Which solar PV products does Spirit Solar use?
To view our Solar thermal (hot water) products, click here. Read on for information about our Solar PV (electricity) products.
To give you and us peace of mind, we always use high quality accredited products. We do not buy pre-assembled kits; instead we source components individually ensuring we can always buy at the best prices. The following should be taken as a guide only; if you are set on one particular panel or inverter we can usually source it for you.
The two key components in a PV system are the solar panels (or roof tiles – see below) and the inverter.
For information on each of these read on or click on one of our Quick links.
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Solar panels – On-Roof, In-Roof or roof tiles?
There are three ways of installing solar on your roof:
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by attaching solar panels to the roof using "on-roof" mounting brackets which sit above the tiles;
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by removing tiles in the area in which the panels are to go, and mounting the panels directly onto the rafters using "in-roof" mounting brackets;
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by installing solar tiles directly onto the roof.
- Solar panels with on-roof mounting brackets.
- Roof integrated solar tiles
- Solar panels with in-roof mounting brackets
Most people are installing systems to their existing house ('retrofit') and choose to attach panels onto the roof using mounting brackets.
For new build or re-roof situations, or where there may be an issue with planning (eg a conservation area), an in-roof mounting or solar roof tiles may be the solution of choice.
In roof systems use the same panels as on roof systems. The only difference is that the panels are mounted on the rafters, not on the tiles (usually with a metal tray backing between the panels and the rafters). The installer will tile up to the panels, often using lead flashing to make a tight seal around the panels.
In general we don't recommend In-Roof systems for several reasons:
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Customers often believe the top of the panels will sit flush with the tiles. This is not the case - usually tiles are a few centimetres thick whereas the brackets and panels stand 11cm off the rafters. So unless the rafters around the PV system have been deliberately built up, the tiles will not sit flush with the roof.
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The performance of the system will be reduced by 5-7% relative to an on roof system due to the fact that to operate efficiently, panels need a gap behind them for ventilation. The In-Roof system doesn't provide this ventilation and the performance of the system is compromised as a result.
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In order to create a watertight seal between the system and the surrounding tiles, lead flashing usually needs to be used. This is often ugly and defeats the point of using an in roof system in the first place which is usually to create an unobtrusive system blending with the rest of the roof.
If you want your system to sit flush with the surrounding tiles and to blend seamlessly into the roof, you would be better off using solar roof tiles. These are more expensive than an On-Roof or In-Roof system, but are a better bet if you are particularly worried about aesthetics. For example English Heritage have chosen System Photonics roof tiles (see below) for some of their projects.
Solar panels – Which panel should I choose?
The table summarises our most popular panels, giving power output, dimensions and Watts per square metre.
| Make | Model | Output | Dimensions (mm) | Area (m2) | Watts/m2 | Module Efficiency | Defects Guarantee | Performance Guarantee Term/Min performance guaranteed (as a % of initial output) |
Type | Colour | Picture | Technical Spec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sanyo | HIT-N240SE10 | 240 | 798 x 1580 | 1.26 | 190 | 19.0% | 10 | 10 yrs/90%; 25 yrs/80% | Hybrid Mono | Black with Black Frame |  |
Download PDF |
| Sanyo | HIT-H250E01 | 250 | 861 x 1610 | 1.39 | 180 | 18.0% | 10 | 10 yrs/90%; 25 yrs/80% | Hybrid Mono | Black with Black Frame |  |
Download PDF |
