Power Responsive success stories: South Mimms battery storage and EV charging

At South Mimms Motorway Services, Open Energi own and operate a 250kW/500kWh Powerpack alongside one of Tesla’s largest and busiest UK charging locations. The project, which is one of the first of its kind globally, was selected as a demand side flexibility success story and showcased by National Grid at their 2018 Power Responsive summer reception.

The Supercharger site can charge up to 12 cars at one time, and since popular charging periods often coincide with peak periods of grid demand – between 4pm and 7pm, when electricity prices are at their highest – flexible solutions are needed to ease the strain on local grids and control electricity costs.

Integrating a Powerpack at the location has meant that during peak periods, vehicles can charge from Powerpack instead of drawing power from the grid. Throughout the remainder of the day, the Powerpack system charges from and discharges to the grid, providing a Firm Frequency Response (FFR) service to National Grid and earning revenue for balancing grid electricity supply and demand on a second-by-second basis.

Combining batteries and electric vehicles makes vehicle charging part of the solution to integrating more renewables without affecting drivers, unlocking vital flexibility to help build a smarter, more sustainable system.

Robyn Lucas, Head of Data Science at Open Energi explained “[the battery] provides a source of flexibility to what is otherwise a very inflexible demand. We do frequency response for most of the time, and over the peak period we use the battery to charge the car up, rather than them charging from the grid.

“Open Energi hope to repeat this blueprint with multiple other stationary storage assets next to EV charging stations. Having stationary storage assets used in this way allows both transport and electricity networks to be decarbonised and allows for greater renewable penetration.”

Power Responsive success stories: Aggregate Industries

National Grid’s Summer Reception 2018 profiled Aggregate Industries’ pioneering partnership with Open Energi as an example of real life achievements to unlock demand side flexibility and the innovation and collaboration within the industry.

Aggregate Industries is the first business to deploy Open Energi’s artificial intelligence-powered flexibility platform, Dynamic Demand 2.0, to deliver electricity cost savings of 10%.

40 bitumen tanks at ten Aggregate Industries’ sites UK-wide have already been connected to the platform, which uses artificial intelligence to automatically optimise their daily electricity use in response to a variety of signals, including wholesale electricity prices, peak price charges, fluctuations in grid frequency, and system imbalance prices.

Aggregate Industries is accessing the imbalance market via Renewable Balancing Reserve (RBR), a product offered by its renewable electricity supplier, Ørsted. RBR enables Aggregate Industries to tap into the financial benefits of participating in the imbalance market, by reducing its demand at certain times.

Over time Aggregate Industries plans to expand its use of Dynamic Demand 2.0 to 48 asphalt plants UK-wide – representing up to 4.5MW of demand flexibility. It is also exploring its wider portfolio of assets and processes to identify where further benefits may lie.

Talking to National Grid, Richard Eaton, Energy Manager at Aggregate Industries explained: “What we’re doing now is rolling out Open Energi’s Dynamic Demand 2.0 platform, where what we do is we flex our assets, not only to calls from National Grid, but also now to calls from Ørsted under their Renewable Balancing Reserve.

“The artificial intelligence within Dynamic Demand 2.0 is helping us to optimise our bitumen tanks leading to a predicted 10-15% reduction in the operating costs of those assets.”

Why the UK needs an energy security rethink

London at night
Sebastian Blake
Sebastian Blake, Commercial Analyst, Open Energi

Blackout Britain is a headline which has become increasingly common over recent years. Many argue that decades of under investment in generation infrastructure has left the margin between demand and supply in the UK desperately short, raising the possibility of network outages at times of high power demand. Given the blame that would be landed at the Government’s feet were the lights to go out, energy security has been given top priority over the other facets of the energy trilemma; decarbonisation and affordability.

The Government’s solution to this was to devise the Capacity Market as a mechanism to encourage investment in new power plants, with yearly auctions for participants who can provide capacity over the winter peak. Crucially, auctions are held four years in advance of the capacity ‘go live’ date, to guarantee revenue and give investors the confidence they need to build new power stations.

