Solar Roofing Compared: Tiles, Shingles, In-Roof and Racks

A roof can carry solar in two ways: the solar product becomes the roof covering, or it sits on brackets above a covering that is already there. Each of the four approaches in this guide sits on one side of that split.

This guide compares four approaches across four roof situations, with measurable trade-offs for each. It ends with a six-step selection method and a plain split of what a supplier does and what an installer does.

What is solar roofing? Four terms buyers mix up

Solar roofing is the umbrella term for roofs that produce electricity from photovoltaic cells on the roof plane, whatever the mounting method. Buyers, search engines and AI assistants use four related terms, and they do not mean the same thing.

• Solar roofing: the whole category, integrated or rack-mounted. The term describes the outcome, a generating roof, not a product.
• Solar roof tiles: glass or composite units shaped and fixed like roof tiles, with cells laminated inside. They replace conventional tiles on the area they cover.
• Solar shingles: flatter strip-format units fixed like asphalt shingles, usually nailed or screwed through a top lap. The name is also used loosely for tiles, so read the fixing method, not the label.
• Rooftop solar: conventional framed panels on hooks, rails and clamps above the existing roof covering. It is the most common form of solar on homes.

Solar roof tiles, solar shingles and in-roof modules are all building-integrated photovoltaics (BIPV). The IEA PVPS Task 15 programme on BIPV defines BIPV as photovoltaics integrated directly into building elements such as windows, roof tiles or façade cladding, so the element keeps its building function while generating power.

The U.S. Department of Energy notes in its solar PV system design basics that rack mounting is currently the most common method, while BIPV can combine redundant parts and use existing building structures. So the choice is between fewer roof layers and the more common, usually cheaper rack-mounted method.

Solar roofing decision matrix: four approaches across four roof types

The solar roofing approach that fits best depends first on the roof covering and second on whether the roof is being built or replaced. The matrix below rates each approach against the four roof situations buyers ask about most.

Read the matrix by row, not by column. A pitched tile roof being replaced opens up every integrated option, while a flat membrane roof narrows the choice to rack-mounted frames straight away.

The ratings describe fit with the roof system, not product quality. A "not suited" cell means the approach was not designed for that covering, so it would need custom flashing details that no standard product ships with.

BIPV interlocking solar roof tiles: the roof covering is the generator

BIPV interlocking solar roof tiles are roofing units with cells laminated between glass, fixed to battens like conventional tiles so that one product both sheds water and generates electricity. They suit pitched roofs that are being built or re-covered, and roofs where design codes restrict visible panels.

The crystalline tiles LinkSolar supplies come in two lengths from one construction. The shorter tile measures 650 × 432 × 22 mm and is rated 43 W; the longer tile measures 1208 × 432 × 22 mm and is rated 85 W (supplier datasheet).

Solar roof tiles weigh about 19 to 20 kg per m² of tile outline, calculated from datasheet dimensions. Compare that figure with the dead load of the tile you would otherwise lay, and have the roof structure checked against the heavier of the two.

The outline calculation gives 153 W/m² for the 43 W tile and 163 W/m² for the 85 W tile, below the supplier-stated ~170 W/m². Use the lower outline figure for early sizing, and let the final layout drawing set the real number.

A 4 kW solar roof tile field needs 48 tiles of the 85 W format, giving 4,080 W across about 25 m² of tile outline at 480 kg. That is calculated from datasheet dimensions: 48 × 85 W, 48 × 0.522 m² and 48 × 10 kg.

Solar roof tiles add no roof penetrations for racking, because the tile itself is fixed to the battens like any other tile. The trade is more electrical connections: that 4 kW field has 48 junction boxes and 48 MC4 pairs, against far fewer for a framed-panel array of the same size.

Replacing one failed solar roof tile means lifting one 5.5 kg or 10 kg unit, not unbolting a large framed module. Access for maintenance is the same as on a tile roof, so the roofer works from the surface rather than reaching under an array.

The crystalline tiles we supply are tested to IEC 61215:2021 / IEC 61730:2016, test reports available on request (see IEC 61730-1:2016).

Shingle-format solar strips: a low profile for shingle-style roofs

Shingle-format solar strips are thin, wide units fixed through a top lap onto a solid deck, laid in courses like asphalt shingles so the solar field sits almost flush with the surrounding roof. They belong on roofs covered in shingles, not on tile or slate roofs.

The strip format keeps the profile low, which is its main appeal on streets where a raised array looks out of place. Because each strip is long and narrow, a solar field is made of many units in overlapping courses.

Strips need a continuous deck, usually boarded sheathing, because they are fixed with nails or screws through the lap. That makes them a poor match for roofs built on battens for tiles.

Weight, output per m², minimum pitch and walkability vary widely between strip products, so check the datasheet for each figure rather than assuming the tile numbers above. Ask specifically for the minimum pitch and the fixing pattern, since both decide whether the strip will stay watertight.

