Solar terms, in plain English.
No jargon, no engineering degree required — just clear, simple definitions of every word you’ll hear during a solar, battery, EV or electrical project.
Every solar, battery, EV and electrical word you’ll hear — explained in plain English, simple enough for a fifth-grader. Grouped by topic and listed A–Z. Don’t see a term? Just ask us.
Solar basics
Grid
The big network of power lines that brings electricity to your home from the power company. Most solar homes stay connected to it.
Kilowatt (kW)
How much power something uses or makes at one moment, like the speed on a car. A bigger kW number means more power right now.
Kilowatt-hour (kWh)
How much energy you use over time — like miles driven, not speed. Your electric bill counts kWh. One kWh runs a typical fridge for about a day.
Off-grid
A system that runs on its own, with no power-company lines — just solar, batteries, and sometimes a generator. Common for cabins and remote land.
Offset
How much of your electric use your solar covers. 100% offset means your panels make about as much power in a year as you use.
Peak sun hours
The number of hours each day the sun is strong enough to make full power. Minnesota gets plenty — more than Germany, a longtime solar leader.
Photovoltaic (PV)
The science word for turning sunlight into electricity. "Photo" means light and "voltaic" means electricity. When you see "PV," think "solar."
Production
How much electricity your panels actually make, usually counted in kWh per year. It's the number every savings estimate is built on.
Shading
Shade from trees, chimneys, or buildings that lands on panels and lowers how much power they make. Even a little shade matters.
Solar array
The whole group of panels working together — on your roof or on the ground. "Array" is just a fancy word for the full set.
Solar panel
A flat board that turns sunlight into electricity. No moving parts, no noise. A bunch of them together make up your solar system.
Watt (W)
A tiny unit of power. 1,000 watts make 1 kilowatt. A modern solar panel makes around 400–440 watts in full sun.
Money & savings
Cost per watt ($/W)
The price of a solar system divided by how many watts it makes. It lets you compare two different-sized quotes fairly, like price per ounce at the store.
Dealer fee
A hidden charge added to the system price to pay for a super-low loan rate. Always ask for the cash price next to the loan price to spot it.
Demand charge
An extra fee on business bills based on the single highest burst of power they use. Solar and batteries can shave it down.
Federal tax credit (ITC)
A discount on your taxes for going solar. Important: the homeowner version ended December 31, 2025. Businesses and farms can still get the 30% credit.
Lease / PPA
A deal where someone else owns the panels on your roof and you just rent the power. iSolar does not do this for homes — we believe you should own it.
MACRS depreciation
A tax rule that lets a business write off the cost of solar quickly. It only helps companies and farms, not homeowners.
Net metering
When your panels make extra power, it goes to the grid and the power company gives you credit. You use that credit later, like a bank for electricity.
Payback period
How long it takes for energy savings to add up to what you paid for the system. After that, the power is basically free for many more years.
Residential Clean Energy Credit (Section 25D)
The old federal tax credit for home solar. It ended December 31, 2025 — there is no federal home-solar credit for new systems in 2026.
Solar loan
Borrowing money to buy your solar system and pay it back monthly — so you own it. Watch for a low rate that hides a big fee in the price.
USDA REAP grant
Government money that can help farms and rural businesses pay for solar. Note: the grant part is paused and under review in 2026, so we never promise it.
Panels & equipment
Bifacial panel
A panel that catches sunlight on the front AND the back. On a ground mount, sunlight bouncing off snow hits the back and makes extra power.
Degradation
Panels slowly make a little less power as they age. Good panels still make about 90% of their original power after 25 years.
Efficiency
How much of the sunlight hitting a panel becomes electricity. Higher efficiency means you need fewer panels to make the same power.
Monocrystalline
The most common, most efficient kind of solar panel today, made from a single pure crystal. It's what we use — usually all-black for a clean look.
Spec sheet
The one-page list of facts about a panel or part — its power, size, and warranty. A good quote names the exact models, not just "high quality."
Tier-1
A label for big, financially strong panel makers. It's about the company's size, not always the panel's quality, so always check the actual model.
Wattage
How much power one panel makes in full sun. Higher-wattage panels mean fewer panels for the same result.
Inverters
DC and AC
DC is the kind of power panels and batteries make. AC is the kind your house uses. The inverter switches DC into AC.
Hybrid inverter
One smart box that runs solar, batteries, and the grid together. Great for whole-home backup and off-grid setups. Sol-Ark and EG4 are popular ones.
Inverter
The part that changes the power from your panels (DC) into the kind your house uses (AC). It's the brain of the system.
Microinverter
A small inverter under each panel, so every panel works on its own. If one panel is shaded, the others keep going. iSolar's home default is Enphase.
Power optimizer
A small device on each panel that helps it perform its best, used with some string inverters (like SolarEdge). It helps with shade.
String inverter
One central inverter for a whole row of panels. Cheaper and great for big sunny areas, but shade on one panel can slow the rest.
Batteries & backup
Backup power
Using a battery (or generator) to keep your lights, fridge, and furnace running during a power outage.
