How Solar Works
240 real questions, answered
Every how solar worksquestion across Sunnify's blog, grouped by article. Click one to jump straight to the answer.
7 Solar Myths in Singapore, Debunked
- Myth 1: solar panels stop working on cloudy or rainy days
- Myth 2: Singapore needs net metering for solar to make financial sense
- Myth 3: solar panels will keep the lights on during a blackout
- Myth 4: Singapore's heat damages solar panels over time
- What's actually regulated
- What this means for a homeowner
- Myth 6: solar panels need constant cleaning and maintenance to keep working
- Myth 7: solar is simply too expensive to be worth it
- Do solar panels actually stop working when it rains in Singapore?
- Will my solar panels keep my home powered during a blackout?
- Is solar actually too expensive to be worth it in Singapore?
- Is a rooftop solar system actually a fire hazard?
- Do solar panels really need frequent cleaning to keep working properly?
Do Solar Panels Work on Cloudy and Rainy Days in Singapore?
- Why do panels keep generating without direct sunlight?
- Does Singapore's climate make this a bigger concern than elsewhere?
- How rainy is Singapore's climate actually, in real terms behind the 4.33 PSH figure?
- How much does a single heavy rain day actually cut generation, in real terms?
- Does rain actually help the system in any way?
- Does haze affect generation differently from ordinary cloud cover?
- What should a homeowner actually take away from this?
- Do solar panels stop working when it's cloudy or raining?
- Does Singapore's frequent cloud cover and rain make solar less viable here?
- Does rain help or hurt a solar system?
How a Real Shading Analysis Actually Works: Tools and Methods
- Why isn't a quick visual check enough?
- What is the Solar Pathfinder, and how does it actually work?
- What does reading a Pathfinder result actually look like?
- What about electronic and software-based methods?
- When does a drone-based survey actually earn its cost?
- Does Singapore's sun path change how this analysis should be done?
- What should you ask an installer about their shading survey?
- Is a quick site visit enough to check for shading?
- Do I need to pay for a drone survey, or is a simpler method good enough?
- Can I check for shading myself before calling an installer?
- Does Singapore's near-equatorial sun path make shading analysis simpler or more complex?
How Home Insulation and Solar Panels Work Together in Singapore
- Why does insulation matter so much for a Singapore home's electricity bill?
- How does this actually connect to solar system economics?
- What insulation actually helps most under Singapore's typical roof types?
- Does BCA Green Mark treat insulation and solar as connected, or entirely separate?
- Do solar panels themselves act as a form of insulation?
- Should insulation be planned before sizing a solar system?
- Is this worth prioritising over just installing solar first?
- Does adding solar panels reduce my need for roof insulation?
- Should I insulate my home before or after installing solar?
- Does insulation affect solar payback period?
How Many Solar Panels Do I Need for My Singapore Home?
- Usable roof area
- Electrical supply type
- The easy shorthand, and where it breaks
- What to check instead
- What does this look like on a real, documented roof?
- How does panel wattage affect the count?
- Should I size for today's usage or the maximum my roof allows?
- How many solar panels does a typical Singapore landed home install?
- Does electrical supply type limit how many panels I can install?
- Is it better to size for my current electricity bill or install the maximum my roof allows?
How to Calculate Your Singapore Electricity Bill Before Solar
- What's the actual formula?
- Where do you find your actual kWh usage?
- Does this simplified formula match your real bill exactly?
- Does this calculation differ if you buy electricity from an OEM retailer instead of SP Group?
- How does this formula change once solar is actually generating?
- What if you don't have a recent bill to check?
- What does a worked example actually look like, start to finish?
- Why is this the right first step before estimating solar savings?
- How do I calculate my electricity bill in Singapore?
- Where do I find my monthly kWh usage if I don't have a recent bill?
- How does this calculation relate to what solar would save me?
How to Clean Solar Panels in Singapore
- Why does soiling actually reduce generation?
- Does rain clean panels on its own?
- Does soiling loss ever become permanent if a cleaning is delayed too long?
- Does roof type or mounting method actually change how a panel gets cleaned?
- Is the cost of professional cleaning actually worth it in generation terms?
- Should you clean your own panels?
- Does cleaning also double as a useful maintenance check, or is it a purely separate task?
- What should never be used on solar panels?
- How often should solar panels be cleaned in Singapore?
