Solar Jargon Buster

Array

A group of solar panels (also known as solar modules) that work together to generate electricity which then feeds into an inverter.

Battery storage

Solar battery storage lets you store any extra solar power you generate during the day, so you can use it later when the sun's not shining. It's a handy way to make the most out of your solar panels and can help you save even more on your electricity bills. Most home battery systems use lithium-ion batteries and come in different sizes to match your needs. More about solar batteries...

Diverter

The power or hot water diverter is a device that captures the surplus electricity that your property is producing. It then sends this energy to your hot water tank, rather than allowing it to be sent back to the grid for export.

Export

The electricity that is generated but not used in the property. Exporting will happen when the property is using less electricity than is being generated by the solar array. Therefore, this excess electricity spills over and is exported to the grid.

Feed-in Tariff

A feed-in tariff is a payment you get for any surplus electricity your solar panels generate and you send back to the grid. It's a great way to earn a bit of extra money from your solar system, on top of the savings you make on your electricity bills.

Inverter

The inverter is a box that sits in the building. It changes the DC electricity that is produced by the solar array into AC electricity that is acceptable for your appliances and the national grid. Inverter position is extremely important. We always advise on the optimum place to put your inverter. Inverters are sized according to their maximum output power, expressed in kW (kilowatts). It is normal practice to undersize the inverter for the array, e.g. a 4kWp array may be paired with a 3.68kW inverter.

Kilowatts (kW)

A unit of power, equal to 1000 Watts.

kWh (kilowatt-hours)

This is the same as one unit of electricity. We buy electricity in units or kWh, so you might recognise this from your energy bills. If you use 1 kW () continuously for one hour, then you will have used a single unit of electricity i.e. one kWh.

kWp (kilowatts peak)

1kWp is equal to 1000 Watts peak. If refers to the power output of a system. For example, domestic arrays are usually between 3kWp and 6kWp. This means when a 3kWp system is working at its maximum capacity for one hour will produce 3kWh. Commercial arrays average between 20kWp and 500kWp and industrial rooftop arrays can be 1000kWp (or 1MWp) or more.

Mounting system

This is the frame, brackets, hooks etc required to hold the panels in place. Various solutions are available to deal with the many situations in which solar PV panels can be mounted. We have experience in all types of mounting and can discuss every option with you.

Panel

Also known as solar panels or modules. These are the units which are actually installed on your roof, typically measuring around one meter wide and up to two meters long. It is a collection of silicon cells that generate electric current when photons (light particles) hit the silicon.

PV

PV stands for photovoltaic. This is the conversion of light energy (photo) to electric energy (voltaic).

SEAI

The Sustainable Energy Authority of Ireland (SEAI) is a governmental body responsible for promoting the development of renewable energy in Ireland, including solar. Among other things, they award loans and grants for energy solutions such as solar electricity, heat pumps and insulation.

Shading

Shading is any form of shadow which consistently falls on any part of the surface of your solar array. There are two types of shading, soft and hard. Soft shading is caused by faraway objects, mostly clouds. Because soft shading is more than likely to be uniform (covering the entire solar array), it is easier to manage. Shading of the whole system will cause a decrease in power output (rather than a bottleneck at a given point).

Hard shading is caused by objects closer to the panel. This type of shade is usually non-uniform and can be trickier to tackle. Some physical objects that cause hard shading include trees, poles, chimneys, dust/sand, ice/snow and fallen leaves.

Thankfully, modern solar technology allows the impact of shading on solar panels to be prevented or mitigated. Microinverters, attached to each individual panel, allow them to work independently. The maximum power output of each panel is taken, regardless of the performance of any other panel. Bypass diodes can also be installed to allow a series of connected panels to bypass any affected panels.

Watts

A measurement of power. All your electrical devices use power to function, but some use more power than others.

Wp (Watts peak)

Watts peak refers to the peak power of a panel and is measured under STC (Standard Test Conditions) which are similar to a bright sunny day. This is considered to be the 'peak' because this is likely to be the highest output you'll see from the panel. Typical panels for the Irish market are between 350Wp to 450Wp.