Module 1 · Solar Theory & General Knowledge

Welcome — let’s talk solar

This course is about building solar energy systems in (and with) First Nation communities. It’s four short modules — here’s the path.

Finish this module and you’ll be able to read a solar panel’s spec label and explain how a solar system turns sunlight into usable power — and you’ll earn your Solar Theory badge.

The four modules:

1 · Solar Theory

You are here

How solar works and the parts of a system.

2 · Project Management

Planning, procurement, financing and scheduling.

3 · Solar Build

Site design and overseeing construction.

4 · Post-Build

Commissioning, warranties and monitoring.

Module 1 · Solar Theory & General Knowledge

How a solar panel makes electricity

It starts with light. Sunlight hits the panel and knocks electrons loose — that flow is electricity.

Diagram: sunlight strikes the solar panel, the inverter converts DC to AC, and power flows to the home and grid. — The real path: sunlight → panel → inverter → your home (and the grid).

This is the photovoltaic effect — “photo” (light) + “voltaic” (voltage).

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Where does the term “photovoltaic” come from?

Module 1 · Solar Theory & General Knowledge

What is electricity?

Electricity is the flow of electrons through a closed circuit.

Diagram defining electricity as electron flow, with a simple battery circuit pushing electrons through a light bulb, plus a DC versus AC waveform comparison. — A source pushes electrons along a wire; a closed loop lets current flow and light the bulb.

A closed circuit is a complete, unbroken loop — electricity only flows when the path connects all the way around. Open the loop (flip a switch, cut a wire) and the flow stops.

DC flows steadily in one direction. AC flips back and forth 60 times per second (60 Hz).

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AC voltage…

Module 1 · Solar Theory & General Knowledge

The three things that make electricity work

Electricity behaves a lot like water moving through a pipe. Once you picture it that way, three words do all the heavy lifting — volts, amps and watts.

Pressure pushes water through the pipe to light the bulb — exactly how volts push amps to make watts.

Volts

The push

The pressure that pushes electricity through a wire.

In the pipe: water pressure.

Amps

The flow

How much electricity is actually moving. A wider wire carries more.

In the pipe: the rate of water flow.

Watts

The power

The actual work done — lighting a bulb or running a motor.

The formula: Watts = Volts × Amps.

Watts = Volts × Amps

A panel pushing 29.5 V at 7.8 A → 230 W

Real label from a solar panel

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What is voltage?

Module 1 · Solar Theory & General Knowledge

Ohm's Law

Ohm's Law links voltage, current, and resistance in a circuit.

V = I × R

Voltage (volts) = Current (amps) × Resistance (ohms)

V is voltage, I is current, R is resistance.

Module 1 · Solar Theory & General Knowledge

Finding power

Know any two values and you can find the third.

Circular Ohm's Law wheel mapping Volts, Amps, Watts, and Ohms, with a worked example calculating 120 volts times 4 amps equals 480 watts. — The wheel shows how volts, amps, watts, and ohms relate.

Watts = Volts × Amps

120 V × 4 A = 480 W

An appliance rated 120 V drawing 4 amps uses 480 watts.

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If a circuit is 120 volts and 480 watts, what is the current (amps)?

Module 1 · Solar Theory & General Knowledge

Inside a solar panel

A panel is built like a sandwich — layers that protect the cells while letting the light through.

Diagram of solar module components: frame, glass, encapsulant, solar cells, backsheet and junction box. — The layers inside a panel — glass, encapsulant, cells, backsheet, frame and junction box.

Module 1 · Solar Theory & General Knowledge

Inside a solar panel

Cells are wired in series, so their voltages add up.

Cutaway diagrams of a solar module showing cells wired in series and parallel, layered construction, and per-cell and per-panel voltage figures. — Thin busbars carry electrons between cells; wiring cells in series adds their voltage.

Each cell makes about 0.5 V, so a 60-cell panel produces roughly 30 V.

Module 1 · Solar Theory & General Knowledge

Why we need inverters

Panels make DC power, but homes and buildings run on AC.

Photographs of dark blue monocrystalline solar panels, representing the DC side of a solar installation. — Panels on the roof produce direct current (DC); an inverter changes it to AC for use indoors.

AC is more dangerous than DC. The AC side is wired by an electrician and needs Electrical Safety Authority approval.

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Solar panels produce…

Module 1 · Solar Theory & General Knowledge

Types of solar panels

Solar cells are made of silicon, which creates the photovoltaic effect.

