A grid-connected home solar system has eight kinds of equipment: solar panels, roof mounts (racking), an inverter or panel-level electronics, rapid-shutdown and disconnect hardware, wiring and breakers, monitoring, the utility meter, and an optional battery. Panels are the part most people shop for, but two other choices change a proposal more: the inverter architecture and whether a battery is included. Every item on the proposal should have a manufacturer and a model number you can look up.
Home solar equipment, component by component
The table lists each part in the order the electricity flows, what it does, what the proposal should name, and the question that tells you whether the installer has designed it for your house.
Component | Its job | What the proposal should name | Ask this |
|---|---|---|---|
Solar panels (modules) | Turn sunlight into direct-current (DC) electricity | Manufacturer, full model, quantity, watts per panel, total DC size, datasheet, product and power warranties | “Is this exact model on the contract, or can you substitute it?” |
Racking and roof attachments | Hold the array and carry wind and snow loads into the roof structure | Racking and attachment brand/model, flashing or clamp method for your roof type, structural review | “How many years does your workmanship warranty cover roof penetrations?” |
Inverter (string, microinverters, or optimizers with a central inverter) | Converts DC into the alternating-current (AC) electricity your home and the grid use | Architecture, exact model and quantity, AC capacity, warranty term and whether labor is covered | “Why does this architecture fit my roof’s shade and layout?” |
Rapid-shutdown devices | Drop the voltage on rooftop wiring when the system is shut down, so firefighters can work safely | The device or listed system used, and where the shutdown switch will be | “Where is the shutdown switch, and what does it turn off?” |
Disconnects, breakers and wiring | Connect the array to your electrical panel and let it be isolated for service | Conduit route, breaker size, AC disconnect if required, main-panel or service upgrade, surge protection if included | “Does my main panel need an upgrade, and is it priced in?” |
Monitoring and communications | Record production, and with extra meters, household consumption | Gateway, consumption monitoring, Wi-Fi or cellular connection, data-plan term, homeowner account access | “Who watches it and calls me if output drops?” |
Utility meter and interconnection | Measures electricity you import and export; the utility’s approval lets the system run | Who files the utility application, any meter swap or reprogramming, permission-to-operate (PTO) steps | Ask the utility: “Will my meter be changed, and is there a fee?” |
Battery and backup hardware (optional) | Stores energy for evening use or outages; backup needs equipment that separates the home from the grid | Usable kWh, continuous and surge kW, backed-up circuits, operating modes, warranty | “Which circuits will run in an outage, and for how long?” |
Small extras show up on some proposals: critter guard (mesh that keeps squirrels and birds from nesting under the panels, simpler to add at installation than later), trim skirts and conduit painting. They are fine to include; they should be priced as line items, not used to make two bids look different.
How the equipment works together
- Panels produce DC electricity.
- A string inverter, microinverters or an optimizer-plus-inverter system converts it to AC.
- The home uses solar electricity first while the system is producing.
- Depending on the design and the utility’s rules, extra electricity charges a battery or flows to the grid through the meter.
- When solar is not enough, the home draws from the battery (if set to discharge) or from the grid.
Grid-tied solar does not keep the lights on in an outage by itself. For safety, a grid-tied inverter stops when the grid goes down. Backup requires a battery or other equipment designed to isolate the house from the grid and run the circuits you chose.
The three choices that change the design
Inverter architecture
A single string inverter is generally cheaper and easier to cool and service; microinverters let each panel work independently, which helps when some panels are shaded. The U.S. Department of Energy expects inverters to need replacement at least once over a 25-year array life, so ask what the inverter warranty covers and plan for a replacement. The solar inverter guide compares the architectures roof by roof.
Mounting and the roof
Flush roof mounts are the residential standard; tilt racks are used on flat roofs; ground mounts trade yard space for better orientation. Shingle, tile and metal roofs each need different attachment hardware. Check the roof’s remaining life before installation, not after. Metal roofs have their own options; see solar panels on a metal roof.
Battery now, later or never
A battery is not required for a grid-tied system. It earns more where the utility pays little for exported electricity, where time-of-use rates make evening power expensive, or where outages are common. If you might add one later, ask whether the inverter you are buying is compatible.
Rapid shutdown and disconnects
Rooftop wiring can stay energized whenever the sun is shining, even with the inverter off. The National Electrical Code (NEC) section 690.12 therefore requires a rapid-shutdown system for PV wiring on buildings. Under the 2020 edition, wiring outside the array boundary (1 foot around the panels) or more than 3 feet inside the building must drop to 30 volts or less within 30 seconds of shutdown. Inside the array boundary, the code allows a few compliance methods, which is why proposals list panel-level devices or a listed “PV hazard control” system.
