Environmental Information and Papers

Air source heat pumps – the basics

With the government’s Future Home Standards set to come into force in 2028, most new homes will need to be equipped with heat pumps. What about existing homes – is it worth retrofitting and what are the pros and cons?

How do they work?
An air source heat pump looks like an air conditioning unit and generally sits on the ground outside the home. Heat is extracted from the outside air and turned into heat through compression, essentially working like a refrigerator in reverse.

Air versus ground source heat pump
A ground source heat pump is more efficient, but requires significant work to install pipes buried in trenches or deep boreholes which absorb low-grade heat from the ground. An air source heat pump can be plumbed into the existing central heating pipework without the need for much external work. As a result, an air source heat pump is around three to five times cheaper than a ground source system (£11,000 versus up to £57,000) (1).

Efficiency advantage versus the higher cost of electricity
While the most efficient condensing gas boiler achieves 98% efficiency (2), an air source heat pump can convert energy into as much as 300 to 400% the amount of heat. However, the cost of electricity in the UK is currently around four times higher than gas on a per kWh basis (3), which represents one of the highest electricity-to-gas cost ratios in Europe. With this in mind, the operating economics are not clearcut. The Energy Saving Trust calculates annual savings of £260 compared to an old G-rated gas boiler or £40 compared to a modern A-rated boiler (1).

What about the installation cost?
It is more expensive to install an air source heat pump versus a gas boiler today, which reflects not only greater complexity, but the lack of competition especially in terms installers. While heat pumps account for over 90% of new heating installation in Sweden (busting the myth that heat pumps do not work in cold climates), the UK installed only 125,000 units in 2025 compared to 1.5 million gas boilers typically installed in any given year. To offset the cost disadvantage, the UK government is currently offering a £7,500 grant towards the replacement of a fossil-based heating system with a heat pump. According to the Energy Saving Trust, it costs around £11,000 to install a system in a typical house (3). Replacing an existing combi boiler can cost as little as £2,500.

Are heat pumps really better for the planet?
Many question the real environmental benefits, as fossil fuels are burned to generate electricity. The good news is that over the past 20 years the UK’s grid has made remarkable progress in decarbonising. Back in 1990, two thirds of our electricity was generated by burning coal (4). Today, coal has entirely disappeared from the UK’s energy mix; in this regard we are way ahead of the Germans or Americans. Last year, renewable energy, as defined by wind (30%) and solar (7%), accounted for a total of 37% of the UK’s mix, ahead of gas (27%) and nuclear (12%). The balance came from imports (15%), biomass (7%) – which is the burning of wood (5) – hydro (1.6%) and storage (1.6%) (6).

While a gas boiler consumes 100% fossil fuel, only 27% of an air source heat pump’s input energy in 2025 was fossil fuel based. Octopus Energy has calculated that on average an air source heat pump emits 83% less CO2 than a gas boiler (7). There is also the added benefit of zero air pollution on a local level!

References
1 Energy Saving Trust: Heat pumps: how they work, costs and savings
2 Future Heat: Boiler guides – 7 Most Efficient Combi Boilers in the UK 2025
3 Ofgem: Energy Cap Explained
4 Department for Energy Security & Net Zero: UK Electricity capacity and generation by fuel between 1920 and 2020
5 the official government statistics include biomass under renewables. We have only included wind and solar as the supply of wood is limited and what is burned today will take decades to grow back
6 NESO: Britain’s Energy Explained: 2025 Review
7 Octopus Energy: Are Heat Pumps better than Gas Boilers?

Air source heat pumps – do they work in an older home?

A Wimbledon case study

In late 2021, a local resident replaced a condensing boiler with an air source heat pump in a 250m2 semi-detached Edwardian home, built in 1904 with uninsulated solid walls. The roof had been insulated and all windows had already been replaced with double glazed units, but this home was far from being as energy efficient as a typical new build.

Installation costs
The cost for the 14-kW heat pump installation amounted to £12,860 and including the £3,666 cost to replace the radiators the total reached £16,526. At the time, the government grant amounted to £5,000. The gas hob was also replaced, allowing the property to be disconnected from the gas grid and saving the standing charge on gas (£106 per year).

Operating costs – roughly similar
During the last full year operating with gas (2020), the home consumed 17,680 kWh of gas and 2,124 kWh of electricity, which at today’s energy prices (April 1-June 30 Ofgem price cap) would cost £1,854.