Replacement on shingle-format solar strips usually means lifting the course above to reach the fixings of the failed strip. Ask the maker to describe that process in writing before you commit to a product.

A detailed spec comparison between shingle strips and interlocking tiles is a separate topic. For choosing an approach, the point is placement: strips belong on shingle-style decks, where their low profile matches the roof around them.

In-roof solar systems: standard modules set into a flashing tray

An in-roof solar system replaces part of the roof covering with a flashing tray or sub-frame, then sets standard framed modules into that tray so the array sits nearly level with the surrounding tiles or slates. The module is a normal panel; the integration comes from the tray and flashings.

In-roof systems use standard modules, so output per m² follows the panel datasheet rather than a special roofing product. That is their main advantage over tiles and strips when the owner wants maximum watts from a given roof area.

An in-roof array still reads as a rectangle of modules set into the roof. It is flush, but it does not blend in the way colour-matched tiles do.

Flashing kits for in-roof systems are specific to the roof covering and the module frame size. Confirm that the kit matches both, because a flashing detail designed for one tile profile may not seal against another.

In-roof modules usually sit closer to the roof structure than rack-mounted panels, with less air moving behind them. Check the module's own temperature coefficient on its datasheet and multiply it by the expected extra heat. For scale, the tiles we supply are rated −0.38 %/°C, so 20 °C of extra heat would cost them about 7.6 % of rated power (20 × 0.38), calculated from datasheet coefficients.

Replacing a failed in-roof module means removing a full-size panel from the tray, which is a two-person job on a pitched roof. Maintenance access is from the roof surface, as with tiles.

Rack-mounted solar panels over the finished roof: the default for sound roofs

Rack-mounted solar panels are framed modules clamped to rails that sit on hooks or clamps above an existing roof covering, and they are the default choice when the roof is sound and will outlast the array. The roof covering stays in place and keeps doing its job.

Rack-mounted systems add a second layer to the roof: rails and modules above a full covering. On a pitched tile or shingle roof, each roof hook creates one penetration or one lifted tile that has to be flashed, so every hook adds a detail the roofer has to seal.

On a metal standing-seam roof, clamps grip the raised seam, so the sheet is not drilled at all. On a flat membrane roof, ballasted or fixed frames set the tilt, and the flat roof solar mounting guide compares the ballasted and fixed options in detail.

Output per m² for rack-mounted panels follows the module datasheet, and full-size modules usually beat tiles on watts per dollar when no roofing work is needed. Weight per m² is the module plus rails and hooks, so check the datasheet for both and add them together.

The U.S. Department of Energy homeowner's guide to going solar advises weighing roof age and how long until the roof will need replacement before adding panels. A rack array removed and refitted halfway through its life for a re-roof adds cost that an integrated system avoids.

The bracket, rail and clamp choice decides how well a rack-mounted system handles wind, snow and corrosion. The guide to choosing a solar mounting system walks through that decision, and the solar panel brackets for rack-mounted arrays cover the common roof and wall fixings.

How the four solar roofing approaches compare on weight, penetrations and output

The four solar roofing approaches differ most in what sits between the sun and the roof deck: one layer for tiles and strips, a tray plus module for in-roof, and a full covering plus racking for rack-mounted panels. The diagram shows each build-up from the sun side down.

Roof build-up

What sits on the roof deck in each solar roofing approach

Note: Diagram of generic build-ups; actual batten, underlay and deck details are set by the roof designer.

On a pitched roof, a tile or tray system that removes the hooks also removes the flashing detail around each one. Weight still has to be checked, but it is a structural calculation rather than a waterproofing risk.

Output per m² matters most when roof area is the constraint. When area is plentiful and the roof is sound, rack-mounted modules usually win on cost per watt.

Solar roofing by roof type: pitched tile, standing seam, flat membrane, slate and heritage

Solar roofing choices narrow quickly once the roof covering is known, because each covering has a fixing method that only some solar products are designed to work with. The four situations below cover most enquiries.

Pitched tile roof, new build or re-roof

A pitched tile roof that is being built or replaced is the strongest case for BIPV solar roof tiles or an in-roof tray. The solar tiles replace part of the tile order, so the project buys one covering on that area instead of two.

The U.S. Department of Energy says solar panels typically perform best on south-facing roofs with a slope between 15 and 40 degrees. Most pitched tile roofs fall in that band, so the question becomes appearance and budget, not orientation.

Choose tiles when the roof must read as a tile roof, for example under a developer design code. Choose an in-roof tray when a flush module field is acceptable and the owner wants maximum watts per m².

Metal standing-seam roof

A metal standing-seam roof is usually best served by rack-mounted panels on seam clamps, because the clamps grip the raised seam and leave the sheet undrilled. Tiles, strips and in-roof trays are designed for other coverings and do not seal against a metal seam profile.

