[{"data":1,"prerenderedAt":273},["ShallowReactive",2],{"page-\u002Fguides\u002Firvine-balcony-test-kit":3,"author-mike":215},{"id":4,"title":5,"author":6,"bare":7,"body":8,"dateModified":193,"datePublished":194,"description":195,"extension":196,"howToSteps":197,"kits":197,"layout":198,"meta":199,"navigation":200,"path":201,"schemaType":202,"seo":203,"sources":204,"stem":208,"targetKeywords":209,"titleTag":213,"translationOf":197,"__hash__":214},"content\u002Fguides\u002Firvine-balcony-test-kit.md","Checking the model against a real Irvine balcony","mike",false,{"type":9,"value":10},"minimark",[11,24,29,32,35,38,44,48,52,102,106,113,119,122,126,133,139,145,151,157,161,164,167,171,174,177,181,184,190],[12,13,14],"answer-box",{},[15,16,17,18,23],"p",{},"Every savings figure on this site is model output, and the model is ",[19,20,22],"a",{"href":21},"\u002Fmethodology","published in full",". Published arithmetic is only worth something if somebody checks it, so there's a kit on a west-facing balcony in Irvine logging output against a prediction written down before the readings started. When the comparison comes in we'll publish the gap, including if it's embarrassing.",[25,26,28],"h2",{"id":27},"why-check-it-at-all","Why check it at all",[15,30,31],{},"A model is a set of assumptions with arithmetic on top. Ours is public and every figure on the site traces to it, which is the whole basis on which we ask anyone to believe a number here.",[15,33,34],{},"That only means something if the assumptions get tested against the world occasionally. Most balcony solar content is manufacturer specifications restated, or model output presented as fact, or German figures applied to California without adjustment — and none of it is checkable, because none of it shows its working.",[15,36,37],{},"We'd rather not add to that. So: a prediction written down first, a logger, and the gap published either way. This isn't a test lab and it isn't a study. It's one reading against one forecast, which is enough to catch a model that's badly wrong.",[39,40],"illustration",{"brief":41,"caption":42,"ratio":43},"The full installation, plus a close shot of the energy meter display showing live watts. The meter reading is what makes this evidence rather than an anecdote.","A prediction written down before the data came in. That order is the point.","wide",[25,45,47],{"id":46},"the-setup","The setup",[49,50],"measured",{"note":51},"Make and model, rated output, exact heading, mounting method, sky view, logging method and start date go here. Publishing the specification before the results is the point — it is what stops us quietly picking a flattering configuration later.",[53,54,55,66],"table",{},[56,57,58],"thead",{},[59,60,61,64],"tr",{},[62,63],"th",{},[62,65],{},[67,68,69,78,86,94],"tbody",{},[59,70,71,75],{},[72,73,74],"td",{},"Location",[72,76,77],{},"Irvine, California — SCE territory",[59,79,80,83],{},[72,81,82],{},"Orientation",[72,84,85],{},"West-facing balcony",[59,87,88,91],{},[72,89,90],{},"Utility rate used for value",[72,92,93],{},"33.2¢\u002FkWh blended (June 2026)",[59,95,96,99],{},[72,97,98],{},"Logging",[72,100,101],{},"Daily",[25,103,105],{"id":104},"what-our-model-predicts","What our model predicts",[15,107,108,109,112],{},"Before any data, here's the shape of what ",[19,110,111],{"href":21},"our methodology page"," says a balcony like this should do:",[15,114,115],{},[116,117,118],"code",{},"1,586 kWh\u002FkW\u002Fyr × kW × direction factor × tilt factor × shade factor = annual kWh",[15,120,121],{},"The specific numbers go up alongside the kit specification, and they're written down before the first month's readings so we can't quietly revise them later.",[25,123,125],{"id":124},"what-were-measuring","What we're measuring",[15,127,128,132],{},[129,130,131],"strong",{},"Daily production",", which is the headline.",[15,134,135,138],{},[129,136,137],{},"Production against forecast weather",", so we can separate \"the model is wrong\" from \"it was cloudy in June.\"",[15,140,141,144],{},[129,142,143],{},"Self-consumption",", which is the harder and more interesting one. Producing 4 kilowatt-hours means nothing if the flat is empty and 2 of them go to the grid for free. We're logging household draw alongside production to work out what share is actually used.",[15,146,147,150],{},[129,148,149],{},"The tilt experiment."," At some point we'll run the same panel vertical on the railing for a month and tilted for a month, in comparable conditions, to test the 0.62 factor we've been quoting. If that number is wrong, a lot of our advice about tilt brackets is wrong with it.",[15,152,153,156],{},[129,154,155],{},"Seasonal spread."," December production in California is roughly half of June's. Anyone quoting an annual figure from a summer month is overstating by a wide margin, and we want the real curve.",[25,158,160],{"id":159},"what-well-publish","What we'll publish",[15,162,163],{},"A monthly update with the numbers, and a proper comparison at twelve months.",[15,165,166],{},"Specifically, we'll publish the gap between