As we move to smart grid, or what is called Distribution System Operator (DSO) in Europe, there will be a fundamental change in electricity supply. In order to deal with the more extreme peaks and troughs of supply, there are 2 options: vastly increase network capacity, costing billions and causing massive disruption, or to manage power at a local level. DSO assumes the latter case (as no one is prepared to pay for the former), however this will move the systems from an ‘on demand’ basis, to some form of rationing. ‘Rationing’ means that people will sometimes have to wait to charge their vehicle, or to supply the network from their DER, as if all possible sources and demands were used at once, then that would cause the network to fail.
However, it is not reasonable to expect companies or organisations who provide electricity to set the rules for rationing. These rules will be complex, as they must cover example such as below:
1. Consider a street where the network can only manage 10 EV’s on fast charge at any one time, but 20 people want to fast charge at the same time and are willing to pay the premium price for that fast charge. What rules determine who gets the fast charge, and who must wait?
2. Price is also an inequitable mechanism for determining access to charge. Consider someone who works for the emergency services and may be called out at any time. Should they have to pay a premium price to ensure they can attend a call out? This could apply to others we rely on, such as tradespeople who deal with emergencies (e.g. plumbers, electricians). Such people may also be on lower wages than others who do not have to attend emergencies.
3. There is the issue of the vulnerable customer categories, and company registers for these. This area will need to be revisited, as the current categories are based on need for supply, not on flexible demands. For example, older people can go on the register, however most could be very flexible as to when they charge their vehicles.
4. Peer to peer trading present several challenges. 2 people/groups/organisations may arrange to trade, however a constraint on the day means that this is not possible, as it would overload parts of the network. Quite apart from the commercial considerations (who is liable for what?), what priority should this trade take? For example, a trade may be arranged from a DER to a production facility, but this takes all the capacity from a local network, meaning that there is not enough power for a community hall, and local groups (often the only real support mechanisms in villages) may have to cancel meets. Without some form of overall rules for the DSO to base decisions on, who gets what and when would be difficult to determine.
5. There is also the issue of different types of flexible use. For example, winter evenings would cause a peak in Heat Pump usage but may also be when many need to charge their EV. Normally one would expect heating homes to take priority, however that may not always be the case (e.g. item 2). What rules would apply here to ensure critical vehicles are charged, whilst not leaving people with cold homes?
6. In terms of DERs, these will increase, including Vehicle to Grid (V2G). Overall demand and network constraints will mean that none are likely to be able to supply the maximum power that they could. What are fair rules around what DERs get used and when? If not carefully thought through, some could sell a significantly higher percentage of their available power than others, again not an equitable position.
7. In terms of DERs and flexible demands, it is likely that as these increase some level of work will be required on the network (e.g. reinforcement). Who should pay for this work? Some getting EV charging points may be on low incomes, and not able to pay for the reinforcements. However, should others who have not got the new facilities subsidise their provision (i.e. through their bills)?
The examples set out above are only a few of the social dilemmas that will need to be resolved before DSO can deliver on its promise. Such matters can only be determined by Governments and Regulators in consultation with society at large. The time to resolve these issues is however getting short, as the drive for large Electric Vehicle and local Distributed Energy Resource deployment is increasing across the world.