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Please see below for a list of our most frequently asked questions.

If you still need help, please contact us.

Q. What is a solar hot water system and how does it work?
Q. What are the benefits of a solar hot water system?
Q. What are the components of a solar hot water system?
Q. What type of solar collector is Tesco installing?
Q. What is the difference between flat plate and evacuated tube panels?
Q. Where is the best place to install the solar collectors (i.e. panels/tubes)?
Q. How much space is required for the solar hot water collectors and can I still use my loft?
Q. How does a solar hot water system integrate with my existing heating system?
Q. Will a solar hot water system work with a combi boiler?
Q.Do I need a new hot water cylinder to install solar hot water, and if so, how big does it need to be?
Q. Do I need to have a new boiler for the installation of my solar hot water system?
Q. How much will a solar hot water system cost?
Q. Can I get a grant for installing a solar hot water system?
Q. Who applies for the grant?
Q. How much money will a solar hot water system save?
Q. Is planning permission required to install a solar hot water system?
Q. Who will install the system?
Q. How long does it take to install a solar hot water system?
Q. How long will the solar hot water system last and what are the guarantee periods?
Q. What maintenance is required to the solar hot water system?
Q. Can I use a solar hot water system to provide space heating for my home?
Q. Will a solar hot water system work in the UK, and will it work during the winter?
Q. If my house is not south facing can I have split panels, one of front and one on back?
Q. Can I have panels on my garage? 

Q. What is a solar hot water system and how does it work?

Solar hot water uses the radiation from the sun to heat a liquid (usually a mixture of water, antifreeze and a corrosion inhibitor) that flows through a solar collector, often sited on the roof of a building, which in turn heats water contained within a storage cylinder via a heat exchanger for use at the taps/shower etc within a building. A solar hot water system does not produce electricity. A conventional boiler or immersion heater is generally used as a back up to heat water within the hot water cylinder in order to reach the temperature set by the cylinder’s thermostat when the solar system is unable to heat water to that required temperature (for instance, during winter months).

Q. What are the benefits of a solar hot water system?

• Produce up to 70% of your annual hot water requirements from the power of the sun (up to 100% in the summer months, approx 15-20% in the winter months)
• Reduce & future proof your fuel bills – sunlight is free so once you have paid for the initial installation your bills for producing hot water will be significantly reduced for the lifetime of the system (around 25 years)
• Cut your carbon footprint – solar hot water uses the renewable resource of the sun and does not release any harmful carbon dioxide or other pollutants (other than from using a very small amount of electricity for powering the pump)

Q. What are the components of a solar hot water system?

A solar hot water system includes the collectors (either flat plate or evacuated tubes), a new hot water cylinder (either to replace an existing cylinder or to be coupled with an existing cylinder) and control system, as well as all the pipe work and connection with your boiler.

Q. What type of solar collector is Tesco installing?

Tesco is using a flat plate collector system.

Q. What is the difference between flat plate and evacuated tube panels?

The main component of a solar water heating system is the collector (often referred to as a solar panel) and its function is to collect the heat from the sun and transfer it to a fluid in the collector which in turn transfers it to the water in a hot water cylinder. In the UK the types of collectors fall into two main categories – flat plate or evacuated tubes. Although there are variations available for each type of collector, the way they work is very similar. However, flat plate collectors can be either fixed onto the existing roof covering (slates/tiles etc) or integrated into the roof itself, whereas evacuated tubes must always be fixed onto the existing roof. At the operating temperatures of the domestic hot water system, both types of panel can be considered to have similar efficiencies.

Q. Where is the best place to install the solar collectors (i.e. panels/tubes)?

Ideally the collectors should be south facing, usually on the roof of a dwelling or they can be mounted on a frame attached to a wall of a dwelling or even ground mounted. However, there is a good deal of tolerance with solar hot water systems and their efficiency will only decrease by a small amount if the collectors face anywhere between south east and south west. If you only have east and west facing roofs, collectors can still be installed on each of these roofs but costs will increase as you will require more collectors than would be the case on a south facing roof. North facing roofs are not acceptable for solar hot water systems.

Q. How much space is required for the solar hot water collectors and can I still use my loft?

A good rule of thumb is that, for each occupant of the household, approximately 1m2 of solar collector is required. Therefore, for the average family, the solar hot water collectors will require 3-4m2 of roof space (NB usually sited on the roof but can be wall or ground mounted). Although pipework from the collectors will normally have to run through the loft space, this will not prevent you using your loft.

Q. How does a solar hot water system integrate with my existing heating system?

In the UK a solar hot water system can never be the sole provider of hot water as there is simply insufficient sunshine in the winter months to heat water to the required temperature and you therefore need to have a conventional water heating system as well, such as a gas, oil or wood fired boiler (or even just a back-boiler on a wood stove). This is required to top up the heat from the solar system when necessary and to provide hot water and space heating in the winter. You can add a solar hot water system to most existing hot water systems, although you will usually have to change your existing hot water cylinder to a twin coil cylinder (to allow for water heating from the solar system and from the conventional boiler) or, as an alternative, add an additional water cylinder to pre-heat the water from the solar system to feed into the original cylinder. You will also need a pump to circulate the water around the solar system and some regulating equipment to prevent overheating.