Since 2022 (the first year operating the home only on electricity), total electricity consumption for the entire home ranged between 6,687 kWh and 7,771 kWh. Taking the average level at today’s electricity price yields an annual electricity cost of £1,979 (the actual costs are lower as the benefits from the solar system have not been taken into account).

Taking the consumption of the heat pump alone (both space heating and hot water), the annual cost during these four years averaged £1,112. This compares to £1,121 for all gas purchased in 2020 (which also included the old gas hob).

Costs aside – what is the experience of living with a heat pump?
Compared to a gas boiler system, the radiators do not get as hot (60-75°C) being typically around 35-45°C. Whereas the boiler can cycle on and off, the heat pump is most efficient when running for longer periods. During typical British cold weather days with temperatures just above zero, the unit is relatively efficient. However, on days with temperatures dipping considerably below zero, daily electricity consumption can reach 60 kWh. Servicing requirements are minimal in contrast to a gas boiler as the heat pump operates essentially as a refrigerator in reverse.

Key considerations
• Heat pumps work in older, less energy efficient homes, but do consume a lot of electricity in sub sub-zero temperatures
• Internal temperature matters – keeping the thermostat down makes a real difference, especially during very cold days
• It is most efficient to let the unit run for an extended period of time
• Noise: from the outside the noise is not dissimilar to the fan of a condensing gas boiler and newer models are significantly quieter
• The UK still lacks enough qualified engineers which led to problems during the installation. Service provided by the manufacturer costs close to £300 as local heating engineers are generally still unable to service these units. While there is little servicing to do, the manufacturer requires the annual check-up to maintain the warranty.
• When replacing a gas boiler with a heat pump, it is generally recommended to upgrade radiators. The owner did so, but did not notice much of a difference. Newer heat pumps can operate at higher temperatures which may in future obviate the need for this additional expense.
• Replacing a combi gas boiler with an air source heat pump will require space to be made for a hot water cylinder, which can be challenging in smaller homes.

Insulation and efficient appliances matter

Whether heating with gas or electricity, focusing on insulation is key (‘fabric first’ principle).

As shown in the table below, electricity consumption was down by 52% and gas consumption dropped by 44% from the 2001 peak (both prior to the installation of the heat pump). This was driven by a combination of insulation (roof, floor, windows), more efficient equipment (condensing boiler on the gas side, A-rated appliances and LED lights on the electricity side) and possibly also behavioural changes and warmer winters.

The installation of solar panels provided an additional benefit with electricity purchases down 69% from the peak in 2001.

The Long Term View
In this case study, the owners aimed to reduce their energy usage by insulating and installing energy efficient appliances. Subsequently they focused on heating and powering their home with as much renewable energy as possible. Although, the economic case of the air source heat pump is not clearcut from a short-term perspective, the owners not only permanently reduced their energy usage and lowered their carbon footprint – whilst reducing their contribution to local air pollution – but thanks to PV (solar) panels and battery storage enjoy very low energy bills during the summer months.

Electric Vehicles (EVs) – a compelling choice for many drivers

From being a small and – to many – an unaffordable niche in the automotive market, EVs accounted for 23% of new cars sold in the UK last year (1) (though still far below the 97% reached in Norway). We discuss affordability, range and charging as well as the benefits for the environment. In conclusion, EVs are now a cleaner and compelling choice for many drivers.

What is an EV like to drive?
Compared to a conventional car, EVs are both quiet and powerful. Braking is done in most cases through regeneration, allowing for one-pedal driving. This recuperates a significant amount of energy, especially in urban driving, and reduces the wear on brake pads as well as the related toxic dust emissions.

Can I afford one?
Long gone are the days when the choice was between a high-end vehicle or a small city car with almost no range. Manufacturers now cover essentially all market segments and some are selling the petrol and electric versions at the same price. In light of the rapid technological changes – batteries are constantly improving in terms of efficiency – it may be worth considering leasing a car. A small car with a 200-mile range can now be found for under £200 per month. Over the past years, the used car market for EVs has also expanded significantly. However, it is worth bearing in mind that repairs on an out-of-warranty vehicle can be very expensive. Batteries tend to be reliable, but the electronics around them less so.

Currently EVs pay no road tax and those lucky enough to have off street parking can charge during the night using discounted rates (as low as 7p/kWh (2)) or use electricity generated from solar panels. For those without off street parking, public charging is unfortunately still considerably more expensive, ranging anywhere from 45p to 75p/kWh (3). According to UK government statistics, 75%-90% of EV charging currently takes place at home (4).

