MARTIN LEWIS’S JANUARY PRICE CAP WARNING – AND WHAT SOUTH-WEST HOMEOWNERS CAN DO ABOUT IT

UK home and rising energy bill graphic illustrating Martin Lewis's warning that the January 2027 energy price cap could rise by more than 20%.
Energy price warning

Energy bills could rise by more than 20% in January, according to predictions aired on the latest Money Show.

Below we explore the implications for South-West homes and recommend measures you can take now to fend off the price rises.

January 2027 forecast Forecast
0 % +
Potential price cap rise
What this means Another substantial rise could be coming after October's already confirmed increase.
From the Money Show

THE KEY POINTS FROM THE SHOW

Martin Lewis opened his energy bills special with the warning nobody wanted to hear:

01
October · confirmed Confirmed
0%

New predictions suggested the energy price cap would rise by over 20% in January 2027, on top of the 3.6% already confirmed for October.

02
EDF + E.ON Supplier figure
0%

The figure from two suppliers, EDF and E.ON, was 24%. As Martin put it, for every £1,000 you pay today, you would be paying £1,240 in the new year.

Today £1,000
New year £1,240
03
Energy Secretary Likely rise
0%

The Energy Secretary, pressed later in the same programme, put the likely rise at 18%. But Martin was pretty blunt: the cap is definitely going to rise in January, and probably substantially.

1 October price cap

GAS UP NEARLY 9%.
ELECTRICITY UP LESS THAN 1%.

But we’ve got energy price rises to deal with already next month.

On 1 October the cap rises 3.6%, but the cap isn't a limit on your total bill. It's a limit on unit rates and standing charges. If you use more, you pay more.

If you look at the two fuels separately, they tell very different stories:

Household energy bill and smart meter representing gas and electricity costs
From 1 October ONE CAP.
VERY DIFFERENT IMPACT.
At a glance

SAME CAP. DIFFERENT STORY.

The headline rise is 3.6%, but the change looks very different when gas and electricity are separated.

Overall cap +3.6%
Headline increase
Gas
≈ +9%
Unit rate · standing charge +2.2%
Electricity
< +1%
Unit rate · standing charge down

Gas: unit rate up nearly 9%, standing charge up 2.2%.

Electricity: unit rate up less than 1%, standing charge down.

Temporary VAT cut
Before 5%
From 1 Oct 0%
Typical household ≈ £45 a year
Runs until 31 MAR 2027

One reason electricity looks relatively tame is the temporary VAT cut.

From 1 October, domestic electricity in Great Britain is charged at 0% VAT instead of 5% – a temporary cut HMRC has confirmed runs to 31 March 2027, worth roughly £45 a year to a typical household.

GAS

Gas didn't get the same VAT treatment, and the show flagged that as a deliberate policy choice rather than an oversight.

How the market works

WHY ELECTRICITY IS PRICED THE WAY IT IS

Martin’s point was simple: gas is relatively cheap, while electricity is expensive.

And that price gap affects the running-cost comparison between gas boilers and electric heat pumps.

Why the electricity price stays high
More generation CHEAPER
RENEWABLES
Price setter GAS-FIRED
POWER
Wholesale electricity market
ONE MARKET
PRICE

Gas-fired power stations often set the wholesale electricity price.

Result ELECTRICITY STAYS EXPENSIVE

More power now comes from cheaper renewables, but the wholesale price can still be set by gas-fired generation.

01
The price gap

HEAT PUMP ECONOMICS

Reducing the gap would improve the economics of heat pumps further and strengthen the case for moving homes away from fossil-fuel heating.

Gas
Relatively cheap
Electricity
More expensive
02
The market

GAS CAN SET THE PRICE

Part of the problem is how the electricity market works. Gas-fired power stations often set the wholesale electricity price, even though more of our power now comes from cheaper renewables.

03
The network

MANAGING THE GRID

There are also costs associated with managing the grid. When electricity cannot be moved efficiently from where it is generated to where it is needed, the system operator may have to pay some generators to switch off and others to switch on.

When the grid is constrained THE SYSTEM HAS TO REBALANCE.
Some generators SWITCH OFF
Other generators SWITCH ON
Your energy bill

THE PART OF THE BILL A HOME CAN ACTUALLY CONTROL

Some costs are fixed by the market. Others give your home room to act.

01 What's on your bill 02 Who sets it 03 What a South-West home can do
Variable Unit rates

Ofgem's cap, then your supplier

Generate your own electricity with solar panels, store it in a battery, buy the rest in an off-peak window.

Fixed daily cost Standing charges

Ofgem's cap and network costs

You can’t reduce a standing charge by using less energy – it’s charged daily regardless of consumption.

Fixed
Home system Heating

Gas, oil or electricity

A well-designed air source heat pump can typically deliver around three to four units of heat for each unit of electricity it uses.

