The term "Big Six" has been used for many years to describe the largest energy suppliers in the UK.
Traditionally, these companies were British Gas, EDF Energy, E.ON, npower, Scottish Power, and SSE. However, the
energy market has undergone significant changes in recent years, with mergers, acquisitions, and the emergence of
new players.
The Big Six energy suppliers in the UK as of May 2024, based on electricity market share, are:
Octopus Energy (22%)
British Gas (20%)
E.ON/ E.ON Next (17%)
OVO Energy (13%)
EDF Energy (11%)
Scottish Power (9%)
These six companies collectively supply energy to the majority of UK households, but their market shares have
shifted considerably over the past decade.
Detailed Analysis of Each Big
Six Energy Supplier
British Gas is one of the oldest and largest energy companies in the UK, serving millions of British households.
E.ON, part of the German utility E.ON SE, has established a strong foothold in the UK market. EDF Energy, a
subsidiary of the French state-owned EDF Group, is another prominent player in the Big Six. Scottish Power, owned
by
Iberdrola, focuses on renewable energy offerings. Npower, now part of E.ON, has seen changes in recent years,
while
SSE maintains a significant customer base in the UK.
Octopus Energy – Overview and history Octopus Energy, founded in 2015, is a relatively new
entrant
to the UK energy market. Despite its short history, the company has experienced rapid growth and now holds the
largest share of the electricity market. Octopus Energy is known for its commitment to 100% renewable electricity,
innovative technology, and excellent customer service.
Octopus sources its power from:
Onshore and offshore wind: 83.3%
Solar: 12.1%
Biomass: 4.4%
Hydro: 0.2%
By investing in its own renewable generation and partnering with green power producers, Octopus has achieved a
completely renewable electricity mix. For environmentally conscious consumers, Octopus is a top choice.
British Gas – Overview and history British Gas is the oldest and most well-known energy supplier
in the UK, with a history dating back to 1812. The company has maintained a significant market share, particularly
in the gas sector. In recent years, British Gas has been working to improve its customer service and increase its
use of renewable energy sources.
As of 2021-2022, British Gas sourced its electricity from:
Natural gas: 62.3%
Renewables: 28.6%
Nuclear: 7.4%
Coal: 1.7%
While still heavily reliant on natural gas, British Gas has significantly increased its use of renewable energy
sources compared to previous years. The company has committed to reducing carbon emissions and has investments in
wind and solar power generation.
Eon / Eon Next- Following E.ON’s acquisition of npower in 2021, the company consolidated its
customers under the E.ON Next brand. E.ON Next’s fuel mix for the latest period included:
Renewables: 61.4%
Natural gas: 32.8%
Nuclear: 4.2%
Coal: 1.6%
E.ON Next has made significant progress in embracing renewable energy, with nearly two-thirds of its electricity
coming from green sources. The company has invested heavily in wind power and also offers customers the option to
choose 100% renewable electricity tariffs.
OVO Energy – Overview and history OVO Energy was founded in 2009 and has grown to become one of
the largest energy suppliers in the UK. In 2019, OVO acquired SSE’s retail business, further expanding its
customer base. The company is known for its focus on sustainability and digital innovation.
In 2021-2022, OVO’s electricity came from:
Renewables: 49.2%
Natural gas: 45.1%
Nuclear: 4.4%
Coal: 1.3%
While not yet majority renewable, OVO is making progress towards cleaner energy. The company offers green tariffs
and invests in renewable projects. However, it still relies heavily on natural gas for almost half its supply.
EDF Energy – Overview and history EDF Energy is a subsidiary of the French state-owned EDF
Group.
The company has a significant presence in the UK energy market, with a unique fuel mix heavily reliant on nuclear
power. EDF Energy has invested in renewable energy projects and aims to play a key role in the UK’s transition
to a low-carbon future.