Service costs tend to be much lower. There are no oil changes and brake pads can last for the life of the car if driven carefully. Tyres, however, may wear out sooner, especially on the heavier and high performance vehicles.

An efficient EV can travel 5 miles per kWh, translating into electricity costs as low as 1.4p per mile. According to government statistics, it currently costs between 14p to over 22p per mile to drive a petrol car (5). The cost advantages are underlined by the fact that many professional drivers (especially minicabs) are switching to EVs.

Range and charging
Range anxiety remains a key concern amongst car buyers. In 2025, the average range of EVs sold in the UK was 300 miles (6), although it is important to note that highway range will always be lower. According to the RAC Foundation, the estimated average annual mileage across the UK was 6,200 for petrol and 8,900 for battery electric cars in 2024 (7). This works out at between 17 and 24 miles per day, well within the range of any EV.

When travelling away from home it is good to know that there are now 118,321 EV chargers across 45,561 charging locations around the UK (8). In the best-case scenario, a charge from 20% to 80% (the most efficient range when travelling) can take as little as 15 minutes (9).

How clean are EVs?
While EVs emit zero tailpipe emissions, more carbon is emitted during the manufacturing stage, especially for the battery. The break-even point is reached after driving between 12,000 and 20,000 miles. How the vehicle is charged makes a significant difference. In the best-case scenario – charging at home using excess electricity from solar panels – the payback is much quicker. On average, an EV will emit around one quarter the amount of carbon dioxide per kilometre travelled over its lifetime compared to an internal combustion car (110g/km vs 410g/km). (10)

References:
1 SMMT: UK new car market breaches two million as almost one in four buyers go electric, January 2026
2 Money Saving Expert: Electric Vehicle Energy Tariffs, March 2026
3 Carwow: EV charging prices are falling, January 2026
4 Department for Transport: EV Driver Tracker – Year 1 findings
5 Gov.UK: Advisory fuel rates
6 Gridserve: Average UK EV range in 2025 is almost 300 miles – enough to go two weeks without charging, August 2025
7 RAC Foundation: Motoring Facts
8 Zapmap: How many public EV chargers are there in the UK?
9 Carwow: Fastest charging electric cars in 2026
10 Recurrent Auto: How dirty is your EV?

Funding energy efficiency upgrades in your home

Retrofitting your home is unfortunately not cheap and in the case of certain large investments, such as wall insulation, payback times can extend over many years. Following funding options are available today.

‘Warm Home-Local Grant’
While the ‘Great British Insulation Scheme’ and ‘ECO4’ programmes have both recently closed, the ‘Warm Homes-Local Plan’ was launched last year. It is available to residents on benefits or low income (<£36,000), living in a home with an Energy Performance rating of D or worse (Energy Performance Certificates, or EPCs range from A to G). Funding of up to £15,000 covers wall/loft insulation, double glazing, solar panels, and low-carbon heating systems. Apply here.

How to I get an EPC?
If your home does not have an Energy Performance Certificate or it has expired, you can find a qualified assessor here. Depending on your home size, the cost can range from £35 to £120. If your household income is below £31,000, you receive a means-tested benefit or spend more than 10 per cent of your household income on gas, electricity of heating, SHINE London may be able to offer funding.

Low or zero interest government loans
Announced in mid-January, we are still awaiting details on this new low and zero-interest loan scheme, which will be made available for homeowners regardless of income.

‘Boiler upgrade scheme’: £7,500 grant for heat pumps
Anyone upgrading from a fossil fuel system or an electric system to an air or ground source heat pump can apply for this government grant. Air-to-air heat pumps (which both heat or cool air) will qualify for a £2,500 grant. Apply here.

Lendology for Merton residents
Merton residents can borrow up to £20,000 at 4% fixed over up to 10 years through the Local Authority-financed Lendology scheme to fund energy efficiency upgrades in their home. One positive aspect of this programme is that applicants can choose their own builder/installer. Apply here.

Pension fund
At present, pensions are already used to finance 7% of solar PV installation and 3% of heat pump installations in the UK. For retirees unable to quality for a grant, this may be an option.

Plug-in solar coming to the UK

On 24 March, the UK government announced that plug-in solar solutions would be available across retail outlets ‘within months’. Very popular in Germany (426,000 registrations last year), this affordable solution is opening up the market to many more residents, in particular those living in a flat and/or renting.

A DIY solution
The system, consisting of one or several solar panels plus an inverter – a device converting the direct current (DC) electricity produced by the panel into alternating current (AC) – can be plugged into a mains socket without the need to hire an electrician. The system size is limited to below 800 W, which equates to two typical solar panels. A popular application is to attach the solar panels to the balcony railing or to place them in the garden. As this is seen as a temporary solution, no planning approval is required.

