Questions and Answer's 

Q. How does it work?

A. A huge amount of solar energy falls every year from the sun to the Earth, we can use this energy to power electrical energy for our Homes and Businesses , The energy falls onto the panels, which creates DC electricity, an inverter then converts this into AC electricity, which is then used to run your household or business needs.


Q. How much will it cost?

A. The size of the installation will of course depend on the size of your roof space available and dependant on the quality of the system you have installed. prices can range from £9000 down to as little as £3000 dependant upon theses factors. The important thing is to make sure your system is well balanced and you have a system you are confident with. like with anything else you get what you pay for.


Q. How much energy does the average home need?                                                                                                                                     A. This depends on you the consumer, obviously the less you waste the less you need. To assess your current needs add up your units consumed on your last 4 electricity bills, or contact your supplier and ask them what your average electrical consumption is per annum. This is by far the best way to size a system rather than individual use. An average size 3 bedroom semi-detached house can produce 30-50% of its electrical needs using a 2kw system.

Q. Do I need constant sunshine for my PV system to work?

A. Your PV system does not need direct sunlight for it to work, even on cloudy days your PV system will still produce electricity.

Q. What if it is not producing enough electricity for my needs?                                                                                                                   A. In this case the system will allow energy to come into your home from the national grid. This will be necessary on winter days and of course night time when your PV system turns itself off.


Q. What if the system is producing more electricity than my needs?                                                                                                         A. In this case the system will export your additional electricity back into the national grid and of course you will be paid for it.

Q. Do I need planning permission?                                                                                                                                                                      A. most of the time you do not need planning permission – installing solar panels is considered permitted development. You do need planning permission for example, if you have a listed building, if you are installing a ground mounted system, or if you live in a conservation area. If in doubt the best thing to do is approach your local planning officer.

Q. Do solar PV panels produce hot water?                                                                                                                                                                A. PV panels only produce electricity. Solar thermal collectors produce hot water.

Q. How long will the system last?                                                                                                                                                                        A. Solar PV systems are designed to last at least 25 years. There are no moving parts and little maintenance required and generally little to go wrong. The weak point of the system is the inverter which could need replacing once over the life of the system. At today’s prices inverter replacement would cost between around £1,000 - £1,500.

Q. What gets installed?

A. We install everything required for your PV system to be working perfectly when we handover. This includes a mounting system for the panels to fix to, the solar panels themselves, an inverter to convert DC to AC electricity, DC and AC isolators,  a generation meter to measure how much electricity you generate and the necessary cables, conduit and connectors.

Q. What happens if the system generates more than the building is using?

A. When the solar PV system is generating more electricity than the load demand in the building, all excess is exported to the grid. Export occurs automatically and can be measured (and income collected) using an "export meter".


 Q. This is of interest, what is the next step?

A. Initially, we will do a desktop survey. All we need to know is the property address or in the case of land, the address and proposed area. Very quickly, we can give an accurate estimate of potential income from a solar installation at that property. If this meets your approval, we would then do a more detailed 'on site' survey, design the best possible system, issue a quotation and agree terms.

Q. Are there any other factors you need to be aware of?

A. One of the most critical aspects is knowledge of the power supply in the building or local area. Information on sub-stations in terms of distance from the property or the level of supply/use in an area will allow our client determine the potential size of installation that the property can accommodate.

Q. What range of systems are available?

A. Systems can vary in power output and type. We provide both solar panels and solar tiles. Applications can vary and we provide a wide range of products and mounting solutions - suitable for roofs, facades, glazing and ground mounted applications. 

Q. What are the effects of shade?

A. Shade can make a large impact on the performance of a PV system. Even a small degree of shading on a small section of an array has a significant impact on the overall array output. To work effectively, the whole PV array needs to be located in a predominantly shade free position. Shade can be produced by obstacles such as trees or adjacent buildings, or be inherent from the building or roof design.

Q. What range of array pitch is acceptable?

A. The ideal array pitch is between 30 and 45 degrees from horizontal. However, pitches between 5 and 60 degrees will result in less than 10% losses for a south facing array.

Q. Does a solar PV array have to be exactly south facing?

A. No, arrays work effectively and are commonly installed at other orientations - from East through to West. However, annual output is reduced if the array faces significantly away from south. With information on roof pitch and orientation, we can provide site specific output estimates.

Q. How much CO2 emissions will a PV system prevent?

A. Every 1kWh generated by a solar array means 1kWh less has to be generated by conventional power stations. According to the Carbon Trust the carbon produced to generate 1kwh of electricity is .537 tonnes. Therefore a 2.5kwp system would prevent 1.34 tonnes, a 10kwp system would prevent 3.57 tonnes of CO2 being produced.

Q. Do PV systems work in the UK?

A. Solar PV systems work very effectively in the UK, though the annual output is obviously lower than in sunnier countries. That they provide a viable means of electricity generation in the UK is demonstrated by on-going government support and from the thousands of systems that have already been installed.

Q. How is a system sized?

A. Solar PV systems are entirely modular and can be of almost any size. Systems are usually sized to meet one of three criteria: a) to cover a defined area (e.g. a certain section of roof); b) to meet a defined energy target (e.g. to generate 10% of a buildings annual electricity requirement); or c) to fit within budgetary requirements.

Q. What happens during a power cut?

A. A grid connected system instantly switches off when a power cut occurs. This is required to meet electricity regulations and is implemented by control circuits integrated within the inverter. Disconnection during a power cut is necessary to ensure power quality and protect workers who may be repairing the fault. The system will automatically re-start once the power cut ends (a 3 minute restart delay is required by regulations).


Contact Andy 


Phone: 01664 812225

Mobile: 07791 583498


Email: info@21cenergysol.com


16 Saxelby Road, 

Asfordby, 

Melton Mowbray, 

Leicestershire, 

LE14 3TU


Company No: 07742151

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