What you Need to Know When Buying Solar Panels in 2020

So, you’ve decided to go solar but have no idea how large a system your roof can support or even whether your home is suitable. No doubt you have lots of questions such as where to put the panels, how many kilowatt hours the system will generate and what type of panels you should buy.

There’s no need to worry as there is a lot of expert help available. If you decide to go ahead and purchase solar panels you will find that they are an excellent way to provide energy for your home and lower your annual energy bills in one go. It is thought that your average power system can save you money on your electricity bills from £85/£410 a year.

Aside from saving money on your electricity bill solar panels are a great source of renewable energy and will without doubt lower your carbon footprint. As well as being environmentally friendly they require hardly any maintenance.

Solar technology is constantly evolving and improving.  Last year saw milestones in solar efficiency, solar energy storage and solar design technology. Furthermore, solar panels have never been as affordable as they are now. The price of solar is 70% cheaper than in previous years.

Before buying it is important however, to have a rough idea of the panel size and number of panels that you will need. It is advisable to consult with a professional and accredited installer to discuss all of this. This article is aimed at giving you a rough idea of the things you need to consider before buying solar panels.

Typically, the size of your solar array is defined by two factors, space and budget. The amount of power you can generate will be less if your roof is small, but this outcome can be mitigated if you install more expensive panels that generate more energy per m2. The most efficient panels on the market are around 22.8% efficient, so shopping around is important. Residential systems over 4kW require an additional survey that can delay your installation.

What is Your Home’s Daily Electricity Usage?

The first step you need to take is to work out how much energy your home uses. In order to do this, you need to look at your past electricity bills and work out your average energy usage. These bills will show you how much electricity you’ve used in kilowatt-hours (kWh) over a time period depending on how frequently you’re billed (every month or quarter, for example). To work out how many solar panels you’ll need to power your home, you will first need to calculate your electricity usage per day. If you’re billed monthly, you’ll need to divide your electricity usage in kWh by 30; if you’re billed quarterly, you’ll need to divide the figure by 90, and so on. A UK home with a monthly electricity usage of 320kWh, for example, will use about 11kWh of electricity each day (320/30).

What is the Average of Daily Sun Hours in Your Location?

Broadly speaking, the peak hours of sunlight are between 9am and 3pm each day, although there can be variations depending on your location. Some areas will have more light than others, and there can be a bit of a difference between the north and south of the United Kingdom. However, this doesn’t mean that you won’t be able to produce as much energy if you live in a shadier area, it simply means that you might need more panels in order to fully benefit. To calculate roughly how much energy, you need to produce in kWh, you need to divide your daily kWh usage by the peak number of sunlight hours in a day. You can multiply this number by 1000 for the watt usage. It’s important to also consult your installer about this.

That said, solar panels will not always work at full efficiency for a number of reasons. For example, it could be a cloudy day or there could be some unexpected shade. For this reason, experts recommend that you leave a cushion of 25% when it comes to calculating how much energy you will use on a daily basis. This offsets any inefficiencies that may occur.

How Many Panels Do You Need?

The capabilities and performance of solar panels can vary and so the quality can really make a difference. PV solar panels tend to range between 150w to 345w per panel, depending on the size of the panel and the cell technology used to create each of the modules.

To work out how many panels you need, divide the hourly energy usage of your home by the wattage of the solar panels. To make sure your expectations are realistic you should do this for a low and high wattage option which will allow you to create a range of sizes.

Doing this will give you an estimate for the number of panels that you need to generate electricity. At this point you will need a professional installer to come and access your roof to determine what angle would be best and how the panels would be arranged on your roof.


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Solar Panel Cost?

How much your solar panel array will cost you depends very much on the panels you choose and the size of your roof. Your average solar set up will cost you between £800 and £8,000 including the installation cost. There are also solar tiles, but these are more expensive than the traditional panels costing between £5000 and £14000 depending on how many are needed.

All government incentives, schemes and support for this industry have now ended but the price of solar panels continue to fall.

However, electricity and gas bills continue to rise and are unlikely to stop going up so having a solar panel system will help insulate you from these rising prices that you have no control over.