Cost and benefits
Systems are currently on the market from around £400. The Government estimates that a typical UK home could save £70 to £110 a year on their energy bills depending on size, location and energy consumption patterns. In the best-case scenario, the system could pay for itself in four years.

A few questions remaining
It remains to be seen what standards are required to attach panels on the outside of an apartment building and what restrictions landlords and freeholders are able to impose. There is clearly a safety aspect to ensure that panels do not detach during strong winds.

Wall Insulation – expensive, but effective

Once your loft has been insulated and windows replaced with modern double or triple glazed units, the next step home you may consider is wall insulation, by far the most expensive measure. The benefits include reduced heat loss and lower energy bills, a reduced risk of condensation forming on your walls and a reduction in draughts.

Most of the energy in your home goes towards space heating
Since space heating uses on average 62% of all energy consumed in a home(1) the best way to cut your energy bill and reduce your carbon emissions is to insulate your home.

Major source of heat loss
In a typical uninsulated house, walls represent the greatest source of heat loss (~49%), followed by windows (~18%), the roof (~14%) floors (~14%) and doors (~5%)(1).

Solid versus cavity walls
Most UK houses prior to the 1930s were built with solid brick walls which offer very limited insulation. Not sure about your home?

• Bricks in a solid wall have an alternating pattern with some bricks laid across the wall so you can see the smaller ends from the outside.
• Bricks in homes with cavity walls are generally laid in an even pattern.

1 Solid Walls

The options for solid walls are either external or internal insulation. Your choice will depend on the type of house and your budget.

External Insulation
Expanded Polystyrene (EPS) rigid boards or mats made of breathable materials such as mineral wool (non-combustible) or wood fibre (flame resistant) are attached to the outside of your house’s external walls with adhesives and special screw fixings. The insulation is covered with a type or render (such as a breathable silicon render), cladding or brick slips.

External wall insulation works best with rendered homes. Existing brickwork or other designs (e.g., mock Tudor or Edwardian features) can be replicated, but this is expensive.

Costs
Costs will vary considerably, based on

• the size of the house
• the number of external walls to be insulated (mid-terrace: two, semi-detached or end of terrace: three, fully detached house: four)
• the complexity of the façade (simple rendered façade versus decorated brick, mock Tudor or Edwardian façade)
• the type of windows
• outbuildings and extension
• the need to extend the roof if there is an insufficient overhang

In London, costs range from £16,000 for a mid-terrace house with a simple rendered façade and no outbuildings to significantly over £100,000 for a detached house. It is essential to work with specialist installers.

The Energy Saving Trust calculates annual savings on energy bills ranging from £200 for a mid-terrace house to £550 for a detached house, representing a very long financial payback (2).

A word of caution: Under the last government grant programme (ECO4), 98% of external wall insulation installations were found to be faulty. Incorrectly installed insulation can lead to damp and mould as well as causing damage to the fabric of the house. It is therefore essential to work with established specialists operating under the government’s TrustMark scheme which are able to offer a 25-year insurance-backed warranty.

Internal wall insulation
For some homes (especially in conservation areas), external insulation may not be possible. Flat or maisonette owners are also unable to install external wall insulation unless the freeholder agrees to insulate the entire building.

There are several options on how to install internal wall insulation, ranging from insulated plasterboard, rigid insulation boards to an internal stud wall filled with insulation, preferably a non-combustible and permeable material such as mineral wool. While expensive slim insulation boards can reduce the room width by only 60mm per wall, using studwork can take away over 100mm, which may be a problem in smaller homes or flats.

In order to prevent damp being trapped inside your walls it is advisable to use permeable insulation materials as well as permeable finishings such as paint, wallpaper or any other wall covering.

Costs
Costs range between £4,000 and £13,000 for a standard three-bedroom semi-detached house, with an average of around £7,400. One a per square metre basis, costs generally range from £60 to £100 for materials and installation, although basic insulating boards can be cheaper, while complex stud work can exceed £100 per square meter (3).

2 Cavity Walls

Early cavity walls were usually uninsulated, designed primarily to combat dampness. From the 1970s onwards, cavities started to be insulated, which only became mandatory in the 1990s.

Insulating cavity walls is a much easier and cheaper process than solid wall insulation. Holes are drilled into the mortar joints of the outside wall and bead or fibre insulation material is injected using specialist equipment. When the cavity is full, the holes are filled in to match the existing wall so that it is almost impossible to detect any difference after the work is completed.