EDF Energy stands out among the Big Six for its heavy reliance on nuclear power. In the 2021-2022 period, EDF’s
electricity fuel mix consisted of:
Nuclear: 66.6%
Renewables: 21.2%
Natural gas: 10.8%
Coal: 1.4%
EDF operates several nuclear power stations across the UK and is a strong proponent of nuclear energy as a
low-carbon solution. However, some consumers may have concerns about the environmental impacts and safety risks
associated with nuclear power.
Scottish Power – Overview and history Scottish Power, founded in 1901, is one of the oldest
energy
companies in the UK. In recent years, the company has made a significant commitment to renewable energy,
particularly wind power. ScottishPower now generates 100% of its electricity from renewable sources.
Scottish Power’s fuel mix has consistently been:
Onshore and offshore wind: 90.3%
Solar: 4.6%
Hydro: 4.4%
Biomass: 0.7%
With a focus on wind power, Scottish Power has invested significantly in its own renewable generation capacity.
The
company operates several large wind farms across Scotland and the rest of the UK.
How Do the Big Six Compare on
Customer Complaints?
While market share is one key metric, customer satisfaction and complaint handling are also crucial factors when
evaluating energy suppliers. According to recent data from Ofgem, the energy regulator, there are notable
differences among the Big Six in terms of complaints received per 100,000 customer accounts.
As of Q4 2023, the best-performing large supplier was British Gas, with around 275 complaints per 100,000
customers. Scottish Power had the highest complaint rate among the Big Six at over 800 per 100,000.
Looking at smaller and medium-sized suppliers, Good Energy had the fewest complaints in Q2 2022 at under 100 per
10,000 customers. Shell Energy, on the other hand, received nearly 2,000 complaints per 10,000 accounts in Q3 2019
before showing improvement in subsequent quarters.
Overall, the data suggests that some Big Six suppliers need to do more to address customer service issues and
resolve complaints promptly. Newer entrants like Octopus Energy have an opportunity to differentiate themselves by
prioritising customer satisfaction.
Comparing the Big Six with New
Market Entrants
How do new suppliers disrupt the
market?
New energy suppliers, such as Octopus Energy and Bulb, have disrupted the UK energy market by offering
competitive
prices, innovative technology, and a strong focus on customer service. These companies have challenged the
dominance
of the Big Six and have driven changes in the industry.
Advantages of choosing a new energy supplier over the Big Six Some advantages of choosing a new energy supplier
include:
Competitive pricing and flexible tariffs
Excellent customer service and easy-to-use digital platforms
Strong commitments to renewable energy
Innovative technology and services, such as smart meters and energy management tools
The Impact of Renewable
Energy on the Big Six
Shift towards green energy among the Big Six In response to growing consumer demand and government targets, the
Big
Six energy suppliers have been increasing their investments in renewable energy. Many of these companies have set
ambitious goals to reduce their carbon footprint and increase the share of green energy in their fuel mix.
Comparison of renewable energy
offerings
When it comes to renewable energy offerings, the Big Six energy suppliers in UK have different options available
for consumers. Here is a comparison of their renewable energy offerings:
British Gas: Offers a range of renewable energy tariffs, including100% renewable electricity and green gas options.
Octopus Energy: Provides 100% renewable electricity and offers tariffs with a focus on
sustainable energy sources.
E.ON / E.ON Next : Supplies 100% renewable electricity and offers tariffs that support
renewable energy generation.
OVO: Offers 100% renewable electricity and provides access to the OVO Beyond program, which
supports carbon offsetting initiatives.
EDF Energy: Provides renewable electricity and offers a variety of green tariffs to cater to
different consumer preferences.
Scottish Power: Offers 100% renewable electricity and has invested heavily in renewable
energy
projects across the UK.
It is important for consumers to compare the renewable energy offerings of these suppliers and choose the one
that
best suits their needs and sustainability goals. Switching to a renewable energy tariff can contribute to reducing carbon emissions and supporting the
transition to a greener future.
