oil\">Request capitalized loss data<\/span><\/div>\n <\/div>\n <\/div>\n\n <\/div>\n <\/section>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s2-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">09<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s2-heading\">Common Mistakes, Quick Reference<\/h2>\n <p>The same handful of errors keep showing up across otherwise well-engineered projects.<\/p>\n\n <div class=\"hc-table-wrap\" role=\"region\" aria-label=\"Common transformer sizing mistakes on PV and BESS projects\">\n <table class=\"hc-table\">\n <thead>\n <tr>\n <th scope=\"col\">Mistake<\/th>\n <th scope=\"col\">Consequence<\/th>\n <th scope=\"col\">Fix<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td>Sizing off DC nameplate<\/td>\n <td>Oversized, more expensive transformer for the actual AC duty<\/td>\n <td>Size to realistic continuous AC output plus POI power factor<\/td>\n <\/tr>\n <tr>\n <td>Skipping harmonic derating<\/td>\n <td>Unit runs hotter than nameplate suggests; early insulation loss<\/td>\n <td>Get vendor THD data at partial load; apply C57.110 derating or spec K-factor<\/td>\n <\/tr>\n <tr>\n <td>Ignoring altitude \/ ambient correction<\/td>\n <td>Transformer derated more than planned on desert or high-elevation sites<\/td>\n <td>Check correction factors against actual site conditions before finalizing<\/td>\n <\/tr>\n <tr>\n <td>Adding PV + BESS nameplates<\/td>\n <td>Oversized shared transformer relative to real coincident load<\/td>\n <td>Model coincident power flow against the POI interconnection limit<\/td>\n <\/tr>\n <tr>\n <td>Grounding\/vector group decided late<\/td>\n <td>Rework at commissioning; nuisance tripping or undetected ground faults<\/td>\n <td>Lock in with protection settings early in design, not at commissioning<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n <p class=\"hc-note\">Figures throughout are directional industry norms. Confirm exact ratings, derating factors, and grounding requirements against the applicable interconnection utility spec and local code before finalizing a design.<\/p>\n <\/section>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s3-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">10<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s3-heading\">Where to Start on a Given Project<\/h2>\n <div class=\"hc-obs-grid\">\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\u2600\ufe0f<\/div>\n <h4>PV-Only Plant<\/h4>\n <p>Start with realistic AC output from irradiance data and POI power factor, then layer in harmonic derating from actual inverter THD figures.<\/p>\n <\/div>\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\ud83d\udd0b<\/div>\n <h4>BESS Plant<\/h4>\n <p>Model the duty cycle for the specific use case \u2014 frequency regulation runs a transformer far harder than occasional peak shaving.<\/p>\n <\/div>\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\ud83d\udd17<\/div>\n <h4>Hybrid PV + BESS<\/h4>\n <p>Model coincident load against the POI limit rather than adding nameplates \u2014 this is where oversizing most often creeps in.<\/p>\n <\/div>\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\ud83c\udf21\ufe0f<\/div>\n <h4>Hot or High-Elevation Sites<\/h4>\n <p>Confirm ambient and altitude correction factors early, and weigh ONAF against plain ONAN before locking in a cooling class.<\/p>\n <\/div>\n <\/div>\n <\/section>\n\n \n <div class=\"hc-cta-single\">\n <div class=\"hc-cta-card full\">\n <div class=\"hc-cta-copy\">\n <span class=\"hc-cta-eyebrow\">Transformer Series<\/span>\n <h3>Built for PV, BESS, and Distribution Duty<\/h3>\n <p>Oil-immersed, dry-type, and amorphous alloy core options engineered for harmonic-rich, cyclic, and high-utilization loads typical of solar and storage plants.