prediction and reality, whichever direction it runs. If the model overstates by 20 percent, that's the most useful thing we could tell you, and we'll change the model and say what changed.",[25,168,170],{"id":169},"what-this-cant-tell-you","What this can't tell you",[15,172,173],{},"One balcony. One orientation. One year of weather. It'll tell you whether our model is roughly calibrated for a west-facing Irvine balcony, and it won't tell you what happens on a shaded east-facing one in Fresno.",[15,175,176],{},"That's the honest limit of a single logger, and we'd rather say it than imply this is a study. It's here to check whether the model is roughly calibrated — not to stand in for the sourcing and arithmetic the rest of the site runs on.",[25,178,180],{"id":179},"if-you-have-one","If you have one",[15,182,183],{},"If you've got a plug-in system running anywhere in California, we'd like your numbers — kit, orientation, tilt, and monthly kilowatt-hours. A dozen real installations would be worth more than our one, and we'd publish the aggregate with the model comparison.",[185,186],"newsletter-capture",{"body":187,"button":188,"heading":189},"What it actually made, against what we said it would. Plus everything else that changes.","Send me the data","Monthly numbers from the test kit",[191,192],"sources-block",{},"2026-09-07","2026-09-01","Every savings figure here is model output. How we check it against a real balcony, the prediction written down before the data, and what we publish if the model is wrong.","md",null,"article",{},true,"\u002Fguides\u002Firvine-balcony-test-kit","Article",{"title":5,"description":195},[205],{"title":206,"url":207,"accessed":194},"NREL PVWatts Calculator","https:\u002F\u002Fpvwatts.nrel.gov\u002F","guides\u002Firvine-balcony-test-kit",[210,211,212],"balcony solar real world results","balcony solar test","how much does balcony solar actually produce","How Much Does Balcony Solar Actually Produce? Our Model, Checked","YST0YW92k_56RuD7x1ZGb-BnScDqh4FhYJPlE0fCJkg",{"id":216,"title":217,"body":218,"description":264,"email":262,"extension":196,"location":265,"meta":266,"name":224,"navigation":200,"path":267,"photo":268,"role":269,"sameAs":197,"seo":270,"stem":271,"__hash__":272},"authors\u002Fauthors\u002Fmike.md","Mike",{"type":9,"value":219},[220,226,232,239,243,246,249,253,256],[15,221,222,225],{},[129,223,224],{},"Mike Yu"," is the editor of SmallSolarCo. He started it after working out that a plug-in panel was the only kind of solar available to him — he rents in Irvine with a west-facing balcony and no roof of his own — and found that nothing written about it in California was both plain and sourced.",[15,227,228,231],{},[129,229,230],{},"He is not an electrician, a solar installer, or a lawyer",", and the site says so wherever it matters. What he does is read the primary sources — bill text, CPUC filings, utility tariff sheets, UL standards, manufacturer specification sheets — and put them in one place with the arithmetic attached and a date on every claim.",[15,233,234,235,238],{},"He has a background building web products, and built the savings model here himself, using NREL irradiance data and Southern California Edison's published rates. It's published in full on ",[19,236,237],{"href":21},"the methodology page",", and the site's tests fail if an article and the calculator ever disagree.",[25,240,242],{"id":241},"what-this-site-does-and-doesnt-do","What this site does and doesn't do",[15,244,245],{},"It explains, catalogs, and calculates. It does not test hardware. Kit pages are built from published specifications with the date they were checked, not from a test bench, and the site says so rather than implying otherwise.",[15,247,248],{},"There is a plug-in kit on the Irvine balcony logging output, which is used to check whether the model is roughly calibrated. Figures from it are labelled measured and carry their conditions. Everything else on the site is labelled as an estimate, and there are far more estimates than measurements.",[25,250,252],{"id":251},"editorial-independence","Editorial independence",[15,254,255],{},"Affiliate commissions don't reach the savings model — it's the same arithmetic for every kit, and the current recommendation for anyone spending under $400 is a nonprofit that pays nothing. We don't accept hardware on terms that involve anyone approving coverage first. If a manufacturer sends something, the page says so.",[15,257,258,259,263],{},"Reach him at ",[19,260,262],{"href":261},"mailto:hello@smallsolarco.com","hello@smallsolarco.com",".","Mike Yu is the editor of SmallSolarCo. He started it after working out that a plug-in panel was the only kind of solar available to him — he rents in Irvine with a west-facing balcony and no roof of his own — and found that nothing written about it in California was both plain and sourced.","Irvine, California",{},"\u002Fauthors\u002Fmike","\u002Fimages\u002Fauthors\u002Fmike.jpg","Founder and editor",{"description":264},"authors\u002Fmike","2UYfVkomBje4XbTXMc-HWSa7jliDKILElV8MEZxfPVw",1788880326696]