Words you’ll see on a quote

Every word on a solar quote, in plain English.

Estimates, surveys and quotes come with their own vocabulary. Find a word, or read down the list before you sign anything.

The glossary

52 words, one plain sentence each.

Type a word to jump to it.

A

AC-coupled battery
A battery with its own inverter, wired in on the alternating-current side, so it can join an existing system without a new solar inverter.
Array
The panels on your roof, taken together.

B

Ballast
Weights that hold panel frames down on a flat roof, so fewer fixings, or none, go through the covering.
Battens
The thin timber strips across your rafters that hold the tiles or slates.
Bird mesh
Mesh fitted around the edge of the array to stop birds nesting under the panels, also called a pest guard.

C

Consumer unit
Your fuse box, where the solar circuit needs its own place.

D

DC-coupled battery
A battery that shares the solar inverter and stores the panels’ direct current before it is converted, so less is lost on the way.
Degradation
The gradual fall in what a panel makes, or a battery holds, as it ages; the manufacturer’s warranty sets a limit on it.
Deposit protection
Cover that protects your deposit if the installer stops trading before the job is done, required of every RECC member.
Diverter
A device that sends spare power from your roof to the immersion heater, heating water instead of exporting it.
DNO
The distribution network operator: the company that runs your local grid, and is told about your system.

E

Earthing
The safe path to the ground for stray current, and one of the things the survey checks.
Export limitation
A setting that caps how much power your system can send to the grid, sometimes required by the DNO.
Export rate
What you’re paid for each unit your roof sends to the grid.

G

G98 and G99
The grid-connection rules an installer follows with the DNO: smaller systems are usually notified after connection, larger ones need approval first.
Generation meter
A meter that counts what your roof makes.

H

Hybrid inverter
An inverter that runs the panels and a battery together, so one box does both jobs.

I

In-roof and on-roof
In-roof panels replace a patch of tiles and sit flush; on-roof panels sit on rails above the covering.
Insurance-backed guarantee
Insurance that keeps a workmanship warranty good if the installer stops trading.
Inverter
Turns the panels’ direct current into the alternating current your home runs on.
Irradiance
The strength of the sunlight falling on your roof at any moment; the more there is, the more the panels make.
Isolator
A switch that cuts the power to part of the system, so it can be worked on safely.

K

kWh
A kilowatt-hour: the unit your bill counts, and the unit a roof’s yearly output is measured in.
kWp
Kilowatt peak: the size of an array, as its output in full sun.

L

LFP
Lithium iron phosphate: a battery chemistry common in home storage, valued for its long life and stability.

M

MCS
The Microgeneration Certification Scheme, which certifies installers of small-scale renewables and the products they fit.
Micro-inverter
A small inverter behind each panel, so one shaded panel doesn’t hold back the rest.
MPPT
Maximum power point tracking: the part of an inverter that keeps each string working at its best as the light changes.

N

NICEIC
A scheme that registers electrical contractors and checks their work.

O

Optimiser
A small box behind a panel that keeps it working at its best on a shared inverter.

P

Part P
The Building Regulations rules for electrical work in homes in England and Wales; a registered contractor self-certifies and notifies the work.
Payback
The years it takes for the saving to cover what the system cost.
Performance warranty
A manufacturer’s promise that a panel will still make a stated share of its original output after a set number of years.
Permitted development
Work that can go ahead without a planning application; most home solar qualifies, but listed buildings, conservation areas and flats can need permission.
Pitch
The angle of your roof.
Product warranty
A manufacturer’s promise to repair or replace a panel, inverter or battery that fails through a fault in how it was made.

R

Rafters
The sloping timbers that carry your roof; the brackets for the panel rails are screwed into them.
Rails and clamps
The metal rails fixed to your roof, and the clamps that hold each panel to them.
RECC
The Renewable Energy Consumer Code: the rules installers agree to follow when they sell to you.

S

Scaffold
The temporary frame that lets installers work on your roof safely, up before the install and down after.
Self-use
Power from your roof that you use at home instead of buying.
Shading loss
The output lost to shade from chimneys, trees or next door, which we trace through the day before we price your roof.
Smart Export Guarantee (SEG)
The scheme under which suppliers pay you for power you export; each sets its own rate, and the system must be MCS-certified.
Smart meter
A meter that sends your readings to your supplier automatically, including what you export.
Standing charge
The fixed daily charge on your electricity bill, paid whatever you use.
String
Panels wired together in series to one inverter input.
Surge protection
A device that protects the system and your appliances from sudden spikes in voltage, such as from a nearby lightning strike.
Survey
A visit to check the roof, loft and electrics before a price is final.

T

Time-of-use tariff
Prices that change through the day, usually cheapest overnight.
TrustMark
The government-endorsed quality scheme for trades working in your home.

U

Usable capacity
The energy a battery can actually give you, often a little less than its total capacity; it’s the figure to compare on quotes.

W

Workmanship warranty
The installer’s promise for the fixings, the wiring and the work itself.

Before you sign

Read the quote with us.

A bungalow with a panelled roof across an evening field

Estimate or survey

Start with a postcode.

Our estimate is free. If you proceed to survey, our partner installer invoices you directly; we receive a referral fee from them, never from you, and it never affects which installer we introduce.

We use these details only to send your estimate and arrange a survey. Privacy Policy

This form needs JavaScript switched on.

Or ring us free on 0800 593 0413