Skip to main content
This project ended in Feb 2017 and is now closed.

Sunshine Tariff

DurationJul 2015 - Feb 2017
  • South West
  • February 2017

    The project has now closed. The final closedown report will be published shortly.

Project description

Distribution Network Operators have an obligation to provide connections to customers in the most cost effective manner. However, due to the high penetration of distributed generation, several areas now require extensive reinforcement before additional generation can be connected. This can add significant time and costs to projects and can often make them unfeasible. 

Even with the introduction of alternative connections, where reinforcement costs are avoided on the acceptance of export constraint, the curtailment can be too severe for projects to be viable. 

As such there is continued interest in ways of connecting additional generation at minimal costs without compromising the security and quality of supply to existing customers. 

Scope and objectives

The project had 2 phases; the first investigated and reported on the commercial viability of the tariff, exploring current and future value streams to fund it. Whilst there was clear value to the generator, we also explored the value for both supplier and DNO. 

Phase 2 was the domestic demand side response trial. With a tariff subsidised by the supplier, we investigated the effects of the tariff on demand, exploring the extent and reliability of any increase. Four levels of intervention were trialled: tariff only; tariff and feed-back; basic automated water heating; and fully automated flexible load switching. The tariff was managed and administered by Tempus, however the customer engagement was conducted by the local energy cooperative WREN. 

We envisaged that this type of connection could be of particular interest to community energy groups, such as WREN, who don’t have the movability of commercial developers but would have the links to change customer behaviour. 

No generator was connected as part of the trial due to the inherent financial risk. Also the technical systems for regulating or disconnecting such a generator were not be trialled as the systems required were dependant on the knowledge this trial sought to gain.

Objectives were as follows:

Whether and how an offset connection agreement could be structured to be commercially viable for a generator?Complete  
Whether and how an offset connection agreement could be structured and implemented to provide confidence to a DNO that the network will remain within operating limits?Complete  
What mix of low tariff, behavioural signals and technology options would be most effective in shifting demand? 
What mix of low tariff, behavioural signals and technology options would be most effective in shifting demand?Complete  
What scale, longevity and reliability of demand side response would be achieved by the most effective method?Complete  

Success Criteria

Details of the success and measurement criteria are tabled below.

Success criteriaStatus
Understanding of feasibility of an offset connection agreement for both DNO and developer (including legal arrangements)Complete  
Understanding of the capacity, longevity and reliability of domestic demand side responseComplete  
Recruitment of over 200 participants in the trial, on time and on budgetNot complete  
Retention of at least 80% of participants through to the end of the trialComplete  
Learning gained in the project successfully disseminatedComplete  

A WREN solar opening at Olde House.

For more details, please go to WREN’s website:


The webinar on the 7th February discussed the findings of the Sunshine Tariff project. This includes a quick introduction of the project and it's aims, the outcomes of project recruitment, analysis of customer shifting patterns and the next steps for WPD. 

You can download the FAQs here and view the video below.

Area of Works

The trial took place in Wadebridge, Cornwall, and used incentives and education to achieve a demand side response from domestic customers. 

Project Partners

WPD had 3 partners for the trial:

  • Wadebridge renewable energy network logo
  • Tempus energy
  • Regen logo

Wadebridge from the River Camel