- Can I clean my own solar panels, or should I hire a professional?
- What should never be used to clean solar panels?
How to Read Your Solar Monitoring App Data
- What do kW and kWh actually mean on the dashboard?
- What does the self-consumption versus export split actually tell you?
- How do I tell a normal low day from an actual problem?
- Is comparing this month against last month actually the right way to spot a problem?
- Do monitoring apps actually alert you automatically, or does a homeowner have to check manually?
- What should you actually check periodically in the app?
- Does the self-consumption figure actually matter for anything beyond curiosity?
- What is the difference between kW and kWh on my solar monitoring app?
- How do I know if a low-generation day is a problem or just weather?
- What does self-consumption versus export actually show me?
Net Energy Rebate (NER) in Singapore: What the Term Actually Refers To
- What are the two real export schemes?
- So where does the term NER actually come from?
- Does the homeowner personally need to do anything with this form, or is it fully handled by someone else?
- Does the term NER appear anywhere official, or is it purely informal shorthand?
- What does this actually look like once export credit starts flowing?
- Does it matter which term an installer or article uses?
- Is Net Energy Rebate a real solar export scheme in Singapore?
- Why do I see the term NER used as if it were a scheme name?
- What should I actually check if I see the term NER in my research?
P50 vs P90 Solar Energy Estimates: Why Two Installers Quote Different Numbers
- Why do two installers quote different generation numbers for the same roof?
- Where does this uncertainty actually come from?
- What does the actual P50-to-P90 gap look like in real numbers?
- Is this the same thing as the confidence level shown on Sunnify's own estimate tool?
- How should this change how you compare quotes?
- What does the payback-period impact actually look like in real numbers?
- Does this affect my payback period calculation?
- What is a P50 solar energy estimate?
- What is a P90 solar energy estimate, and why is it more conservative?
- Which figure should I use when comparing solar quotes?
Reviewing Your First Full Year of Solar Generation
- What's actually worth checking after a first full year?
- What if year one actually comes in above the quoted estimate?
- How do I fairly compare actual generation against what I was quoted?
- What counts as genuinely underperforming, versus normal variance?
- Does the self-consumption split from year one predict future years?
- What if my first year came in meaningfully below what I was quoted?
- Is there anything else worth doing at the one-year mark?
- Is it worth checking the export credit line on my SP Group bill too?
- What's actually worth checking after a first full year of solar?
- How do I fairly compare actual generation against what I was quoted?
- What counts as genuinely underperforming, versus normal variance?
- Does the self-consumption split from year one predict future years?
- What if my first year came in meaningfully below what I was quoted?
SCT and ECIS: How Singapore's Solar Export Credit Actually Works
- What is SCT, and why does it apply to most homeowners?
- What is ECIS, and when does it apply instead?
- Why is the export rate lower than the import rate under either scheme?
- What does SCT credit actually look like in practice?
- How does the export credit actually reach me?
- What happens if my export credit is bigger than my bill in a given month?
- Do I need to apply for either scheme myself?
- Has ECIS actually paid more or less than SCT in 2026?
- Why does solar's own timing work against ECIS specifically?
- Should I switch to a retailer to get ECIS instead of SCT?
- What does ECIS stand for, and does it apply to me?
- What is SCT, and how is it different from ECIS?
- What is the current SCT rate?
- Do I need to apply for SCT or ECIS separately?
- Is export credit paid to me in cash, or applied to my bill?
Should You Change Your SP Group Meter Option After Installing Solar?
- Why does solar change the plan-comparison picture?
- What are the general plan options in Singapore?
- Who are the actual retailer options under the Open Electricity Market?
- Does your retailer choice affect your solar export credit?
- Does the timing of a plan review actually matter, or can it happen right after installation?
- Is switching plans complicated after installing solar?
- Should everyone switch plans after installing solar?
- Does installing solar automatically change my SP Group meter or plan?
- Why would installing solar be a reason to review my electricity plan?
- How do I actually find out if a different plan makes sense after installing solar?
- If I switch to a retailer plan, does it change how much I earn from solar export?
Solar Panel Shading: Causes, Diagnosis, and Fixes in Singapore
- Why does shading cause a disproportionate output drop?
- Why does a single shaded cell cost so much more than its physical share of the panel?
- Does Singapore's near-equatorial location change how a shade analysis should actually be done?
- What actually causes shading on a Singapore landed home roof?