Photos comparing mono and poly solar panels, with a chart contrasting the dark uniform mono cell against the blue speckled poly cell, plus a thin-film panel. — Four main types: bifacial, monocrystalline, polycrystalline, and thin film.

Choose a panel type by weighing your budget against the efficiency you need.

Module 1 · Solar Theory & General Knowledge

Bifacial panels

Comparison of the four solar panel types. — The four panel types compared.

Bifacial panels capture sunlight on both the front and back surfaces. They are about 22-23% efficient and are now common across Ontario and North America.

Module 1 · Solar Theory & General Knowledge

Monocrystalline panels

Comparison chart showing the dark, uniform appearance of a monocrystalline cell next to a blue speckled polycrystalline cell. — Mono cells have angled corners and small white diamonds between them.

Grown from a single silicon crystal, mono panels are about 18-23% efficient and great for rooftops.

Module 1 · Solar Theory & General Knowledge

Polycrystalline panels

Poly panels have square cells with straight corners. They run about 17-21% efficient, a bit lower than mono, but they cost less.

Poly is melted, cut into crystals, and sliced thin, making it more cost effective than mono.

Module 1 · Solar Theory & General Knowledge

Thin film panels

Thin film is a flexible, delicate sheet that can be rolled up like a spool, handy for deploying solar quickly. It is the least efficient at 8-14% and is rarely used in Canada.

It damages easily from hail or wind, and hidden micro cracks can quietly drop its output.

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Which statement is true?

Module 1 · Solar Theory & General Knowledge

Panels keep getting more efficient

Solar panels make more power from the same size every year.

Comparison strip showing solar modules in 1954, 2013 and 2018 getting smaller as efficiency rises, beside a bell curve of daily sunlight. — Same-size panels went from about 6% efficient in the 1950s to over 23% today.

More efficient panels mean more power from the same area.

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How are solar panels sized?

Module 1 · Solar Theory & General Knowledge

Peak sun hours

Panels make the most power when the sun is high, around noon.

Bell curve graph of solar irradiance in watts per square meter against time of day, peaking near midday. — One peak sun hour = 1000 watts per square meter. Most arrives mid-day.

Peak sun hours also depend on location and time of year.

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Peak sun hours…

Module 1 · Solar Theory & General Knowledge

Peak sun hours by month

Software estimates the sun each site gets every month.

PVWatts calculator results table listing month-by-month solar radiation values for an example location. — This site averages 4.04 peak sun hours per day across the year.

This data helps plan how much a system will produce before you build it.

Module 1 · Solar Theory & General Knowledge

Why higher efficiency matters

Two panels make the same power, but one is smaller.

Two SunPower 345-watt panels side by side: a 21.5% efficient panel at 1.628 square meters and a 16.7% panel at 2.062 square meters. — Both make 345 watts. The more efficient panel does it in less space.

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Which statement is true?

Module 1 · Solar Theory & General Knowledge

Wiring panels: series and parallel

The positive and negative wires, called whips, connect panels together.

Diagram of positive and negative connector whips with male and female MC4 connectors, showing series versus parallel wiring. — Series wiring adds up voltage. Parallel wiring adds up amperage.

Panels wired in series are called a string.

Module 1 · Solar Theory & General Knowledge

Bypass diodes: a shaded cell

A panel is only as strong as its weakest cell.

Illustration of a solar module with internal cells, current-flow arrows, and a shaded cell blocking current at the bottom. — Shade one cell and it stops making power, blocking current like a resistor.

Without help, current gets stuck at the shaded cell.

Module 1 · Solar Theory & General Knowledge

How bypass diodes help

Bypass diodes route current around the shaded section.

Same solar module illustration with a bypass diode activated, routing current around the shaded sub-group of cells. — The diode skips the blocked section so the rest of the panel keeps working.

You lose about one-third of power, but still keep two-thirds instead of none.

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The junction box on a solar panel contains…

Module 1 · Solar Theory & General Knowledge

Solar module warranties

Panels come with two kinds of warranty.

Bar chart of solar panel warranted capacity declining year by year over 25 years down to about 80%. — Panels degrade about 0.5% a year, to roughly 80% of output by year 25.

Two warranties: a workmanship warranty (20-25 yrs) and a performance warranty for output.

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Solar panels degrade from…

Module 1 · Solar Theory & General Knowledge

Reading the warranty

Most makers guarantee about 80% output in year 25.

Bar chart showing warranted panel output declining over 25 years to about 80% of the original capacity. — Different makers offer different percentages, so study the terms carefully.

