A smart solar panel is a solar panel with a small electronic device added to it, either a microinverter or a DC optimizer. The device lets each panel work on its own, so shade on one panel does less harm. It helps most on shaded roofs and on roofs that face more than one way.
This page explains what the devices do and how they differ. It shows the best public test data on shade, and it lists the market numbers you can check. It ends with a way to work out if the extra cost pays back on your own roof.
What makes a solar panel “smart”?
A smart panel has a power electronics device at the panel. The US Department of Energy (DOE) calls these devices module-level power electronics (MLPE). There are two kinds.
- Microinverter: a small inverter on each panel. It turns the panel’s DC power into AC power right there.
- DC optimizer: a small converter on each panel. It adjusts the panel’s DC power. A central inverter then turns it into AC power.
Both kinds do maximum power point tracking (MPPT) at the panel. MPPT means the device finds the best voltage for that panel at each moment. In a normal setup, one string inverter does this once for a whole row of panels.
A 2015 DOE case study adds that most modern MLPE products include web-based monitoring. That lets the owner and the installer see how each panel is doing. This is the “smart” part that people notice most.
Our guide to microinverters and optimizers (MLPE) goes deeper on design rules. The page on smart solar panels and whether they are worth it covers the buying side.
How do the three setups compare?
The table uses the DOE’s own words where it can. It does not give prices per watt, because no neutral public source gives them.
| Setup | What happens at the panel | If one panel is shaded | Cost note from the DOE |
|---|---|---|---|
| String inverter | Nothing. One inverter serves the whole string | Power on the string drops | Generally less expensive, easier to cool and to service |
| String inverter with DC optimizers | Each panel has an optimizer | Other panels keep working | First cost tends to be higher than a central inverter |
| Microinverters | Each panel has its own inverter | Power from the other panels is not affected | Can cost more |
Sources: DOE, Solar Integration: Inverters and Grid Services Basics, DOE, Solar Photovoltaic System Design Basics, DOE Building America case study on MLPE (2015).
The DOE also notes that inverters are expected to need replacing at least once in a 25-year PV system. Ask how many devices you would need to replace in each setup.
How much more energy do smart panels make in shade?
In one NREL test, a microinverter system made 3.7% to 12.3% more energy than a string inverter system, depending on how much shade there was. NREL is the US National Renewable Energy Laboratory. The test is from May 2012.
NREL built two identical 8 kW arrays side by side. One used a string inverter. The other used Enphase M215 microinverters. NREL shaded both arrays in many set patterns and compared the AC energy.
| Shade level (share of sunlight lost over the year) | Extra energy from the microinverter array |
|---|---|
| Light (7%) | 3.7% |
| Moderate (15% to 19%) | 7.8% |
| Heavy (25%) | 12.3% |
Source: NREL technical report NREL/TP-5200-54876, May 2012 (the lab’s website has moved to nlr.gov). With no shade, the microinverter array made about 0.5% more, partly because the microinverter had a higher rated efficiency.
Read these numbers with care.
- The test used one microinverter model and one string inverter model. Newer products may act differently.
- NREL says the test error is about 1 percentage point.
- NREL used a dense shade screen for all levels. It says real shade is often softer. Softer shade would likely cut the gain.
- The test did not include optimizers. Your result also depends on your roof.
A DOE case study gives a wider range. It says MLPE recover 20% to 35% of the energy lost to partial shading, and about 100% of the loss from panels that face different ways. The DOE does not say where it got those two figures, and the study is from 2015. Treat them as a general guide, not a promise.
When do smart panels make sense?
They make the most sense when panels do not all get the same sun. The DOE says microinverters can raise system output when panels sit on more than one roof plane, or when they are unevenly shaded.
Think about smart panels if:
- Trees, chimneys or nearby buildings shade part of the roof.
- The array covers more than one roof face.
- You want to see how each panel is doing.
- Local rapid shutdown rules apply (see the next section).
A plain string inverter may be enough if the roof faces one way and has no shade. The DOE says one central inverter is generally less expensive and easier to cool and service.
What about rapid shutdown rules?
Rapid shutdown is a safety rule. In the US it is in section 690.12 of the National Electrical Code (NEC). It covers how fast energized PV circuits must shut down in an emergency.
The DOE case study says MLPE can help meet recent NEC rapid shutdown requirements. Enphase says its IQ8 microinverters are UL Listed as PV rapid shutdown equipment, and that they meet NEC 2014, 2017, 2020 and 2023 section 690.12 when installed as the maker instructs (source: Enphase IQ8 and IQ8+ data sheet, July 2026).
The rules differ by code edition and by state. Ask your local authority which NEC edition applies before you choose equipment.
How big is the smart solar market?
