Solar Yield Network Constraints
|Duration||Sep 2015 - Jun 2017|
WPD has connected significant amounts of embedded generation to its distribution network in recent years. This includes a large variety of different technologies, dominated at first by wind and more recently by solar PV.
With so much generation already connected, and significant quantities in the pipeline, most of the latent capacity within the network has now been utilised. As such WPD is looking at ways of releasing extra capacity in the most economically efficient manner. Alongside the use of traditional reinforcement, the roll out of alternative connections has been one of innovative manners this has been done, building on the flexibility of generators. These give the option of trading off capital expenditure and time delays against potential curtailment. This moves from a passively operated network to a more active one.
Whilst the inherent flexibility of generation is now being used, the flexibility of the demand side is as yet untapped.
As part of the SYNC project we looked to test a range of Demand Side Response (DSR) techniques to help address many of the different challenges being posed by PV generation. By engaging with industrial and commercial (I&C) customers we could release additional capacity or even improve power quality.
There are 4 techniques that project SYNC looked to investigate:
(T1) - Automated demand increase / generation limiting in line with variation in solar yields.
(T2) - Directly matching flexible load with flexible generation
(T3) - Manually dispatched response signals from a WPD control facility (DSR)
(T4) - Creation of suitable ToU (Time of Use) tariffs to encourage appropriate demand
The project required significant engagement and involvement of third parties including demand customers, generators, storage operators and National Grid. WPD built on the learning gained in the FALCON project and directly manage a full service program directly. By doing so we attempted to demonstrate how to maximize value to the industry and minimize the cost to customers.
Scope and objectives
As with other DR projects the scope can be limited by the necessity to gain the support and engage with customer’s willingness to participate. WPD will however identify suitable areas in the South West franchise area, where there are current issues arising from high penetration levels of solar generation coupled with insufficient load at times of high yield.
The trial will be limited to half hourly metered supplies. Particular focus will be centred on large energy users who are expected to have greater volumes of potentially beneficial latency within their processes as well as a comprehensive presence across the affected areas.
Initial work will be required to develop an attractive proposition that will be acceptable to I&C site operators to vary their electrical load so that it is more compatible with peak output from embedded renewables on the same 33kV feeders. It is expected that public engagement will be primarily direct to customers but aggregator routes will also be investigated to verify if they can meet the trial service requirements. The various methods will be applied over a two year trial period to establish the most effective when measured against the key criteria:
• Cost of operation
• Reliability / effectiveness
• Ease of participant recruitment
• Ease of ongoing operation.
The objectives of the trial were to validate the following:
|Customers can be incentivised to alter their behaviour to manage operational issues arising from excess embedded generation.||Complete|
|DR can be used as a reliable and economic alternative to manage generation constraints.||Complete|
|Generation can be adequately absorbed through customer behaviour changes to address immediate issues and potentially facilitate further connections.||Complete|
|Which methods of operation and customer proposition are most successful at achieving the above?||Complete|
|Develop contracts, processes, skills and systems to manage the above trials along with potential migration path to business as usual.||Complete|
|Compatibility of DR Service / incentives with Energy Storage developers.||Complete|
|Establish if adequate consumer flexibility exists to have a meaningful impact on generation constraints.||Complete|
|Identify compatibility or conflicts that such a scheme may have with TO, SO & market.||Complete|
|Development of suitable proposition to present to customers along with associated contracts and public engagement collateral.||Complete|
|Engagement of appropriate I&C customers with the ability to have the desired impact on network loads through behaviour change.||Complete|
|Demonstrable improvement in the currently experienced issues including high voltage, reverse power, power factor and thermal constraints.||Not complete|
The services tested offer comparable or improved performance over conventional reinforcement
|Partially met ≈|