Frequently Asked Questions
Questions about my home and solar
Questions about choice of technology
Questions about Spirit Solar
- Is Spirit Solar accredited under the Microgeneration Certification Scheme?
- Where does Spirit Solar install?
- Why Spirit Solar?
Questions about choosing your installer
Questions about the Feed in Tariff (FITs), Renewable Heat Incentive (RHI) and the financial returns
- How does the Renewable Heat Incentive work?
- How do the feed in tariffs work?
- What sort of payback time and financial return can I expect?
- How much energy can I expect to generate from Solar PV?
- How much energy can I expect to generate from Solar thermal?
Questions about the installation process
Questions about the System – Solar PV
- Which products do you use?
- Should I choose roof integrated tiles or panels?
- How much maintenance is required?
- How long will a solar system last?
- What guarantees do you offer?
- Is it safe?
Questions about the System – Solar Thermal
- How does a solar hot water system work?
- Will I need a new hot water tank?
- I have a Combi boiler. Can I still install solar hot water?
- How much maintenance is required?
- How long will a solar system last?
- What guarantees do you offer?
- Which products do you use?
Questions about my home and solar
Is my roof suitable?
A sloping roof will be suitable as long as:
- It faces south, south east, south west, east or west (or anything in between these). A south facing roof is best and gives the highest output. If your roof is north east, north west or north facing it will still generate power, but not enough to justify the installation from a financial point of view.
- There is little or no shading.
A flat roof will be suitable as long as:
- There is little or no shading.
- We can find a suitable means of attaching the panels to the roof (either by fixing to the underlying joists or by using free standing ballasted mounting frames).
Installing panels on a flat roof may require planning permission (see below).
Do I need planning permission?
Recent changes to planning law mean that a PV system on a domestic dwelling usually counts as 'permitted development' and can be installed on a sloping roof without the need for planning permission, as long as the panels project no more than 200mm from the roof surface (our panels will comply with this, as long as your installation is on a sloping roof). If you are in any doubt we have a standard letter which you can send to planning.
If your installation is on a non-residential property, a flat roof or if your property is a flat, listed building or located in a conservation area or World Heritage site you will require listed building consent or planning consent.
Please remember to tell leaseholders, freeholders, mortgagors and insurers about the planned work and remember to obtain the relevant consent.
Questions about choice of technology
Which solar technology should I choose: solar PV or solar hot water?
In general we favour solar electricity for several reasons, which we have listed below. There is a case for saying do both if you have the space and budget, particularly if you have already installed 4kWp of solar electricity on your roof, and would be into the lower tariff band if you installed more. Also if hot water generation is your main concern then it is worth installing solar hot water rather than electricity – it is inefficient to generate electricity and use it to heat water, it is much more efficient to generate heat energy in the first place.Our reasons for choosing solar electricity over hot water are as follows:
- Firstly the financial returns are currently better. The Renewable Heat Incentive has yet to be finalised so this may change; however at the time of writing (January 2011), the FITs offer a better financial return.
- Secondly solar electricity is a real 'no hassle' technology. There is no need to install a new tank, possibly resulting in a perfectly good tank being needlessly thrown away. Solar thermal systems also need more maintenance and do sometimes get air locks in them.
- Thirdly the energy generated by solar electricity is much easier to measure - and must be measured using a 'Total Generation Meter' for the purposes of working out the feed-in tariff.
In contrast it is much more difficult to know exactly how much energy has been generated by solar hot water panels. All you can do is look at the thermostat in your hot water tank and read the temperatures at the top and bottom of the tank at various points during the day. The problem is that as soon as you let more water in from the mains, the temperature at the bottom of the tank will fall by several degrees, regardless of whether the sun is shining or not. Keeping track of gains from the sun is very difficult. It is for this reason that the Renewable Heat Incentive will be based on the energy the system is 'deemed to produce' rather than the energy it actually produces
- Finally solar PV uses the light from the sun rather than the heat. A solar PV system will generate a high return on a sunny day, whether that day is in January or in July. It relies on light from the sun, not heat. In fact it will generate energy even on an overcast day.
Solar hot water panels will warm up in winter. However because the surrounding air is so much cooler, the heat will quickly dissipate into the air. Relatively little of it will be transferred to your hot water tank.
Questions about Spirit Solar
Is Spirit Solar accredited under the Microgeneration Certification Scheme?