<\/p>\n <\/div>\n <a href=\"https:\/\/haochengcompany.com\/transformer-series\/\" class=\"hc-cta-btn\" target=\"_blank\" rel=\"noopener\">\n View Transformer Series\n <svg width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><line x1=\"5\" y1=\"12\" x2=\"19\" y2=\"12\"\/><polyline points=\"12 5 19 12 12 19\"\/><\/svg>\n <\/a>\n <\/div>\n <\/div>\n\n \n <aside class=\"hc-references\" aria-label=\"Sources referenced\">\n <h5>Sources & Standards Referenced<\/h5>\n <ul>\n <li>IEEE C57.12.00 \/ C57.12.90 \u2014 General Requirements & Testing<\/li>\n <li>IEEE C57.110 \u2014 Harmonic Loading Derating<\/li>\n <li>IEC 60076 \u2014 Power Transformers<\/li>\n <li>NFPA 850 \u2014 Fire Protection for Electric Generating & Converter Stations<\/li>\n <li>Local Interconnection Utility Transformer Specifications<\/li>\n <\/ul>\n <\/aside>\n\n <\/main>\n<\/div>\n<\/body>\n<\/html>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Transformer Sizing for PV and BESS: What Trips People Up Field Notes Transformer Sizing for PV and BESS: What Trips People Up Sizing a transformer for solar or storage is never just picking a kVA number off an inverter datasheet. The load basis, the harmonics, the cooling class, and the grounding scheme all decide whether […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1859","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts\/1859","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/comments?post=1859"}],"version-history":[{"count":4,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts\/1859\/revisions"}],"predecessor-version":[{"id":1864,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts\/1859\/revisions\/1864"}],"wp:attachment":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/media?parent=1859"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/categories?post=1859"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/tags?post=1859"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

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\n\t\t\t\t\t\n\n\n\n\nTransformer Sizing for PV and BESS: What Trips People Up<\/title>\n<meta name=\"description\" content=\"A field-engineering look at transformer sizing and selection for solar PV and battery storage plants \u2014 load basis, harmonics, cooling, grounding, and the mistakes that keep showing up on real projects.\">\n\n<script type=\"application\/ld+json\">\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@graph\": [\n {\n \"@type\": \"TechArticle\",\n \"@id\": \"https:\/\/haochengcompany.com\/transformer-sizing-for-pv-and-bess\/\",\n \"headline\": \"Transformer Sizing for PV and BESS: What Trips People Up\",\n \"description\": \"A field-engineering breakdown of transformer sizing and selection considerations for solar PV and battery energy storage plants.\",\n \"author\": { \"@type\": \"Organization\", \"name\": \"Haocheng Electrical\", \"url\": \"https:\/\/haochengcompany.com\" },\n \"publisher\": {\n \"@type\": \"Organization\",\n \"name\": \"Haocheng Electrical\",\n \"logo\": { \"@type\": \"ImageObject\", \"url\": \"https:\/\/haochengcompany.com\/wp-content\/uploads\/logo.png\" }\n },\n \"image\": \"https:\/\/haochengcompany.com\/wp-content\/uploads\/2026\/08\/Transformer-sizing-for-PV-and-BESS-some-things-that-trip-people-up.webp\",\n \"datePublished\": \"2026-08-12\",\n \"dateModified\": \"2026-08-12\",\n \"mainEntityOfPage\": \"https:\/\/haochengcompany.com\/transformer-sizing-for-pv-and-bess\/\",\n \"about\": [\n { \"@type\": \"Thing\", \"name\": \"Solar PV Transformer\" },\n { \"@type\": \"Thing\", \"name\": \"BESS Transformer\" },\n { \"@type\": \"Thing\", \"name\": \"Transformer Sizing\" },\n { \"@type\": \"Thing\", \"name\": \"Harmonic Derating\" }\n ],\n \"keywords\": \"PV transformer sizing, BESS transformer, harmonic derating, step-up transformer, K-factor transformer, renewable energy substation\",\n \"inLanguage\": \"en\",\n \"technicalAudience\": \"Electrical engineers, EPC contractors, solar and storage developers, substation planners\",\n \"proficiencyLevel\": \"Intermediate\u2013Expert\"\n },\n {\n \"@type\": \"Product\",\n \"name\": \"Haocheng Transformer Series\",\n \"description\": \"Transformer product line covering dry-type, oil-immersed, and amorphous alloy core transformers for solar PV, BESS, and distribution applications.\",\n \"brand\": { \"@type\": \"Brand\", \"name\": \"Haocheng Electrical\" },\n \"url\": \"https:\/\/haochengcompany.com\/transformer-series\/\",\n \"category\": \"Power Transformer\"\n }\n ]\n}\n<\/script>\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Sora:wght@300;400;500;600;700&family=DM+Serif+Display:ital@0;1&display=swap\" rel=\"stylesheet\">\n\n<style>\n:root {\n --hc-primary: #0A2540;\n --hc-accent: #E8A020;\n --hc-accent-light: #FFF4DE;\n --hc-teal: #1A7A6E;\n --hc-teal-light: #EAF6F4;\n --hc-text: #1C2B3A;\n --hc-text-muted: #5A7080;\n --hc-border: #D9E4EC;\n --hc-bg: #F7FAFC;\n --hc-white: #FFFFFF;\n --hc-rule: #C8D8E4;\n --hc-font-display: 'DM Serif