Project SIM unlocks inertia issues
Whether at home or at work, we all rely on a stable electricity network to provide power at the flick of a switch. Now, thanks to a successful innovation project led by National Grid and partner Reactive Technologies, grid stability can be measured around the clock in real time. Business Change Manager Bernie Dolan explains more.
Project SIM unlocks inertia issues
"Project SIM takes our ability to monitor the grid to the next level"
Bernie Dolan, Business Change Manager, National Grid.
GridMetrix enables control room teams at National Grid to access inertia data at a national level, right down to postcode level.
Source: National Grid.
If you’ve ever tuned in to a TV talent show, you’ll be familiar with the plate spinning act. Plates balanced on poles must be kept spinning at an optimum speed and constantly adjusted so that they don’t wobble and tumble.
There is an analogy here with Great Britain’s electricity grid, albeit with a dash more technology involved! We need to monitor the stability of the grid to keep system frequency within strict limits. It’s a constant balancing act between supply and demand.
Project SIM takes our ability to monitor the grid to the next level. Until now, system inertia – which is a measure of how stable the grid is at any moment – could only be estimated at specific points in time. These estimates gave us a snapshot but not the full picture.
Now, for the first time, a new GridMetrix system pioneered by Reactive Technologies, can provide data 24/7, based on actual, continuous inertia measurements. This is important on two levels. Firstly, it will give us clearer insight into how inertia changes on the GB system and we’ll be able to respond more quickly.
Secondly, we currently spend £50 million a year on managing the effects of inertia. From a consumer point of view, better data means we will potentially be able to develop more cost-effective ways of managing the system.
Behind the story
Project SIM has its roots in an earlier innovation project called SAMUEL. We also worked together with Reactive Technologies on this piece of work. Both projects are funded via Ofgem’s Network Innovation Allowance (NIA). The allowance is a way of encouraging advances in state-of-the-art technology that benefit customers.
The SAMUEL project focused on demonstrating a new way of broadcasting signals across the network. It uses existing infrastructure and deploys Reactive Technologies’ Grid Data Measurement System (GDMS). Instead of using the Internet, GDMS harnessed system frequency as a communication channel to send instructions to electrical equipment.
During the project, Reactive Technologies built a series of five load banks around the country. These are devices that allow us to generate a small deviation of system frequency in a controllable way.
Sensors detect these tiny changes in frequency. Encoded messages can be sent to control demand side response services. It’s a new and hi-tech way of helping us to balance the system and keep it stable. For Project SIM (SAMUEL Inertia Measurement), the same assets were used but applied in a different way – this time to analyse inertia around the clock.
Why inertia matters
Britain’s energy system is undergoing a transformation, with more renewable sources of energy such as solar connecting to the network. Historically, our power was supplied by large power stations that provided higher levels of inertia because they use large rotating masses in the form of turbines.
Inertia is important to the grid because it acts as a buffer to fluctuations in frequency, helping to smooth their effect.
In contrast renewable sources, such as wind farms, do not detect changes in frequency and so do not provide inertia. Solar panels don’t have any moving parts, so when the sun stops shining, they stop generating power straight away. This acts to reduce inertia on the system.
As the amount of intermittent energy such as wind and solar on the network increases, the importance of managing inertia grows too. A sudden drop in frequency causes stability problems. For example, embedded generation, connected directly to the distribution network, can disconnect from the system as a precautionary measure.
Benefits and looking ahead
Project SIM is important because it will help us understand and deal with inertia better. The benefits of Reactive Technologies’ GridMetrix tool and its unique ability to accurately measure grid inertia are wide-reaching.
Our control rooms will be able to make better-informed decisions thanks to access to real-time data. We will also look to build models based on this information so that we can predict inertia issues before they affect the stability of the grid. Ultimately, the goal is to reduce the overall cost of managing the system, which in turn benefits consumers.
Project SIM is just one of the innovation-led projects we’ve undertaken in 2016/17. In total, we’re investing the £6.7 million innovation allowance in a variety of studies. They range from better solar forecasting through to a reduction in our use of greenhouse gases. You can read more about the NIA projects here.
There’s also more work ahead to realise the full benefits of Project SIM. The technology has proven its ability to monitor inertia changes in real time. The next step is how to channel that data into making actual load adjustments to help balance the system. It’s not the whole solution, but it will help us keep those plates spinning successfully!