Risks
If the outer wall has cracks, poor pointing, or is in an area with high wind-driven rain, the insulation can absorb water and create a bridge, allowing moisture to travel to the inner wall. Improperly installed insulation can lead to cold spots (cold bridging), where warm, humid indoor air condenses, causing mould growth and damp patches. It is essential to have this work done by a specialist.

Costs
Installation costs range from £950 to £4,600 depending on the size of the house, according to Eon Energy. Annual energy cost savings average £240 (4).

A general word of caution: Ventilate when you insulate
When increasing the air tightness of your home, it is essential to ensure sufficient controlled ventilation to avoid the risk of poor internal air quality and excess moisture which can lead to condensation and mould. To many this is counterintuitive as one of the aims of insulation is to removed uncontrolled draughts. The key is to control the amount of fresh air to ensure the correct moisture level.

This can be done via trickle vents in windows as well as extractor fans in wet rooms. To limit heat loss, consider a mechanical ventilation heat recovery system (MVHR). These are designed to heat incoming fresh air with the warm moist air being extracted from your home. While decentralised units require minimal building work, a central system – the gold standard in ventilation – will require ductwork to reach every room and is very expensive to retrofit into an existing home (£6,000-12,000) (5).

References

(1) RICS: Retrofitting and improving the energy efficiency of your home
(2) Energy Saving Trust: Home insulation to reduce home heat loss and Energy Saving Trust: Internal and external wall insulation for solid walls
(3) MoneySuperMarket: Save Energy with Solid Wall Insulation
(4) Eon Energy: Cavity wall insulation
(5) Home Building & Renovating: I’m a quantity surveyor and this is how much an MVHR system will cost

Air quality matters – what can you do to improve our local air?

Air pollution was a contributing factor to around 30,000 deaths in the UK in 2025 and cost more than £27 billion annually in healthcare, productivity losses and reduced quality of life (1). While there are encouraging signs, a lot of work needs to be done. We discuss below the key issues and highlight steps that we can take in our everyday lives to help reduce pollution.

The basics: The two types of air pollution that are most relevant are particulate matter (PM), tiny particles which are inhaled into the lungs cause breathing and heart problems, and nitrogen dioxide (NO2) primarily emitted by burning fossil fuels. No levels of this type of pollution are safe due to their causing respiratory problems and inflammation of the lungs’ lining. One in 11 children in London have asthma and a life time of exposure to high levels of PM2.5 pollution can contribute to increased risk of strokes, heart attacks and other diseases such as cancer. To check out real-time pollution levels in London or Wimbledon visit the AQI or the IQAir websites. Merton generally experiences “Good” to “Fair” real-time air quality, though it is designated as an Air Quality Management Area due to NO2 levels often exceeding guidelines, particularly near traffic-heavy town centres (2).

The good news: According to a study released in March 2026 (3), air quality in London has improved considerably between 2010 and 2024 with a 40% drop in NO2 (4) and 25% drop in PM2.5 (5) emissions. This has been driven by reduction in the emissions of London’s transport fleet, supported by the introduction of lower emission vehicles, party aided by the ULEZ scheme and the gradual electrification of vehicles, including TFL buses, over 30% of which are now fully electric (6). Any of us who are walkers or cyclists have likely noticed the difference between the smelly old buses and the much cleaner running electric ones!

The bad news: The shift away from gas boilers to heat pumps remains slow. However, even more detrimental to local air quality is the growth in the use of wood-burning stoves and fireplaces which is partially offsetting the improvements made in the field of transport. In fact, burning wood at home now produces roughly 20% of PM2.5 emissions in the UK (7). In fact, a solid fuel open fire generates almost 4,000x greater PM2.5 emissions than a gas boiler. In the US, recent research (8) has uncovered a link between rising wood burning emissions and increased concentrations in particle-bound lead.

What you can do:

1. Avoid burning wood – or indeed any solid fuel – unless it is your primary source of heating. Many people have purchased wood burners, seeing them as cosy additions to their homes, not realising their significant contribution to air pollution within their own home and especially to neighbours who are exposed to the smoke resulting from the fires.
2. Walk or cycle instead of driving short distances
3. Avoid idling when stationary for any period of time. Every minute, an idling car produces enough exhaust to fill up to 150 balloons with harmful chemicals, including cyanide, nitrogen oxides and PM2.5 (9). These three behavioural changes represent the easiest ways to reduce local pollution.

