Anthony Price Swanbarton Limited, Dairy Farm, Pinkney, Malmesbury, Wiltshire, SN16 0NX Telephone

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1 SMARTER GRID AND SMARTER STORAGE HOW DO BUSINESS AND TECHNOLOGY MEET? Anthony Price Swanbarton Limited, Dairy Farm, Pinkney, Malmesbury, Wiltshire, SN16 0NX Telephone Introduction The technical case for electricity storage is now well proven, and a similar case has been established for development of the smart grid. With the increasing adoption of renewable, and distributed energy sources, the integration of electricity storage technologies and smart grid technologies is an opportunity to re-examine the technical and commercial structures of the power industry. This paper considers a) Why a new business model is needed to cover the installation of storage b) A comparison of business models against types of storage and their locations and ownership c) Develop some of the ideas from last year, taking into account feedback and current trends. Background Electricity storage is simple in concept, but complex in its implementation. If we look at examples from other industries we can see that the process of including storage is generally to optimise the flows of particular goods to deal with variable production, variable demand or a combination of both. The effect of including storage is to optimise other assets in the production and distribution chain. For many products, construction of a warehouse is a lower cost option than the cost of varying production or curtailing demand. For electricity, however, the headline cost of storage is considerably higher than for other products, which has often been used as the reason to only adopt electricity storage when there is no alternative viable solution. Storage should be used whenever it is the economic thing to do. Our previous work looked at the business model for the introduction of electricity storage as a separate business activity within the power industry 1. We were considering the commercialisation prospects for a business based on storage products, typically in the MW category. We proposed different business categories depending on the business sector as follows: a) Extensions of existing power businesses; b) Entrepreneurial developers 2 ; c) Sole benefit models; d) Societal operators. Our analysis of these categories suggests that existing companies within the power industry, especially vertically integrated companies, are more likely to gain advantage from storage by 1 Price, The Business Model For Electrical Energy Storage Within The Regulatory Framework Of The Power System, IRES Symons, Price; Market development for large scale battery energy storage, Proceedings of the 5 th International Battery Conference, Gelsenkirchen 1999

2 incorporating it into their portfolio than other business categories. In those jurisdictions where a company is able to own and operate both generation and transmission/distribution, most value is created and captured. In the past two years a number of portfolio power businesses have added storage to their asset base. Examples include merchant power generators in North America who have incorporated lithium ion batteries to run alongside conventional generation as well as large vertically integrated utilities who are introducing distributed storage projects. Those businesses which are already active in the power industry as sole traders (whether buyers or sellers) are also well placed to gain commercial advantage from using storage as a means of optimising either their own production or use of power. The roles of the entrepreneur and the societal operator are worthy of closer study, particularly with regard to the implementation of the smart grid. Different business models are proposed, differentiated by countries and local regulations and a significant number of different participants in the development and operation of the smart grid is causing confusion. The lack of clarity on this point may prove to be a significant barrier to the deployment of storage within the smart grid. The Smart Grid There are many definitions of Smart grids such as A Smart Grid is an electricity network that can intelligently integrate the actions of all users connected to it - generators, consumers and those that do both in order to deliver efficiently sustainable, economic and secure electricity supplies. 3 This definition gives visibility to the role of generators and consumers and defines the smart grid in terms of the network. The critical part of the implementation is to understand and develop the business models that reflect the investment in the network required for operation of the Smart grid. The future smart grid will bring together a number of themes: Policy: legislation, regulation, codes and standards Data: data storage and retrieval, data processing Market: wholesale, retail & ancillary services Global issues: corporate, globalisation trends People: society, consumers, demand takers and producers. It is in the aggregation of these themes that the application of energy storage offers new opportunities and added value. Today s typical power distribution networks are one-way flow systems,sending power away from centralised power sources to consumers at the end of the network. At the centralised level, transmission system operators use a well defined set of data to control the system, but the data at the point of use is less available. But in order to achieve the smart grid objectives to use the network in a sustainable, economic and efficient manner, much more data will have to be exchanged between the point of use and other parts of the network both power flows and data flows will be bi-directional across the network. An efficient network would control both generation and demand, at all times, across the network to minimise the costs of production, minimise losses and maximise security of supply to the network. In the first instance, consider a network operated by a vertically integrated company, which has its generation, transmission, distribution and supply business operating without boundaries between the sectors. The tools at the disposal of the Local System Operator 4 (LSO) are generation control, network routing (so that power can be directed as required, using interconnectors, islanding etc to 3 EU Smart Grids Forum definition: 4 LSO is defined for the purposes of this paper as an operator or co-ordinator of the smart grid. It may be the same as the Distribution System Operator, or include elements of the Transmission System Operator or some other wider control organisation.