Display', Georgia, serif;\n --hc-font-body: 'Sora', sans-serif;\n --hc-radius: 10px;\n --hc-shadow: 0 4px 24px rgba(10,37,64,0.09);\n --hc-shadow-hover: 0 8px 36px rgba(10,37,64,0.14);\n --hc-max-width: 860px;\n --hc-transition: 0.22s cubic-bezier(.4,0,.2,1);\n}\n\n.hc-article-wrap * { box-sizing: border-box; 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box-shadow: 0 8px 24px rgba(232,160,32,0.4); }\n.hc-cta-btn svg { transition: transform var(--hc-transition); }\n.hc-cta-btn:hover svg { transform: translateX(3px); }\n\n\/* REFERENCES *\/\n.hc-references { margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--hc-border); }\n.hc-references h5 { font-size: 11px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--hc-text-muted); margin-bottom: 12px; }\n.hc-references ul { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }\n.hc-references ul li { font-size: 12px; color: var(--hc-text-muted); background: var(--hc-bg); border: 1px solid var(--hc-border); padding: 4px 12px; border-radius: 100px; }\n\n\/* NOTE BOX *\/\n.hc-note { font-size: 12.5px !important; color: var(--hc-text-muted) !important; background: var(--hc-bg); border: 1px solid var(--hc-border); border-radius: var(--hc-radius); padding: 14px 18px; margin-top: 18px; line-height: 1.7 !important; }\n\n\/* RESPONSIVE *\/\n@media (max-width: 640px) {\n .hc-hero { padding: 48px 20px 44px; }\n .hc-featured-image-wrap { padding: 0 16px; }\n .hc-article-body { padding: 16px 20px 48px; }\n .hc-obs-grid { grid-template-columns: 1fr; }\n .hc-stat-grid { grid-template-columns: repeat(2, 1fr); }\n .hc-cta-card { flex-direction: column; align-items: flex-start; }\n .hc-table td:first-child { white-space: normal; }\n .hc-step-header { gap: 12px; }\n}\n<\/style>\n<\/head>\n\n<body>\n<div class=\"hc-article-wrap elementor-widget-wrap\">\n\n \n <header class=\"hc-hero\">\n <div class=\"hc-hero-inner\">\n <span class=\"hc-hero-eyebrow\">Field Notes<\/span>\n <h1>Transformer Sizing for PV and BESS: <em>What Trips People Up<\/em><\/h1>\n <p class=\"hc-hero-lead\">Sizing a transformer for solar or storage is never just picking a kVA number off an inverter datasheet. The load basis, the harmonics, the cooling class, and the grounding scheme all decide whether the unit runs cool for 30 years or gets replaced at year ten.<\/p>\n <div class=\"hc-hero-meta\">\n <span class=\"hc-meta-tag\">\n <svg width=\"13\" height=\"13\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><circle cx=\"12\" cy=\"12\" r=\"10\"\/><polyline points=\"12 6 12 12 16 14\"\/><\/svg>\n 8 min read\n <\/span>\n <span class=\"hc-meta-tag\">\n <svg width=\"13\" height=\"13\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M12 20h9\"\/><path d=\"M16.5 3.5a2.121 2.121 0 0 1 3 3L7 19l-4 1 1-4L16.5 3.5z\"\/><\/svg>\n Haocheng Electrical Technical Team\n <\/span>\n <span class=\"hc-meta-tag\">\n <svg width=\"13\" height=\"13\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M4 19.5A2.5 2.5 0 0 1 6.5 17H20\"\/><path d=\"M6.5 2H20v20H6.5A2.5 2.5 0 0 1 4 19.5v-15A2.5 2.5 0 0 1 6.5 2z\"\/><\/svg>\n Updated August 2026\n <\/span>\n <\/div>\n <\/div>\n <\/header>\n\n \n <div class=\"hc-featured-image-wrap\">\n <div class=\"hc-featured-image\" role=\"img\" aria-label=\"Transformer sizing considerations for solar PV and battery energy storage plants\"><\/div>\n <p class=\"hc-image-caption\">A PV or BESS step-up transformer sees a very different duty cycle than a standard distribution unit \u2014 sizing has to reflect that.<\/p>\n <\/div>\n\n \n <main class=\"hc-article-body\" itemscope itemtype=\"https:\/\/schema.org\/TechArticle\">\n\n \n <div class=\"hc-intro\">\n <p>Transformer selection is one of those areas on solar and storage projects where a lot of people get burned early on. There isn't a lot of plain-language material out there on this, since most vendor datasheets assume the reader already knows what they're doing. The sections below cover what actually matters \u2014 from load basis and harmonics through grounding, cooling, and the mistakes that keep showing up on real projects.