On the more expensive side of the scale, consider

1. Switching to an electric vehicle, taking advantage of government incentives of up to £3,750.
2. When your gas boiler reaches the end of its life, consider an air source heat pump which currently qualifies for a £7,500 government grant.
3. Increasing plant cover across our community, especially in front gardens. This not only adds colour but can also improve air quality. A study undertaken by Lancaster University examining the impact of planting around school playgrounds (10) indicated that western red cedar, the most effective plant studied, captured 49% of black carbon and around 46% and 26% of the fine particulates, PM2.5 and PM1 emitted by passing traffic.

Indoor pollution is a bigger problem than many realise: According to a study by the University of Birmingham (11) gas hobs can produce higher levels of PM2.5 and NO2 than busy roads with peaks exceeding 100-600 𝜇g/m3 and levels remaining elevated for several hours after cooking is finished (12).

What you can do:

1. Ensure proper ventilation when cooking. Research by the author of the forementioned study has found that many people do not use their extractor fans.
2. Consider switching to a high efficiency induction hob when the time comes to replace your appliance.
3. When insulating your home remember that the correct ventilation is crucial. An airtight home lacking sufficient ventilation will not only suffer from a deterioration of air quality but is also at risk of mould growth linked to excessive humidity levels.

On the pricier side, consider a whole house mechanical ventilation heat recovery system (MVHR), which ensures a continued level of fresh air which is heated using the exhaust air from bathrooms and kitchens.

References

(1) Royal College of Physicians: A breath of fresh air: responding to the health challenges of modern air pollution, 2025 
(2) Merton Council: Local air quality management
(3) Breathe Cities: How leading cities have rapidly cut air pollution, March 2026
(4) Nitrogen oxide (NO2) causes respiratory issues, particularly asthma, and contributes to ozone and smog formation.
(5) Fine inhalable particles with diameters 2.5 micrometres are small enough to penetrate deep into lungs and enter the bloodstream. These have been classified by the World Health Organization as a carcinogen that causes lung cancer and is associated with an increased risk of bladder cancer
(6) London Bus Forum: Go-Ahead Celebrates 1,000th Electric Bus as London’s Zero Emission Fleet Grows, 5 March 2026
(7) British Medical Journal: The growing threat of domestic wood burning stoves—and industry’s legal attempts to shut down clean air campaigns, 6 March 2026
(8) Journal of Exposure Science & Environmental Epidemiology: Back to the future: trace lead in ambient air from wood fuel combustion, 2026
(9) Merton Council: Tackling vehicle idling
(10) Lancaster University: New evidence shows planting around school playgrounds protects children from air pollution, 26 August 2022
(11) University of Birmingham: Gas hob can raise indoor air pollution higher than busy UK road, 7 March 2025
(12) World Health Organization guideline: 24-hour average exposure limit of 15 𝜇g/m3

Fixing the UK’s electricity grid and promoting electrification

Back in 2012, coal accounted for 40% of the UK’s power generation but completely disappeared from our grid in 2025. Last year, renewables (excluding biomass) generated 37% of our electricity, followed by gas with 27% which presently still sets the wholesale price. As a result, our electricity prices rank as some of the highest in Europe (behind Germany and Ireland) and substantial investments in upgrading the grid are set to increase the structural costs of our bills.

In April, we attended a panel discussion arranged by Everything Electric titled: ‘The Energy Market Is Rigged. And EVs Expose It’  featuring Greg Jackson, the CEO of Octopus and Rory Sutherland (Behavioural Science, Ogilvy) (1). The discussion touched on the challenges, opportunities and benefits of electrifying the UK economy and why electric transport and heating are more efficient. The views expressed below represent those of the speakers, but may be of interest to our members.

The current geopolitical events highlight again the risk of most countries’ dependence on fossil fuels. Countries, such as Norway or Spain, which are further advanced on electrification, are seeing a significantly lower impact on their electricity prices. China is winning the battle to control the technology on electrification (solar PV, batteries, electronics) and is much further ahead in EV adoption (cars, two wheelers, buses and trucks, where 25% of new purchases are now electric).

There is currently a 4x difference in the price between electricity and gas, which compares to 1.5x in France. While the government has taken the first steps to remove structural costs (leading to the April electricity price cut), more needs to be done. At present, the wholesale electricity price represents only around 35% of current electricity bills. Structural costs, including what some argue is an unnecessary build-out of the grid continue to add to this cost. Year to date, the UK has spent over £600m to pay windfarm operators to disconnect from the grid.