- How do I actually diagnose a shading problem after installation?
- What can actually be done about shading once it is confirmed?
- What does this actually look like for a real string of panels?
- Should shading be checked before a system is even installed?
- Why does shading on one panel affect the whole solar system's output?
- How can I tell if shading is actually the cause of underperformance?
- Do power optimizers actually fix a shading problem?
Solar PV vs. Solar Water Heaters: What's Actually the Difference
- What does each technology actually do?
- Can both be installed on the same home?
- Is a solar water heater a substitute for solar PV panels?
- Does a solar water heater need the same EMA and SP Group approval process as PV?
- How do the two technologies actually compare on cost and payback?
- Which one should a homeowner actually consider?
- Do the two systems actually compete for the same roof space?
- What is the actual technical difference between solar PV and a solar water heater?
- Can I install both a solar PV system and a solar water heater?
- Is a solar water heater a good substitute for solar PV panels?
The Solar Panel Installation Process in Singapore, Step by Step
- What happens during the site survey?
- What should I ask the surveyor while they're on site?
- What should a written survey report actually include?
- What is a red flag at this stage?
- How is the system designed and quoted?
- What determines the system size the installer proposes?
- How many quotes should I actually get?
- How much does the system itself cost, separate from the process?
- What permits and approvals are required before installation?
- Why doesn't this delay installation day?
- How should I prepare my property before installation day?
- What actually happens on installation day?
- How many people are on a typical crew, and is it the same company throughout?
- What does scaffolding safety actually involve?
- What happens to my roof surface during mounting?
- How does the system get switched on and connected to the grid?
- What does the LEW actually test before switch-on?
- How is the export credit calculated once the system goes live?
- Does property type change the timeline?
- Does weather affect the schedule?
- Does installer choice affect the timeline?
- What if the crew discovers a roof problem mid-installation?
- What if SP Group's approval is delayed?
- What if the installer's workmanship turns out to be poor?
- What if the installer subcontracts part of the work?
- How do I confirm the system is actually generating as expected?
- When should warranty registration actually happen?
- What does proper post-installation cleanup look like?
- Can I cancel or pause the process after signing, before installation begins?
- How long does solar panel installation take in Singapore?
- Do I need to be home during solar panel installation?
- What happens if the installation reveals a problem with my roof?
- What happens if it rains on my scheduled installation day?
- Can I request specific equipment brands during the design stage?
What 11 Real Solar Installations in Singapore Actually Show
- What does the actual size range across these 12 homes show?
- Why do so many of these installations land right around 12kWp?
- What does the real roof-type diversity actually show?
- Does the ballasted, zero-penetration option actually hold up as a real choice, not just a theoretical one?
- How fast do these installations actually go from start to generating?
- What does the East Coast sequence actually demonstrate?
- What do the savings figures across these case studies actually represent?
- Does this consistency across savings figures mean roof type does not actually affect performance?
- What does this data honestly not show?
- Is this data available anywhere beyond this article?
- Are the savings figures in Sunnify's case studies actual measured results?
- Why do so many of these installations cluster around 12kWp specifically?
- Does Sunnify install these systems itself?
What Happens to Solar Panels at Night?
- What actually happens as the sun sets?
- What does the inverter do while in standby?
- Where does your home's power actually come from overnight?
- Is nighttime standby the same mechanism as the anti-islanding shutdown during a blackout?
- What does the monitoring app actually show overnight, if anything?
- Does this mean solar is less useful for a household that uses more power at night?
- What does the actual cost difference between day and night electricity look like in real terms?
- Do any of Sunnify's documented installations include battery backup for nighttime coverage?
- Do solar panels generate any electricity at night?
- What does the inverter do overnight?
- Where does my home's electricity come from overnight without a battery?
Will I Still Have an Electricity Bill With Solar Panels in Singapore?
- Why can't solar generation cover nighttime use?
- Why doesn't exporting surplus solar zero out the bill?
- How much does the bill actually drop?
- What does this actually look like on a real, documented installation?
- Does a household's starting bill size change how much of a percentage reduction is realistic?
- Is there any way to actually reach a zero bill?
- Does the size of the original bill itself matter for whether solar is worth pursuing?
- Will solar panels eliminate my electricity bill completely?
- Why does Singapore not have net metering that would zero out the bill?
- What actually changes on my SP Group bill after installing solar?