A fixed rate tariff offers a set price per unit of energy for a fixed term, usually 12, 24, or 36 months. This
type
of tariff provides price certainty and protection against potential price rises.
Standard variable tariff
A standard variable tariff is a supplier’s default tariff, with prices that can go up or down depending on
market conditions. While these tariffs offer flexibility, they are often more expensive than fixed rate tariffs.
Dual fuel tariff
A dual fuel tariff combines both gas and electricity from the same supplier. This can be convenient and may offer
discounts compared to purchasing gas and electricity separately.
Time-of-use tariff
A time-of-use tariff offers different prices for energy depending on the time of day. These tariffs can be
beneficial for households that can shift their energy usage to off-peak hours.
Prepayment tariff
A prepayment tariff requires customers to pay for their energy in advance using a prepayment
meter. While these tariffs can help with budgeting, they are often more expensive than other tariffs.
Renewable energy tariff
A renewable energy tariff provides electricity generated from renewable sources such as wind, solar, or hydro
power. These tariffs are becoming increasingly popular among environmentally conscious consumers.
Looking for a specific type of energy?
If you are looking for a specific type of energy, such as gas-only or electricity-only deals, there are options
available from various suppliers. Here are some key considerations for different types of energy deals:
Gas-only energy deals: British Gas is a prominent supplier for gas-only deals. It’s important to consider
your gas usage and compare the rates and benefits offered by different suppliers.
Electricity-only energy deals: When it comes to electricity-only deals, it’s worth considering suppliers
like Octopus Energy, which offers competitive rates and renewable energy options.
Dual fuel energy deals: If you prefer the convenience of having both gas and electricity from one supplier,
dual
fuel energy deals from British Gas, Octopus Energy, and other suppliers can be a suitable option.
Gas-only energy deals
Gas-only energy deals are suitable for customers who primarily rely on gas for their energy needs. British Gas is
one of the main suppliers in the UK that offers gas-only deals. When considering a gas-only energy deal, it’s
important to calculate your gas usage and compare the rates and benefits offered by different suppliers. Look for
suppliers that provide competitive rates, good customer service, and flexible payment options. It’s also worth
considering the supplier’s reputation and customer reviews to ensure a positive experience. By comparing
gas-only energy deals from different suppliers, you can find the best option that meets your gas usage and budget
requirements.
Electricity-only energy deals
Electricity-only energy deals are suitable for customers who primarily rely on electricity for their energy
needs.
When searching for the best electricity-only energy deals, it’s important to compare rates, customer service,
and renewable energy options offered by different suppliers. Octopus Energy is one of the suppliers known for its
competitive rates and renewable energy focus. It’s also important to consider any additional benefits or
incentives offered by the supplier, such as smart meter installation or energy-saving tips. By evaluating and
comparing electricity-only energy deals from different suppliers, you can find the best option that aligns with
your
electricity usage and sustainability goals.
Dual fuel energy deals
Dual fuel energy deals combine both gas and electricity supply from the same supplier. They offer convenience and
potential cost savings for customers who use both energy sources. When searching for the best dual fuel energy
deals, it’s important to consider the rates, customer service, and additional benefits offered by different
suppliers. British Gas and Octopus Energy are two suppliers that provide competitive dual fuel tariffs. It’s
also worth comparing the renewable energy options and sustainability commitments of the suppliers. By comparing
dual
fuel energy deals from different suppliers, you can find the best option that meets your gas and electricity usage
needs, as well as your sustainability preferences.
What makes an energy company the best?
Several factors contribute to determining the best energy supplier for your needs. These include:
Customer service: The level of customer support and satisfaction provided by the supplier.
Tariff cost: The price of the energy tariff and any associated fees.
Tariff type: The type of tariff that aligns with your energy usage and budget preferences.
Payment options: The flexibility and convenience of payment methods, such as direct debit or prepayment.
Meter type: The availability and benefits of smart meters or other metering options.
Contact options: The ease of communication and contact channels with the supplier.
