Advice advocated by the Local Government Energy Doctor’s scheme

(Note that this scheme is no longer taking applications.)

Low-Cost Easy Retrofit Resource Efficiency (or Cheaper Easy Solutions)

Measures include:

• Electric heated throws
• Draught proofing windows, doors, letterboxes, and chimneys
• Hot water cylinder insulation jackets
• Reflective radiator panels
• Secondary glazing film
• Portable solar generators
• Electricity consumption monitors
• Thermometer cards
• LED lights
• Smart plugs
• Water saving measures including:
  • Shower timers
  • Aerating shower heads
  • Toilet cistern bags

General Advice, from the Marlow Energy Team

• Assess the needs of your home’s occupants.

Everyone’s level of warmth and comfort is different, and temperatures around the house will depend on the external weather. How warm you feel will also depend on how active you are. If you are busy and moving around you are less likely to feel the cold, but if you sit still reading, watching TV, or working, you may feel colder after a while.

Windy days are likely to increase the penetration of draughts into your living space and sometimes make it hard for heating systems to maintain adequate temperatures. Older or more sedentary folks may need higher temperatures or more blankets than younger, more active folks.

• Keep your body warm rather than heating the whole house.

Wearing several, thinner, layers of clothing may be more effective than one thick layer. Training your children to wear adequate clothing inside in winter can also save on energy bills! If you are sitting still for a longer period, use a blanket or an electrically heated throw. In some cases, radiant heaters may be more energy-efficient than convector heaters.

• Concentrate heat in spaces you use.

Use doors, radiator valves, thermostatic valves, or heaters to heat the rooms you are using rather than the whole house.

• Remember that electricity costs more than gas for heating (unless you are using a heat pump).

At the moment, in the UK, gas is the cheapest fuel to heat a house. Electricity costs are 3 to 4 times the cost per kWh of energy. So, if you use grid electricity directly for heat, it will cost you more than gas.

However, sometimes heating one room with electricity is cheaper than using gas to run a heating system for the whole house. An energy monitor is available from energy supply companies on request. It is digitally connected to a Smart Energy Meter which the supply company will fit to your electricity and gas supply. With smart gas and electricity meters a monitor can help you work out when you are using gas and electricity and how much you are using at any time of the day. This can help you to decide how best to manage your energy use.

• Exclude draughts.

Keeping windows closed and draughts out are easy and practical first steps in heat management. Most older UK built, houses are draughty. Windows with “trickle vents” can cause draughts. Whilst trickle vents are a good idea in summer and help maintain necessary ventilation all year round, they can cause significant energy leaks in windy or very cold weather.

To reduce energy loss, it is helpful to draught-proof windows, doors, letterboxes, and chimneys. Using your hands to feel for draughts around doors, windows and letter boxes is a simple and effective way of tracking down significant draughts. There are now companies who can undertake tests which are more definitive, at a cost. Cheap temporary improvements can be made using draught- excluding tapes over gaps and secondary glazing film (plastic sheet) over single- glazed windows. Simple draught excluders under doors and in letter boxes can also help. An open chimney flue can cause significant draughts in a room with a fire place and no fire. Chimney balloons or chimney sheep are a reasonably simple, low-cost method of blocking a flue to stop the draught from an open chimney. They are readily removed and must be removed before lighting a fire! Look online or in DIY stores for all of these items.

Maintain necessary ventilation

• As draughts are excluded and windows and vents shut to save heat energy, it is important to ensure adequate ventilation is maintained. Gas boilers and fires require a source of outside air and should be fitted near an open vent. Carbon monoxide is a poison that can build up if gases from boilers and fires are not exhausted from the house. Fit a carbon monoxide alarm near gas boilers or fires.
• Build-up of moisture in the home is also a problem and can lead to mould if allowed to continue. People, pets, washing, drying clothes and cooking all generate steam or water vapour which increases moisture within the home. Moisture alarms are available to buy. Occasional window opening for a brief period during the warmer parts of the day can help reduce moisture build up without losing large amounts of energy, especially for kitchens and bathrooms. External humidity is high during rain, fog and mist and is not a good time to open windows to reduce moisture. External humidity meters help to determine when to open windows.

Insulate your loft

• The majority of heat loss from a poorly insulated house is through the roof. The UK Government advises that a minimum of 270mm of mineral wool or fibreglass should be used in lofts. Check how deep your insulation is and build it up to 270mm or 300mm. This is not a very expensive upgrade and can pay for itself in a few years by cutting heat energy bills from the moment it is installed. Most UK homes have been built with naturally ventilated roof spaces so concentrate on insulating the ceilings of the living space below the loft. Sealing the loft space and insulating the underside of the roof should only be undertaken in special circumstances. If in doubt, ask a professional, as some unscrupulous insulating companies have been known to cause serious problems to householders by applying insulation in a way which can damage the property or cause problems with mortgage lenders.

