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Reviewed by
Ludis.app Team
Published
Apr 15, 2026
Updated
Apr 15, 2026
Astronautics Solar Meter is a solar investment calculator for anyone trying to figure out whether rooftop panels are actually worth the money. You put in your country, panel count, and system specs — the app handles the rest, turning raw inputs into a clear financial and environmental picture. It sits somewhere between a serious planning tool and an unusually stylish app, wrapped in a deep-red, space-themed interface that makes running the numbers feel less like homework.
Solar calculators tend to be either dry spreadsheets or vague marketing tools that tell you solar is great without ever saying how great, or for whom. Astronautics Solar Meter occupies a different position: it takes a country-specific electricity tariff, your panel count and wattage, peak sun hours, and a performance ratio, then produces a Mission Report with daily, monthly, and yearly energy output alongside actual dollar savings and a payback timeline.
The Profile Setup screen auto-fills local electricity costs and peak sun hours based on your selected country — though you can override any value manually. Results are displayed in a card-based Mission Report: a sample configuration of 12 panels at 400W in Germany returns 10.2 kWh/day, $1,500/year in savings, and a payback period of 4.8 years. CO₂ reduction is shown in kg per year and translated into a tree-planting equivalent, making the environmental side tangible rather than abstract. The Energy Timeline screen adds a line chart showing seasonal variation across the year.
The aesthetic here is genuinely unusual for a utility app. Deep red gradients, gold particle effects, scattered stars, and a fierce purple-and-gold dragon dominating the splash screen give the whole thing a fantasy-gaming atmosphere. If you've spent time with visually dramatic slot or arcade games — the kind built around mythical creatures, glowing embers, and ornate golden frames — this interface will feel strangely familiar. The dragon clutches a red rocket in its claw; the main menu has a "Start Mission" button. It's committed to the bit.
The multi-button results screen can feel crowded, and terms like kWp, PSH, and PR appear without in-line definitions — newcomers to solar may need a moment to orient themselves before the numbers start making sense.
| Input Parameters | Country, number of panels, panel power (W), roof size (m²), electricity cost (USD/kWh), Peak Sun Hours (PSH), Performance Ratio (PR 0.50–0.95) |
| Auto-fill by Country | Electricity cost and Peak Sun Hours are pre-filled automatically based on selected country; values remain editable |
| Energy Output Calculation | Calculates daily, monthly, and yearly energy generation in kWh (e.g., 10.2 kWh/day, 320 kWh/month, 3,720 kWh/year) |
| Financial Savings Estimate | Shows monthly and yearly savings in USD based on country electricity tariff (e.g., $125/month, $1,500/year) |
| Payback Period | Calculates simple payback time in years (e.g., 4.8 years); stated as simple payback without discounting |
| CO₂ Reduction Tracker | Estimates annual CO₂ savings in kg with tree-equivalent analogy (e.g., 1,300 kg/year ≈ planting trees) |
| Roof Planner Tool | Grid-based visual roof planner; inputs available roof area (m²), default panel size 1.7 m² and 400 W per panel; shows planned panels, used area, and total system size |
| Solar Tips & Knowledge Section | Educational content covering panel orientation, cleaning/maintenance, seasonal output variation, and efficiency (15–22% for residential panels, up to 200W per m²) |
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okay so i downloaded this mostly out of curiosity because we've been going back and forth about whether to put panels on the roof for like two years now... and honestly? this app kind of made the decision feel a lot less overwhelming. you just pick your country, punch in …
3 replies
terra_m: terms like PSH and PR that have little notes but i kept second-guessing whether i was entering the right values
PSH and PR confused me too. No glossary. App assumes you already know what peak sun hours means. Most homeowners don't. That's a real usability gap.
Auto-fill is useful but inaccurate in some regions. Tested on Germany profile. PSH defaulted to 17 — that's too high for annual average. Real figure closer to 3–4 h/day. Results will be optimistic.
the dragon thing threw me off at first lol. solar calculator with a dragon mascot. ok sure. but the numbers actually check out so ill take it 🌞
Roof Planner grid is genuinely useful. Simple but functional. CO₂ section is a nice touch — translating kg into trees makes it tangible. App has a solid core. PSH data accuracy is the main thing holding it back.
yeah that's kind of where i land too... the bones are good. the roof planner and the CO₂ analogy stuff are genuinely helpful for conversations with people who aren't technical. if they sort out the regional data accuracy it could be a really solid tool.
Astronautics Solar Meter does something I genuinely appreciate: it tries to give you a realistic picture of solar investment rather than just cheerleading for the technology. You plug in your country, the number of panels, their wattage, and it auto-fills a bunch of values — local electricity cost, peak sun …
3 replies
honestly the dragon mascot threw me off so much when I first opened it... like I was expecting a game not a solar calculator lol. but once you get past that it's actually pretty decent? the auto-fill for electricity costs was surprisingly accurate for where I live. I do wish the performance ratio had a little tooltip or something though, I had no idea what to put there
The PSH discrepancy you mention is something I have noticed as well, and it is not a trivial concern. Solar planning tools have, historically, had a tendency to present best-case irradiance figures without adequately flagging the assumptions behind them. I will say that the current version of this app is at least transparent enough to show you the value it has auto-filled, which is more than some earlier iterations of similar tools managed; I have used comparable calculators that buried those defaults entirely. Still, a brief contextual note — even just a line explaining what PSH means in practical terms — would meaningfully improve the experience for users who are not already versed in photovoltaic concepts. The CO₂ section is well-intentioned, though I would echo the point about methodology: knowing that your system is 'equivalent to planting 60 trees' is evocative, but without a source it is difficult to know how seriously to weight it.
To be fair, the PSH auto-fill issue is real. Mine defaulted to something noticeably higher than what I found from a couple of external solar databases, and that kind of error compounds — your projected savings end up looking rosier than they probably are. That said, the fact that you can manually override everything is what saves it from being genuinely misleading. The Roof Planner is the feature I keep coming back to, actually. It is a much more grounded way to figure out how many panels are realistic before you start calling contractors.
60 trees though, that's kind of wild :) never thought about it that way. makes the whole thing feel more real somehow
The point about methodology is well taken. To be fair, the trees analogy is more of a communication device than a scientific claim, and it does its job — it makes the CO₂ figure feel tangible. But you are right that a source citation, or at least a note on the conversion factor used, would make it much easier to trust. That said, I am not sure the average person opening a free solar calculator is going to dig into the references even if they are there.
Roof Planner is genuinely fun to mess around with. Spent way too long dragging panel counts up and down :)