| Trina | TSM-DC01 | 185 | 809 x 1581 | 1.28 | 149 | 14.5% | 10 | 10 yrs/90%; 25 yrs/80% | Monocrystalline | Black with Silver Frame |  |
Download PDF |
| Trina | TSM-DC05 | 235 | 992 x 1650 | 1.64 | 144 | 14.4% | 10 | 10 yrs/90%; 25 yrs/80% | Polycrystalline | Blue with Silver Frame |  |
Download PDF |
| Sharp | NU185R1H | 185 | 994 x 1318 | 1.31 | 141 | 14.1% | 5 | 10 yrs/90%; 25 yrs/80% | Monocrystalline | Black with Silver Frame | .jpg "NU185R1H") |
Download PDF |
| Sharp | NUR245J5 | 245 | 994 x 1652 | 1.64 | 149 | 14.9% | 5 | 10 yrs/90%; 25 yrs/80% | Monocrystalline | Blue with silver frame | |
Download PDF |
| Suntech | STP190S-24/Ad+ | 190 | 758 x 1580 | 1.20 | 149 | 14.9% | 10 | 5 yrs/95%; 12 yrs/90%; 18 yrs/85%; 25 yrs 80% | Monocrystalline | Black with Silver Frame | |
Download PDF |
| Suntech | STP240S-20/Wd | 240 | 991 x 1665 | 1.65 | 145 | 14.5% | 10 | 5 yrs/95%; 12 yrs/90%; 18 yrs/85%; 25 yrs 80% | Monocrystalline | Black with Silver Frame | |
Download PDF |
| ET Solar | ET-M572190B | 190 | 808 x 1580 | 1.28 | 149 | 14.9% | 10 | 12 yrs/90%; 25 yrs/80% | Monocrystalline | Black with Black Frame |  |
Download PDF |
Our recommendations:
First note all panels that we supply have been tested to obtain MCS accreditation and they are all guaranteed to give 80% power output after 25 years.
Most of the solar cells which make up the panels are made in the same few factories in China / Asia, and in our view, apart from the Sanyo hybrids which are a different technology, one is pretty much like another. The one possible consideration is, should you need to make a warranty claim in 20 years' time, which company will still be around to honour the warranty? That said, it should be stressed that not alot can go wrong with a solar panel - it has no moving parts - and there really is very little likelihood that you will ever need to make a warranty claim.
The best value for money is currently provided by the Suntech panels. They are very well made with a high efficiency. Suntech is a large established company, quoted on the New York Stock Exchange - visit www.suntech-power.com to find out more about the company.
Sharp panels are more expensive than the Suntech panels. They are popular because Sharp is a household name, which is why we offer them. However they are not quite as efficient as Suntech.
The Sanyo are the most expensive per Watt of power generated. Their one big advantage is that by using a different 'hybrid' technology they give approximately 25% more power per square metre than any other panel. From the table you can see that the Sanyo gives 190 Watts per square metre, compared to between 134 and 149 Watts per square metre for the other panels. The downside is that they currently cost around 50p more per Watt - so for a 2 kWp system you will pay around £1000 more if you choose Sanyo. So if you are wondering whether to buy Sanyo or not, ask yourself what are you trying to maximise - the total power you can squeeze out of your roof or your financial return? If your objective is simply to maximise the power output from your available roof space without regard to budget, then you should choose the Sanyo hybrids. Don't choose the hybrids if you want to maximise your financial return.
Click here for more information on the different types of panel: monocrystalline, polycrystalline, hybrid and thin film.
Solar roof tiles – products and prices
If you compare the cost per Watt peak of a solar roof tile with that of an on roof solar pv system, you find that the cost per Watt peak of a roof tile system is usually over double that of the panels. Put another way, if a small 1.5 kWp system costs you £8500 with panels, it will cost you more like £15,000 with tiles.
In addition whilst panels generate over 134 Watts per square metre, tiles typically generate between 50 Watts and 120 Watts per square metre. So tiles are more expensive and give less output per square metre of roof.
The tiles obviously serve a dual purpose in that they both provide power and they cover the roof. However given that a square metre of plain roof tile costs around £10, and a square metre of solar photovoltaic tiles costs over £500 (tiles only), tiles are really not the most economic choice. They can only be justified on aesthetic grounds where budget is not important or for buildings where, for whatever reason, panels are ruled out.