• When insulating loft space make sure water pipes in the loft, or outside insulated walls, are properly lagged to prevent freezing.

Update your heating controls

• Management of heating controls is vital to good energy performance. This could be as simple as checking the programming to ensure set temperatures make sense and on/off times match your lifestyle. Why heat your house whilst you are out when frost protection is all that is required?

• Install thermostatic radiator valves and set them to suit the room use. Modern control systems are now available that can be adjusted using phone apps for families with variable heat demands. When coupled with Wi-Fi controlled radiator valves, different rooms can be set to heat at different times, e.g. switch off bedroom heating during the daytime. If you do choose not to heat a room, remember to shut the door so that it doesn’t draw heat from the rest of the house.

Check insulating efficiency of windows, walls, doors, and floors.

• Where possible replace single glazed windows and old draughty frames. Drawing curtains closed as temperatures drop, e.g. in the evening, will reduce energy loss through the windows they cover. Insulated (heavily lined) curtains or blinds can help reduce heat loss more than unlined curtains when drawn. Replacement windows with double glazed glass units with thermally insulated window frames will reduce heat loss but are more effective when sealed well between the frame and brickwork. Secondary double glazing is a possible solution for complex windows or listed buildings.

• Heat loss through walls can be a significant problem, particularly in older houses which were built without cavity walls. Cavity walls grew in popularity from the late 19^th Century / 1920s but were rarely insulated until the 1970s. Insulated cavities were compulsory in the UK for new builds across the UK from the 1990s. Some homes have been retrofitted with blown cavity wall insulation, but in some cases the insulation blown in has deteriorated, causing loss of insulation, or damp. Internal or external wall insulation is being used more commonly now, especially for houses with solid walls, but this must be carried out by reputable companies and can be expensive.

Details of insulation required for new builds or renovations are available in Building Regulations and on some UK Planning Portals.

Underfloor insulation has been required in new builds since 1976 in the UK. Retrofitting underfloor insulation is frequently expensive but can be done as part of a general renovation and is required if more than 25% of a floor is renovated.

Smart or intelligent meters can be fitted to your gas and electricity supplies. Energy supply company regulations mean the company has to provide a householder with a smart meter if requested, by the householder, to do so. Energy supply companies vary in how quickly they will fit a Smart Meter. The Smart Meter means the supply company can monitor consumption via internet and should be able to bill more accurately. The Smart Meter provides the householder with better information on energy use and provides access to advantageous energy tariffs. A Dumb Meter is one which must be read by the householder, or by an employee of the energy supply company by visiting the meter and making a reading.

*An Advanced Tariff is one that charges different prices for energy depending on the Time of Use. These tariffs can be applied to both energy used (Import) and energy generated (Export) based on consumption every 30 minutes.

How to save money with a smart meter

There are 3 ways to reduce your energy bill:

1. Use less energy (manage your usage using the displays, home insulation)
2. Pay less for the energy you import (Advanced Tariffs)
3. Generate your own energy (Solar Panels)

Or a combination of these (consuming electricity at expensive times of day after filling up batteries at cheaper times or from own generation).

What are heat pumps?

• Heat pumps are a means of heating your house or building using
  electricity rather than gas, LPG or oil.
• Heat pumps for residential houses are mainly Air Source Heat Pumps (ASHP), i.e. they draw heat from the air outside. ASHPs are cheaper to install than other types of heat pump and do not require a garden or water source.
• Ground Source Heat Pumps (GSHP) draw heat from under the ground, usually via a long pipe buried in a garden or field. The installation of this kind of heat pump is typically more expensive than an ASHP and will require a large trench or borehole to be dug near the house. In the long term a GSHP can cost less to run as ground temperatures do not drop in winter. A GSHP starts to become more efficient than an ASHP when air temperature drops below 10 °C. It is a marginal difference until air temperatures get much lower and that it is why the additional cost of a GSHP is only recovered over a long period of time. Also, for a large system, a GSHP may recover additional cost more quickly.
• For properties near a lake, river or other water course, heat pumps can also be designed to draw heat from that water source. Permission may be required from the Environment Agency.
• An ASHP works in the same way as your refrigerator, only in reverse. It takes heat out of the air and brings it into the house. The heat pump used in a fridge takes heat out of the fridge or freezer and emits into the room the fridge or freezer is in.
• A heat pump is literally a pump that pumps, or compresses, a refrigerant through a radiator and around a circuit. Air blown through the ASHP’s radiator heats up cold refrigerant before it is compressed. The refrigerant warms further as it is compressed and the heat is then transferred from the hot refrigerant to the water used to circulate in the heating system of the house. The cooled refrigerant is depressurised, expanding and cooling the refrigerant further, before it returns to the radiator to be heated again by external air. Most domestic ASHPs can extract heat from ambient air at very low temperatures, but most systems are designed to maintain house temperatures as long as the outside temperature is above minus 20 °C.
• If you live in an area which sees temperatures of -20 °C regularly, or is prone to lengthy power cuts, it may be helpful to have a backup heating system e.g. wood burning stove or fireplace. Electric radiators or fan heaters will not help in a power cut.