There are, however, major flaws in the thinking behind such an approach. There is much evidence to suggest that the UK is in fact well supplied with power station capacity, that building more stations is unnecessary and that running the system more efficiently on tighter margins is a good thing. And by ensuring there is sufficient power plant capacity to meet the instance of highest demand in the year other potentially greater threats to security of supply are being ignored.

The graph below shows the frequency of the UK grid, which is the primary indicator of the system stability. The network is in balance when the frequency is hovering around the 50Hz mark, however any significant variation either side is a sign of a serious imbalance between generation and demand and could result in a potential shutdown of the network. This isn’t a distant threat: whole towns had to be shut off as an emergency measure in 2008 when grid frequency dropped to 48.8Hz.

Grid frequency graph

In this case, we can see what happed to the frequency when a large supply source – an interconnector between the UK and France – failed, leading to more power being drawn by consumers than was being supplied to the grid. To counteract the resulting frequency drop and avoid a system shut down, a series of automatic measures kicked into action, including turning up thermal power plants (coal and gas) and sending water reserves cascading through turbines of hydroelectric plants.

More recently on the 9th May 2016 there were 37 significant failures across 27 different coal and gas plants as well as the France interconnector; with each one disrupting frequency and testing the grid’s resilience. At one point in the day National Grid issued a warning that insufficient spare capacity would be available in an hour’s time. This is too short notice for a thermal plant to start up (which takes around four hours) so not something the Capacity Market would have helped with.

National’s Grid’s Head of Commercial Operation Cathy McClay has said managing the grid frequency is becoming an increasing headache for our island system. However, the technologies traditionally used to respond in these situations look increasingly unfit for the role. The best new candidate is demand side flexibility – in the form of batteries and demand side response – which offers numerous benefits.

 Energy storage and demand side response offer five core advantages over traditional solutions

  1. Speed of response: Demand side response and batteries can deliver their full power in under 1 second from receiving a request from the network. By comparison thermal plants and hydroelectric generators need around 10 seconds. As the interconnector example shows, this difference is crucial for avoiding a potential network shutdown and will be needed more and more due to continued reductions in system inertia.

 

  1. Decentralisation: Demand side response and batteries are distributed technologies meaning a required level of response can be made up from aggregating together many smaller sites. We have seen how relying on large centralised technologies (like the undersea link to France) poses increased risk to system stability as they represent significant single points of failure. Thermal power stations fail on a daily basis so individual plants cannot be relied upon for response; whereas with distributed technologies this risk is shared across many assets; if one fails the whole service is not compromised.

 

  1. No need for spinning reserve: Traditional providers are only able to achieve the 10 seconds or so when starting from an already running position, hence the generators must be operating at some partial output to provide the quick response. This impacts fuel efficiency by around 10-20%, greatly increasing costs and CO2

 

  1. Flexibility: The network can only absorb as much power as there is demand, so at times of low demand, National Grid must turn down clean and zero marginal cost power from renewable sources like wind to accommodate the thermal generators which must be kept running for frequency response. Demand side response and batteries overcome this problem.

 

  1. Low carbon: By maximising the use of demand side response and energy storage technologies, the UK will be able to achieve further growth in renewable generation; while reducing its reliance on interconnectors and its exposure to volatile gas prices.

 

The high capacity fossil fuel plants which have historically been used to respond to the demands of the grid are increasingly unfit for purpose in a modern electricity network, yet the Capacity Market fails to encourage the development or implementation of smarter, cleaner and decentralised solutions which would provide a more efficient means of addressing both our energy security and other elements of the trilemma.

Neglecting these alternative solutions via the Capacity Market will undermine exactly the thing Government is trying to advance: security of supply. National Grid should be applauded for its efforts to implement change through its Power Responsive campaign – designed to encourage demand side participation in the balancing markets – but many policy makers remain locked into the old paradigm of an archaic industry; no doubt weighed down by the stranglehold of well-established energy incumbency (better known as the Big Six).

For these parties, using distributed assets to balance the system still represents a significant departure from the orthodoxy of constructing and operating a few large centralised assets like Hinkley Point C, which will deliver 7% of all UK electricity when completed.

To achieve a real paradigm shift towards a secure, affordable and low carbon economy, we don’t even need to find new solutions. Distributed and demand side technologies are ready to deliver; we now need to change the supply-focused mind set of our policy makers and operators.