Air source heat pumps
Income Export income via the Smart Export Guarantee (SEG)

Your supplier's export tariff

Shop around for the best deal. The SEG actually creates an energy income for you, rather than a cost.

Energy out → income in
Martin Lewis discussing household energy costs, with solar panels and home energy technology in the background.
The opportunity BUY LESS.
GENERATE MORE.
HOME CONTROL
04 Standing charges THE COST YOU CAN'T SHIFT.

Standing charges got a segment of their own on Martin’s show, and it’s not surprising why.

Audience member 70%

One audience member said they were 70% of her bill.

Another audience member

Another called them a moral hazard.

Martin has campaigned on them for three years and expects the picture to look different within a year. Until then, they are the one part of the bill that no amount of solar can shift.

For solar owners

MARTIN'S 10% RULE FOR SOLAR OWNERS, EXPLAINED

If you already have solar panels, Martin’s advice comes down to one simple comparison: how much electricity you buy from the grid and how much you export.

Martin Lewis discussing energy tariffs
Martin's rule of thumb COMPARE WHAT
YOU BUY WITH
WHAT YOU EXPORT.
10 %
Worked example 10%

Look at your annual figures. If you buy 3,000 kWh of electricity from the grid and export more than 300 kWh, your exports are above Martin’s 10% threshold.

Buy from grid 3,000 kWh / year
Export threshold 300+ kWh / year
3,000 kWh Grid electricity bought
×
10% Rule of thumb
=
300 kWh Export threshold
Which price matters most?

CHECK WHICH SIDE OF 10% YOU'RE ON.

Your exports >10%
Higher exporter

EXPORT RATE MATTERS MORE

In that case, a tariff offering a higher export rate could leave you better off overall, even if the electricity you buy costs slightly more.

Your exports <10%
Lower exporter

IMPORT PRICE MATTERS MORE

If you export less than 300 kWh, the price you pay for electricity is usually more important. Focus on finding a low-cost supply tariff, then choose the best compatible Smart Export Guarantee (SEG) rate.

Compare the whole year

DON'T JUDGE A TARIFF ON ONE RATE.

The 10% figure is only a guide. To compare deals properly, estimate what you would pay for electricity over a year, subtract your expected export payments, and choose the deal with the lowest overall cost.

Annual electricity COST
SEG export PAYMENTS
=
Compare this OVERALL COST
Whole-home energy

HEAT PUMPS WORK BEST WITH SOLAR AND BATTERY STORAGE

Instead of burning fuel like gas or oil, an air source heat pump moves heat from outside your property to inside, and typically produces around three to four units of heat for each unit of electricity used.

Air source heat pump installed outside a South West home
Air source heat pump MOVE HEAT.
DON'T BURN FUEL.
EFFICIENCY 3–4× heat output
How it works

1 UNIT IN.
3–4 UNITS OF HEAT OUT.

That efficiency is why the running-cost comparison between fossil fuel and electricity can be much closer than the raw electricity prices alone might suggest.

Electricity 1 unit in
Useful heat
1 2 3 4
3–4 units out
How you power it matters

MOVE ENERGY TO CHEAPER HOURS.

How the system is powered can make a significant difference to running costs. A smart heat-pump tariff can run the heat pump and heat the hot-water cylinder during cheaper off-peak hours. The cylinder stores that heat for later, reducing the amount of full-price electricity needed during the day.

OFF-PEAK
CHEAPER electricity
Hot-water cylinder STORE HEAT
DAYTIME
USE LATER when needed
One connected system

HEAT PUMP + SOLAR + BATTERY

Put together, the heat pump, solar panels and battery act as one system: the heat pump uses electricity efficiently, the panels generate part of that electricity, and the battery shifts cheaper energy to the times it is needed.

01
Generate

SOLAR

Solar panels can lower costs even further by supplying some of the heat pump’s electricity directly. In spring and autumn, when heating is still needed and solar generation is useful, the two technologies work particularly well together.

02
Store

BATTERY

A battery can store spare solar power – or cheaper off-peak electricity – for the evening, when demand is often highest.

03
Use efficiently

HEAT PUMP

The heat pump turns that electricity into useful heat efficiently.

Result LESS RELIANCE ON PEAK-RATE ELECTRICITY.

This can reduce reliance on peak-rate electricity and make household energy costs more predictable.

Design matters

THE SYSTEM HAS TO FIT THE HOME.

Good design is essential. The heat pump must be correctly sized, with suitable radiators, hot-water storage and tariff.

01 Correctly sized
02 Suitable radiators
03 Hot-water storage
04 Right tariff
Boiler Upgrade Scheme

UPFRONT SUPPORT.

The Boiler Upgrade Scheme reduces the upfront cost significantly: most eligible homes can receive £7,500 towards an air-to-water or ground source heat pump, rising to £9,000 until 31 March 2027 for eligible off-gas-grid homes replacing oil or LPG heating.

Most eligible homes £7,500 towards a heat pump
Before you commit

A proper home survey should show the likely grant, running costs and savings before you commit.