Why are UK Households being encouraged to switch to using heat pumps for building heating?

• This is part of trying to make the UK a greener, “Net Zero” carbon economy and would make a large contribution to lowering the carbon footprint of the country if heat pumps become the main source of home heating.
• It reduces the UK’s dependence on fossil fuels and reduces the UK’s exposure to the volatility of fossil fuel (gas and oil) prices.
• By reducing our dependence on overseas gas (usually from Russia, the Middle East or Asia, in the form of Liquified Natural Gas (LPG)) our energy security is improved.
• As the UK electricity grid is decarbonised by using more renewables and nuclear power the carbon emissions from home heating will reduce further and become the costs less volatile.
• Once the investment is made in renewables the ongoing costs of energy for the UK are very low, as the renewable energy is free (wind and solar power). We will only have to pay to maintain the renewable generators and the distribution system (the National Grid). Fossil fuel power requires a continuing investment in fuel (oil and gas) for each kW of electricity generated, as well as the maintenance costs.

Why would a householder consider converting to a heat pump heating system?

• Heat pumps are more than 3 to 5 times more energy efficient than
  traditional gas boilers, depending on ambient air temperature, meaning they’ll substantially reduce the carbon footprint of your home. The reduction in carbon footprint has increased as the UK electricity grid uses more renewable and nuclear energy and is likely to increase further with time as more renewables and nuclear energy comes on line.
• A properly designed heat pump heating system in a reasonably well
  insulated house can save significant money against an oil, or LPG based heating systems, and, to a lesser degree, against a condensing, gas boiler heating system. If you have an older or non-condensing gas boiler, they are less efficient than the condensing gas boiler, so you will save more money.
• As heat pumps run on electricity, so there is potential to make higher bill savings by using smart energy tariffs, with cheaper off-peak rates, e.g. Octopus Cosy Homes, or by using energy from your home solar panels, if you have any.
• The government is offering a grant of £7,500 in England and Wales to help cover the cost of installation, as long as the installation replaces a fossil fuel heating system (gas or oil) and the installer is MCS registered. Check the detailed requirements of the Boiler Upgrade Scheme grant. It is not clear how long this support will continue to be available.
• The UK Government has recently introduced an increased grant of £9,000 for households changing from oil or LPG-based heating systems to heat pump-based heating systems.
• There are also grants available for air-to-air heat pump systems suitable for some apartments.
• Heat pumps are used in many parts of Europe where winter temperatures are colder for longer than the UK, and they have been used successfully in Scandinavia for many years. The technology is thoroughly tried and tested.
• If you have an old gas or oil boiler which is likely to require replacing soon, it is a good time to consider moving to a heat pump. Avoiding the cost of gas boiler replacement can justify part of the cost of changing to a heat pump system.
• Although a heat pump is far more efficient than a gas or oil boiler, in terms of kWh of heat it provides to your house per kWh of electricity, gas or oil consumed, a kWh of electricity in the UK is around 3.3 times (autumn 2026) more than the cost of a kWh of gas. Therefore, operating a heat pump will only produce marginal savings in heating costs on standard variable rate electricity tariffs, and may not reduce your energy bill for heating at all if the
  house is poorly insulated. However, the UK government has indicated that it will reduce electricity costs per kWh and heat pump electricity tariffs are available which can save additional money by using cheap electricity at off-peak times.
• ASHP efficiency reduces as ambient air temperature reduces, or as it is required to heat the circulating water to higher temperatures, but it should maintain and efficiency better than 3 kWh heat per 1 kWh or electricity. A modern condensing gas boiler will produce around 0.9 kWh of heat in the house for each kWh of gas burnt. Older or non-condensing gas boilers have much lower efficiencies.
• If your home does not require gas for anything else your gas supply will be disconnected saving you the daily charge for being connected to the gas grid.
• If your internal hot water / radiator system operates using micro-bore piping it may not be suitable for converting to a heat pump-based system. (Most systems run on 15 mm diameter piping, which is fine for a heat pump system).
• Check that the quote you receive indicates the ASHP to be used, guarantees offered and the heat pump’s coefficient of performance (COP). This is a measure of efficiency (kWh electricity consumed to provide a kWh of heat). The higher the COP the lower the running cost. But like car mileage figures, COP is measured in a standard set of “laboratory” conditions. In reality COP or efficiency will be lower. Installers should also be able to give you a “Seasonal Coefficient of Performance” (SCOP). This is corrected for a
  theoretical set of seasonal variations in ambient air temperature. It should be a more realistic measure of average efficiency over a whole year. Again, it is a theoretical assessment and in practice performance is unlikely to be quite as high.