Please see the table below to give you a rough idea of costs for different size properties.

Property TypeApprox roof sizeApprox system sizeAverage System CostCo2 Saved Per year (tonnes)Approx yearly yield
Small8m21kWp£2500-£30000.5900 kWh
Small semi-detached15m22kWp£3000-£400011800 kWh
Average semi-detached21m23kWp£4000-£60001.52700 kWh
Average detached28m24kWp£6000-£800023400 kWh

Can You Make Money With Solar Panels?

Though the Feed-In tariff has come to an end, some of the excess electricity generated by your solar energy will inevitably go back to the grid and as under current legislation it would be illegal not to be paid for this a new system has been devised. You may have heard about the Smart Export Guarantee which is coming into force this year. The Smart Export Guarantee requires medium – large electricity supply companies including SSE, EDF Energy, British Gas, npower, EON UK and ScottishPower (those with more than 150,000 electricity customers) to offer a Smart Export Guarantee (SEG). All qualifying suppliers will have to offer you terms of payment for your solar power, wind power & other renewable energy exports. Instead of a subsidy, the new guarantee will be a minimum rate and once the new system has kicked in, it seems inevitable that there’ll be competition between energy suppliers to offer better tariffs in order to gain your loyalty. Two crucial points on the Smart Export Guarantee were confirmed last year:

  • To benefit from the new proposed Export Guarantee scheme, you must have an MCS certified installation.
  • Anyone who installed solar panels between the end of the Feed in Tariff and the start of the new scheme will be eligible for the new scheme.

Here is a table as a rough guide that shows you which suppliers are offering you the best price for your surplus solar power:

Solar Panel Power Purchase Table

SupplierTariff NameTariff TypeTariff length Tariff Rate
Octopus EnergyOutgoing FixedFixed12-month fixed term5.5p
Octopus EnergyOutgoing AgilePegged to half-hourly wholesale rate
Social EnergySmarter ExportCurrently FixedNo Fixed End Date5.6p
Bulb EnergyExport PaymentsFixedNo Fixed End Date5.38p
E.ON EnergyFix & Export ExclusiveFixed12-month fixed term5.5p
OVO EnergyOVO SEG TariffFixed12-month fixed term4.0p
ScottishPowerSmart Export Variable TariffCurrently FixedNo Fixed End Date4.0p
SSESmart Export TariffFixedNo Fixed End Date3.5p
EDF EnergyExport+EarnFixed12-month fixed term3.5p
Shell EnergySEG V1 TariffCurrently FixedNo Fixed End Date3.5p
UtilitaSEG V1 TariffUnknownUnknown3.0p
E.ON EnergyFix & ExportFixed12-month fixed term3.0p
Green Network EnergySEG Tariff FixedUnknown1.0p
British GasExport & Earn FlexCurrently fixedNo Fixed End Date1.5p
Utility WarehouseUW Smart Export GuaranteeFixedNo Fixed End Date0.5p
This table shows you what different energy companies are willing to pay you for the excess power your solar panel system generates (Per kWh).

It is important to note that the best price may not always be the best deal for you, such as in cases where you are required to also be a customer of the supplier. Where the tariff is listed as currently fixed it means that the supplier has given warning that the current fixed price might change in the future.

Another option is to store the extra energy in a solar battery to use during non-daylight hours. Using your ‘free’ electricity will always be cheaper then purchasing electricity from the grid and energy companies will never pay you for your electricity at the same rate they sell it back to you.

Battery technology has improved a great deal and the price of buying one with a solar panel system has also fallen. As they increase in efficiency, they will give householders and businesses the potential to use very little electricity from the grid.

More and more people are choosing to install photovoltaic systems causing the solar technology industry to grow rapidly. Technological advances are happening all the time.

Solar power has become a part of our daily life in the 21st century from sun-powered homes to solar heated pools. There are many examples that clearly demonstrate the importance of using clean energy. As concerns mount regarding the dire effects of over-reliance on fossil fuels the future of solar energy can only get brighter.

Find out more about solar panels here.



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