<\/p>\n <\/div>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s0-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">At a Glance<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s0-heading\">The Numbers That Usually Decide It<\/h2>\n <div class=\"hc-stat-grid\">\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>1.2\u20131.4<\/span><\/div>\n <div class=\"hc-stat-label\">Typical DC\/AC ratio \u2014 why sizing off inverter nameplate overshoots reality<\/div>\n <\/div>\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>15\u201330%<\/span><\/div>\n <div class=\"hc-stat-label\">Extra capacity typically gained by adding an ONAF fan stage over plain ONAN<\/div>\n <\/div>\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>0.95<\/span><\/div>\n <div class=\"hc-stat-label\">Common lagging power factor requirement at the POI \u2014 eats into kVA margin<\/div>\n <\/div>\n <div class=\"hc-stat-card\">\n <div class=\"hc-stat-num\"><span>20\u201330<\/span><\/div>\n <div class=\"hc-stat-label\">Years over which loss evaluation usually outweighs sticker price<\/div>\n <\/div>\n <\/div>\n <div class=\"hc-callout\">\n <p>The transformer that fails early was almost never undersized on paper. <em>It was sized to the wrong load basis in the first place.<\/em><\/p>\n <\/div>\n <\/section>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s1-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">01\u201308<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s1-heading\">The Factors That Actually Matter<\/h2>\n <p>These are worked through roughly in the order they tend to come up during design \u2014 starting with what defines the load, then what the transformer has to survive, then what protects it long-term.<\/p>\n\n <div class=\"hc-step-list\">\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">1<\/span>\n <div class=\"hc-step-title\">Load Basis, Not Nameplate<span>The most common first-project mistake<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Sizing off the sum of inverter nameplate ratings overshoots the real requirement, since DC\/AC ratios of 1.2 or higher mean the inverter rarely pushes full nameplate outside a handful of clipping hours. Realistic continuous AC output \u2014 based on site irradiance data, plus whatever power factor the utility requires \u2014 is the number that matters.<\/p>\n <p>BESS is different again, since power flows both directions and, depending on the application (arbitrage, frequency regulation, peak shaving), the unit can sit near rated power far more often than a PV plant ever would.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Load-profile dependent<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">2<\/span>\n <div class=\"hc-step-title\">Harmonic Loading<span>The most underrated failure mode<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Inverters and PCS units are switching devices, and harmonic current still flows into the transformer regardless of how clean the filtering looks on paper \u2014 driving extra eddy current and stray losses that a plain 60 Hz sine-wave design never accounted for. Actual THD data at partial load, not just rated output, matters more than most vendor sheets suggest.<\/p>\n <p>A K-factor rated unit, or a derating calculated per IEEE C57.110, is the difference between normal insulation life and replacing it ten years early.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag oil\">Requires vendor THD data<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">3<\/span>\n <div class=\"hc-step-title\">Oil-Filled vs. Dry-Type<span>Fire code usually settles it<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Most ground-mount utility-scale sites still run oil-filled, pad-mounted units \u2014 cheaper per kVA, better overload handling. BESS sites increasingly push toward dry-type or ester-fluid transformers even at a cost premium, mainly because it simplifies the fire protection conversation with the AHJ when the unit sits next to battery enclosures. Rooftop and carport PV is almost always dry-type given the installation location.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Site and code dependent<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">4<\/span>\n <div class=\"hc-step-title\">Cooling Class and Overload Margin<span>Cheap insurance, frequently skipped<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>On sites that run hot, or where the load profile sits near rated output often, ONAN\/ONAF instead of plain ONAN is usually worth the extra cost \u2014 the fan stage buys roughly 15\u201330% more capacity for a small fraction of total transformer cost. Ambient temperature and altitude correction factors are worth double-checking too; this gets missed constantly on desert and high-elevation sites.