Frequently asked questions

• How does solar PV work?
• Are there different types of solar power systems?
• Why solar PV not Solar Thermal?
• Why solar PV not wind?
• How do I get paid for the energy generated?
• What is the VAT rate?
• What warranty is provided?
• Do I need planning permission?
• What if I move house?
• What happens if there is a power cut?
• How durable are the panels?
• Do the panels require cleaning?
• Why do you get more money for electricity produced than you pay for electricity used?
• What happens at night?
• What effect will solar PV have on my carbon footprint?
• What is the carbon payback period for the manufacture and transport of Solar PV?
• Is solar PV suitable in the UK with our climate?
• Will solar PV work in winter?
• Will I still have to pay electricity bills?
• Do panels have to go on the roof of my house?
• How long do the panels last?
• Why BSOLAR?
• Mono vs. Poly solar panels
• What inverter should I get?
• Will I be taxed on my income?
• Why Local solar electricity is better?
• Do solar panels have to face South?
• Can every home have solar panels?
• Where will the inverter be located?
• Are Sanyo HIT panels better than other makes?
• Are there any British made panels?

How does solar PV work?

Photovoltaic solar panels (PV panels) convert the sun's light energy into electrical energy. This energy can be used to supply a mains electrical system via an Inverter.

PV cells are panels you can attach to your roof or walls. Each cell is made from one or two layers of semiconducting material, usually silicon. When light shines on the cell it creates an electric field across the layers. The stronger the sunshine, the more electricity is produced.

PV cells come in a variety of shapes and colours, from grey "solar tiles" that look like roof tiles to panels and transparent cells that you can use on conservatories and glass.

The strength of a PV cell is measured in kiloWatt peak (kWp). That's the amount of energy the cell generates in full sunlight under standard test conditions.

Are there different types of solar power systems?

There are two distinct types of solar system you can install on your house:

• Solar thermal for making hot water.
• Solar electric panels (also known as 'photovoltaics' or 'PV') which make electricity.

BSOLAR only offers 'photovoltaics' or solar electricity systems; we will not provide solar thermal systems until their installation can pay for itself within its lifetime.

Why solar PV not Solar Thermal?

Solar thermal (according to the official OFGEN figures) can typically provide around 30% of the typical home hot water requirement. How water accounts for approximately 30% of the gas used by your boiler. You will therefore save in the region of 12% per annum on your gas bills. For a normal home this is in the region of £50 to £70 per annum. At an installed price of £3000 that equates to a 50 year payback period. As Solar Thermal panels are such a poor investment BSOLAR will not install these. Their sale is also not subject to the same strong code of practice as Solar PV and BSOLAR does not wish to be associated with the high pressure sales techniques used by Solar Thermal installers.

You can have hot water efficiently from the sun in the UK. Simply install a programmer on the immersion heater in the hot water cylinder and use the free electricity from any large PV installation.

BSOLAR now provide a device which we have developed with the help of Lancaster University which monitors the output from the solar arrays and turns on the immersion heater only when it can be powered for free from the electricity being generated by the solar PV panels.

Why solar PV not wind?

Wind is great on larger scale installations or on coastal areas or windswept hills, but your average urban location means performance and efficiency is low. You need a very large turbine to make a sizeable dent in the average domestic energy bill, this has been confirmed by government testing. Urban locations do not have the correct wind speeds, suffer from building turbulence and vibration problems could lead to structural building damage. In an open field Wind power is an excellent choice and could realise a slightly higher return on investment than Solar PV.

"The likely output of a micro-wind turbine on a pitched roof house in a large city such as Manchester would be less than 150kWh a year; 2% of the energy consumption of an average house"

How do I get paid for the energy generated?

The energy suppliers pay the feed-in tariffs to those who generate the clean electricity. When you apply for the feed-in tariff, you should ask your energy supplier how and when payments will be made. Payments must be made at least quarterly and are usually made directly into your bank account.

You will have two separate contracts, one to buy electricity and one for the electricity you generate. You can still change who you buy electricity from and this will not effect the new contract for the sale of power.

What is the VAT rate?

Domestic Solar PV installations are rated at 5% VAT in order to encourage consumer investment in this area.

What warranty is provided?