By Sebastian Blake, Commercial Analyst, Open Energi

The IOT technology meeting the UK’s grid balancing needs faster than a power station

Tech image

Chris Kimmett, Commercial Manager, Open Energi

It’s a well reported fact that electricity margins are tighter than they have been for a number of years and, as we move towards winter, talk will increasingly turn to the need to balance energy supply and demand in order to mitigate the risk of power black outs in the UK.

Almost all of the UK’s grid balancing has traditionally been done by coal and gas. But the EU’s Large Combustion Plant Directive has limited running hours at a number of plants and in the past twelve months both Longannet and Eggborough power stations, which currently provide around 5% of the UK’s capacity, have announced they will be closing their doors in 2016.

Add to this the solar and wind explosion – by the end of 2015 experts predict the UK will have 10GW of solar power, a benchmark most thought wouldn’t be reached until 2020, and by 2020 National Grid’s Future Energy Scenarios indicate that small-scale, distributed generation will represent a third of total capacity in the UK. This considered, we see that tomorrow’s electricity landscape will look very different to that of today.

The transformation of the energy system away from centralised generation to small-scale, distributed power means that speed of response to changes in energy supply and demand will be more important than ever.

Indeed, while most people are focusing on the tight capacity margin between supply and demand, the real blackout threat could come from generators being unable to respond within the required window to balance instantaneous shifts on the grid.

For more than 12 months, energy data analysts at EnAppSys have been monitoring grid frequency and analysing large deviations which, if not managed, can lead to instability. EnAppSys’ director Paul Verrill says that while we need to ensure the system has sufficient supply to meet demand, the real risk of blackouts could come from this second issue that often falls under the radar: a lack of capacity able to deliver additional power within the required timeframe.

Grid agility and flexibility will be essential as we move away from models of centrally dispatched generation, and National Grid, via its Power Responsive campaign, has already asserted that demand side response (DSR) will play an increasingly vital role in building a resilient, sustainable and affordable electricity system for the future.

This is especially pertinent given the results of new research by Open Energi, National Grid and Cardiff University, which suggests that smart demand side response (DSR) technology can meet the UK’s crucial grid balancing requirements faster than a conventional power station.

The latest research paper, which forms part of the ongoing collaborative research programme between Open Energi, National Grid and Cardiff University, titled Power System Frequency Response from the Control of Bitumen Tanks, looks at the feasibility of DSR to provide a significant share of frequency balancing services.

To test the scale of the opportunity for industrial heating loads to provide frequency response to the power system, bitumen tanks (which contain the glue that binds our roads together) equipped with Dynamic Demand technology were tested in combination with National Grid’s model of the GB transmission system.

Dynamic Demand deployed at scale is able to contribute to the grid frequency control in a manner similar to, and, crucially, faster than that provided by traditional peaking power generation – not to mention more cleanly and cheaply.

Field tests showed that full response could be provided in less than two seconds, as compared to 5 – 10 seconds for a thermal generator. Large scale deployment of Dynamic Demand will reduce the reliance on frequency-sensitive generators and ensure that the grid stays balanced in a cost-effective, sustainable and secure manner.

The research simulations help to shape National Grid’s understanding of DSR as a replacement for frequency-sensitive generation and will be used when they are planning their requirements for grid network operation in the future – with huge impacts on the future of our energy mix.

When launching Power Responsive, National Grid CEO Steve Holliday said: “The move to a low carbon economy coupled with rapid advances in technology and innovation are transforming our electricity supply. But supply is only half the story. The challenge now is to exploit new opportunities to radically evolve our energy system by changing the way we use electricity.”

And this is why the research findings are so significant.

With more renewables and decreased thermal generation, ‘inertia’ on the Grid will decrease, making frequency more unstable. To counteract this effect we need faster response, so by rolling out Dynamic Demand today we are future proofing the Grid.

With their new Power Responsive campaign, National Grid has recognised the need for a new source of flexibility and have stated they are committed to scaling the smart DSR industry.

Demand side response is intelligent energy usage. By knowing when to increase, decrease or shift their electricity consumption, businesses and consumers will save on total energy costs and can reduce their carbon footprints. It is the smart way to create new and efficient patterns of demand.