Q. Will a solar hot water system work with a combi boiler?

Combi boilers take water direct from the mains and provide instantaneous water and space heating without the need for a hot water storage cylinder and most combi boilers are not designed to take pre-heated water from a solar system. Connecting a solar system, although not impossible, can present some problems and it is always recommended that the householder checks with the manufacturer of the combi boiler to establish if it can be used with a solar hot water system. Generally there will be an increase in cost for installing a solar hot water system with a combi boiler. All solar systems require a hot water storage cylinder.

Q. Do I need a new hot water cylinder to install solar hot water, and if so, how big does it need to be?

In the majority of solar hot water installations the existing hot water cylinder (where the heating is from a conventional boiler or possibly an immersion heater) is replaced with a new twin-coil cylinder so that the water it contains can be heated by the solar system and by the conventional boiler when that is required as a back-up (e.g. in the winter months). The twin-coil cylinders are generally taller than a normal cylinder so you will need to have sufficient space (usually in an airing cupboard) to house it. An alternative is to fit a new ‘pre-heat’ dedicated solar cylinder alongside the existing cylinder though this will require more space and is also considered to be slightly less efficient than using just one cylinder.

Q. Do I need to have a new boiler for the installation of my solar hot water system?

This is purely dependent on the age and condition of your existing boiler and, in most cases, a new boiler is not required. However, if the boiler is old, it is likely that it will not be working very efficiently and a replacement with a modern efficient boiler would be recommended. In any case you will need to have modern thermostatic and timer controls for the boiler in order to qualify for the government grant. An assessment of your property will determine if you require a new boiler.

Q. How much will a solar hot water system cost?

Tesco sell 3 types of system and they cost

System                                Price                 Price after LCBP Grant (if applicable)

703 kW                                £3899                              £3499
1309 kW                              £4399                              £3999
2052 kW                              £5399                              £4999

All prices are subject to survey and may involve extra charges.

Q. Can I get a grant for installing a solar hot water system?

Yes, currently there is a grant of £400 available through the government’s Low Carbon Building Programme. However, in order to qualify for the grant, you must have installed certain energy efficiency measures into your home. This ensures that energy use is minimised prior to installing solar hot water, to enable the most efficient use of the technology. The measures required are loft insulation, to meet current building regulations e.g. 270mm (approx 11”) of mineral wool or suitable alternative, cavity wall insulation (if you have cavity walls),low energy light bulbs in all appropriate light fittings and basic controls for your heating system to include a room thermostat and a programmer or timer.

Q. Who applies for the grant?

The homeowner would need to apply for the grant. Individuals who own their own home and reside within England, Wales, Northern Ireland or Scotland (excluding the Isle of Man and the Channel Islands) can all apply.

Q. How much money will a solar hot water system save?

This is dependent on a number of factors, especially the size of the system installed and the type of fuel that traditionally heated your water but savings can be up to £170 per year.

Q. Is planning permission required to install a solar hot water system?

Most domestic properties do not require planning permission provided the solar collectors do not project more than 200mm above the surface of the roof covering and do not project above the ridge of the roof. However, you may need permission if the panels are of an unusual design, they project significantly beyond the roof slope, or your house is a listed building or is situated in a National Park, an Area of Outstanding Natural Beauty or in a conservation area.

Q. Who will install the system?

We only use fully MCS (Microgeneration Certification Scheme) accredited installers for the installation of solar hot water and solar electricity systems. The Microgeneration Certification Scheme is an independent scheme that certifies microgeneration products and installers in accordance with consistent standards and is designed to evaluate microgeneration products and installers against robust criteria providing greater protection for consumers. An MCS approved installer must be used in order for the householder to qualify for the government grant. See the following website for further information http://www.microgenerationcertification.org

Q. How long does it take to install a solar hot water system?

Depending on the size and type of system and the number of people employed, the installation can take between 1 and 2 days to complete.

Q. How long will the solar hot water system last and what are the guarantee periods?

The expected lifetime of a solar hot water system is at least 20-25 years. All solar collectors are guaranteed for 10 years, cylinders for 5 years and all other parts and labour for 2 years.

Q. What maintenance is required to the solar hot water system?

A well installed solar hot water system should only require servicing by an accredited installer at 3-5 year intervals although it may be advisable to couple this on a more regular basis with the general servicing requirements of your boiler. During the lifetime of the system (approx 25 years) it is possible that some minor components may need to be replaced (e.g. the pump) but these are not of significant cost.

Q. Can I use a solar hot water system to provide space heating for my home?

The systems currently on offer under Tesco Renewable Energy will not be sufficient to provide space heating on their own, however it is possible to expand the system in the future to meet the higher demands and a technical assessment would be required to make sure your property is suitable.
There is 5 times more sun energy in the warmest months of summer than in the coldest months of winter and the majority of the energy received is during the period April to September so current systems would be insufficient to be used for space heating when required in the winter months.

Q. Will a solar hot water system work in the UK, and will it work during the winter?

Many parts of the UK have annual solar radiation levels equal to 60% of those experienced at the equator, and this means a solar hot water system in the UK can produce up to 70% of the annual hot water requirements for an average household. Most of the sun’s radiation will be received over the period of April – September when a solar hot water system can produce up to 100% of the hot water required within a household, but a system can still provide some useful hot water even on overcast days during the winter months.

Q. If my house is not south facing can I have split panels, one of front and one on back?

Yes, you would simply have a larger system. It may be twice the cost though of a conventional system.

Q. Can I have panels on my garage?

If the garage is within 25 metres of the property then this will be possible. However, it is always best to have the shortest distance between the collector and the tank as possible.