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag oil\">Favors ONAF in hot\/high-load sites<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">5<\/span>\n <div class=\"hc-step-title\">Impedance and Grounding<span>Not a default vendor setting<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Impedance should be worked out with a protection engineer before finalizing anything \u2014 too low and downstream fault currents get nasty, too high and voltage regulation problems show up, which matters more on PV because of cloud transients and on BESS because of fast power swings during cycling. Vector group matters too: Dyn11 (or Dyn1, region dependent) is the usual choice for step-up transformers, since it provides a grounded reference point that most inverters and PCS units need on their side.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Coordinate with protection engineer<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">6<\/span>\n <div class=\"hc-step-title\">Tap Changers<span>DETC covers most projects<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Unless there's a specific requirement for active voltage regulation as a grid service, an on-load tap changer usually isn't worth the added cost and maintenance burden. A de-energized tap changer, set once at commissioning based on measured site voltage, is sufficient for the large majority of PV and BESS installations.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag dry\">DETC sufficient in most cases<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">7<\/span>\n <div class=\"hc-step-title\">Hybrid PV + BESS on a Shared Transformer<span>Nameplate addition overstates the real load<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>Nameplate ratings shouldn't just be added together. The actual coincident power flow needs modeling, since PV generation and BESS charge\/discharge rarely peak in the same direction at the same time \u2014 and the real ceiling is usually the POI interconnection limit, not the sum of equipment nameplates.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag depends\">Model coincident load, not nameplate sum<\/span><\/div>\n <\/div>\n <\/div>\n\n <div class=\"hc-step-card\">\n <div class=\"hc-step-header\">\n <span class=\"hc-step-num\">8<\/span>\n <div class=\"hc-step-title\">Losses Over Project Life<span>Rarely the deciding factor upfront, always one in the end<\/span><\/div>\n <\/div>\n <div class=\"hc-step-body\">\n <p>A loss evaluation \u2014 no-load losses and load losses, capitalized \u2014 is worth requesting before picking a transformer on price alone. Over a 20\u201330 year project life, losses can outweigh the purchase price difference between two otherwise similar units. Utilities usually have their own loss evaluation formula available on request.<\/p>\n <div class=\"hc-winner-row\"><span class=\"hc-winner-tag oil\">Request capitalized loss data<\/span><\/div>\n <\/div>\n <\/div>\n\n <\/div>\n <\/section>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s2-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">09<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s2-heading\">Common Mistakes, Quick Reference<\/h2>\n <p>The same handful of errors keep showing up across otherwise well-engineered projects.<\/p>\n\n <div class=\"hc-table-wrap\" role=\"region\" aria-label=\"Common transformer sizing mistakes on PV and BESS projects\">\n <table class=\"hc-table\">\n <thead>\n <tr>\n <th scope=\"col\">Mistake<\/th>\n <th scope=\"col\">Consequence<\/th>\n <th scope=\"col\">Fix<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td>Sizing off DC nameplate<\/td>\n <td>Oversized, more expensive transformer for the actual AC duty<\/td>\n <td>Size to realistic continuous AC output plus POI power factor<\/td>\n <\/tr>\n <tr>\n <td>Skipping harmonic derating<\/td>\n <td>Unit runs hotter than nameplate suggests; early insulation loss<\/td>\n <td>Get vendor THD data at partial load; apply C57.110 derating or spec K-factor<\/td>\n <\/tr>\n <tr>\n <td>Ignoring altitude \/ ambient correction<\/td>\n <td>Transformer derated more than planned on desert or high-elevation sites<\/td>\n <td>Check correction factors against actual site conditions before finalizing<\/td>\n <\/tr>\n <tr>\n <td>Adding PV + BESS nameplates<\/td>\n <td>Oversized shared transformer relative to real coincident load<\/td>\n <td>Model coincident power flow against the POI interconnection limit<\/td>\n <\/tr>\n <tr>\n <td>Grounding\/vector group decided late<\/td>\n <td>Rework at commissioning; nuisance tripping or undetected ground faults<\/td>\n <td>Lock in with protection settings early in design, not at commissioning<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n <p class=\"hc-note\">Figures throughout are directional industry norms. Confirm exact ratings, derating factors, and grounding requirements against the applicable interconnection utility spec and local code before finalizing a design.