3 avoid constraints or congestion) demand instructions, and if available, storage. Demand instructions may be active that is an instruction sent to a switched demand, or responsive, such as a response to a pricing signal. There are a number of data flows, all of which require management and bring with them issues connected with the ownership, quality and subsequent use of the data. The role of energy storage In considering the role of storage in the smart grid, we need to examine technical and commercial effects. Not all storage is the same, as the technical characteristics of one device over another mean that different storage types may have to be controlled in different ways, depending on the technical parameters of each device. Examples of a range of storage devices are shown in table 1. Storage type Energy rating Discharge power capability(1) Charging power capability Maximum depth of discharge Available cycle lifetime Lead acid battery 2 MWh 1 MW 0.75 MW 50% 1000 High temperature 12 MWh 2 MW 2,4 MW % 2000 (2) battery Flow battery 8 MWh 1 MW 1 MW 100% 10,000 Flywheel 0.25 MWh 2 MW 2 MW 50% 100,000 Table 1: Typical parameters of energy storage technologies (1) Typical figures (2) At maximum depth of discharge It can be seen from table 1, that the control algorithm for a flywheel device, which has little energy capacity but a significant cycle lifetime, would be substantially different from that for a lead acid battery or flow battery. This extends beyond a duty cycle based on the performance of the storage device, but also includes the technical requirements of each specific application. There is a similarity to primary generation, where base load generating plant is not expected to operate under the same conditions as highly responsive plant or peaking generating units, but may be subject to transmission or distribution constraints. A storage unit will be required to comply with demand, supply and its own internal storage limits. It is necessary to consider the ownership of the storage device, and the energy contained within the device. In the simple LSO model, the LSO may choose to own and operate the storage device, treating it as an extension of its network assets, in other words it has the same status as a transformer, SVC, circuit breaker or similar device. It is switched in and out of service in order to meet the objectives of the operator, to deliver a sustainable, economic and secure supply of electricity. As a buffer of energy, it can store and discharge energy received from the central resources, as well as store and discharge energy received from local generation towards the consumer. The operational question is whether this takes place solely on the basis of information available to the LSO, or whether it is operated in response to local signals, for example from the supplying energy companies or the end consumer. Another option is to pay for the device from the savings in energy costs and capacity payments that come from its operation. The additional complication comes from the introduction of market based signals within the power industry. In general terms, the introduction of competition for both generation and supply is seen as a positive means of improving efficiency by lowering costs through choice of the best supplier. However while this model is straightforward for simple one way power flows, and could be adapted for two power flows - by taking the net flow; the complication arises when there are multiple transactions through the same feeder, and potentially through the same storage device. To some