Yes we are accredited to install solar pv, reference NIC 1220. Please note you need to use an accredited installer to be able to register for feed in tariffs. To read more about our accreditations and warranties, click here.
Where does Spirit Solar install?
The short answer is that we install nationwide. Our head office is in Reading; however we are building a network of locally based installation teams to manage installations across the UK. All installers are employed directly by us - we do not sub-contract work out (except scaffolding).
Why Spirit Solar?
We have devoted a whole page to answering this question! Please click here for more information
Questions about choosing your installer
Things to ask any potential installer
We have devoted a whole page to answering this question! Please click here for more information
Questions about the Feed in Tariff (FITs), Renewable Heat Incentive (RHI) and the financial returns
How does the Renewable Heat Incentive work?
As at the time of writing (January 2011), the details have yet to be finalised. We will keep this page updated as more information comes out. You can read a summary of everything we know so far if you click here.How do the feed in tariffs work?
We have devoted a whole page to this, click here. For very comprehensive information, including copies of legislation and lots of frequently asked questions, we recommend this site: www.fitariffs.co.ukWhat sort of payback time and financial return can I expect?
Solar PVBased on current levels of feed in tariffs and on our current prices, we have calculated payback times of between 11 years for larger systems (2.5 kWp or larger) and 12 to 13 years for smaller systems.
The income from feed in tariffs is non-taxable, making the investment very attractive. For a basic rate tax payer, the financial return is equivalent to a 25 year taxable investment paying between 7% and 9% per annum. For a higher rate (40%) tax payer, the financial return is equivalent to a 25 year taxable investment paying between 9% and 11.5%.
Solar ThermalWatch this space! When the final terms of the RHI are published we will be able to estimate this with a lot more accuracy than we can at the moment.
How much energy can I expect to generate from Solar PV?
This depends on the size of system you install and the location / orientation of the system. We have a calculator on our website which calculates an official performance estimate, taking into account system size, roof orientation and slope. This is an official 'Government' forecast. You can also link through to a more accurate calculator from this page.How much energy can I expect to generate from Solar thermal?
Obviously, the hot water produced is proportional to the strength of the sun; therefore it varies over the course of the year. During summer months (April – September) a solar system can provide 100% of your hot water requirements, and in the winter months it can still provide approximately 15 – 20% of your needs.Overall you will generate 60 – 70% of your hot water from the solar system. The energy required to heat water in the average home is around 1064 kWh per occupant per year (based on usage of 50 litres per day per occupant). So a correctly sized system will generate around 700kWh of thermal energy per occupant per year.
Questions about the installation process
How long does the installation take?
Our installations typically take two or three days. We can usually fit your installation in within two to four weeks of receiving your signed quotation acceptance.
Will there be a lot of disruption?
There will obviously be some but we work hard to ensure that we make as little impact as possible on your routine. The internal electrical work takes about a day. The roof work takes one to two days, depending on how many panels you have. We always tidy up after ourselves!
Will scaffolding be required?
For most installations scaffolding will be required. This is to protect our workmen whilst working on the roof and to comply with health and safety legislation. In the case of 'new build' installations scaffolding is usually already in place.
Questions about the System – Solar PV
Which products do you use?
We use top quality products.
Specifically we use SMA (Sunny) or Fronius inverters. SMA is a German company, Fronius is Austrian.
We offer a range of panels; we can supply pretty much any panel you want. Trina, Sharp, Romag and Sanyo are our most popular brands.. All panels are accredited under the Microgeneration Certification Scheme and come with a 5 year defects warranty and a 25 year performance warranty.
For a detailed analysis of panels please click here.
Should I choose roof integrated tiles or panels?
If you are concerned about maximising financial return and maximising the power output from your roof, use panels. If you are primarily concerned about aesthetics or cannot fit panels for planning or other reasons, then consider roof tiles.
For more information about panels and roof tiles, click here.
How much maintenance is required?
Very little maintenance is required for solar photovoltaic systems. On a sloping roof panels will automatically be cleaned by the rain; in addition the glass on the panels is self-cleaning glass. As a precaution we recommend the panels should be cleaned every five years. This can usually be carried out from the ground using a low pressure washer and a long lance (no detergent or abrasives). The inverter manufacturer will typically recommend that the inverter is inspected every five years. We do offer inspection / maintenance should your require.
Should you have any problems regarding the installation we will deal with the problems with no call out fee for 5 years (see our guarantee below).