No one number is agreed. Research firms use different meanings of “smart solar”, “smart solar solution” or “intelligent photovoltaic solution”. Some count only panel-level devices. Some add software, batteries and services. Most sell their full reports, so this page does not repeat their forecasts. We cannot check them.
These figures are public and you can check them yourself.
| Figure | What it covers | Source |
|---|---|---|
| An estimated 698 GW of new solar installed in 2025; nearly 3 TW in total | All solar worldwide, not only smart solar | IEA PVPS Snapshot 2026 |
| More than 55% of US home solar systems used some form of MLPE in 2014 | US homes, 2014 (a GTM Research figure quoted by the DOE) | DOE case study, 2015 |
| Net revenues of $1,472,985 thousand in 2025 (2024: $1,330,383 thousand) | Enphase, the microinverter maker, all products | Enphase Q4 2025 results, SEC filing |
| Total revenues of $1.18 billion in 2025 (2024: $901.5 million). 10.8 million optimizers were counted as revenue | SolarEdge, the optimizer maker, all products | SolarEdge Q4 2025 results, SEC filing |
The two company rows include batteries and other products, so they are not the size of the “smart solar” market. They show how large two of the main makers are. The 2014 row is old. This page does not give a newer figure from a neutral source.
Does the extra cost pay back?
You can check this with simple math. Take the extra energy per year, multiply by your power price, and divide the extra cost by the result.
Here is an example. The inputs below are made up to show the steps. They are not data from a real project.
- Your array makes 10,000 kWh a year with a string inverter.
- Your power price is $0.20 per kWh.
- NREL’s gains: 3.7% (light shade), 7.8% (moderate) and 12.3% (heavy).
| Shade level | Extra energy a year | Value a year at $0.20 per kWh |
|---|---|---|
| Light | 10,000 x 0.037 = 370 kWh | 370 x $0.20 = $74 |
| Moderate | 10,000 x 0.078 = 780 kWh | 780 x $0.20 = $156 |
| Heavy | 10,000 x 0.123 = 1,230 kWh | 1,230 x $0.20 = $246 |
Now say your quote is $1,200 higher with microinverters. At moderate shade the payback is $1,200 / $156 = 7.7 years. At light shade it is $1,200 / $74 = 16.2 years.
The NREL numbers come from one old test, so use them only as a rough guide. For a real project, model the shade on your own roof. A shading analysis shows which panels lose sun and when, and the generation and financial tool turns the yield into savings.
Installers can also work out whether design software pays for itself. See our page on solar installer software ROI.
What about batteries?
A battery is a separate choice from the panel hardware. A battery can be charged from the solar power over DC, or after the power is turned into AC. Ask your installer which design they plan to use. Our guide to DC vs AC coupling explains the difference. If you are choosing a battery size, read whole-home vs partial backup batteries.
What about warranties?
Warranty terms are set by each maker, and they change by product and region. Enphase’s IQ8 data sheet says “limited warranty of up to 25 years”. Read the full warranty document for your region before you rely on that number. It is the maker’s own wording, not a promise for every product.
See how SurgePV handles shade and yield
SurgePV covers roof modeling, array layout, shading analysis, energy-yield modeling, financial modeling and proposals. Book a guided demo to see them on a roof like yours.
Book a Free DemoFrequently Asked Questions
What is a smart solar panel?
A smart solar panel is a solar panel with a small electronic device added to it, either a microinverter or a DC optimizer. The device lets each panel work on its own, and many versions also report data for each panel online. The US Department of Energy calls these devices module-level power electronics (MLPE).
Are smart solar panels worth it?
It depends on shade. In a 2012 test by the US National Renewable Energy Laboratory (NREL), one microinverter model made 3.7% more energy than a string inverter under light shade, 7.8% under moderate shade and 12.3% under heavy shade. On an unshaded roof that faces one way, the gain is small, and the extra cost may not pay back. Ask for a quote for both options and compare.
What is the difference between a microinverter and a DC optimizer?
A microinverter turns the panel’s DC power into AC power at the panel. A DC optimizer adjusts the panel’s DC power at the panel, and then a central inverter turns it into AC power. Both let each panel work on its own.
How big is the smart solar market?
No single figure is agreed, because research firms define “smart solar” in different ways. Public numbers you can check: an estimated 698 GW of new solar was installed worldwide in 2025 (IEA PVPS), Enphase reported 2025 revenue of $1.47 billion, and SolarEdge reported 2025 revenue of $1.18 billion.
Do I need smart solar panels for rapid shutdown?
Rapid shutdown is a safety rule in the US National Electrical Code, section 690.12. It covers how fast energized PV circuits must shut down in an emergency. The US Department of Energy says module-level devices can help meet it. The details change by code edition, so check the edition your local authority uses before you pick equipment.
Where this fits
This article is part of SurgePV's Solar Technology hub, which works through the topic from first principles to the decisions a project team actually has to make.
