FAQs

Solar PV (photovoltaic) is a silent, renewable energy source that generates electricity from sunlight without the harmful side effects of conventional electricity production. It works even in low light conditions, such as during UK winters, though the amount of power produced will vary with the amount of daylight.

Solar PV systems provide emission-free electricity for immediate use in your property, and any excess power is automatically exported to the National Grid. During long summer days, the average household produces more energy than it needs, though this excess cannot be stored with a grid-connected PV system. You’ll only pay for additional power supplied by your electricity provider when your usage exceeds production.

PV stands for photovoltaic, derived from Greek words meaning ‘light’ and ‘volt.’ PV panels are commonly known as solar panels, but this term can be confusing as it may also refer to solar thermal panels.

kWp (kilowatt peak): Represents a system’s maximum power under ideal test conditions, like 4 kWp. It doesn’t guarantee a specific energy output.

kWh (kilowatt-hour): The unit of electricity. For example, 1 kWh is equal to 1 unit of electricity.

PV cells are the individual components within a PV panel that converts sunlight into electricity. High cell efficiency is crucial but doesn’t guarantee overall panel performance. Good cells can still be part of poorly performing panels.

It is a more accurate performance indicator than cell efficiency but measured under controlled lab conditions. Real-world performance may differ due to factors like temperature.

Compare panels of the same kWp size to avoid misleading comparisons. Larger panels may appear more efficient due to test conditions.

Panel performance varies outside the lab and can decrease with higher temperatures. Panels behave differently in real-world conditions, so it’s important to consider how they perform in daylight.

Panels have slight manufacturing variations. A panel rated at 240Wp may produce slightly more or less. Manufacturers often provide a +/- tolerance, but some only guarantee a minimum output, which is a positive indicator of quality.

Solar panels degrade over time, with high-quality panels showing slower degradation than low-quality ones. This degradation rate depends on the panel’s build quality.

PV panels are generally reliable, with failure rates under 5% over 20 years. REC panels, for example, have a failure rate of just 1 in 10,000.

Vertical integration refers to a manufacturer controlling the entire panel production process. Companies like REC, JINKO, JA SOLAR and others are vertically integrated, ensuring higher quality. In contrast, some manufacturers source parts from various suppliers, which can affect panel quality.

A solar PV panel produces electricity when exposed to light. A system of these panels, typically installed on your roof, connects to your property’s fuse board. During daylight hours, the system generates energy for use in your home. Surplus electricity is fed back into the national grid. If your consumption exceeds production, the extra power is drawn from your mains electricity provider. This happens automatically, reducing your electricity bills without any noticeable change to your daily routine.

Solar PV systems generate electricity from light, not heat. While more power is produced in summer due to the longer days, solar panels can also perform well on sunny, cold days in winter.

The cost of a solar PV system varies depending on factors such as roof type and system design. Options include:

• Retrofit: Framed solar PV panels installed on top of an existing pitched or flat roof.
• Semi-integrated: Solar PV panels fitted within the roof covering, surrounded by conventional roof tiles.
• Integrated: Solar PV tiles that form the roof covering are often used in new constructions.

We provide bespoke solutions and will only recommend viable installations for the customer. Contact us for a detailed estimate.

Yes, solar PV systems are safe. They do not emit toxic chemicals and have no moving parts. Independent chartered structural engineers approve all fixing methods for new or existing roofs.

The photoelectric effect was discovered in 1838, but efficient working cells were developed in the 1950s. Initially used in satellites, solar PV technology has seen significant advancements and cost reductions, leading to widespread use in remote villages and, since the 1990s, in developed countries.

A solar PV system can last the lifetime of the building. Panels generally come with a 25-year guarantee, inverters with a 5-year guarantee, and we offer a 5-year installation guarantee. Inverter guarantees can be extended, and all materials comply with British Standards to ensure durability.

Efficiency varies by technology, roof space, angle to the sun, roof pitch, and budget. For an overview, refer to our Guide to Solar.

Most solar PV installations fall under ‘permitted development rights’ even for Conservation Areas. Some cases may still require planning permission and we recommend you contact your local planning authority for confirmation for your own property if you are not sure. We will assist you with any necessary documentation.

Solar PV systems installed by Chelsfield Solar typically require no maintenance. We use high-quality components and provide a workmanship guarantee. If a component fails, we will repair it as per our guarantee. For systems installed by others, please get in touch with us.

Contact us for a free consultation.

The average household won’t use all of the energy their system produces, so the excess electricity gets exported back to the grid. The Smart Export Guarantee allows you to still benefit from that excess electricity, in the form of payments from an energy supplier participating in the scheme. This doesn’t happen automatically, so you need to sign up to get the SEG tariff. You will need some of the commissioning documentation to apply for this, but Chelsfield Solar will provide this and guide you through the process.