Panels are one of the most expensive parts, so make sure the warranty covers you.

Module 1 · Solar Theory & General Knowledge

Will the maker still be there?

A warranty only helps if the company is still in business.

Solar panel warranty and manufacturer bankability. — Warranties run ~25 years — the maker has to still be around to honour them.

A performance warranty can run 25 years, so check the maker's bankability: is their technology durable and reliable, do they follow regulations, and are they well regarded in the industry? If the company is gone in year 15, you cannot claim it.

Pick makers likely to last, so the warranty is still worth something later.

Module 1 · Solar Theory & General Knowledge

The Spec Label

Every panel has a spec label that tells you what it can do.

Solar module specification label terms next to a photo of an actual panel nameplate with its electrical rating table. — The nameplate lists the panel's key electrical ratings.

The big ones to read first: Maximum power (peak watts), open circuit voltage, short circuit current, efficiency, and tolerance.

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The maximum power on a solar panel is measured in…

Module 1 · Solar Theory & General Knowledge

Where Max Power Comes From

The top line, maximum power, is just volts times amps.

Watts = Volts × Amps

29.49 V × 7.8 A = 230 W (the max power on this label)

Comparing labels this way helps you pick the right panel for a project.

Module 1 · Solar Theory & General Knowledge

Reading the Whole Label

Each line on the label tells you something useful about the panel.

Solar module specification label terms next to a photo of a real panel nameplate showing voltage, current, efficiency and tolerance values. — A worked example: a 230 W, 60-cell poly panel rated +/- 3%.

Tolerance means the real output sits within +/- 3% (about 223-237 W). Operating temperature limits (-40 to +90 C) matter when claiming a warranty.

Module 1 · Solar Theory & General Knowledge

Grid-Tied Systems

A grid-tied system connects your panels to the utility grid.

Schematic of a grid-tied PV system: solar panel to disconnect to inverter to AC main panel to the utility grid, with labelled current-flow steps. — DC from the panels runs to the inverter, becomes AC, then powers the building.

The inverter turns panel DC into household AC. That AC feeds the main panel and is used by the building first.

Module 1 · Solar Theory & General Knowledge

Sending Power Back

Extra solar power flows back to the grid and earns you credits.

Diagram of a solar-powered house connected through a bi-directional meter to the grid, showing electricity flowing both ways. — The building uses solar first; any excess flows out through the meter to the grid.

A meter tracks the extra power you export. You get Hydro credits for it, which lowers your bill.

Module 1 · Solar Theory & General Knowledge

Four Inverter Options

Inverters change panel DC into the AC homes use, in four main types.

Comparison of four grid-tie inverter types - central, string, micro and hybrid - each shown with hardware photos and small wiring diagrams. — Central, string, micro, and hybrid are the four grid-tie inverter choices.

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A grid-tied inverter…

Module 1 · Solar Theory & General Knowledge

Central Inverters

Central inverters are huge units built only for very large projects.

Schematic of a central inverter layout connecting combiner boxes and solar arrays into one large central inverter unit. — One big inverter (50-1000 kW) handles a whole utility-scale array.

One central inverter means one single point of failure - if it breaks, the whole system stops. Too large for small JAZZ projects.

Module 1 · Solar Theory & General Knowledge

String Inverters

String inverters are the most common choice and fit projects our size.

String inverter wiring diagrams connecting panel strings to an inverter, plus a photo of a wall-mounted string inverter unit. — One inverter handles up to four strings of series-wired panels.

Only one inverter to maintain, so it is easy to troubleshoot. But it lasts 5-10 years, so plan to replace it around Year 10 - well before the panels.

Module 1 · Solar Theory & General Knowledge

Micro Inverters

Micro inverters put one small inverter on every single panel.

Each panel gets its own inverter, so conversion happens at the panel level. You need one micro inverter per panel.

Module 1 · Solar Theory & General Knowledge

Micro Inverter Trade-offs

Micro inverters avoid one big failure point but cost more.

Comparison of string versus micro inverter setups, listing advantages and a disadvantage of micro inverters. — If one micro inverter fails, the other panels keep producing.

Plus: no single point of failure and shade on one panel won't drag down the rest. Minus: many units to maintain and about 30% more expensive.

Module 1 · Solar Theory & General Knowledge

Hybrid inverters

Hybrid inverters can work with or without batteries.