<\/p>\n <\/section>\n\n \n <section class=\"hc-section\" aria-labelledby=\"s3-heading\">\n <div class=\"hc-section-label\"><span class=\"hc-section-num\">10<\/span><div class=\"hc-section-rule\"><\/div><\/div>\n <h2 id=\"s3-heading\">Where to Start on a Given Project<\/h2>\n <div class=\"hc-obs-grid\">\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\u2600\ufe0f<\/div>\n <h4>PV-Only Plant<\/h4>\n <p>Start with realistic AC output from irradiance data and POI power factor, then layer in harmonic derating from actual inverter THD figures.<\/p>\n <\/div>\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\ud83d\udd0b<\/div>\n <h4>BESS Plant<\/h4>\n <p>Model the duty cycle for the specific use case \u2014 frequency regulation runs a transformer far harder than occasional peak shaving.<\/p>\n <\/div>\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\ud83d\udd17<\/div>\n <h4>Hybrid PV + BESS<\/h4>\n <p>Model coincident load against the POI limit rather than adding nameplates \u2014 this is where oversizing most often creeps in.<\/p>\n <\/div>\n <div class=\"hc-obs-card\">\n <div class=\"hc-obs-icon\">\ud83c\udf21\ufe0f<\/div>\n <h4>Hot or High-Elevation Sites<\/h4>\n <p>Confirm ambient and altitude correction factors early, and weigh ONAF against plain ONAN before locking in a cooling class.<\/p>\n <\/div>\n <\/div>\n <\/section>\n\n \n <div class=\"hc-cta-single\">\n <div class=\"hc-cta-card full\">\n <div class=\"hc-cta-copy\">\n <span class=\"hc-cta-eyebrow\">Transformer Series<\/span>\n <h3>Built for PV, BESS, and Distribution Duty<\/h3>\n <p>Oil-immersed, dry-type, and amorphous alloy core options engineered for harmonic-rich, cyclic, and high-utilization loads typical of solar and storage plants.<\/p>\n <\/div>\n <a href=\"https:\/\/haochengcompany.com\/transformer-series\/\" class=\"hc-cta-btn\" target=\"_blank\" rel=\"noopener\">\n View Transformer Series\n <svg width=\"16\" height=\"16\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><line x1=\"5\" y1=\"12\" x2=\"19\" y2=\"12\"\/><polyline points=\"12 5 19 12 12 19\"\/><\/svg>\n <\/a>\n <\/div>\n <\/div>\n\n \n <aside class=\"hc-references\" aria-label=\"Sources referenced\">\n <h5>Sources & Standards Referenced<\/h5>\n <ul>\n <li>IEEE C57.12.00 \/ C57.12.90 \u2014 General Requirements & Testing<\/li>\n <li>IEEE C57.110 \u2014 Harmonic Loading Derating<\/li>\n <li>IEC 60076 \u2014 Power Transformers<\/li>\n <li>NFPA 850 \u2014 Fire Protection for Electric Generating & Converter Stations<\/li>\n <li>Local Interconnection Utility Transformer Specifications<\/li>\n <\/ul>\n <\/aside>\n\n <\/main>\n<\/div>\n<\/body>\n<\/html>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Transformer Sizing for PV and BESS: What Trips People Up Field Notes Transformer Sizing for PV and BESS: What Trips People Up Sizing a transformer for solar or storage is never just picking a kVA number off an inverter datasheet. The load basis, the harmonics, the cooling class, and the grounding scheme all decide whether […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1859","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts\/1859","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/comments?post=1859"}],"version-history":[{"count":4,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts\/1859\/revisions"}],"predecessor-version":[{"id":1864,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/posts\/1859\/revisions\/1864"}],"wp:attachment":[{"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/media?parent=1859"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/categories?post=1859"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/haochengcompany.com\/es\/wp-json\/wp\/v2\/tags?post=1859"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}