How would a homeowner go about investigating the cost of a heat pump heating system?

• There are many sources of online advice, but consider the vested interest concerned with many online sources of information, and check several sources focused on the situation in the UK to ensure that the advice is relevant to our weather, our energy prices, our electrical systems and our government support.
• We recommend that only MCS qualified installers are used as the
  accreditation requires that the installer carries out design calculations using safe, conservative assumptions, carries adequate insurance for guarantees and an MCS installer is a requirement for UK Government Boiler Upgrade grants. MCS installers can be identified through the MCS website.
• An MCS qualified installer will usually provide an initial estimate based on information you can provide about your house, e.g. address, number of rooms, levels of insulation etc. Installers will usually advertise their MCS Accreditation on their website.
• Check the references of local MCS installers and select ones which appear to give the service you require. Initial estimates can lead to
  conversations which will allow many of your questions to be answered and help select your preferred installer.
• To move on to having a survey and an accurate estimate for your house may require some expenditure on the survey work. It is therefore helpful if you have established which installer appears to be the one you can best work with at this stage. If not, you may end up paying for more than one survey.
• To get a final and accurate quote an installation in your house the
  installer should survey the house to check number and size of radiators, size of rooms, the heat retaining properties of the house (insulation, windows, doors etc) and potential external locations for the ASHP. The installer will also check what space is required inside and outside, for the equipment required with the heat pump system. Usually, an interior cupboard is required for a hot water tank and the various controls the heat pump requires. The heat pump sits outside, and planning constraints help determine where it can go without the need for planning permission.
• Most installers will charge a few hundred pounds for the survey and updated quote. A survey is currently costing in the order of £300 to £350 and is usually treated as a first payment for the quoted price of the system.
• This is usually deductible from the quoted price. Some still offer free surveys. The survey fee may or may not provide an Energy Performance Certificate and may or may not be refundable if you decide not to go ahead with the installation. Check before buying.
• Installers generally do not take responsibility for planning compliance. That is usually the householder’s responsibility. Installing a heat pump at most houses is a “Permitted Development” depending on where the heat pump will be located. This means that provided the installation meets the requirements of Permitted Developments no planning permission is required. Planning permission can be required for certain installations,
  e.g. in protected areas, or non-standard installations. Buckinghamshire Planning control has an automated system which allows you to check if your installation is likely to be a “permitted development” or one which requires a planning application.
• The installer is required to undertake noise calculations to check that noise levels at any neighbours nearest window (in a bedroom or living room) are not high enough to cause a nuisance. Hence the position of the heat pump, the distance to the neighbour’s relevant window and the noise emitted by the particular heat pump used are all important considerations. Generally, a heat pump produces a similar level of noise to a kitchen refrigerator. If it is likely to disturb your neighbour, it may be possible to install noise reducing fencing or features near the heat pumps to reduce the noise transmitted.
• A heat pump does produce a small amount of condensed water and
  therefore it will be necessary to allow a drain to drop condensate from the heat pump. This is only ever likely to be a few drops of pure water, similar to the amount of condensate dropped by a car AC system.
• Heat pumps are generally mounted on the ground but can be mounted on wall brackets if necessary. Vibration is a potential challenge for wall mounted units to check with your installer that suitable antivibration mounts are used.
• The installer will look for a site as close as reasonably possible to your boiler, so that they can easily connect to the boiler hot water system without excessive pipe runs or extra work. It may not always be possible or desirable to provide a site for the heat pump with the shortest pipe run.
• Bucks’s Planning Checker asks about the volume of the heat pump. Less than 1.5 m3. Most heat pumps comply unless the house heat demand is particularly large. We understand this requirement has been relaxed in national planning regulation in favour of low noise impacts. Bucks may update their requirements in due course.
• Check that your quote includes the full design, the heat pump, the heat pump base, all piping and cabling, a suitable control system, hot water tank and any radiators which require to be upgraded to provide adequate heat in all rooms. It is quite likely that some of the existing radiators do not require replacement as they are large enough.
• There are several control systems on the market and installers tend to have favourite systems which work with their designs or the heat pumps they are suggesting. Make sure you are comfortable with the system being offered to you and the training and help the installer will provide to make sure you can use it to get the performance you require from the system.
• Check how much post-installation support is included in the quoted price and how much your installer charges for follow on maintenance. As with gas boilers, an ASHP system benefits from regular maintenance to ensure it is cleaned (of leaves and airborne deposits) as well as lubricated, full of clean refrigerant and adjusted to stay efficient and reliable.

How would a heat pump work once installed?