4 extent, these can be summed in each direction and the net flow calculated, but it is quite possible that different supply companies may have price signals and indications that are counter to other suppliers on the same feeder. In this instance it is not clear how these transactions can take place. At various levels, this leaves the operator of storage with a number of options, each with its own set of challenges, advantages and disadvantages. As examples of storage operating on the smart grid, we can consider the role of some common storage devices already in, or close to being in common service. a) UPS uninterruptible power supplies: A consumer installs a relatively small battery to protect a computer from interruptions to the power supply. For normal levels of service, the device will rarely operate. Consequently the energy flows are small and usually of very low consequence to the system operator. The UPS is financed by the end consumer and considered as an insurance policy. b) Electric vehicles In the simple case, electric vehicles are charged from the network and therefore appear to be simply an additional load. In the future, the time of charging such the EV may be selected to be at an optimum time for generation, for example during off peak price periods. In a more active grid, the charging may be delayed until the time that local generation can be used directly to charge the EV. The most complex situation occurs when the EV is itself considered to be a two way device and can discharge back to the network. While this is frequently stated to be an objective of smart grids and electric vehicles, the business model contains many caveats, as the additional cycling of the battery may impair its operational life. The value of the battery is high when it is considered as the motive power for an EV, but it is much lower when it is considered as a storage device for the electricity network. There is much technology to be considered here, including standardisation of charging points, establishment of common protocols for charging and use of advanced techniques that may improve battery life instead of reducing it. c) Domestic electricity storage: where there is an incentive for consumers to install local renewable generation, and it is not possible for the consumer to balance supply and demand continuously, a surplus of energy may be collected during the day and discharged back to the consumer, or the network during other periods. This model could be self financing, depending on the local tariffs and can operate independently of the LSO. In this example, the storage device is located on the customer side of the meter, and is under the direct or at least passive control of the consumer. More complicated scenarios occur when the storage is located on the network, in the network region controlled by the LSO. In such examples, the storage can be used for energy management purposes, (such as buying and selling energy over and different time periods. This action may be simply to act as a means of balancing overall supply and demand, or it may be tom ensure that local supply or demand does not exceed the limits of the supply lines or cables. Under such a scenario, the storage device will be subject to the power flows of all the consumers downstream (and each consumer may be associated with a separate energy company), as well as the constraints of the LSO. The LSO may be required to balance the overall system to maintain frequency and therefore will seek to procure energy and ancillary services. The issues for the electricity storage business In order to progress towards the objective of an electricity network that integrates the actions of all users connected to it so as to deliver efficiently sustainable, economic and secure electricity supplies, it is necessary to collate not only new technologies such as storage and intelligent metering, but also data management and financial control. The situation is not unlike that of the introduction of the mobile telephones and the first cellular networks radio technology and control was solved alongside the matters of tariffs, charging and data encryption and security. Real time control of the system and tariffs is a significant challenge. Interoperability across networks has been seen more of a political

5 and commercial challenge rather than a technical difficulty. International roaming brought together expertise in charging, cost recovery, subscriptions and access charges. At the same time, governmental and European regulations aim to ensure consumers are protected against excessively high costs. The electricity supply industry has remained remarkably resilient to the changing commercial pressures brought about by changes in regulation and markets over the past twenty or so years. In most countries, the power system continues to operate, with consumers being supplied through a centrally controlled network. However the introduction of smart grids and storage, as well as installation of new portfolios of renewable generation, will change the financial balance of the industry. The critical business decision is one of future investment, and that is related to the expected rate of return. The introduction of the new infrastructure, including smart grid storage, is likely to take one of the following business models: a) Ownership / operation by the LSO (local system operator) b) Ownership / operation by a community organisation acting as a societal leader c) Ownership / operation by an independent energy systems company In our previous work, we concluded that private investment could only take place if there was a reasonable rate of return that would cover the overall capital and operating costs. Investors will need confidence in the rate of return, reassurance that the market structure will be stable enough to balance the expected risk and in particular not subjected to changing regulatory requirements. The case for the investment from a community or society s point of view is perhaps simpler to make. If all the participants in a street, housing area or other social group can see a shared benefit stream and join in common objectives, they may be more willing to forgo a market based rate of return and provide a financial subsidy for the project. Where there is more than one supplier of electricity to consumers downstream of a storage resource, we believe that it is more likely to proceed as a community based storage resource than a solely owned device, which would have its own issues of inter-operability between electricity suppliers. In some areas, municipal power companies, owned by the consumers either directly or through the town council may adopt this role. 5 While in the near term, there may be advantages in an independent energy services company owning and operating storage under these circumstances, we believe that this may not be long lasting, as when the price differential becomes eroded, the financial incentives to adopt this model will be reduced, leading to a much less attractive business. 5 Tim Fuchs: Kommunalisierung von Energienetzen, Solarzietalter 3/2011