Check the clamp against the seam profile and the sheet thickness before ordering. The guide to solar panel racking systems covers rails and clamps for this kind of array.

Flat membrane roof

A flat membrane roof is a rack-mounted job: ballasted or mechanically fixed frames tilt the modules and keep water draining under the array. Integrated tiles and strips depend on pitch to shed water, so they are not designed for flat roofs.

The choice between ballast and fixings depends on the structure's spare load capacity and on whether the membrane may be penetrated. Weigh both with the roof designer before picking a frame.

Slate or heritage roof

A slate or heritage roof is where planning and appearance decide the solar roofing approach before cost does. Visible raised arrays on street-facing slopes are often refused in conservation areas, and slate is brittle around hooks and under foot.

Colour-matched BIPV tiles or a flush in-roof tray are the usual routes to approval. Check local rules first, and bring a physical sample to the planning discussion, because a committee judges colour and sheen by eye.

How to choose a solar roofing approach in 6 steps

Choosing a solar roofing approach takes six decisions in a fixed order, because each one removes options for the next. The flow chart shows the first three; the numbered steps cover all six.

Decision flow

Which solar roofing approach fits this roof?

Note: A first-pass filter only; structure, local codes and budget still decide the final choice.

1. Date the roof. Estimate how many years the current covering has left. A roof due for replacement within the solar system's life points to an integrated approach or a re-roof first.
2. Name the covering. Tile, slate, shingle deck, standing seam or membrane decides which products are even designed for the roof, as the matrix above shows.
3. Check planning and design rules. Find out whether visible panels are allowed on each slope. A restriction on street-facing slopes often decides between tiles and racks on its own.
4. Size the system against the area. Divide the target power by output per m². For the tiles we supply, 4 kW needs about 25 m² of tile outline, calculated from datasheet dimensions.
5. Check structure and strings. Have the structure checked against the dead load, for example about 19 to 20 kg/m² for the tiles. For the 85 W tile we supply, Voc of 16.4 V rises to about 18.5 V at −10 °C (−0.36 %/°C × 35 °C), so a 1000 V string holds at most 54 of them, calculated from datasheet coefficients.
6. Approve a physical sample. Check colour, fit and the overlap or flashing detail on a real unit before the production order. Solar roofing products are hard to change once the roof is closed.

Steps 1 to 3 choose the approach. Steps 4 to 6 turn it into a specification a supplier can quote against.

Solar roofing supplier vs installer: who does what

A solar roofing supplier provides the product, its datasheet, test reports and samples, while a solar roofing installer surveys the roof, designs the layout, obtains permits, fits the product and connects it to the electrical system. Most "solar roofing companies" people search for are installers; the supplier sits one step behind them.

LinkSolar is the supplier in that chain. We source crystalline solar roof tiles for roofing contractors, developers and distributors, and the solar roof tiles project page lists both formats, colour options and the quote route.

Commercial terms for solar roof tile orders are set per project: minimum order, lead time, unit price and warranty are all set out in the project quote. Samples are paid and quoted on request.

Colour, size and encapsulant changes follow the same drawing-to-sample route as our custom solar panels. Send the roof plan, the tile profile you are matching and the target output, and request a quote for the format mix.

Solar roofing FAQ

Is solar roofing worth it?

Solar roofing is worth it when the roof is being built or replaced anyway, or when planning rules block visible panels, because the solar product replaces roofing material you would otherwise buy. On a sound roof with years of life left and no appearance restriction, rack-mounted panels usually deliver more watts per dollar.

How much do solar roofs cost?

Solar roof cost depends on roof area, covering type, the share of the roof that generates power and local labour, so it is quoted per project rather than per watt. Compare the installed cost of a finished, generating roof against a new conventional roof plus a rack-mounted array, not module price against module price.

What happened to solar shingles?

Solar shingles are still sold, in formats ranging from strips fixed like asphalt shingles to glass tiles that interlock like concrete tiles. Individual product lines have come and gone, so check the current datasheet and warranty terms rather than relying on older reviews.

Are solar roof tiles as efficient as solar panels?

Solar roof tiles usually produce less power per m² than full-size panels, because the tile shape leaves more frame and overlap area without cells. The tiles we supply reach 153 to 163 W/m² of tile outline, calculated from datasheet dimensions, so compare that with the panel datasheet for your roof.

Does solar roofing need a new roof?

Integrated solar roofing, meaning tiles, strips or in-roof trays, is installed as part of a new or replaced covering, so it makes most sense at a re-roof. Rack-mounted panels go on top of an existing roof, provided that roof will outlast the array.

Can you walk on solar roof tiles?

Walking on solar roof tiles is a question for the product datasheet and installation manual, because load ratings differ between products and formats. Installers normally use roof ladders and crawling boards on any glass roof product rather than stepping on units directly.