• A heat pump will dramatically reduce carbon dioxide emission or the carbon footprint of the house, as electricity is increasingly being produced from non-fossil fuel sources, e.g. wind, solar and nuclear power.
• A heat pump is frequently used to supply hot water to an existing circulating water-based central heating system in the house. Typically, these systems heat rooms via wall-mounted radiators or underfloor heating, or heating hot water in a hot water tank. Underfloor heating is ideal for a heat pump as it requires lower temperature hot water (40 to 50 °C).
• Heat pumps can be used to supply heat to hot air systems which blow warm air around the house or mechanically ventilated heat recovery systems (MVHR). Each internal heat distribution system requires a variation in the choice or heat pump and how it is used.
• A modern heat pump can supply heat at the same temperature as a gas boiler, but when it is used to create high-temperature water (60 to 70 °C as a gas boiler does) it is less efficient than when it creates hot water at 40 to 50 °C. Therefore, the design is usually based on using these lower temperatures unless extreme winter temperatures require hotter circulating water for a period.
• In order to get optimum efficiency and lower heating bills, it is sometimes necessary to upgrade or enlarge some of the radiators in a house, to provide extra heat transfer area. This allows circulating water at lower temperatures (40 to 50 °C) to provide the heat necessary to maintain the house at the desired temperature. Extremely low external temperatures may require the heat pump to increase the temperature of the water it circulates for the period of the cold snap. Your installer should design the system to cope with all UK weather conditions and to run at optimum energy efficiency over the whole year.
• Because the hot water from a heat pump is not generally as hot as hot water from a gas boiler, it may take longer for a heat pump system to respond to sudden temperature drops of when you first put the heating system on. For this reason, heat pump controls are usually upgraded to take account of external temperatures automatically and can often be switched on remotely if, for instance, you are returning from a holiday. It is also generally recommended to keep the system running through the night to maintain the temperature of the house, rather than to switch it off, allowing the house to cool, before reheating in the morning. By maintaining the house temperature around the clock, the ASHP can continue to operate at its maximum efficiency and take advantage of off-peak electricity.
• The lower circulating temperature is usually not a problem for hot water within the house, as the heat pump circulating water temperature is much hotter than the temperature of water required to wash safely. It may take slightly longer for the hot water tank to regain its set temperature if you have used all of the stored hot water.
• For a heat pumped system to perform well, the house needs to meet a minimum level of insulation to retain the heat that is produced. Hence, ventilating the house to change the air and manage moisture inside the house should be carried out short bursts in winter, rather than leaving windows or doors open for long periods. This practice is common throughout Europe and Scandinavia.
• Opinions vary, but at current gas and electricity prices a well-designed heat pump system in a reasonably well insulated house will cost a similar amount or slightly less in a year to run than a condensing gas boiler-based system. By using one of the cheap heat pump electricity tariffs now available a heat pump can save several hundred pounds a year. If electricity prices continue to fall relative to gas prices this saving should increase.
• However, even with current government incentives, replacing a gas boiler with a heat pump is still likely to cost several thousand pounds and it may take several years to pay back the money spent on the installation.
• If a heat pump system is not possible for your house, make sure that you are using a condensing, gas boiler and not setting the flow temperature too high. A condensing gas boiler is far more efficient at turning gas into heat than an older style (non-condensing) boiler. A modern condensing boiler can be 90 to 98% efficient, whereas on old non-condensing boiler might be 70 to 80% efficient, with some as low as 55% efficient. Hence, they should save 10% to 40% or more of your gas bill depending on how old and inefficient your old boiler is.
• If you are keeping your gas boiler or oil-fired boiler, make sure you have your boiler serviced regularly, at least annually, by a qualified gas safe plumber or engineer. Minor checks and adjustments at the service keep the boiler safe and ensure it is running as efficiently as possible.
• If you have a gas or oil boiler in your house it is important to make sure it is adequately ventilated and that you have a working carbon monoxide detector. A noisy boiler or a flickering yellow pilot light may indicate that maintenance is required for safety and efficiency.

