Marshfield Electrical Distribution
All of Marshfield’s electricity is supplied by Western Power Distribution WPD). You will pay your bill to a different company, the electricity retailer, but the network that supplies electricity is owned and maintained by WPD. Most of Marshfield is supplied via 4 sub-stations (the far west of the village has different arrangements). A detailed map of how houses in Marshfield are supplied can be found on the Marshfield Village Substation and Feeder Map.
Marshfield CLT EWG are engaged with WPD in a project called OpenLV to find out more read on…
Description and Programme
In their Guidance to Applicants, Western Power Distribution (WPD), set out in December 2018 the objective of the Open LV project; to make electricity data from WPD “open access” for the first time ever. Community organisations were invited to “come up with novel ideas for using data from the low voltage (LV) network to develop software applications that will change the way their community uses electricity”.
WPD, working with EA Technology, have developed hardware units which to be installed in substations to make a range of measurements, in real time, which can then be provided to community organisations. The examples of uses to which these measurements might be put were listed as applications which;
- encourage collective efforts to reduce electricity demand at peak time and in total
- match demand to local renewable generation
- alert consumers of the best times to charge electric vehicles (EV)
The OpenLV proposition is to install hardware in up to 3 ground mounted sub-stations in relevant communities, and to support;
- communities to develop applications to distribute information to members
- community engagement and consultation efforts
- development of communication materials, web presence, press releases, etc.
The outline project programme provided by WPD suggested;
- community consultation events–April 2018
- App design workshops – May 2018
- Software development for Apps – May to Sept 2018
- App deployment and trial – Sept 2018 to June 2019
- Evaluation – July to Sept 2019
The Centre for Sustainable Energy (CSE Bristol) have been appointed as project managers by WPD.
The Marshfield Community Land Trust (MCLT) Energy Working Group (EWG) application was submitted on 22 January 2018, and two members attended an interview in Bristol on 28 February. We were notified by e-mail on 16 March that Marshfield had been selected to be part of the OpenLV project.
We submitted a non-compliant application, as we did not envisage developing phone apps, due to poor mobile signal in the village and perceived lack of immediate demand for such a facility.
The Energy Working Group has a “vision” of renewable electricity generation within the parish potentially and ultimately of a scale to meet the total demand of the village. The Rural Community Energy Fund (RCEF) study revealed that the LV network is unable to absorb generator outputs greater than 100kW without significant and costly upgrading of the network. Therefore any large generator will have to feed, in the first instance, batteries, regulated to release electricity at a rate commensurate with local grid/network capacity. The Working Group recognised that profiles of demand on the village substations would be an essential input to the specification of the batteries to be applied to a large generator. On this basis we responded to the OpenLV invitation requesting only output of demand profiles at the 4 village substations.
The Working Group has also recognised that Electric vehicles (EVs) are coming into the village and that, if widespread, could add up to 50% additional demand to the early evening peak. On this basis it would again be valuable to understand current demand on substations in order to be able to model the effect of the EV demand.
Community engagement will be required if behaviour change is to be encouraged to help regulate peak hour demand for electricity. This clearly is a benefit to WPD, but also to the community in terms of reduced risk of black or brown out. A battery system which delivers balanced, rather than highly variant, output, will be cheaper, and therefore of value to all consumers. A programme of Engagement should be devised around making available substation data which shows real time current demand on the substations as well as profiles for the day and month.
We noted at the interview that the Trial period of less than 12 months as outlined in the programme was limiting. We understood CSE (managing agents for WPD) agreed with this position but that WPD were only prepared to maintain their installation in the substations for this length of time. Outputs may be available for a longer period but increasingly erratic if the hardware is not supported by WPD.
Implementation of the OpenLV Project
Monitoring equipment has been installed in the 4 village substations, Withymead, Hay Street, West Littleton Road, St Martins Lane. Software has been developed to give EWG access to live data as 30 minute records on Electricity usage for each cable route (feeder) out of the substations (13 in total). Other software is being prepared to allow EWG to download, at monthly intervals, more detailed 1 minute records of usage from the substations. Live data from the substations is now accessible at https://openlv-cse.uk/marshfield/graphs. A guide to aid understanding of the graphs can be found here. The monitoring equipment will be maintained until at least the end of 2019.
A dialogue has started with WPD regarding the frequency of outages to our electricity supply, and Outage Monitors have been appointed to record and report on date and time of supply outages. A first account of the OpenLV project has been published in AAM.
Work is continuing to specify the nature of the information which can be provided from the substations, any manipulation required of WPD, and the format of the files to be downloaded to the Group. It is envisioned that the substation output data will be used to develop and record the profile of overall village demand, to translate this data into a visualisation of demand for graphical display, and to identify any time demand comes close to the limiting capacity of a substation.
Another aspect of the data analysis and display, should be aggregation of local generation information, both in terms of sharing with the village generally and in terms of gaining an understanding of the interplay of generation and demand. A survey has been completed to identify the domestic PV installations (30 in total), the number of panels and their orientation. CSE are developing a tool to predict total generation based on this panel survey.
The implications of EVs on demand profile and on need for behaviour change will require data collection from both village consumers and perhaps wider experience. Village based EV users might be persuaded to keep a diary if their system does not include a log of connection times and draw down. Monitoring data at a national level will need to be explored from which generalised data could be abstracted in the absence of, or prior to, wider application of EV charging in the village.
Thought might be given to the value, if any, of an app to provide information to individual phones. The Working Group submission did not seek this facility but if it becomes apparent that differential time dependent tariffs are to be introduced, having access to a means of prompting users to avoid the most expensive times of consumption may become important.
CSE, through a fortnightly telephone conversations and less frequent webinars, provide the link between EWG and the project, and deal with procedural and technical questions.
The EWG work is led by Tony Kerr.