Considering these factors can help you choose an energy company that offers competitive prices, good customer
service, and aligns with your preferences.
Top-scoring energy companies
In terms of customer satisfaction and service, several energy companies have consistently ranked highly.
According to the Which? annual customer satisfaction survey, Octopus Energy, E, and Ecotricity have been named
Which? Recommended Providers for 2024.
These companies have received positive ratings for customer service, supporting customers who need it, complaints
performance, and performance against smart meter targets.
Utility Warehouse also scored well in terms of customer satisfaction.
Lowest-scoring energy companies
According to a customer survey and assessment of practices, British Gas has the lowest overall score among energy
companies. While it remains the largest supplier overall, its customer score and practices assessment score are
lower compared to other suppliers.
Boost and So Energy also ranked low in terms of customer satisfaction.
The energy price
cap, updated every 3 months by Ofgem, determines the maximum amount suppliers can charge for standard
variable
tariffs. With the fall in the energy price cap, consumers can expect to save on their energy bills. The amount
saved
will vary based on individual consumption and tariff type. It is advisable to compare tariffs
and
consider fixed-rate deals for guaranteed prices over a specific period. This will help consumers take advantage of
the price cap fall and save on their energy bills.
Smart Export Guarantee
rates: the best and worst SEG tariffs for solar panel owners
For solar panel owners, the Smart Export Guarantee (SEG) offers the opportunity to sell excess energy back to the
grid. Different suppliers offer varying SEG tariffs, and it is important for solar panel owners to compare these
rates.
Octopus Energy, E.ON Next, and OVO are among the suppliers offering competitive SEG tariffs. It is recommended to
consider the rates, contract lengths, and terms of the SEG tariffs when choosing an energy supplier for solar
panel
owners. This will ensure maximum benefit from renewable energy generation.
Frequently Asked Questions
Which Big
Six supplier is most recommended for customer service?
Among the Big Six energy suppliers, British Gas, Sainsbury’s Energy, and So Energy are known for their customer
service. These suppliers have received positive reviews and high customer satisfaction ratings. When choosing an
energy supplier, it is important to consider customer service as a key factor, as it can greatly impact the
overall
experience and satisfaction with the supplier.
How
easy is it to switch from one of the Big Six to another supplier?
Switching from one Big Six supplier to another supplier is relatively easy. Consumers can compare
different energy suppliers and tariffs using online platforms or energy comparison
websites. The switch can be initiated by providing
necessary details such as meter readings, current supplier information, and preferred tariff. It is also important
to consider factors like direct debit payments and any exit fees associated with the current supplier. With the
energy price cap in place, consumers can switch suppliers without any interruption in their energy supply.
Are there
any incentives for staying with or leaving the Big Six?
Staying with a Big Six supplier may offer the advantage of dealing with a larger, more established company.
However, switching to a smaller supplier can often result in competitive prices, better customer service, and
innovative energy solutions. Some smaller suppliers may offer incentives such as cashback, loyalty rewards, or
renewable energy options. It is important to consider these incentives and compare them with the overall benefits
and savings that can be achieved by switching from a Big Six supplier.
What are the
implications of Brexit on the Big Six?
Brexit has had some implications on the energy market, including the largest energy companies. The energy market
crisis in recent years, coupled with Brexit-related uncertainties, has impacted the stability and competitiveness
of
the Big Six. Tariffs and energy bills have been subject to fluctuations, and the overall market dynamics have
changed. It is important for consumers to stay informed about these changes and consider the potential impact on
their energy costs and options.
How do the Big Six
handle energy supply in remote areas?
The Big Six energy suppliers have different strategies for handling energy supply in remote areas. Some
suppliers,
like Utility Warehouse and SSE, have a nationwide presence and provide energy supply to remote areas. However, the
availability and options may vary based on the postcode and location. It is advisable for consumers in remote
areas
to check with different suppliers and compare their offerings to ensure reliable energy supply and competitive
prices.
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