Differences in Heat Pumps

• Heat pumps are built to a range of different designs in many countries including Europe and the UK.
• Each heat pump manufacturer produces a range of heat pump sizes to suite different houses and different heat demands.
• Different heat pumps use different refrigerants and are designed and built specifically for the refrigerant they use. Each refrigerant has a different “global warming potential”, GWP. The GWP is the amount of warming caused by release of the refrigerant into the atmosphere. The choice of refrigerant is a complex balance between safety, efficiency, cost and global warming potential. The best refrigerant from the point of view of GWP is the one with the lowest GWP. Currently the lowest generally available is R290 which has a GWP of 3.
  • Some older refrigerants have GWPs of 76 (R123), 670 (R32) or 1800 (R22) some are higher still. R290 is a hydrocarbon (propane). All refrigerants will eventually leak or need to be replaced. If replaced responsibly escape to atmosphere is minimised, but manufacture of refrigerants and their use does impact global warming hence the lower the GWP the better. Ammonia has a GWP of 1 and its use is being considered. However, it is not currently in use for most domestic ASHPs.
• Generally, heat pumps produce a similar amount of noise as a large refrigerator, but it is placed outside and can therefore impact noise outside the house or entering through nearby windows. Hence planning regulation in the UK require installers to undertake noise calculations to ensure that noise levels at a neighbour’s window is acceptable. This is the openable window of a room which is counted as a living room e.g. living room or bedroom, not a kitchen.
• The ASHP compressor noise varies according to its design and how hard it is working, but most ASHPs are now fitted with significant noise insulation and vibration reducing fittings, to reduce emissions. Some are designed with quieter or slower fans and quieter pump motors.
• Different designs of ASHP vary in shape colour and external dimensions. Planning regulation on maximum size have recently been relaxed in favour of ensuring low noise at a neighbour’s window. (The planners seem to have understood that noise insulated ASHPs may be larger and have therefore amended the regulations to favour low noise over small size).

Why have a solar installation on your house

• Solar panels generate electricity from the sun. Energy from the sun is free. You just have to have the equipment to convert it to energy you can use. Each time you use a kWH of energy from gas or oil you must buy another kWH of gas or oil for the next kWH. You must continue to pay at whatever the current price is, as you use fossil fuel energy. Solar energy remains free.
• The complete solar installation is free of VAT in the UK at the time of writing. This includes any battery that is installed at the same time.
• Solar panels are getting cheaper and more efficient all the time, and many have 20 year or more guarantees. The installation may reduce in efficiency by 1 or 2% per year and will eventually need replacing. By then much more efficient equipment is likely to be available.
• Solar panels produce more electricity on clear days with sun and since we have longer sunnier days on the summer that is when you get most electricity from the panels. Solar panels will produce also electricity on cold winter days if they are sunny but for a shorter period as the daylight hours are shorter and the sun is lower in the sky.
• Solar panels produce maximum electricity in the middle of the day when the sun is highest, so it makes sense to think about having a battery to store the energy for use in the evening.
• South facing sloping roofs produce more solar energy but east and west facing roofs produce 80% of that energy. Even north facing roofs produce 50% of the energy.
• Roofs which are overshadowed by buildings or large trees will see less sun and therefore may not be the best roof for panels installations. Shadow becomes less of a challenge with new panel developments and by use of micro inverters. However, micro inverters can introduce a point of failure in the system which some installers will warn against.
• Flat roofs can be used for installations and are covered by planning rules. Usually, a mounting system is required to tilt the panels to the correct angle and ensure they are not damaged by wind.
• Standard sized panels approximately (1.7m by 1.2m) can weigh over 20 kg each and mounting system also adds weight. Installers are supposed to review the roof structure to ensure it is strong enough to support the installation. If in doubt, ask for s structural engineer to review to structure.
• You can install solar panels in most roofs without planning permission as long as the installation fits within the parameters allowed for a “permitted development”. No planning permission is required for a Permitted Development. Permitted development for Renewable Energy on domestic residences is defined by the Town and Country Planning Act, Part 14. Most installers will understand this, but it is the homeowner’s responsibility to apply for planning permission if it is required. In Bucks the Planning Portal allows you to answer several questions online to determine if the development you are planning requires planning permission.
• If your building is listed, you are in a protected area or the installation does not fit the parameters allowed for permitted development, you may still get permission but may have to make a planning application.
• With the right equipment you can sell electricity you don’t use back to the grid.
• Solar thermal panels are still available and are the most efficient means of heating hot water using solar energy. However, they require a circulating hot water system to flow from the panels to your hot water tank. The plumbing can be hard to achieve depending on the layout of the house. Thermal panels can also be Permitted Developments.

Getting a Quote for a Solar Installation

• Most installers can give you a preliminary quote as long as they have your address. They look at satellite images and maps to check your roof, what space there is for panels, whether the roof is overshadowed, and the orientation.
• Prices can vary significantly and the equipment offered can also vary, so we recommend talking to at least 3 installers to see how the quotes vary and which installer you like best.
• We recommend that you deal with installers that are MCS (Microgeneration Certification System) accredited as the certification checks their capabilities and gives them rules to work by which help protect you from poor installations and exaggerated sales pitches.
• Check installer references to see if they are likely to give you the service and installation you want and will help you understand the design and use the system they provide.
• A solar installation is a significant purchase, so don’t be afraid to ask questions and get revised quotes where required. Make sure the price you finally agree provides all the equipment and services you require.
• Short list the quotes you have had and select the quote you are most comfortable with as the leading offer. You may have to pay a few hundred pounds for a physical survey or your property to ensure that the preliminary design and pricing suites your house. This is a good time to be available and to ask questions about layout etc.
• Following the survey check that your price includes any changes required by the survey.
• Some installers can access finance for installations but check any finance deal has reasonable interest rates and terms and conditions and is overseen by the FCA (Financial Conduct Authority).
• The District Network Operator (DNO) is the company that maintains the electricity grid in your area, and they need to give permission for a solar installation as it can affect the local grid. Most installers will handle the bureaucracy, will design your system to meet the DNO requirements and get approval on your behalf. It may take a few weeks to get approval. It is unsafe to proceed without DNO approval.
• Some companies used to install panels on home owners’ roofs and allow the home owners to use electricity generated. If you are considering a similar scheme, be aware that there were some significant problems with some contracts when it came to selling the house and possibly equity release schemes. Take legal advice.