All BSOLAR installations come with a free insurance-backed warranty. Your deposit is fully secured and the installation is warranted in full for 10 years. Your BSOLAR warranty is a full 10 year parts and labour warranty, it is understood to be the best available in the industry.

In addition to this the solar panels installed are warranted by their manufacturer to operate to at least 80% of their initial efficiency for 25 years. As there are no moving parts there is no reason why the system should go wrong and the expectation is for a 40 years lifespan.

Do I need planning permission?

Solar roof systems fall under permitted development rights so you do not need planning permission, although if you live in an area of 'outstanding natural beauty', a National Park, Conservation Area, Site of Special Scientific Interest or in a listed building you should contact your local council.

What if I move house?

If you get solar installed and start claiming the 'Feed-in Tariff' you will have lower bills and a steady income from the 'Feed-in Tariff' payments. These benefits can be transferred to the new home owner and so when you come to sell your home you can charge more for it as it comes with an inbuilt income.

• Read more about the Feed in Tariff

What happens if there is a power cut?

Solar electric systems for homes are entirely grid connected. If there is a power cut your system is automatically switched off. This is a safety measure designed to stop electricity leaking on to the national grid and to protect people who may be working to restore the power supply.

How durable are the panels?

You should not stand on them but they will comfortably handle the wind loads and snow weight of the UK.

Do the panels require cleaning?

Not as long as they are mounted at a steep enough angle (>20°) so that the self-cleaning glass works. In the same way Velux windows work.

Why do you get more money for electricity produced than you pay for electricity used?

The energy that you produce is from a renewable source. Solar power is free, clean and green. This is in comparison to energy produced from non- renewable sources which are rapidly being depleted and contributing to global warming. The FIT scheme will help drive the UK to meet the EU target of 20% by 2020. This also reduces our dependence on energy sources from other countries. There is an increasing demand for ‘green electricity’, what is the point of an electric car if the electricity is generated by a dirty coal power station?

What happens at night?

At night, when the solar roof is not generating electricity, you buy electricity from your supplier like normal (at less than 1/3 the price they pay you for it).

What effect will solar PV have on my carbon footprint?

A solar PV system can immediately help lower your carbon footprint and reduce your impact on the environment. This will also improve the energy efficiency of the property as recorded in an EPC (energy performance certificate). Solar electricity is green, renewable energy and doesn't release any harmful carbon dioxide (CO2) or other pollutants. A typical home PV system could save around 1200 kg of CO2 per year - that's around 30 tonnes over its lifetime.

What is the carbon payback period for the manufacture and transport of Solar PV?

It is generally agreed to equate to just under 3 years of the electricity production of the Solar PV system. Almost all manufacturers offer a free recycling scheme.

Is solar PV suitable in the UK with our climate?

The UK receives 60% of the solar energy compared with the equator. Each square metre of the UK receives between 900 – 1200kwh of solar radiation each year. Because the UK is generally colder the efficiency of the solar cells is increased making the UK a good climate for solar PV.

Will solar PV work in winter?

Yes solar PV will still produce energy through winter. The shorter length of day and increased cloud cover does affect your output. This is why we look at system production over a whole year. It will not work when covered by snow or leaves.

Will I still have to pay electricity bills?

You will pay reduced bills because of the free electricity you will produce, however, you will still buy the majority of the electricity used by the home. Solar PV typically reduces bills by approximately 30%. You will be paid by direct bank transfer for the electricity you generate. This payment could well exceed the annual payments made for both electricity and gas.

Do panels have to go on the roof of my house?

No. PV can easily be installed on frames or in tubs within your boundaries, or out-buildings with suitable roofing. Installation on walls is possible but not common.

How long do the panels last?

Solar panels have a manufacturer’s performance warranty of 20 or 25 years and a working lifetime of 40 years and beyond. Most solar panels now come with a 10 year manufacturers warranty.

Why BSOLAR?

With a long established background in energy saving consultancy and in training new Energy Consultants we have the credentials to only recommend installations that are truly effective.

You can rest assured with BSOLAR that the energy consultant that visits your property for your free survey will look at a range of measures that will make your home more efficient and cheaper to run. We will recommend that you do not get solar PV installed if it is not suitable. If it is suitable then we will work with you to identify the options and the scale of solution that best meets your needs.