Comparison of four grid-tie inverter types: central, string, micro, and hybrid, each with hardware photos and wiring diagrams. — Hybrid is one of four inverter types. It blends an inverter with a battery charger.

Hybrids can store extra energy for use during a blackout. They are not common on most projects.

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Which of these is not an inverter?

Module 1 · Solar Theory & General Knowledge

Mapping micro-inverters

Each inverter has its own barcode, so you can find it fast.

A barcode sticker on a micro-inverter, an installer scanning a unit on a roof, and a monitoring screen showing per-unit data. — Scan each barcode and map its spot on the monitoring portal.

Mapping each unit means a broken inverter is easy to locate and replace.

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Which of these inverters allows for system monitoring?

Module 1 · Solar Theory & General Knowledge

Example monitoring system

A solar monitoring dashboard showing energy figures, a weather widget, and a grid of blue tiles for individual panels. — On the portal you can see each panel and how it sits in the layout.

Module 1 · Solar Theory & General Knowledge

Maximum Power Point Tracking

The inverter tunes volts and amps to squeeze out the most power.

An I-V curve plotting voltage against current, with the maximum power point marked at the top of the curve. — The red point is where volts and amps together make the most watts.

MPPT aims for the most power, not the most voltage or the most current.

Module 1 · Solar Theory & General Knowledge

Anti-islanding feature

When the grid goes down, the inverter shuts itself off.

A lineworker beside a utility pole with a red X, showing the inverter has stopped producing power during an outage. — Without this, a solar building could still push power into a 'dead' grid.

Anti-islanding is built into all grid-tied inverters. It is a critical safety feature.

Module 1 · Solar Theory & General Knowledge

Why it matters

Anti-islanding stops the inverter exporting power when the grid is down. — Anti-islanding keeps a solar home from back-feeding a dead grid.

During an outage, a solar building could keep feeding the grid and create a live 'island' of power. That is deadly for line workers fixing the lines, so the inverter must shut down.

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What is anti-islanding?

Module 1 · Solar Theory & General Knowledge

Power optimizers

Optimizers are like micro-inverters, but they keep the power as DC.

A row of power optimizer units on a wall and a whole-system protection diagram showing module-level connections. — They tune each panel on its own and have a 25-year warranty.

Optimizers reach 99.5% peak efficiency and cost up to 30% less than micro-inverters.

Module 1 · Solar Theory & General Knowledge

Scenario 1: panels face different ways

Power optimizers working at the module level. — Optimizers fine-tune each panel for maximum power.

When panels point in different directions, they make different volts and amps as the sun moves. An optimizer tunes each panel on its own so each one gives its best.

Module 1 · Solar Theory & General Knowledge

Scenario 2: heavy shading

If a tree shades one panel, that panel acts like a resistor and blocks power. If you cannot remove the shade, an optimizer can bypass the whole panel so the rest keep producing.

Under heavy shade, even the panel's own bypass diodes are not enough on their own.

Module 1 · Solar Theory & General Knowledge

Optimizer system monitoring

Map every panel and watch how each one performs.

Two monitoring screens: a mobile dashboard with per-module figures and a desktop console with green module tiles. — See each panel from a phone, tablet, or computer, and get auto alerts on issues.

If an optimizer fails, you can see where it is and replace it. Monitoring is free for 25 years.

Module 1 · Solar Theory & General Knowledge

Net metering systems

Use your own solar power, and stay connected to the grid.

A solar house connected to grid towers through a bi-directional meter, with electricity flowing both ways. — Extra power goes to the grid. When you need more, you draw it back.

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Net metering is…

Module 1 · Solar Theory & General Knowledge

The bi-directional meter

One meter tracks power going both ways.

A solar house exporting power to the grid and a bi-directional meter that spins forward or backward. — It spins forward when you pull power and backward when you send power out.

Sending extra power earns Hydro credits. The utility installs this meter as the last project step.

Module 1 · Solar Theory & General Knowledge

Does net metering pay off?

Payback tells you how many years to earn back the cost.

Payback years = System cost ÷ Yearly utility bill

$28,479 ÷ $3,754 = 7.58 years

A payback of 10 years or less is generally a good investment.

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How do you calculate ROI (return on investment)?

Module 1 · Solar Theory & General Knowledge

Module summary

Nice work — here’s the quick recap of what this module covered.

You can now explain how a panel makes power, read the three core terms (volts, amps, watts), tell the panel types apart, and follow power from the panel through the inverter to net metering.

Next up: the post-test — then you’ll see your score and anything worth a second look.