Jim Cardwell, head of trading and innovation at Northern Powergrid

A new domestic storage trial was recently announced which will bring together battery manufacturer Moixa with DNO Northern Powergrid to test the impact of domestic storage in limiting the effect of solar on the local grid.

Jim Cardwell, head of trading and innovation at Northern Powergrid, explained to Solar Power Portal what the operator hopes to get out of the scheme, and what the direction of travel is for grid operators around Great Britain.

Why was a trial size of 40 units selected for this latest project? This number has been used in similar storage trials in the past

It’s a reasonable data set and what matters for us is to get a good variation but we also want to get a bit of clustering. From a local power grid perspective we can always model the effects of individual properties and what might happen when they're all bundled together however there's nothing like observing things in action.

What we've got here is some decent clustering to get some good results which we can then [use to] see to what extent domestic batteries can be used in combination with solar power and to what extent the battery can be used to alleviate some of the demands on the network placed by those solar panels.

For a local grid operator, what are you looking to get out of this project with Moixa?

What we're trying to do is avoid digging up the streets and avoid replacing cables with bigger fatter ones and we're also trying to avoid wherever we can spending more money on network equipment to accommodate the new power flows or the voltage conditions that these new demands or generation place on us. But we've got very little data on domestic batteries.

We really want to see how these things work in practice, both in combination with solar panels but also on their own because there's quite a lot of talk and interest among customers in putting smaller batteries in homes and businesses and then aggregating them together to provide services.

But we have very little data of that working in practice. We can do desktop modelling, we can do analysis away from the real network but there's no substitute sometimes for working with real customers, real networks, real every day circumstances.

We also we need to understand different operating modes because if the driver for the customer is to put them in to then get the value through providing those services to National Grid, the question is what does that do to the local grid? We need to understand the implications of that and if the mode of operating is going to benefit us or works counter to what we would like.

A lot of trials have already been carried out in the UK to test the effect of storage in various applications. Is this lack of knowledge specific to Northern Powergrid or is this more widespread?

It's not that we're devoid of any data on domestic storage, there's other data available it just doesn't answer some of the questions we've got on how we can best accommodate and use this technology as a force for good in operating a local power grid, while recognising that some of its operating modes may be driven by other parts of the energy system. This is about recognising that customers will lead this, it’s a domestic appliance but it’s looking at how we can work with customers to get the benefits for a local power grid.”

Our network is not unique and our perspective is probably very similar to the others. We think that what our customers do, what they might do in the future and how our network responds is broadly similar in this respect to the other DNOs.

By working with Moixa we are well aware of other projects and it allows us to build upon and gain access to some of the data that already exists so we're not working blind.

And a lot of the innovation work we do, like this project, we are gladly sharing that with other network operators and indeed looking at some of the work they've done so that we're not duplicating work.

After the results are proven and it's shown that storage can be used to reduce the need for upgrades and keep network charges at their best value for customers, what's next? Do you encourage consumers to take up these systems or would Northern Powergrid fund installations over upgrades?

The primary output is to really understand the benefits of this as a solution and also understand if we were to move forward, what would the likely cost be. Being realistic about it, we know that the costs of batteries are falling…and we do expect economies of scale to drive down cost further.

We don't expect this overnight to become beneficial for us to either contract with homeowners who buy their own batteries or for us to buy batteries and ask people to put them in their homes – and we'll access those routes to market. More than that it's really about understanding the costs and benefits and having real evidence to back that up and then we can compare that to the other options we've got. This includes using vehicle-to-grid technology, other forms of customer flexibility which could be other bits of demand side response or it could be industrial DSR versus domestic battery charging. Or it could even not be customer flexibility options but grid options like putting in bigger cables and putting in smart technology in our neighbourhood substations.

These are all different tools we've got but we need to understand what those different options are and it's about making sure we're ready as the energy system of the future changes. We do expect more renewables to be coming along and we need to make sure we are looking ahead to that future and working out what those different options are. If the cost profile changes it can lead to new solutions coming forward as the most economical.

What other work are you doing in preparation for this ‘energy system of the future’?

In our patch we've got two projects that succeeded in winning [EFR] contracts so in our backyard we've got a couple of sites that we'll see go forward. We also have a 2.5 NVA battery ourselves which we are interested to see how we can use grid utility storage to offer services to National Grid and how that can help us.

You hear this phrase about the transition to a distribution system operator, meaning the network of old was quite a passive system and we've moving to a much more dynamic and active network and that might require us to either be buying from customers or selling services to the system operator and we're starting to look at what changes that might mean for our business.

We recognise that is the direction that is required and I guess the big uncertainty is what we need to do and at which point. But we are keen to make sure we've assessed these options before such time as they are required.

For example we're investing £83 million in upgrading some of our infrastructure to make it is smart-grid ready, to make sure we have a decent platform of capability and to make sure that no matter what's thrown at us in the 2020s as we get potentially a significant rise in EV charging or in electric heat and maybe more solar panels, we've got core systems which can support whatever scenario is thrown at us. That in itself unlocks a lot of value and makes sure we prepare for what is a very uncertain future.

What outcomes are you hoping to see from the smart energy system call for evidence recently conducted by the government and Ofgem?

We are looking for government and the regulator to support more demonstration trials and maybe to think about how we can have more integrated whole system trials. Some aspects of this Barnsley project are whole system trials as Moixa has this [GridShare] platform and are going to aggregate and use that on behalf of the homeowner to help them realise value from their asset.

So it might be to sell a demand side service to an energy supplier or if might be to provide a response to National Grid in terms of the system operator, or it might be to provide assistance to us as the local power grid.

We're working out what the interactions are between those different drivers in how that technology could be deployed so it is a whole energy system approach and we are suggesting that approach continues and we do more of it because this kind of learning is vital so that we do understand some future pathways.