Path to 100 discussed the idea of GridWatch with the creator himself Mark Stolworthy on how the site came to be, and how it helps with power generation transparency in the UK


When looking to create policy, or perhaps to outline what an energy mix of the future should look like for a community (especially when discussing a path to 100% renewables) – having the most up to date data is always ideal.  What does the current portfolio look like for your area in terms of energy generation?  That is, where are you getting the power from?  Is it coal? Nuclear?  Wind? Having this data, alongside knowing what a region’s demand looks like, allows communities, governments, and stakeholders to sit at the table and chart a path forward.  Finding that data, however, is often a chore.

Enter GridWatch – a website which provides this information free of cost for those interested in observing how electricity is being generated in the UK.  The site does this by taking publicly available data and then serving it back to the visitor in intuitive and simple ways, while at the same time offering graphical representations of historical power generation data.

GridWatch shows how the UK is getting their power in real-time and what that energy portfolio looks like

A screenshot of the front page of showing Demand and Output per Production Time, along with historical power graphs below

GridWatch was born as site creator Mark Stolworthy wanted to take complex data from other sites and deliver that data in a way that was sharp and easy to understand.  “All my career I have had projects where I process data,” says Stolworthy – adding, “I was looking for available data feeds and I came across the one for GB (Great Britain) electrical production so decided to code the site to graphical show the output.”

The result of Mr. Stolworthy’s hard work is that GridWatch offers a simple visual analysis by way of metered dials showing GB electrical production by source: from renewables to coal, oil to hydro, even biomass – alongside detailed analysis of the demand placed on the grid and the percentage each type of source is playing in meeting that demand.  All power sources are color-coded for ease of tracking; and for consistency, the site measures all power in Gigawatts (GW).

Clicking on a specific power generation source yields detailed data
From – clicking on a particular energy generation gives you a detailed page showing current supply along with a historical charts on that generation type

While the site may seem very easy to navigate, and its displays visually appealing by way of how intuitively they represent the data – GridWatch was anything but simple to build.  As Mr. Stolworthy explained: “From initial thoughts to going live was 3 weeks – Approximately 100 hours of design and coding.  I rewrote the site in 2019 and this was done part time over about 6 weeks and took again approximately 100 hours… The site is highly optimized with a separate process which runs retrieving and processing the data. This allows the data to be show to the user quickly whilst keeping hosting costs to the minimum.”

Costs have to be kept at a minimum from a server side because the site is free to its users.  With nearly one million visitors in 2019 hitting the server, Stolworthy’s labor of love is built with an eye on simplicity.  He runs the site using a traditional web PHP / MySQL backend (for the non-computer trained, think of these like useful everyday hardworking tools which one doesn’t have to pay for) and does so in his spare time.  Like any good project, though, he keeps a pragmatic view on the future of the site: “I hope to somehow monetize the site but will always keep the site factual and not allow it to be used for propaganda (it is easy to make parts of the data fit an agenda without looking at the whole picture).”

Stolworthy does have a point, as people may look at only small pieces of data to build an agenda.  However, the takeaway here should be the free availability of the data, and Mark Stolworthy’s hard work will allow communities to speak the same language and make responsible decisions on what their energy generation mix should be.