SolarCalcLab

Category: Solar basics

Monocrystalline vs polycrystalline solar panels: black mono panel 20% to 24% efficient beside blue speckled poly panel 15% to 17% efficient

Solar basics, 7 min read

Monocrystalline vs Polycrystalline Solar Panels: Efficiency, Cost and Which to Buy

Monocrystalline panels are 20% to 24% efficient against 15% to 17% for polycrystalline, handle heat better and need less roof. Here is how they compare on cost, space and cell type in 2026.
Pure sine wave vs modified sine wave inverter waveforms compared

Solar basics, 7 min read

Pure Sine Wave vs Modified Sine Wave Inverter: Which Do You Need?

Pure sine wave inverters make grid-quality power with under 3% distortion, while modified sine wave units run 30% or more and make motors, CPAPs and chargers run hot. Here is how they compare on THD, efficiency, price and sizing.
Off-grid cabin with a ground-mounted 9 kWh solar system of six panels in a forest clearing

Solar basics, 8 min read

9kWh per Day Solar System: How Many Panels and What Size You Need

A 9 kWh per day solar system needs about 2.5 kW, or 6 panels at 430 W, plus about 10 kWh of battery and a 70 A MPPT controller off grid.
Suburban two-story home with a 25 kWh solar system of seventeen panels on a south-facing roof

Solar basics, 8 min read

25kWh per Day Solar System: How Many Panels and What Size You Need

A 25 kWh a day home needs about a 6.9 kW solar system, or 17 panels at 430 W. See sizes by city, panel fit, night battery and cost.
Illustration of a raised bifacial solar panel catching direct sunlight on the front and reflected light from the ground on the back

Solar basics, 7 min read

Bifacial Solar Panels: How Much Extra Power Do They Really Make?

Bifacial solar panels make 5% to 12% more energy on raised ground mounts and up to 30% over snow or a white roof, but almost nothing flush on a shingle roof. See gain by surface, the formula and when they are worth it.
Small family home with a 7kW solar system of seventeen panels on one roof face

Solar basics, 8 min read

7kW Solar System: Yearly Output, Panels Needed and 2026 Cost

What a 7kW solar system produces by city and season, how many panels it needs, 2026 cost, payback, and whether to pick a 6 kW or 7.6 kW inverter.
Tiny home with a six-panel ground-mounted 8 kWh solar system in a wooded clearing

Solar basics, 9 min read

8kWh per Day Solar System: How Many Panels and What Size You Need

Size a solar system for 8 kWh a day: about 2.2 kW or six 430 W panels, plus off-grid battery sizing for tiny homes and cabins.
Rows of solar panels on a commercial warehouse roof, the kind of business system that qualifies for depreciation for solar panels

Solar basics, 9 min read

Solar Panel Depreciation: How MACRS Works for Business Solar Systems

How businesses depreciate solar under 5-year MACRS and 100% bonus depreciation, with the credit basis cut and a worked 100 kW example.
Ranch with a 2000 kWh per month solar system on a ground mount beside the house and barn

Solar basics, 8 min read

Solar for 2,000 kWh a Month: System Size and Panels You Need

Size solar for a 2,000 kWh monthly bill: kW by city, panel count, roof or ground space, panel upgrades and late 2026 cost.
Ground-mounted 100 kWh solar system with rows of panels beside a farm barn

Solar basics, 9 min read

100kWh per Day Solar System: How Many Panels and What Size You Need

Size a 100 kWh per day solar system: about 27.8 kW or 65 panels, with space, wiring, battery and late 2026 cost numbers.
Inverter clipping diagram: a solar production curve flattened at the inverter AC limit around midday, with the clipped peak shown above the limit

Solar basics, 8 min read

Inverter Clipping: What It Is and How Much Energy You Really Lose

Inverter clipping caps solar output at the inverter's AC rating when panels produce more. At a 1.2 to 1.3 DC to AC ratio it usually costs about 1% of yearly energy or less.
House roof with solar panels with micro inverters built in, partly shaded by a tree

Solar basics, 9 min read

Microinverters vs Power Optimizers: Cost, Shade Performance and Which to Choose

Microinverters, power optimizers and string inverters compared on cost, shade, rapid shutdown, batteries and lifespan, with worked numbers.