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Energy Storage and Management Study


1 Introduction

1.1 Background

The Scottish Government has set significant emission reduction targets of 42% by 2020. As a result of this target, there is requirement to decarbonise the electricity supply in Scotland, largely this will be achieved by increased renewable energy capacity, as identified in the Scottish Government's Renewables Action Plan in June 2009.

Scotland is developing a leading position in the development and deployment of renewable energy technologies to address the challenge of climate change and, at the same time, to create economic opportunities. The Scottish Government has a number of important targets in relation to climate change and renewable energy. These include:

  • A reduction in greenhouse gas emissions of 80% by 2050.
  • An interim target to reduce greenhouse gas emissions by 42% in 2020.
  • Renewable energy production equal to 20% of final energy demand in 2020.

These targets are part of the Greener Scotland objective of the Government's Economic Strategy, which has as its central purpose the creation of sustainable economic growth. Hence the energy and climate change targets are closely linked to wider objectives of job creation and fuel poverty reduction. A recent study undertaken by AEA (2009) for Scottish Enterprise confirmed that renewable energy offered substantial economic growth opportunities to Scotland over the next decade.

The Scottish Government acknowledges that to achieve these targets Scotland will need to embrace a variety of existing and emerging fuels and technologies. To this end a number of technology-focused programmes and support schemes have been implemented, including the Wave and Tidal Energy Scheme ( WATES) the Renewable Hydrogen and Fuel Cell Support Scheme ( RHFCSS), the Wave and Tidal Energy: RD&D Support scheme ( WATERS) and the Saltire Prize.

Beyond 2020 there will be continuing opportunities for growth of renewable energy, with a greater focus on the opportunities offshore. Hence a number of important studies have been undertaken to establish the scale of the offshore renewable energy potential off Scotland's shores. The recent Offshore Valuation study found that harnessing a third of the potential resource in Scotland could lead to offshore renewable installed capacity of 68 GW by 2050.

1.2 The role of energy storage

The Renewable Action Plan states that at least 50% of electricity should come from renewables by 2020. The Scottish Government's Renewable Action Plan published in June 2009 identifies energy storage as an important technology to support this increasing proportion of renewables. This study represents an important commitment by the Scottish Government to investigate energy storage.

The jointly DECC/Ofgem chaired Electricity Networks Strategy Group have published scenarios of the future grid mix with scenarios up to 2020. This study has reviewed the estimated costs of re-enforcing the UK grid network to deal with an increasing proportion of renewables. This study from July 2009 provides an up to date reflection of the scale of intermittent generation and grid constraints. The study has also recommended that it is vital that energy storage technologies are investigated and understood at an early stage. The Scottish Government is therefore aligned with the recommendations of the ENSG.

More recently, the work of the ENSG Smart Grid Working Group has also identified energy storage as a potential key enabling component of the smart grid. Given the commitments in the recent UK Government Energy White Paper (the Low Carbon Transition Plan ( LCTP)) to developing smart grids it is also important to understand how the deployment of energy storage technologies can be complemented by the exploitation of demand side measures.

The combination of smart metering and smart grids alongside energy storage has the potential, in the medium to longer term, to significantly reduce the cost of implementing the LCTP compared to attempting to achieve the goals without using these technologies.

To this end, the Climate Change Committee has highlighted that there are a number of technologies and solutions that currently exist for addressing the issue of intermittency. Other solutions include predictable renewables, international interconnections, smart metering and energy management. These alternative solutions are important to consider within the context of energy storage technologies to see where synergies lie.

1.3 Project objectives

This study had four key objectives, these are highlighted below:

1. Evaluate the potential scale of the challenge of having increased shares of intermittent renewable technologies in the electricity generation mix of Scotland. This study has explored this objective by modelling the renewable targets set by the Scottish Government. Three Scenarios have been developed to explore the role that energy storage and energy management may need to play by 2020 and 2030. The Scenarios and the results are presented in section 2 but in summary are:

Scenario 1: Reflects the current renewable targets set by the Scottish Government for 2020. It represents a rate of growth for renewables that until recently would have been considered ambitious. Recent market developments and assessments show significantly greater capacity.

Scenario 2: Reflects more recent views on growth rates for renewable energy, with greater growth in the offshore section. This Scenario maintains the same level of demand and thermal generation as Scenario 1.

Scenario 3: This Scenario illustrates growth levels beyond those in Scenario 2 and represents a stress test of the Scottish grid should all planned renewable developments proceed.

1. Assess the potential low-carbon technological solutions for addressing the problem of intermittent generation, with consideration to both energy storage and energy management solutions.Section 3 of this report investigates the energy storage technologies available, their current market status and the suitability of the technologies to the Scottish context. Section 4 explores the demand side management solutions available and the role that they could play in dealing with increasing intermittency.

2. Assess the current and potential constraints to developing energy storage and management.Sections 3 and 4 of this report highlight individual technology constraints; these are also highlighted in an energy storage technology matrix provided in appendix 1 that scores each technology against a range of criteria applicable to Scotland. Section 5 of the report summarises the constraints in a concise manner highlighting the key issues identified in the technology review and from speaking to stakeholders involved in the sector.

3. Assess the potential public and private sector costs associated with developing technological solutions.Section 5 and 6 consider the generic costs associated with installing pumped hydro. In addition we consider the regulatory factors and constraints facing the present day energy storage sector in Scotland.