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Energy Review
Supplier comparison

100Green vs Scottish Power (September 2026)

Overview

Our verdict
Too close to call

There is no single best choice: compare price, service, app and green-energy evidence separately.

Trustpilot
100Green
4.6
1,559 reviews
Scottish Power
4.4
203,838 reviews
Citizens Advice rank
100Green
#1
Scottish Power
#10
Cheapest variable
100Green
£1,762
/year
Scottish Power
£1,611
/year
iOS app
100Green
1.1
21 ratings
Scottish Power
4.8
87,000 ratings
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Tariffs and pricing

100Green
VARIABLE
Sparkling SVT
£1,762/year
No fixed term · Variable rates can change
Best for: maximum flexibility
FIXED 12M
Exclusive Spring 100% Green 12M September 27
£1,717/year
12-month term
Best for: price certainty
Scottish Power
CHEAPEST
VARIABLE
Standard
£1,611/year
No fixed term · Variable rates can change
Best for: maximum flexibility
FIXED 12M
Exclusive Help Beat Cancer Fixed Sep 2027 SM2
£1,830/year
12-month term
Best for: price certainty

Annual estimates use the stored consumption assumptions. Check current regional rates, terms and eligibility before switching.

Customer reviews

Trustpilot
100Green4.6 / 5
Scottish Power4.4 / 5
Citizens Advice
100Green#1
Scottish Power#10
Which?
100Green72 %
Scottish Power56 %

Each review service uses its own method and scale, so the measures below should be read separately.

Smartphone apps

App Store
100Green1.1 · 21 reviews
Scottish Power4.8 · 87,000 reviews
Google Play
100Green1.23 · 32 reviews
Scottish Power4.73 · 96,905 reviews

App-store scores are shown by platform. No winner is declared where either ratings sample is missing or too small.

Service and support

Citizens Advice rank
100Green
#1
Scottish Power
#10
Citizens Advice score
100Green
4.33
out of 5
Scottish Power
2.94
out of 5
Emails ≤2 days
100Green
91%
Scottish Power
94%
Avg call wait
100Green
7 sec
Scottish Power
1.3 min
Channel100GreenScottish Power
PhoneWeekdays 8am–8pm, open Saturday and Sunday 9am–1pmWeekdays 9am–5pm, closed Saturday, closed Sunday
Email24/724/7
Social mediaBusiness hrsBusiness hrs

Only like-for-like service measures with data for both suppliers are ranked.

Complaints and performance

Per 100k customers
100Green
144
Q1 2026
Scottish Power
1,458
Q4 2025
CA per 10k
100Green
14.4
Citizens Advice
Scottish Power
61.8
Citizens Advice
Resolved same/next day
100Green
N/A
Scottish Power
60%
Resolved ≤8 weeks
100Green
N/A
Scottish Power
86%

Complaint figures are shown with each supplier’s reporting period. No winner is declared when periods differ or one figure is missing.

100Green — complaint themes
No complaint-reason breakdown was available in the supplied data
Scottish Power — complaint themes
Billing
32%
Reported complaint category for Q4 2025.
Payment Issues
27%
Reported complaint category for Q4 2025.
Metering
15%
Reported complaint category for Q4 2025.
Customer Services
11%
Reported complaint category for Q4 2025.
Marketing
5%
Reported complaint category for Q4 2025.

Green Energy Comparison

100Green
100%Renewable
January to March 2026
Renewable100%
Scottish Power
7%Renewable
January to March 2026
Renewable7%
Nuclear4%
Fossil fuel84%
Other5%

Published fuel-mix figures are shown only where both a source URL and reporting period are present in the stored data.

Our verdict

Which should you choose?
If you care most aboutChoose
The lowest annual cost on our assumptionsScottish Power
Overall customer service100Green
A greener fuel mix100Green
Our verdict
Too close to call

There is no single best choice: compare price, service, app and green-energy evidence separately.

Use the decision table to match the available evidence to the factors that matter most to your household.

100Green
Pros
  • Cheapest variable tariff at £1,762 / year
  • 4.6 Trustpilot from 1,559 reviews
  • Top-1 Citizens Advice ranking
  • 91% of emails answered within 2 days
×Cons
  • 94% of Google Play ratings are negative
Scottish Power
Pros
  • Cheapest variable tariff at £1,611 / year
  • 4.4 Trustpilot from 203,838 reviews
  • iOS app rated 4.8 out of 5
  • 94% of emails answered within 2 days
×Cons
  • 19% of Trustpilot reviews are 1-star

Frequently asked questions

Which is cheaper, 100Green or Scottish Power?

On the stored annual-cost assumptions, 100Green is £1,717 and Scottish Power is £1,611. Scottish Power is lower by about £106 a year.

Can 100Green and Scottish Power complaint rates be compared directly?

No direct complaint-rate winner is declared because 100Green and Scottish Power do not both have figures for the same stated reporting period.

Which supplier leads on customer service?

On the comparable customer-service measure used in the decision table, 100Green leads.

Which supplier has the better app evidence?

The supplied data does not support a like-for-like app winner.

Do tariff eligibility rules matter?

Yes. Specialist, time-of-use, EV, heat-pump and export tariffs can have equipment, meter or account requirements. Check the current supplier terms before applying.

Which supplier has the greener evidence?

On the comparable green-energy measure used in the decision table, 100Green leads. This row is based on published fuel-mix percentages.

Which is better overall, 100Green or Scottish Power?

There is no single overall winner in this repaired draft. Price, service, app and green-energy evidence are kept as separate choices in the decision table.

When was this comparison updated?

The structured source payload is for September 2026.

What changed this month

This month, Scottish Power's iOS sampled positive reviews rose from 1 to 3, Scottish Power's iOS sampled reviews avg stars rose from 2.33 to 6, and Scottish Power's iOS sampled negative reviews fell from 2 to 0. There were 25 other data changes this month — see the full changelog below for details.

Data changes this month (34)

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Rob Gibbs

Written by

Rob Gibbs

Hi, I'm Rob, and I run Energy-Review.co.uk. I initially started this project in 2018 when I was looking to switch energy suppliers and found there wasn't a website that provided simple, data-backed reviews on all the suppliers available. Since then, I have spent a lot of time (too much, some may say!) looking at all publicly available data about each supplier and writing reviews using this information. These reviews are updated as regularly as possible, and any data is backed up by a source where necessary. I have also started writing guides on various energy-related topics, which hopefully you will find useful. If you find any issues, please use our contact form to let us know.

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