At the same time, the current UK auction system, sets the price of electricity every 30 minutes at the level of the last bidder, which is most often gas. This not only drives up the price, but leads to significant price swings during times of geopolitical turmoil (such as the outbreak of the Ukraine war and the current war in the Middle East). Rachel Reeves (1) is looking to address this issue and at the same time tax the windfall profits made by legacy renewable energy producers which benefit from the higher electricity wholesale price set during times of gas shortages while their costs remain unchanged.

The CEO of Octopus, now the UK’s largest energy supplier, has been very outspoken about the changes that should be made to the UK grid, including:

1. Introduction of zonal pricing: This would incentivise high energy users (such as the growing number of data centres) to locate their facilities to where there is excess energy. Scotland generates three times the electricity it consumes, yet electricity bills are higher as structural costs for the infrastructure are calculated on a per capita basis. This incentivises the building of high use energy businesses around London (Slough is a key location for datacentres), which makes little sense given existing grid congestion. With zonal prices, residents in Scotland and Wales – which are impacted by the negative visual externality of wind farms – would benefit from substantially, at times zero or negative, electricity prices.
2. Installation of more onshore wind in England where there is sufficient grid capacity. This is much cheaper than building offshore wind where there is little or no existing grid infrastructure. At present, some offshore wind farms now earn more money from curtailment payments (being paid to disconnect from the grid) than from selling electricity. This would also save billions being earmarked for grid expansion which will continue to drive up the structural cost side of our electricity bills.
3. Construction of long-distance interconnectors to import energy from areas with growing overcapacity, such as North Africa. China has been a leader in building high efficiency interconnectors (3000 miles +) with minimal grid losses. Saudi Arabia aims to install 70 GW of solar PV capacity (UK grid size: 50 GW) and build long-distance interconnectors to become the leading exporter of solar energy. The more options the UK can chose from, the cheaper the overall cost of electricity. Today, we already benefit from low-cost Norwegian hydro, French nuclear and Continental wind power thanks to the existing cross channel interconnectors.

Longer term, electrification should win as it is simply the more efficient way to generate motion or heat. Even in an electric grid which is 100% powered by gas, it would be more efficient to drive EVs and heat homes with heat pumps. China has realised this and has already achieved an electrification rate of 30% versus ~20% in the UK. Many Southeast Asian countries are following China’s lead. In terms of EV strategies, it is not just Norway (close to 100% of new cars sold are EVs) and China which are leading the way. In any given economy, increasing the rate of electrification by one percentage point, cuts fossil fuel demand by 2-3% given the higher efficiency of electricity-powered appliances.

While the wind does not always blow and the sun does not always shine, as always highlighted by the fossil fuel lobby, whenever we are generating renewable energy, we are not burning gas and sending money to Norway, the US or Qatar. Supporting the better use of renewables is the strong growth in battery storage in the UK. As of early 2026, there was 6.8 GW (12.9 GWh) of operational grid-scale capacity, up 500% since 2020. This is helping to shift excess solar and wind energy from peak production to peak demand times of the day.

However, fossil fuel companies, which have seen a demand impact from the adoption of EVs (100 million on the road across the word today), are fighting back ‘even more aggressively’ than the tobacco industry over the past 40 years (which moved from denying the dangers to heath to partial acknowledgement with the launch of products such as low tar cigarettes, focused their marketing efforts on poorer countries and finally ended up admitting the real dangers of their product). It is essential for voters, governments and the cleantech industry to fight back strongly. Recent calls to drill for more oil and gas are in reality ineffective as the fossil fuel industry will always seek to constrain capacity in order to maintain a certain price level. The substantial amount of fossil fuels consumed to transport fossil fuels, especially LNG, is also seldom discussed by the oil industry (as such, we should be using our own gas resources over imports). Electricity, in contrast can be generated through many means, using local resources, including the sun, wind, hydro resources and the tide and can be complemented with nuclear and backed up with fossil fuels until the transition is completed. There will still be a market for fossil fuel for many years (including air travel and long-distance freight transport), but the incumbents need to adopt new business models and focus more on optimising resources.

Fear of the new and behavioural changes: People generally dislike change and need social reinforcement to adopt new technologies (social contagion). Where there are more solar panels, EVs and heat pumps, more people tend to be willing to follow. Governments and industry need to do a better job in promoting the fact that heat pumps work and EVs are simply better to drive and cheaper to run. This is highlighted by the fact that very few EV drivers revert back to driving an internal combustion car. For those lucky enough to have solar PV and a driveway with a domestic charger, driving an EV makes even more financial sense.