How long will a solar system last?
Solar PV systems are built to last a minimum of 25 years: note that the feed in tariff is payable for 25 years, the performance warranty on the panels is 25 years (specifically guaranteeing a minimum of 80% of original performance). The roof fixings also need to be made of non corrosive materials.
The system will obviously last better if it is looked after well. We recommend a five yearly maintenance with panel cleaning and inverter inspection. The inverter is guaranteed for 10 years although it is expected to last longer and extended warranties are available at additional cost.
What guarantees do you offer?
We install MCS accredited panels which come with a 5 year defects guarantee and a 25 year performance guarantee.
We use SMA (German) inverters. These are the market leaders in inverter technology. They come with a 10 year warranty, which is extendable to 15, 20 or 25 years at additional cost.
We are extremely confident of the quality of our installations and are happy to offer a standard 10 year warranty on all our workmanship. We guarantee all of our workmanship will be free from defects for 10 years from the date of commissioning and that all equipment and materials have been installed in accordance with manufacturer specifications. In the first 10 years after installation we will correct free of charge any fault arising in the system as a result of defective workmanship by Spirit Solar Ltd. Where there is a need to claim on a manufacturer’s warranty within the first 5 years we will make the claim from the manufacturer on your behalf and we will replace the faulty equipment free of charge.
To view our standard workmanship warranty please click here.
Is it safe?
Yes. Solar PV systems do not emit any toxic chemicals and there are no moving parts. A solar system is essentially just another electrical circuit in the house.
All fixing methods we employ have been approved by independent chartered structural engineers. Most roofs are 'standard'; however if your roof is in any way 'non-standard' we will seek a specific opinion from a structural engineer prior to installation.
Questions about the System – Solar Thermal
How does a solar hot water system work?
The premise for the solar hot water system is straightforward; the heat energy of the sun is absorbed by a liquid, usually a mixture of water and antifreeze which can stand a range of temperatures from +150 to -20OC, running through solar panels usually sited on a roof. This is then transferred to heat water in a storage cylinder which can be used throughout the house. This system is integrated in with your existing boiler or immersion heater which is used as a backup to ensure water is hot enough at times when the solar system is not producing sufficient heat, such as during the winter. For a more detailed explanation and diagram, click here.Will I need a new hot water tank?
Usually (but not always) you will need a new tank. The most efficient systems use a twin coil system with a 'solar coil' coming into the bottom of the tank, and the 'back up' coil, connecting in most cases to the boiler, in the top of the tank.Our technicians will advise whether you need a new tank when they visit your property.
I have a Combi boiler. Can I still install solar hot water?
It is possible to install solar thermal with a combi boiler. There are a couple of options for doing this:- If the boiler will accept preheated water, then we install a cylinder in the pipework before the water goes through the boiler. So the solar brings temperature up and the boiler then tops it up.
- We can use a thermal store and have mains pressure hot water heated by the solar and the boiler heating the store as though it was its only radiator, this way the solar can also contribute to space heating as well. The boiler would need to have one outlet on the hot water side for testing.
There are a number of other alternatives depending on occupancy, size of system etc. There is no "one size fits all" when it comes to solar thermal.
How much maintenance is required?
The lifetime of a solar thermal system is 25 years, and over this period it should only need servicing every 3 – 5 years by an accredited installer. This servicing could be done at the same time as your regular boiler servicing to make life easier. Over time, small parts such as the pump may need replacing for a small cost.How long will a solar system last?
All systems we install are expected to last for 25 years. This is not just an expectation – solar thermal systems have now been around for many years and there are certainly examples of systems still going strong after 20 years.What guarantees do you offer?
We use SMA (German) inverters. These are the market leaders in inverter technology. They come with a 10 year warranty, which is extendable to 15, 20 or 25 years at additional cost.
We are extremely confident of the quality of our installations and are happy to offer a standard 10 year warranty on all our workmanship. We guarantee all of our workmanship will be free from defects for 10 years from the date of commissioning and that all equipment and materials have been installed in accordance with manufacturer specifications. In the first 10 years after installation we will correct free of charge any fault arising in the system as a result of defective workmanship by Spirit Solar Ltd. Where there is a need to claim on a manufacturer's warranty within the first 5 years we will make the claim from the manufacturer on your behalf and we will replace the faulty equipment free of charge.
To view our standard workmanship warranty please click here.