States and cities adopt different NEC editions, so the inspector applies the local version. For you, the practical points are simple: know where the shutdown switch is, keep the labels the installer puts on the equipment, and do not let anyone remove or bypass rapid-shutdown devices during a repair or panel swap.
Battery sizing: kWh and kW are different numbers
Capacity (kWh) is how much energy the battery stores; it decides how long your essentials run. Power (kW) is how much it can deliver at once; it decides whether the well pump and the refrigerator can start at the same time. Ask for usable capacity, not the total cell capacity.
Example with made-up numbers: a battery with 10 kWh of usable capacity running 0.5 kW of essentials (refrigerator, lights, internet, furnace fan) lasts about 20 hours before solar recharges it (10 ÷ 0.5), a little less after conversion losses. If you add a 1.5 kW well pump while it runs, the load is 2.0 kW and the same battery lasts about 5 hours of that combined load. Most homes back up chosen circuits rather than the whole house; agree on the circuit list during design, not during the first outage. Batteries also change insurance questions; see does home insurance cover solar panels.
Datasheet claims vs independent evidence
Wattage, efficiency, temperature coefficient, degradation rate and warranty terms on a datasheet are the manufacturer’s own specifications. They are useful for comparing exact models, but they are not independent test results or a ranking.
- Panels: wattage sets output per panel; efficiency mostly decides how much roof each watt needs, which matters when space is tight. Monocrystalline silicon made up 96% of global solar shipments in 2022, according to DOE; the mono vs poly guide explains why. For exact models and warranties, see the solar panel comparison.
- Independent field data: a National Renewable Energy Laboratory review of nearly 2,000 measured degradation rates found a median of 0.5% per year. At that rate a panel would still produce about 90% of its first-year output after 20 years. That is a broad field average across many products and climates, not a prediction for the model on your proposal; the manufacturer’s power warranty is what you can claim against.
- Labels without a model: “Tier 1 panels” or a “premium inverter” with no model number is the equipment version of a quote with no total price. Ask for the model and datasheet.
The equipment schedule your proposal should include
- Panel manufacturer, full model, quantity and total DC watts
- Inverter, microinverter and optimizer models and quantities
- Racking and roof-attachment manufacturer and model, and the method for your roof type
- Rapid-shutdown method and disconnect location
- Battery, gateway, transfer or backup hardware and the backed-up circuit list, if applicable
- Monitoring platform, consumption monitoring and communications equipment
- Main-panel or service upgrades, trenching, roof work and other separately priced scope
- Product, power-output and workmanship warranties, and who handles claims
- Permit, inspection, utility application and commissioning responsibilities
You approve options the installer proposes; you rarely pick parts off a shelf. Your real decisions are the inverter architecture, the battery and the warranty package. Attachment hardware, wire runs and code compliance are the installer’s job, which is what their license and workmanship warranty cover. Bring the questions to ask a solar installer to that conversation, and compare equipment schedules side by side with the solar quote guide. The solar buying guide covers the full purchase sequence.
Documents and access to keep after installation
- Signed contract, final equipment schedule and change orders
- Final layout, single-line electrical diagram and structural documents
- Datasheets, serial numbers, warranty documents and registrations
- Permit approval, inspection sign-off and utility permission to operate
- Monitoring owner login and installer or administrator contact
- Rapid-shutdown and emergency shutdown instructions
If a component fails on a system you already own, start with these documents and the warranty holder, then compare solar repair costs and warranty checks before approving replacement work.
Make the equipment list contract-ready. If a component affects output, compatibility, backup or warranty coverage, its exact model should be written into the contract before you sign.
Sources
- U.S. Department of Energy, “Solar Photovoltaic System Design Basics” (component roles; inverter replacement at least once in 25 years). Accessed October 14, 2026.
- U.S. Department of Energy, “Homeowner’s Guide to Going Solar”. Accessed October 14, 2026.
- U.S. Department of Energy, PV installation and commissioning. Accessed October 14, 2026.
- U.S. Department of Energy, “Crystalline Silicon Photovoltaics Research” (monocrystalline share of 2022 shipments). Accessed October 14, 2026.
- Jordan and Kurtz, “Photovoltaic Degradation Rates: An Analytical Review,” National Renewable Energy Laboratory (DOE OSTI record). Accessed October 14, 2026.
- Mike Holt Enterprises, NEC 2020 section 690.12 rapid shutdown (code text with commentary). Accessed October 14, 2026.
