Specialists in Solar Panel installation

Amorphous

A type of PV solar panel that, unlike multicrystalline and monocrystalline versions, are not made from expensive crystalline silicon solar cells. They can have a plastic substrate and a very thin layer of silicon is sprayed onto a backing material. As much less silicon is used, they are cheaper but less efficient than other systems. A larger area is required in comparison to other silicon panels.

Alternating Current

The standard form of electricity supplied through the grid to residential and commercial buildings.

Array

The entire installation of several PV modules.

BPVA

The British Photovoltaic Association, a non-pofit making association dedicated to photovoltaic energy in the UK.

CO2

Carbon Dioxide, thought to be the gas that is the main cause of anthropogenic climate change.

DECC

The Department of Energy and Climate Change, a government department.

Direct Current

The output current from a PV module. Like the electrical energy produced by a battery.

DNO

The distribution organisation operator is responsible for maintaining the local electricity grids, and delivering the electricity to the home.

FiT

Feed-in-Tariff, a clean energy cashback scheme encouraging the uptake of renewable energy such as Solar PV, where payments are made for small scale localised electricity production.

Giga watt

1 billion watts.

Grid

The distribution network that delivers electricity countrywide.

Grid Parity

The point at which alternative energy is as cheap as conventional grid power. In many countries this is close at hand, and in the UK it is likely to be achieved by 2020 at the latest.

Insolation

This is a measure of solar radiation energy received on a given surface area in a given time. It is commonly expressed as average irradiance in watts per square meter (W/m2) or in the case of photovoltaics it is commonly measured as kWh/kWpa (kilowatt hours per annum per kilowatt peak rating).

Inverter

Converts solar power in the form of DC current into energy in the form of AC current. Power ranges from microinverters of less than 1kW (residential) to more than 1kW (residential and commercial) and more than 1mW (industrial).

Irradiance

The amount of energy coming from the sun. It is defined to be the incidental flux of energy per unit surface area measured in watts per square metre. Within the UK, all other things being equal, the further southwest the better the irradiance and the better the return; so for example the counties of Cornwall, Somerset and Wiltshire receive higher than average solar radiation than other counties in the UK and so will get great yields from solar panel installations. Having said that, Edinburgh installations are still viable and productive. The units are usually shown for PV systems as kWh per kWp per annum, and this is used to calculate the expected return from a PV system.

Isolation Switch

A device that disconnects the PV modules from the inverter, for example during maintenance. It often includes a fuse box.

Kevlar

The trademark name of a synthetic fibre, consisting of long-chain polyamides, having high tensile strength and temperate resistance.

k

Kilo means one thousand.

kWh

Kilowatt Hour. A unit of energy equivalent to 1kilo watt (1 kW) of power expended for 1 hour of time (1h). This is used by electricity utilities as a billing unit of energy delivered to customers.

kWp

Kilowatt peak. Defined as the peak power output of a solar photovoltaic energy system at maximum solar radiation under Standard Test Conditions (STC). For example, a 1kW rated system has demonstrably generated 1kW under STC. In the UK, one kilowatt peak of solar will generate roughly 850 kilowatt hours (kWh) per year.

MCS

The Microgeneration Certification Scheme (MCS) is an independent, internationally-recognised scheme that certifies microgeneration, installers and products in accordance with consistent standards by evaluating them against criteria chosen to ensure greater protection for consumers.

Megawatt

1 million watts.

Microgeneration

The government defines Microgeneration as the production of heat and/or electricity on a small-scale from a low carbon source. The technologies that are covered by this definition can help in ensuring the supply of reliable energy and in tackling fuel poverty. The government's aim is to induce the take-up of this type of energy generation by households, businesses and wherever suitable roof-space can be found.

Module

Solar panel. Approximately 1.5m x 1.5m in size.

Monocrystalline Silicon Cells

These are cut from single crystals of silicon, and represent the most efficient and expensive PV cells.

Mounting System

Range of solutions to fix PV to roofs. At present the mounting systems are not MCS certified but hopefully that will change.

Multicrystalline silicon cells

These are made from cast silicon cut into wafers. Less efficient and cheaper than monocrystalline cells.

Ofgem

Office of the Gas and Electricity Markets. An organisation that protects customers, promotes competition, and regulates the monopoly companies which run the gas and electricity networks.

Payback Period

The payback period is the amount of time it will take for your system to pay for itself in energy cost savings. This is calculated based on the current energy bill and the cost of your system. The more efficient the panels installed, the shorter the payback period.

Photovoltaics, PV

The process of making electricity from the sun. Photo comes from the Greek word for light, and voltaic in honour of the Italian physicist Volta, whose name is used for the volt, a measure of electricity. PV cells are thin layers of semi-conducting material, usually silicon. When the material is exposed to daylight, electricity is generated which is conducted away as direct current. Multiple (72) cells are connected together (usually behind glass) to form a panel.

Polysilicon

Otherwise known as Polycrystalline silicon.

Renewable

An energy source that comes from nature and that is naturally replenished. Renewable sources of energy generation for electricity include solar, wind and hydro, and for heat include solar, biomass and heat pumps (ground-source and air-source).

RPI

The Retail Prices Index (RPI) includes housing costs, such as mortgage payments and council tax which are excluded in the CPI (Consumer Prices Index) measure of the cost of living. Actuaries point out that the RPI is consistently higher than CPI. The Retail Prices Index inflation rose to 5.1% from 5.5% in January 2011, the highest rate for 20 years.

Solar Cell

A building block of a PV module, usually silicon.

STC

Standard Test Conditions. Allows a standardised comparison of PV modules and systems. Comprises of an irradiance of 1000 W/m2, solar spectrum of AM 1.5 and module temperature of 25 degrees celcius.

String

A linking of multiple solar cells inside a module.

t

Tonne, or metric ton (U.S.), is a unit of mass equal to 1,000 kg.

W

Watt, a unit of power.

WEEE Directive

Europe has a Waste of Electrical and Electronic Equipment (WEEE) Regulations law designed so that companies must provide free, environmentally-sound disposal of the electronic equipment they sell.

The age of cheap oil is over. We have no choice but to find and use alternatives now.
Solar Cell - a building block of a PV module, usually silicon