Options to decide during the quote process

• The vast majority of panels and solar equipment installed in the UK domestic market is manufactured in China. It is possible to get European manufactured equipment, but it could be up to 30% more expensive. This is due to the scale of Chinese solar manufacturing reducing the price. Some installers have preferential supply agreements and training with particular suppliers. They may not be willing to buy equipment from others.
• European batteries and inverters are available, but components may still be manufactured in China.
• Check you are being offered equipment with good references and guarantees.
• There are subtle differences in the efficiencies of panels made by different manufacturers, the guarantees and UK support offered by the manufacturers.
• Panels are generally installed on existing roofs by fixing rails to the roof and mounting the panels on the rails. The rail is supported by metal hooks which pass under tiles to attach to the roof. Some installers suggest “notching” the tiles to allow the tiles to lie flatter after installing the hooks. It cost more but there is an argument to suggest it may reduce storm damage to the roof in the long term.
• Check the installer knows the type of tiles or roof you have and that they quote accordingly.
• Bird guards are available to prevent birds taking up residence under your solar panels. There are several types of guard, but they all block the gap between the panels and the tiles to stop ingress. If you want a guard, choose the type you want on your roof.
• On new builds or for visual reasons, panels can be set into the roof on trays. On new builds, or major renovations, this can save on tiles required. On existing roofs, tiles are removed to fit the trays and panels. The use of trays and cutting the tiles to suite is usually more expensive than mounting on rails above tiles.
• If you install a battery at the same time as solar panels your installer should ask if you want to maximise your own use of the solar electricity by charging your battery from the panels when power is available. Alternatively, you can maximise export of power to the grid.
• Devices can be purchased as part of a solar system, to use excess solar power to heat water if you have a hot water tank. The hierarchy of priorities of charging a battery, heating water or exporting to the grid can be set up with in the systems software during commissioning. It can also be adjusted later, if necessary.

Installation of Solar Systems

• The installation itself is usually done within one to three days for a home, depending on the size of the installation and the size of the team. Safety scaffolding is generally required for a roof installation. It will be erected before the solar installers come and taken down after they have finished. It might be in place for a week or more.
• The installation work will mainly take place on your roof and close to the incoming power supply and distribution board. Some access to the inside of your house may be needed to run wires to connect the system together, e.g. through the roof space.
• It is sensible to check your roof does not need repair before panels are installed. Access to the roof under the panels is more difficult and expensive once the panels are in place.
• If you choose to have battery installed at the same time as your panels, discuss the location of the battery and inverter installation with your installer. The installation will need to connect to incoming electricity equipment; inverters can issue a high-pitched hum when operating; batteries function better above 5 ⁰C and below 35 ⁰C, depending on make.
• Battery installations within the roof space are no longer recommended.
• Make sure they quote a fully inclusive price, you know what equipment you will get for the price quoted, meaningful guarantees and good quality equipment which has good reviews and guarantees. 
• Most systems come with a phone App these days. It is useful to have your installer show you how to use it. It should tell you how your system is working and help you understand how the seasons and weather effect its operation.
• Intelligent electricity meters are not a requirement for a solar installation, but they can help you to make the most of your system.
• Power suppliers are required to install intelligent metering if you request it. Some take longer than others.
• Intelligent metering can help you make the most of flexible tariffs or off-peak electricity pricing.

Maintenance of Solar Systems

Although panels are often guaranteed for 20 years or more, inverters tend to be guaranteed for 10 years. Hence be prepared to replace your inverter during the operating life of the panels to keep the system working.

Most installation self-clean during rain. The lower the angle of panel inclination the less efficient rain will be at cleaning it. Occasional cleaning can help improve panels efficiency if they are getting covered with leaves, dust or bird droppings. Most window cleaner with long window brushes will clean panels for a fee.

It seems that climate change has leapt ahead of global computer simulations to make Europe one of the fastest heating continents on the globe! The meteorologists are telling us this is the new reality!