Battery (energy storage)
A box that stores extra solar power so you can use it at night or when the power goes out. Like a giant rechargeable phone battery for your home.
LFP (lithium iron phosphate)
A safe, long-lasting type of battery used in most home batteries today. It handles lots of charge-and-use cycles.
Peak shaving
Using a battery to avoid pulling lots of power from the grid at the priciest moments. It mainly helps businesses lower demand charges.
Self-consumption
Using more of your own solar power yourself — storing daytime sun in a battery to use at night instead of buying from the grid.
Standby generator
A machine that runs on natural gas or propane and makes power during long outages. It pairs well with a battery for layered backup.
Surge
A quick burst of extra power some appliances need to start up, like a well pump or air conditioner. Your battery has to handle that spike.
Whole-home vs. essential backup
Essential backup powers a few important things (fridge, furnace, lights). Whole-home backup runs everything. Whole-home needs a bigger battery.
EV charging
EV charger
The device that charges an electric car at home. A faster "Level 2" charger fills the car much quicker than a regular wall plug.
J1772
The standard plug shape most non-Tesla electric cars use for home charging in the U.S.
Level 2 charging
Home charging on a 240-volt circuit (like a dryer outlet). It adds many miles per hour — much faster than a standard plug.
NACS
The newer charging plug standard started by Tesla that many carmakers are now adopting. Stands for North American Charging Standard.
QMerit
A certification program for trusted EV-charger installers. iSolar is a QMerit partner and can install all the major charger brands.
Roof & mounting
Adjustable tilt
A ground mount you can angle steeper for winter sun or flatter for summer sun, to squeeze out more power across the seasons.
Ballasted mount
A mount held down by heavy weights instead of digging or drilling. Good for flat roofs and some open land because it doesn't make holes.
Detach & reset
Carefully removing solar panels so a roof can be replaced, then putting them back. Best to avoid by re-roofing before you go solar.
Dual-axis tracker
A ground mount that follows the sun two ways — daily and seasonally — for the most power per panel. A premium choice for open land.
Earth-anchored mount
A ground mount held by helical screw anchors twisted into the soil — strong hold-down with little digging, good for certain soils.
East-west array
Panels facing both east and west instead of all south. It spreads power across the morning and evening, which can match how you use energy.
Fixed-axis (fixed tilt)
A ground mount set at one good angle and left there. Simple, sturdy, and the most affordable — the right pick for most installs.
Flashing
Special waterproof covers around the bolts that hold roof panels. Good flashing is how a solar install stays leak-free.
Ground mount
Solar panels set up on a frame in your yard or field instead of the roof. Great when you have open land or a roof that isn't ideal.
Ice-and-water shield
An extra waterproof layer under the roof. iSolar puts it under rooftop arrays — more protection than the minimum code requires.
Pile-driven mount
A ground mount where steel posts are pushed deep into the soil, below the frost line. Strong and built for Minnesota winters.
Poured footing
A ground mount set on concrete piers poured below the frost line. The strongest base, used for heavy arrays and tough soils.
Racking
The metal frame that holds your panels onto the roof or ground. Strong racking and the right mounts keep everything safe for decades.
Single-axis tracker
A ground mount that slowly turns east-to-west during the day to follow the sun, making more power than a fixed array.
Solar carport
A covered structure (like a parking canopy) with solar panels on top. It makes power and provides shade or covered parking at the same time.
Permits, utility & safety
Anti-islanding
A safety feature that shuts your solar off if the grid goes down, so it can't shock a lineworker fixing the wires. Batteries keep you powered safely instead.
Bidirectional meter
A power meter that counts electricity going both ways — what you buy and what your solar sends back. It's what makes net metering work.
Directional boring
A way to run wires underground without digging a big trench, by drilling a path beneath the surface. It keeps lawns and pavement intact.
Inspection
A safety check by your city after the install, making sure the electrical work is done right before the system turns on.
Interconnection
The approval from your power company to connect your solar to the grid and turn on net metering. It's often the longest wait in the process.
Main panel (breaker box)
The gray box where your home's electricity is split into circuits. Solar and EV chargers sometimes need room or an upgrade here.
Master electrician
The highest level of licensed electrician, who can design and sign off on electrical work. iSolar's founder is one — your install is done right.
Monitoring
An app that shows how much power your system makes, panel by panel. If something acts up, you (and we) can see it right away.
Permission to Operate (PTO)
The power company's final "go ahead" to switch your system on. You can't legally run solar until you get it.
Permit
Official permission from your city to do the work. It makes sure the install is safe and follows the rules. We handle it for you.
Service upgrade
Making your home's electrical service bigger so it can safely handle solar, a battery, or an EV charger. Not always needed.
Smart panel
An upgraded breaker box you can control from an app, choosing which circuits get backup power and watching your energy use.
Solar Insure (SI-30)
The 30-year, insurance-backed warranty iSolar puts on every system. It covers parts and labor and keeps protecting you even if a company isn't around.
Still have a question?
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