Heat pump + solar guide
One date · three changes

THREE DEADLINES LAND ON 31 MARCH 2027

Three energy changes arrive on the same date. But only two are decisions a homeowner can act on before the deadline.

THE SHARED DEADLINE

31.03.27

VAT support and the enhanced off-gas heat pump grant all meet at the end of March.

Same day 03 changes
01 Not in your control
Electricity bills

ELECTRICITY VAT CUT

The electricity VAT cut runs out on that date.

ENDS 31 MAR
02 Homeowner can act
Solar · battery · heat pumps

0% INSTALLATION VAT ENDS

So does the 0% VAT rate on installing solar panels, battery storage and heat pumps, which reverts to 5% on 1 April 2027.

Until 31 March 0%
From 1 April 5%
Example installation £10,000
Difference £500
03 Homeowner can act
Eligible off-gas-grid homes

£9,000 GRANT WINDOW CLOSES

And the £9,000 off-gas heat pump grant window closes the same day, back to the standard £7,500.

Enhanced £9,000
Standard £7,500
What happens next ONE NIGHT. TWO SIDES.
31 March 2027 BEFORE
0% installation VAT £9,000 enhanced grant*
1 April 2027 AFTER
5% installation VAT £7,500 standard grant*
The important distinction

THREE DATES COINCIDE.
ONLY TWO ARE IN YOUR CONTROL.

We've written about the VAT change and what it covers in more detail. All three dates coincide, but only the last two are within a homeowner’s control.

Total changes 3
You can act on 2
INSTALLATION VAT HEAT PUMP GRANT
Read next

See exactly when the 0% VAT period ends and what solar, battery and heat-pump installations it covers.

Read the VAT guide
Your action plan

WHAT TO DO THIS WEEK

Four practical checks you can make now — from your current export rate and tariff to the numbers for your whole home.

STEP 01
If you already have solar

CHECK YOUR SEG EXPORT RATE.

If you own solar panels, find out what you're being paid and when your rate last changed.

Your solar
Export payment £? per kWh
01

What are you being paid?

02

When did your rate last change?

STEP 02
If your home uses oil

RING YOUR COUNCIL.

If you heat with oil, ring your council about any heating oil support that might be available before the winter demand hits.

Ask about HEATING OIL
SUPPORT
WHEN? BEFORE WINTER DEMAND HITS.
STEP 03
Before you fix

DON'T FIX YOUR TARIFF BLIND.

Martin's advice on fixes was that the cheapest on the market sit slightly above today's cap but below October's, and that fixing is the risk-averse move if you want certainty. Compare across the whole market, not just your own supplier, and use the "show all tariffs" toggle.

Comparison setting SHOW ALL TARIFFS
YOUR SUPPLIER
ONE VIEW
WHOLE MARKET
MORE OPTIONS
COMPARE THE WHOLE MARKET
STEP 04
The bigger picture

GET THE NUMBERS FOR YOUR OWN HOME.

If you’re weighing up a heat pump, solar or a battery, consider having them priced together as a whole-home system. That lets you see how solar generation, battery storage, heating demand and electricity tariffs could work together.

Instead of pricing:
SOLAR + BATTERY + HEATING
PRICE THE SYSTEM.
Whole-home energy flow ONE SYSTEM
Your HOME
SELECT A PART OF THE SYSTEM SOLAR GENERATION

Solar can generate part of the electricity your home needs instead of buying every unit from the grid.

Free home survey

A free home survey gives you a fixed quote sized to your roof, your usage and your heating. No obligation, no pushy sales.

01 ROOF 02 USAGE 03 HEATING 04 FIXED QUOTE
START HERE
Your home. Your numbers.

SEE HOW THE WHOLE SYSTEM COULD WORK.

Book a free home survey
The takeaway

THE BOTTOM LINE.

01 WHAT YOU CAN'T CONTROL

You can't control the price of gas on the other side of the world, how a half-hourly market clears, or a standing charge you pay whether you use anything or not.

02 WHAT YOU CAN CONTROL

What you can control, on the other hand, is how many units of electricity your home buys over the next 20 years, and when it buys them, by upgrading your home with smart energy technologies.

South-West home with solar panels and smart energy technology
THE NEXT 20 YEARS BUY LESS.
CONTROL MORE.
GENERATE
STORE
USE
The difference

That's the difference between watching the price cap and energy rises with a feeling of helplessness, and taking control of your energy destiny.

Ready to see what's possible?

ARRANGE YOUR FREE HOME SURVEY NOW.

60 SECONDS

Arrange your free home survey now. It takes 60 seconds.

FREE SURVEY FIXED QUOTE SIZED TO YOUR HOME NO OBLIGATION
Next
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THE £9,000 OIL AND LPG HEAT PUMP GRANT IS LIVE NOW – BUT ONLY UNTIL 31 MARCH 2027