(1) Everything Electric: The Energy Market Is Rigged. And EVs Expose It | Greg Jackson & Rory Sutherland, 27 April 2026

(2) The Guardian:Reeves looking to break link between gas cost and electricity prices, 16 April 2026

Practical Guidance for Flood Preparation and Response

Note: Please follow the advice of HMG at all times.

Flooding from natural bodies of water is a growing problem in the United Kingdom, affecting thousands each year. Knowing how to prepare and what to do before, during, and after a flood can help protect your property and wellbeing.

Flooding may also be caused by a burst water main, sewerage pipework surcharging, from surface run-off, from stored water release e.g. a water tank in the roof, or even a simple pipework blockage.

What Matters Most to Wimbledon: Results of Our Environmental Priorities Survey

In autumn 2025, the Wimbledon Society carried out a survey of local residents to help identify which environmental issues should be our priorities for action in the coming years. The survey was advertised through our September 2025 newsletter and by email to members, and we were delighted with the level of engagement it generated.

In total, 160 people responded — far more than we had anticipated — and almost all respondents were Wimbledon Society members. This strong response underlines the importance local residents place on environmental issues and on the Society’s role in representing community views.

Participants were asked to rank nine environmental objectives on a scale from 1 (most important) to 4 (least important). They were also invited to suggest additional priorities in free text and to share wider comments. The results of participants’ ranking of the nine objectives were analysed in three ways: the percentage ranking each objective as most important; the percentage ranking it as either first or second; and the percentage ranking it least important.

The results of the rankings are shown in the table below.

High Streets Thrive When They Are Pedestrian Friendly

A recently published report by the organisation Living Streets highlights the economic and community benefits of making High Streets more pedestrian and cyclist friendly. According to the report, individuals who walk or cycle to their local High Streets tend to spend more money than those who travel by car or public transport.

The report includes several compelling case studies, such as Shrewsbury town centre, where pedestrianisation resulted in a 25% increase in sales growth. This demonstrates how creating a more welcoming environment for pedestrians and cyclists can drive economic success for local businesses while enhancing the quality of life for residents.

It’s in our collective interest to encourage our local council to prioritise improvements that make the area safer and more accessible for pedestrians and cyclists. By doing so, we can support thriving High Streets and foster a stronger, more sustainable community.

Do you live in a pollution hotspot?

This map compiled by Friends of the Earth shows the levels of 4 types of pollution (water, air, noise & light) for every postcode in the country. The map indicates whether or not the pollution in each category is over the recommended limit in the area. You will see that most of Wimbledon exceeds the recommended in limits in 2 or 3 categories.

uPVC windows in Conservation Areas

In 2014 the Wimbledon Society reviewed the acceptability of replacement uPVC windows in Conservation Areas. Some councils expressly prohibit them in SPDs. A recent appeal in Hackney had overturned a refusal of planning permission for replacement of wooden windows by uPVC windows in a conservation area. Our initial view was that, principally from a sustainability point of view, wooden replacement windows were to be preferred.

The arguments for and against were very much hearsay, and there was little clear independent evidence available. Most current evidence is produced by manufacturers of uPVC windows.

The following were the usual arguments:

1. Cost: Wood is usually more expensive then uPVC.
2. Appearance: Traditionally uPVC is considered to look worse, has wider frames and bars, and is never an exact replacement, although at least one member of WSPEC claimed that his uPVC windows were indistinguishable from wood.
3. Maintenance: uPVC windows don’t need painting.
4. Durability: uPVC is generally thought to last a much shorter time than wood, although warranties are apparently available for 10-12 years, with an anticipated lifespan of 35 years. Another member of WSPEC told us that his 25 year old windows are still in good condition. Wood can rot or warp, but can be repaired. uPVC tends to yellow with age.
5. Sustainability:  uPVC windows are made from oil, and consume energy in their manufacture. Generally it is thought that uPVC cannot easily be recycled. However recent investigations revealed that uPVC can be recycled up to 10 times, becoming stronger with age, with much improved recycling facilities, and with much of the production for UK use being carried out in the UK creating UK employment.
6. Our conclusion was that there cannot and should not be an absolute bar on using uPVC for replacement of wooden windows, but that the actual design of uPVC windows should be checked in each case to ensure that their design is as close as possible to the existing windows.

It should be noted that these views do not apply to listed buildings, where replacement windows should be of materials identical to the original.

Solar Panels Installation – some helpful information