So how should we manage? Heat stroke and deaths due to excessive heat or no laughing matter and although the young might find some of the heat great fun, the older you get the more of a toll it takes on your body and most of our houses are not designed with excess heat in mind! If you are concerned about the health effects of heat check NHS guidance.

• Before we all spend a fortune on installing or running air conditioning, passive means of keeping your house as cool can be very effective keeping temperatures inside around 5 0 C cooler than outside and may require no, or little investment and time to organise. Even if you have air conditioning, passive cooling will save a large amount of the energy used by AC.
• Insulation and draught proofing are as important in keeping a house cool in summer as they are in keeping it warm in winter. So, insulate over ceilings, walls and check that gaps around windows and window frames are sealed. Incorporating a reflective film into insulation will help reflect radiant heat entering in the summer or leaving in the winter.
• In recent heat waves the heat has built up over several days. Each day the lowest night temperature has been higher than the night before. The next day therefore gets hotter as the air and the fabric of your house starts from a higher temperature than the morning before. So, it is important to let the house cool as much as possible during the night, to reduce the temperature of walls, floors and furniture by using cooler, night air.
  Open whichever windows you can at night, whilst maintaining security. By opening windows on opposite sides of the house, and doors linking them, you can allow air to flow through the house, which is very effective at cooling. Some window catches allow the window to be locked whilst remaining partially open.
• In the morning keep curtains shut where the sun is going to shine in. Heating by the sun is called “solar gain” and can add a surprising amount of heat to the inside of a room, especially where windows face the sun. Great in the winter, but horrible in a heat wave.
• As the temperature of the air starts to rise outside, shut all windows and external doors to stop hot air coming in. In a heat wave the outside air temperature in the shade is likely to exceed internal temperatures by around 9 or 10 a.m.
• As the day progresses the sun tracks from east to west and it therefore helps to change which curtains are drawn, e.g. close west facing curtains after around 1 p.m. It’s easy to check by looking at how the shadows are cast. Opening east facing curtains in the afternoon will let light in.
• North facing windows will not be impacted by the sun and therefore curtains can open to allow light in.
• Heavy, thermal, curtains or blinds reduce heat gain better than lighter curtains.
• Some rooms will inevitably get hotter than others so try to make sure you shut doors between hot rooms and the rest of the house and use rooms which are cooler when possible.
• Fans can be helpful, as long as the air temperature is less than 37 °C, but remember that they cool your body, not the room. Perspiration is the body’s natural air conditioning system. The body produces perspiration which takes heat from the body as it evaporates. Fans work by providing a stream of air which helps evaporation of perspiration. Its only worth using energy for a fan which is directing air at the person to be cooled. Switch them off when not in the room.
• Fans become less effective as air temperatures approach body temperature, i.e. 37 °C. Above body temperature they may even increase body temperature which may lead to heat stroke.
• In the longer term, reflective, external window covers are the best option as they stop the sun’s energy before it passes through the glass of the window, some estimates suggest they are twice as effective as internal curtains or shutters. However, purpose built external shutters are expensive to retrofit to a house.
• External awnings will help reduce solar gain, especially on south facing windows. Awnings work best when the sun is high in the sky. In the early morning and late afternoon, the sun dips below the awning allowing the sun to impact the window directly and cause significant solar gain.
• Reflective window films can be applied to the outside of a window and are claimed to cut solar gain by up to 80%. There are DIY versions of film which are not too expensive, but references suggest varied results, which may only last for weeks or a few months. There are professionally applied films which offer guarantees of up to 10 years if applied by an authorised contractor.
• If you are replacing windows, you can buy double or triple glazing with glass and film treatments which minimise solar gain, e.g. Low E glass and argon fill. Double glazed windows do reduce solar gain better than single glazing and triple glazing helps reduce it more.

The best solution for you will depend on your house, its position, the position, size and type of windows as well as your tastes and budget. Internal and external (shaded) temperature gauges or a weather station can help you to decide when to open and close the windows to maintain minimum internal temperatures.

Marlow Energy has compiled a list of non-commercial organisations that offer advice and information to householders to reduce energy use and save money.

• Energy Saving Trust (EST)
• National Energy Foundation (NEF)
• Local Authority Delivery (LAD2)
• Centre for Alternative Technology (CAT)
• Gov.UK Find ways to save energy in your home
• DraughtBusters Reading

The list below is of organisations that offer grants which may save energy use, CO2 emissions, and money! Check the qualifications required in each case, as some grants and support are only open to householders on income support.

• Energy Saving Trust

• National Energy Foundation, Green Homes Grant LAD

• Government funded schemes, domestic retrofit

• Warmworks Green Home Grants

• ECO (Energy Company Obligation)

• Warm Home Discount

See the Citizens Advice page. MCS Certification covers most of the low carbon technologies available for homes.