There are a few products on offer, as follows:
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Solar Century
C21e tile – These are the most cost effective PV tiles we have found. They cost around £6,500 per kWp installed, which equates to about £800 per square metre. This includes everything - inverter, isolators etc. The output is around 121 W per square metre. Compatible with a range of clay tiles - see datasheet for list.
Compatible with a range of natural slates and fibre cement slates - see datasheet for list.
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System photonics
– upmarket Italian design which is unique in that it embeds the solar cells into a ceramic tile. Aesthetically the most pleasing on the market, it is available in 16 colours. There are two versions: the first has a power output of 53W per square metre and the second has a power output of 120W per square metre. Plain tiles are available to match. Click here for more information.
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Imerys
PVt 60Wp – designed to fit with Imerys clay tiles. Available in one colour (see picture). Output 92 W per square metre.
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Redland
Redland do a range of photovoltaic tiles to match their plain tiles.
Inverters
Many people spend many hours wondering which panel they should choose and don't give a thought to any other component of the system. However the real heart of the system is the inverter, a very clever piece of kit which costs between £1000 and £2000 on a typical small scale / domestic system (depending on size). For this money it's worth a read on what you are buying!
The role of the inverter
The panels generate DC (direct current) electricity. However the national grid and every electrical item in the house runs on AC (alternating current) electricity. The main task of the inverter is to convert DC into AC, synchronized with the supply voltage. It also has important safety features to protect your system and to protect men working on the national grid in the event of a power cut on the grid.
Our inverters
Sounds simple but if you read on you will start discover some of the clever bits.
Hopefully when you have read them you will understand why we always use the market leading inverters. The best two 'standard inverters' on the market are the Sunny Boy inverters, made by the German company SMA and the Fronius inverters made by the Austrian company Fronius. They typically come with 5 year warranties extendable to 25 years. Our standard package includes a warranty extension to 10 years.
We also use SolarEdge inverters. These optimise the performance of each panel using Power Optimisers. They can improve the output of a system by a few percentage points just by operating the system more efficiently. On a shaded system SolarEdge inverters can add 5-10% (or more) to the output.
If you read our guarantee you will see that we guarantee to investigate any fault with your system with no call out fee for five years. We do this with confidence – we really are not expecting to visit because we use high quality, well engineered, market leading inverters.
Fully automated operation
After sunrise, as soon as there is sufficient output generated by solar modules, the control unit starts monitoring the utility line voltage and frequency as well as the available energy in the panels. Once enough sunlight is received, the solar inverter starts feeding the utility transmission grid. Depending on the type of installation, a few watts of solar power will be enough do the job!
The inverter will now continue to work such that it always draws the maximum of power from the solar modules. This function is called MPPT (Maximum Power Point Tracking) and is carried out with a rate of accuracy of more than 99%. After dark, when the energy offered is no longer enough to feed the utility transmission grid, the inverter automatically cuts the connection to the grid and stops operating, of course with all settings and data being conserved.
Grid monitoring, safety cut out
Inverters need to meet minimum safety standards and conform to industry standard protection settings. This means that they need to monitor voltage and frequency and stop operating in case of irregular grid conditions (e.g. utility outage, interruption). If any protection setting is breached they stop the feed into the grid. This is important. In the event of a power cut engineers will work on the electricity transmission lines to find the fault. Obviously they can't do this if your system is still pumping electricity into the grid.
The inverters also feature a high frequency transformer that ensures a galvanic separation of the DC side from the utility transmission grid.
Display and data communication
One of the most important features from a customer point of view is the data display. SMA systems come with a wireless display which you can put anywhere in the house called a Sunny Beam.
The Sunny Beam shows you exactly how much power the system is generating at any one instant, as well as the cumulative total for the day and the year. There are charts to look back over a month so you can see the trend. You will always know if your system is working and also just how well its doing.
SMA and SolarEdge both offer online tracking systems. These provide data with varying degrees of complexity, ranging from simple output data (current power, accumulated output etc) to detailed technical information (operating voltages etc).
A warning – it's addictive. We guarantee that when you first get your system you'll be checking it every day at least twice a day!