BSOLAR Energy Consultants do not use high pressure selling tactics. You will be advised of a suitable solution and a price. The price is not discounted on the day to encourage you to sign up. In fact – you cannot sign upon the day of the consultant visit. We will send you a written proposal and then contacted later to see whether you intend to proceed.

As an ethical provider we hope to gain your recommendation to others and realise that in order to achieve this we must demonstrate excellence.We are so confident of our systems that we provide a full 10 year parts and labour warranty.

BSOLAR are PV specialists. We do not sell any other renewables and will not do so until they become economically profitable to a large number of situations.

Mono vs. Poly solar panels

Monochrystaline panels have higher raw efficiency figures than Polychrystaline panels, but they suffer from a much higher temperature variability. In the real world Poly panels will produce slightly better full-year performance in the UK than mono. It makes little difference in Cornwall but an increasing amount the further north you get. The difference can be as much as 1% more for poly rather than mono panels, unfortunately they take up more space.

What inverter should I get?

The traditional inverter has a transformer and is very heavy. More modern inverters are transformer-less and are much lighter. Both offer similar efficiency and there is no technical reason to prefer either.

On larger systems you will need more than one string of panels. Some inverters offer MPPTs on all strings which is a major advantage if any shade is present anywhere. These inverters effectively act as two or more inverters in one box.

Some installers will incorrectly size inverters at over the peak output of the panels. The ideal sizing is around 90%. This works best over the full year of different conditions. It also copes best with the slightly declining performance over the life of the system. Oversized inverters are good only in the first few weeks when the panels work beyond their expected output. The Sunny Boy 4000TL inverter is oversized for 4kWp installations in the UK. We will not install it for this reason and the fact that Sunny Boy inverters are noisy at start-up. Also this inverter needs prior approval from the DNO because it is so oversized.

Will I be taxed on my income?

Income of under £4000 per annum is tax free and treated similarly to earnings made from car boot fairs. Commercial installations including landlord installations are treated as taxable income.

Why local solar electricity is better?

Producing electricity from your roof is highly efficient. As over 95% of the electricity collected on your roof is converted into AC for use in your home this is much more efficient than electricity bought from the National Grid. Grid supplied electricity is typically less than 40% efficient due to inefficient production and grid losses. Even if you do not use all the electricity you produce your neighbours will get the clean, more efficient power produced locally.

This benefits the power supply companies by distributing electricity production next to electricity consumption. Hence this electricity is worth more than the power that you buy normally. The more people that produce energy locally, the more dirty old power stations can be switched off. This is why the power companies are behind this.

Solar PV produced electricity is paid at over 4 times the rate that grid electricity is bought for. The people not making electricity (your neighbours) are subsidising this price in the form of higher bills to buy your local, green electricity.

Do solar panels have to face South?

No, whilst a southerly aspect will produce the greatest return, anything from East to West will produce very good returns for your investment. There is a lot to be said for an East & West installation, maximising the useful electricity produced at the times it will be most useful.

Can every home have solar panels?

Apart from the obvious requirement for a reasonably sized southerly aspect roof, the roof will need to have a membrane under it or it will leak.

Some home owners buy power from intermediaries, not power companies. This happens on campus situations for example. Such homes do not have a power supply MPAN and cannot have solar PV. Ensure that you check your bill for an MPAN number if you are in doubt.

Where will the inverter be located?

It is best to site the inverter as close to the solar panels as possible in order to minimise cable power losses. You will want to read the display on the inverter occasionally so it should be accessible. A garage is often as sensible alternative to the loft. Inverters need air for cooling and cannot therefore be put in cupboards.

Are Sanyo HIT panels better than other makes?

Sanyo HIT panels have 2 layers of solar collector and can generate more power per square metre, however they are much more expensive than other panels. If space is not at a premium you should fit other panels to get the most cost effective system. Sanyo panels also suffer very badly in shade, more so than other panels as they only have one blocking diode.

BSOLAR offer Sunpower solar modules instead of Sanyo/Panasonic modules. Sunpower are the highest efficiency solar panels made with three blocking diodes, and we can offer them at a more competitive price than the inferior Sanyo/Panasonic panels.

Are there any British made panels?

Almost all solar cells are made in China. Both ROMAG and Sharp assemble solar panels in the UK. ROMAG are the only British company that make solar panels in any volume.